Influence of Pools and Riffles on Chironomidae Diversity in Headwater Streams of the Atlantic Forest.

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Silveira, L S; Rosa, B F J V; Gonçalves, E A; Alves, R G

2015-10-01

Studies on mesohabitat scale have been used to shed light on the ecology and distribution of chironomid larvae in small streams. Thus, the objective of the present study was to examine the diversity and distribution of the Chironomidae assemblage on the mesohabitat scale in three streams located in different preserved areas of southeastern Brazil. In each stream, litter samples were obtained in the dry season of 2010 in ten pools and ten riffles with a Surber sampler (area 0.04 m(2); mesh size 0.21 mm). The abundance was similar among streams and between mesohabitats, while the estimated richness was highest in riffles. There was a difference in the composition of the Chironomidae assemblages between the mesohabitats, although the litter composition was similar between them, indicating the importance of current speed on the distribution of the taxa. The dispersion of the sample units (β-diversity) of riffles and pools was similar, although it was different among the three streams. The results of this study provide further evidence of the importance of habitat heterogeneity within streams as a generator of diversity for Chironomidae in tropical lotic systems.

Estado del conocimiento taxonómico de la fauna de Chironomidae (Diptera: Nematocera de la Patagonia

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Mariano DONATO

2009-01-01

Full Text Available La familia Chironomidae (Diptera: Nematocera es uno de los grupos de insectos más ampliamente distribuidos y abundantes en cuerpos de agua dulce. Los representantes de esta familia pueden explotar áreas con amplios gradientes ambientales. La información que se presenta está basada en la recopilación de datos distribucionales bibliográficos, del estudio del material tipo de las especies de Chironomidae depositadas en el Natural History Museum (UK y del material de colección del Museo de La Plata (Argentina. En la Patagonia, se registran 9 subfamilias, la subfamilia monotípica Chilenomyiinae es endémica de esta área. Dentro de estas subfamilias, 53 de los 111 géneros conocidos para América del Sur están presentes en la Patagonia. Del total de géneros de la Patagonia, el 20 % es endémico y 7 de ellos muestran relaciones transantárticas. En la Patagonia, se registran 177 especies de Chironomidae, el 98% de éstas son endémicas, el 3 % son consideradas nomina dubia y el 17% requiere revisión ya que su ubicación sistemática es dudosa. Las descripciones originales de las especies patagónicas de Chironomidae están basadas principalmente sobre machos (n=58 y machos y hembras (n=43, ambas representan el 57% del total; el resto de las especies han sido descriptas con diferentes combinaciones de estadios del ciclo de desarrollo.

Impact of damming on the Chironomidae of the upper zone of a tropical run-of-the-river reservoir.

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Brandimarte, A L; Anaya, M; Shimizu, G Y

2016-06-01

We examined the effects of the Mogi-Guaçu river damming (São Paulo State, Brazil) on the Chironomidae fauna. Pre, during, and post-filling sampling was carried out in the main channel and margins of one site in the upper zone of the reservoir, using a modified Petersen grab (325 cm2). We evaluated the total, subfamily, and tribe densities and also their relative abundance. Analysis of genera included densities, relative abundance, richness, and dominance. The Rosso's ecological value index (EVI) determined the ecological importance of each genus. There was a tendency of decrease of the total Chironomidae density, increase in the percentage of Chironomini, and decrease in densities and percentages of Orthocladiinae and Tanytarsini. These changes in percentage were respectively related to Polypedilum, Lopescladius, and Rheotanytarsus, the genera with the highest EVI values. After-filling richness was lower in the margins and dominance of genera did not change significantly. Chironomidae in the margins was more sensitive to damming than in the main channel. This difference in sensibility sustains the use of Chironomidae as bioindicators. Damming impact was indicated by the reduction of both genera richness in the margins and relative abundance of groups typical of faster waters. The results have highlighted the need for multi-habitat analysis combined with a before-after sampling approach in the environmental impact studies concerning the damming impact on the benthic fauna.

New Chironomidae (Diptera) with elongate proboscises from the Late Jurassic of Mongolia

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Lukashevich, Elena D.; Przhiboro, Andrey A.

2011-01-01

Abstract Four new species of Chironomidae with well-developed elongate proboscises are described from a Late Jurassic site Shar Teg in SW Mongolia. These are named Cretaenne rasnicyni sp. n., Podonomius blepharis sp. n., Podonomius macromastix sp. n., ?Podonomius robustus sp. n. PMID:22259285

Chironomidae feeding habits in different habitats from a Neotropical floodplain: exploring patterns in aquatic food webs.

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Butakka, C M M; Ragonha, F H; Train, S; Pinha, G D; Takeda, A M

2016-02-01

Ecological studies on food webs have considerably increased in recent decades, especially in aquatic communities. Because Chironomidae family are highly specious, occurring in almost all aquatic habitats is considered organisms-key to initiate studies on ecological relationships and trophic webs. We tested the hypothesis that the diversity of the morphospecies diet reflects differences on both the food items available among habitats and the preferences of larval feeding. We analyzed the gut content of the seven most abundant Chironomidae morphospecies of the different habitats from the Upper Paraná River. We categorized the food items found into algae, fungal spores, fragments of plants, algae and animal fragments and sponge spicules. We observed the algae predominance in the gut content of morphospecies from lakes. Considering the different regions from each lake, we registered the highest food abundance in the littoral regions in relation to the central regions. From the variety of feeding habits (number of item kinds), we classified Chironomus strenzkei, Tanytarsus sp.1, Procladius sp.1 as generalist morphospecies. We found a nested pattern between food items and Chironomidae morphospecies, where some items were common to all taxa (e.g., Bacillariophyceae algae, especially), while others were found in specific morphospecies (e.g., animals fragments found in Procladius sp.1). The algae represented the most percentage of gut contents of Chironomidae larvae. This was especially true for the individuals from littoral regions, which is probably due to the major densities of algae associated to macrophytes, which are abundant in these regions. Therefore, the feeding behavior of these morphospecies was generalist and not selective, depending only of the available resources.

Larvae of North American Eukiefferiella and Tvetenia (Diptera: Chironomidae). Bulletin No. 452.

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Bode, Robert W.

"Eukiefferiella" and "Tvetenia" are closely related genera belonging to the subfamily Orthocladiinae within the Chironomidae, a family of non-biting midges. All known larvae in these genera are aquatic, being found predominantly in running water. Most species prefer cold, swift-flowing, well-oxygenated streams. Although larvae…

Colonization by Chironomidae larvae in decomposition leaves of Eichhornia azurea in a lentic system in Southeastern Brazil.

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da Silveira, Lidimara Souza; Martins, Renato Tavares; da Silveira, Guilherme Augusto; Grazul, Richard Michael; Lobo, Danielle Pinheiro; Alves, Roberto da Gama

2013-01-01

The objective of this study was to analyze the colonization of Chironomidae (Diptera) larvae during the decomposition of Eichhornia azurea (Swartz) Kunth (Commelinales: Pontederiaceae) leaves in a lake in southeastern Brazil in two seasons of the year. The experiment was conducted from September to November 2007 and February to April 2008. In each period, 21 litter bags were used, each containing 10 g of dried leaves. Three bags were removed after 2, 5, 8, 12, 25, 45, and 65 days of colonization. The decomposition rate of the E. azurea leaves was rapid in both seasons, with no significant difference between them. The Chironomidae showed higher density than the other invertebrates. Goeldichironomus, Tonytarsus, and Corynoneura were the most abundant genera of Chironomidae. The invertebrate density increased during the experiment, differing within days but not between seasons. The faunal composition differed between the decomposition phases (initial and final), but did not differ between the seasons (dry and wet). The taxa Ablabesmyia, Caladomyia, Chironomus, Goeldichironomus, and Parachironomus were the most closely related to the final days of the experiment. Litter was the main food item found in the gut contents of the organisms of all the genera analyzed, both at the beginning and end of the decomposition. We believe that the feeding activity combined with the high larval density is an important factor contributing to the rapid decomposition of the E. azurea leaves. In conclusion, the succession process along the detritus chain of E. azurea was more important in structuring the assemblage of Chironomidae larvae than seasonal variations.

Larvas de Chironomidae arvas (Diptera da planície de inundação do alto rio Paraná: distribuição e composição em diferentes ambientes e períodos hidrológicos = Chironomidae larvae (Diptera from the upper Paraná river floodplain: distribution and composition in different environments and hydrological periods

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Gisele Cristina Rosin

2007-01-01

Full Text Available O presente estudo teve por objetivos, identificar possíveis diferenças na estrutura da comunidade de larvas de Chironomidae em quatro ambientes da planície de inundação do alto rio Paraná com diferentes características e analisar a influência dos fatores abióticos e das variações do nível hidrométrico sobre a comunidade. As coletas foram realizadas em março e setembro de 2003. Em cada um dos 12 pontos coletados foram realizadas quatro amostragens: três para análise biológica e uma para análise sedimentológica. O material biológico foi lavado em conjunto de peneiras com malhas de abertura 2, 1 e 0,2 mm e fixado em álcool 70%. As larvas de Chironomidae foram identificadas até a categoria de gênero. Foram encontradas 1478larvas de Chironomidae pertencentes a 19 gêneros. Polypedilum, Tanytarsus e Chironomus foram registrados em todos os ambientes. As maiores densidades e diversidade de Chironomidae foram registradas nos períodos de águas baixas, especialmente em ambientes lênticos. Avariação da densidade, dominância e diversidade de Chironomidae entre as duas coletas foi influenciada, principalmente, pelo ciclo hidrológico e pelo oxigênio dissolvido, enquanto que a variação espacial esteve associada ao tipo de sedimento, porcentagem de matéria orgânica e a presença ou ausência de macrófitas aquáticas.The present study had the aim to identify possible differences in the community structure of Chironomidae larvae in four different environments of the upper Paraná river floodplain with different characteristics and to analyze the influence of abiotic factors and variations in the hydrometric level of the community. Samplings were carried out in March and September, 2003. Four samplings were taken from each of the 12 collecting points: three for biological analysis and one for sediment analysis. Biological contents were washed with the aid of a system with 2.0; 1.0 and 0.2 mm sieves. Chironomidae larvae were

Composition and structure of the Chironomidae (Insecta: Diptera) community associated with bryophytes in a first-order stream in the Atlantic forest, Brazil.

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Rosa, B F J V; Dias-Silva, M V D; Alves, R G

2013-02-01

This study describes the structure of the Chironomidae community associated with bryophytes in a first-order stream located in a biological reserve of the Atlantic Forest, during two seasons. Samples of bryophytes adhered to rocks along a 100-m stretch of the stream were removed with a metal blade, and 200-mL pots were filled with the samples. The numerical density (individuals per gram of dry weight), Shannon's diversity index, Pielou's evenness index, the dominance index (DI), and estimated richness were calculated for each collection period (dry and rainy). Linear regression analysis was employed to test the existence of a correlation between rainfall and the individual's density and richness. The high numerical density and richness of Chironomidae taxa observed are probably related to the peculiar conditions of the bryophyte habitat. The retention of larvae during periods of higher rainfall contributed to the high density and richness of Chironomidae larvae. The rarefaction analysis showed higher richness in the rainy season related to the greater retention of food particles. The data from this study show that bryophytes provide stable habitats for the colonization by and refuge of Chironomidae larvae, mainly under conductions of faster water flow and higher precipitation.

Effects of bioirrigation of non-biting midges (Diptera: Chironomidae) on lake sediment respiration

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Baranov, Viktor; Lewandowski, Jörg; Romeijn, Paul; Singer, Gabriel; Krause, Stefan

2016-06-01

Bioirrigation or the transport of fluids into the sediment matrix due to the activities of organisms such as bloodworms (larvae of Diptera, Chironomidae), has substantial impacts on sediment respiration in lakes. However, previous quantifications of bioirrigation impacts of Chironomidae have been limited by technical challenges such as the difficulty to separate faunal and bacterial respiration. This paper describes a novel method based on the bioreactive tracer resazurin for measuring respiration in-situ in non-sealed systems with constant oxygen supply. Applying this new method in microcosm experiments revealed that bioirrigation enhanced sediment respiration by up to 2.5 times. The new method is yielding lower oxygen consumption than previously reported, as it is only sensitive to aerobic heterotrophous respiration and not to other processes causing oxygen decrease. Hence it decouples the quantification of respiration of animals and inorganic oxygen consumption from microbe respiration in sediment.

Benthic fauna of 41 acid sensitive headwater lakes in north central Ontario. [Chironomidae salinarius; Chironomidae anthracinus; Tanytarsini

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Dermott, R.; Kelso, J.R.M.; Douglas, A.

1986-01-01

The benthic fauna of 41 nonhumic, soft water lakes situated north of lakes Superior and Huron were sampled during 1980. The pH range of the lakes sampled was 4.6 to 7.7. The benthic infauna displayed regional differences in abundance and composition, with large variation with each district. Total abundance, biomass, and number of taxa were not correlated with lake pH or alkalinity. The Chironomidae displayed a slight change in percent composition of the major species with lower pH. The Tanytarsini and Chironomus Salinarius group decreased, while C. anthracinus group increased in relative abundance in those lakes with lower pH. Other factors appear to control the distribution of the various invertebrate orders, with depth and sediment nature being important variables.

Is similar the distribution of Chironomidae (Diptera and Oligochaeta (Annelida, Clitellata in a river and a lateral fluvial area?

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Daniela Aparecida Silveira Cesar

2017-05-01

Full Text Available Abstract Numerous factors may affect the pattern of distribution of benthic fauna in a river mouth region and, among the macroinvertebrates, Chironomidae and Oligochaeta are the most abundant groups and most tolerant to environmental changes. Aim The aim of this study was to evaluate the controlling factors of and a possible similarity between Chironomidae and Oligochaeta assemblies at two close sites, the mouth of the Guareí River into the Paranapanema River (São Paulo, Brazil and its lateral fluvial area. Methods Fauna samples were collected every three months during one year. Water physical and chemical variables and sediment variables were also determined in the same period. Results Both assemblies presented low density variability over time in the lateral area due to sediment characteristics and environmental factors. Taxa Caladomyia, Parachironomus, Pristina sp., Pristina osborni, Bothrioneurum and Opistocysta funiculus were recorded at this site. The Guareí River presented both greater temporal and spatial variations, attributed mainly to a reduction in the water level. Greater organism abundance, especially of Chironomus and Tubificinae, was observed in the river. Conclusions Dissimilarity in temporal and spatial distributions of Chironomidae and Oligochaeta was attributed to peculiar characteristics of the two study sites, a river channel and a lateral area. Reduction in the water level over the year was the main controlling factor of Chironomidae and Oligochaeta richness and density in the river. In the lateral area, the presence and abundance of certain taxa were determined by the nature of the sediment and water physical and chemical variables.

Sobre uma nova espécie do gênero Aedokritus Roback, 1958 (Diptera: Chironomidae On a new species of the genus Aedokritus Roback, 1958 (Diptera: Chironomidae

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Sebastião José de Oliveira

1989-01-01

Full Text Available In this paper we describe a new species of a non-biting midge of the genus Aedokritus Roback, 1958 (Chironominae, Chironomidae from Brazil and Bolívia. That is the fifth species of this genus. The other species of the genus are: A. penicilligerus (Edwards, 1931, from Argentina and Peru; A. pruinescens (Edwards, 1931, from Argentina; A. platycnemis (Edwards, 1931, from Argentina; and A. sartis Roback, 1960, from Brazil.

Amazonimyia gigantea gen. n., sp. n., a new Tanypodinae (Diptera: Chironomidae) from the Neotropical Region.

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Da Silva, Fabio Laurindo; Wiedenbrug, Sofia

2015-04-15

A new genus, Amazonimyia, is established for a species of the tribe Pentaneurini (Diptera, Chironomidae, Tanypodinae) from the Amazon Rainforest in northern Brazil. Generic diagnoses for adult male and pupa are provided together with descriptions of a new species, Amazonimyia gigantea.

Morphology of the adult male and pupal exuviae of Glyptotendipes (Glyptotendipes) glaucus (Meigen 1818) (Diptera, Chironomidae) using scanning electron microscope (SEM).

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Kownacki, Andrzej; Woznicka, Olga; Szarek-Gwiazda, Ewa; Michailova, Paraskeva; Czaplicka, Anna

2017-02-27

In this paper, a study of the morphology of the pupa and male imago of Glyptotendipes (G.) glaucus (Meigen 1818) was carried out, with the aid of a scanning electron microscope (SEM). The SEM provided additional valuable information on the morphology of the species. Adult male head, antenna, wing, leg, abdomen, hypopygium, pupal cephalothorax and abdomen were examined. It is emphasized that SEM was not often used in Chironomidae studies. The present results confirm SEM as a suitable approach in carrying out morphological and taxonomical descriptions of Chironomidae species.

De dansmug Psectrocladius schlienzi nieuw voor Nederland, met een beschrijving van de larve (Diptera: Chironomidae)

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Beauvesère-Storm, de A.; Tempelman, D.

2009-01-01

De meeste soorten Chironomidae (dans- of vedermuggen) zijn dieren met een aquatische larve. Ze zijn een belangrijk onderdeel van de macrofaunagemeenschap van het zoete water, waarbij ze goede indicatoren zijn voor de milieukwaliteit. Veel soorten zijn met enige moeite goed tot soort of soortgroep te

Checklist and key identification of Chironomidae Larvae (Insecta: Diptera in Marbor River (Isfahan, Iran

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Azam Karami

2014-12-01

Full Text Available Chironomidae (Diptera which are distributed worldwide, are the most abundant and diverse insects in many freshwater ecosystems, as well as inland waters of Iran. However, very few researches were done for identification of this group in Iran, and there is a poor knowledge of their faunal diversity distribution in this country. To investigate chironomid larvae in Marbor river, Isfahan Province, seasonal samplings were done (2003-2004 in five selected sites along the river course, using Dredge sampler 3 times for every site. After collecting, the samples were preserved in formaldehyde at the site. Samples were sorted out in laboratory and the Chironomidae larvae were identified down to the generic level using the identification keys, and light and phase-contrast microscopes. Results revealed 39 genera from four subfamilies in Marbor River: Chironominae (15 genera, Diamesinae (2 genera, Orthocladiinae (17 genera and Tanypodinae (5 genera. From these, 13 genera were reported for the first time in Iran. An identification key for the taxon in Marbor river was provided.

Thalassomya gutae sp. n., a new marine chironomid (Diptera: Chironomidae: Telmatogetoninae) from the Brazilian coast.

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De Oliveira, Caroline Silva Neubern; Da Silva, Fabio Laurindo; Trivinho-Strixino, Susana

2013-01-01

One new species of Thalassomya Schiner, 1856 (Diptera: Chironomidae: Telmatogetoninae), T. gutae sp. n. is described and figured as male, pupa and larva. The specimen was collected in the marine zone between tidemarks, in southeastern Brazilian coast and is the first species of this genus recorded to Brazil.

Temporal and spatial responses of Chironomidae (Diptera) and other benthic invertebrates to urban stormwater runoff

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Susan E. Gresens; Kenneth T. Belt; Jamie A. Tang; Daniel C. Gwinn; Patricia A. Banks

2007-01-01

In a longitudinal study of two streams whose lower reaches received unattenuated urban stormwater runoff, physical disturbance by stormflow was less important than the persistant unidentified chemical impacts of urban stormwater in limiting the distribution of Chironomidae, and Ephemeroptera, Trichoptera and Plecoptera (EPT). A hierarchical spatial analysis showed that...

Diversity and distribution of Chironomidae (Insecta: Diptera of protected areas in North Tunisia

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Boulaaba S.

2014-01-01

Full Text Available In North Africa seasonal streams called wadi are an unique habitats with serve hydrological and thermal regime. Non-biting midges take an important part of freshwater biodiversity in North Africa. We present new data on the distribution and diversity of Chironomidae in North Tunisia. Larvae, pupal exuviae and adult males of chironomids were collected from a various freshwater ecosystems from May 2005 till April 2006. The aim of this study was to recognize the pattern of midge diversity in North Tunisia to estimate ecological value of running waters in the region. In total, 79 taxa were identified. Nearly all of the taxa were typical representatives of the Palaearctic and Mediterranean complexes. The majority of the investigated sites belonged to the protected areas in North Tunisia, such as the Ichkeul National Park, the Kroumerie Mountains and the El Feija National Park, part of the Intercontinental Reserve of the Mediterranean Biosphere. Altitudinal zonation of the communities composition was found in the lowland (250 m a.s.l. with maximum of 760 m. Whereas among the data 39 species are recorded from Tunisia for the first time, the species richness of Chironomidae is higher than previously estimated.

[Key to chironomid pupal exuviae (Diptera: Chironomidae) of tropical high Andean streams].

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Pratt, Narcís; González-Trujillo, Juan David; Ospina-Torres, Rodulfo

2014-12-01

The Chironomidae is a cosmopolitan family of Nematoceran flies with more than 20,000 species described. However the diversity of genera and species of the family in the Andean region beyond the 2,000 m.a.s.l are scarcely known. We conducted faunal surveys and biomonitoring research in different streams of Colombia, Ecuador and Peru from May 2005 to October 2011. Based on specimens collections, a taxonomic key was developed to identify pupae and pupal exuviae of 46 genera of midges (Diptera, Chironomidae) collected from streams at high altitude areas on the Andean tropical mountains. We included illustrations and brief taxonomic descriptions for all genera, of which several ones have not yet been formally described; in this latter case we used the nomenclature of Roback & Coffman (1983). For two genera, Cricotopus and Genus 1, keys to the most com- mon morphospecies were provided. Results showed that in this area the chironomid assemblages are dominated by the members of the subfamily Orthocladiinae (22 genera) followed by the Chironominae (13). Six genera of Tanypodinae were identified, while only three and two genera were present from subfamilies Podonominae and Diamesinae. This key may be very useful for both studies about drift in streams, and for biomonitoring purposes.

Laboratory evaluation of six algal species for larval nutritional suitability of the pestiferous midge Glyptotendipes paripes (Diptera: Chironomidae)

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Ali, A.; Lobinske, R. J.

2004-01-01

Roč. 97, č. 6 (2004), s. 1884-1890 ISSN 0022-0493 Institutional research plan: CEZ:AV0Z6066911 Keywords : Chironomidae * algal food * larval development Subject RIV: EH - Ecology, Behaviour Impact factor: 1.283, year: 2004

De larven van het geslacht Einfeldia Kieffer, 1924: nomenclatuur en tabel tot de soorten (Diptera: Chironomidae)

NARCIS (Netherlands)

Moller Pillot, H.K.M.; Wiersma, S.M.

1997-01-01

The larvae of the genus Einfeldia Kieffer, 1924: nomenclature and key to the species (Diptera: Chironomidae). A review is given of the identities of groups and taxa of Einfeldia in the larval stage as given in the literature. Three species remain on the Dutch list: E. carbonaria (Meigen), E.

Differential efficiencies of dip-net sampling versus sampling surface-floating pupal exuviae in a biodiversity survey of Chironomidae

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Leonard Charles Ferrington Jr

2014-12-01

Full Text Available Relative efficiencies of standard dip-net sampling (SDN versus collections of surface-floating pupal exuviae (SFPE were determined for detecting Chironomidae at catchment and site scales and at subfamily/tribe-, genus- and species-levels based on simultaneous, equal-effort sampling on a monthly basis for one year during a biodiversity assessment of Bear Run Nature Reserve. Results showed SFPE was more efficient than SDN at catchment scales for detecting both genera and species. At site scales, SDN sampling was more efficient for assessment of a first-order site. No consistent pattern, except for better efficiency of SFPE to detect Orthocladiinae genera, was observed at genus-level for two second-order sites. However, SFPE was consistently more efficient at detecting species of Orthocladiinae, Chironomini and Tanytarsini at the second order sites. SFPE was more efficient at detecting both genera and species at two third-order sites. The differential efficiencies of the two methods are concluded to be related to stream order and size, substrate size, flow and water velocity, depth and habitat heterogeneity, and differential ability to discriminate species among pupal exuviae specimens versus larval specimens. Although both approaches are considered necessary for comprehensive biodiversity assessments of Chironomidae, our results suggest that there is an optimal, but different, allocation of sampling effort for detecting Chironomidae across stream orders and at differing spatial and taxonomic scales.Article submitted 13. August 2014, accepted 31. October 2014, published 22. December 2014.

Tanytarsini (Diptera: Chironomidae) from madicolous habitat in Southeast Brazil: new species and new records.

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Trivinho-Strixino, Susana; Shimabukuro, Erika Mayumi

2017-05-23

Tanytarsini (Diptera: Chironomidae: Chironominae) collected from madicolous habitats in Brazil are analyzed, and three new species of Tanytarsus van der Wulp are described and illustrated: T. angelae sp. n. and T. alaidae sp. n. as adult male and T. alienus sp. n. as male and female. New records of another Brazilian Tanytarsus species are also presented, and immature stages of Paratanytarsus silentii Trivinho-Strixino are described.

From the Gut of an Insect to the Global Climate: Denitrification and Nitrous Oxide Production inside Lake Chironomidae

DEFF Research Database (Denmark)

Stief, Peter; Nielsen, Lars Peter; Revsbech, Niels Peter

2006-01-01

FROM THE GUT OF AN INSECT TO THE GLOBAL CLIMATE: DENITRIFICATION AND NITROUS OXIDE PRODUCTION INSIDE LAKE CHIRONOMIDAE P. Stief, L.P. Nielsen, N.P. Revsbech, A. Schramm Department of Biological Sciences, Microbiology, University of Aarhus, Denmark Denitrifying bacteria in lake sediments drive...

Spatial distribution of the assemblage of Chironomidae larvae (Diptera in five floodplain lakes from Ilha Grande National Park (Paraná - Mato Grosso do Sul State, Brazil - doi: 10.4025/actascibiolsci.v35i2.10799

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Alice Michiyo Takeda

2013-05-01

Full Text Available Chironomidae larvae (Diptera are one of the most important families among aquatic insects due to the higher abundance and species richness, considered an important tool for ecological studies. This study evaluated the richness of Chironomidae assemblage and related the distribution with physical and chemical variables in five lakes of the Paraná river, in the Ilha Grande National Park. There were two samplings, one in the central region and another in the marginal area of the floodplain lakes. In each region were collected six samples, five for biological analysis and one for granulometric analysis. The granulometric composition and organic matter content were the principal variables influencing the density and richness of Chironomidae. The scores of the abiotic data distinguished the marginal lakes (São João, Jacaré and Xambrê from the island lakes (Saraiva and Jatobá. The same segregation was observed in the distribution of Chironomidae morphotypes, and environments with higher values of organic matter, presented the lowest density and taxa richness. Thus, in this study the environmental variables directly interfered in the distribution, abundance and richness of Chironomidae of the floodplain lakes from Ilha Grande National Park, contributing to the knowledge of the diversity of this group in this area.

High altitude Chironomidae (Diptera of Serra da Estrela (Portugal: Additions to the Portuguese and Iberian Peninsula fauna

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Rieradevall, M.

2007-12-01

Full Text Available A Chironomidae (Diptera fauna list for headwater streams of high altitude areas in Serra da Estrela (Portugal is presented, doubling the previously established species richness for the region. The findings include 17 new records for Portugal, which represent an increase to 219 species for the Continental Portugal Chironomidae fauna. Two new records were detected for the Iberian Peninsula: one species (Tvetenia duodenaria, and one subgenus –Psectrocladius (Mesopsectrocladius–; and the presence of the genus Natarsia is confirmed. The last two occurrences correspond to monoespecific taxa of the Palearctic region. However, as taxonomic identification has been based on larval material, instead of pupae, pupal exuviae or imagoes, species level assignment is still uncertain.

Se presenta una lista de especies de Chironomidae (Diptera recolectadas en los ríos de cabecera de zonas de alta montaña en la Serra da Estrela (Portugal. Con esta aportación se duplica la riqueza de especies regional conocida hasta el momento y se eleva la fauna de quironómidos del Portugal continental a 219 especies. Se incluyen dos nuevas citas para la Península Ibérica, una especie (Tvetenia duodenaria y un subgénero –Psectrocladius (Mesopsectrocladius–, y se confirma la presencia del género Natarsia. En los dos últimos casos se trata de larvas de taxones hasta el momento monoespecíficos en la región paleárctica, pero al no haberse recolectado pupas o adultos no se puede asegurar la identificación específica.

The species of the genus Diamesa (Diptera, Chironomidae) known to occur in Italian Alps and Apennines.

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Montagna, Matteo; Urbanelli, Sandra; Rossaro, Bruno

2016-11-15

Some rare species from Italian Alps, belonging to the genus Diamesa Meigen, 1835 (Diptera, Chironomidae) are here redescribed as adult males, because only old, incomplete descriptions are available for these taxa. Terminology of male genitalia is reviewed, diagnostic features are illustrated in detail, and notes on biology and geographical distribution of the examined species are provided. An identification key to the known adult males is presented.

First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera

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Susana Trivinho-Strixino

2012-09-01

Full Text Available First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera. This study constitutes the first record of Temnocephala Blanchard, an ectosymbiont on Corydalidae, as a possible predator of chironomid larvae. Twenty-eight Corydalidae larvae (Corydalus and Protochauliodes were examined under stereomicroscopic in search for Temnocephala and Chironomidae larvae, of which five megalopteran larvae had 24 Temnocephala sp. associated. Furthermore, eight of these Temnocephala worms had chironomid larvae in their gut contents, an interaction previously unknown. Gut content analyses revealed Corynoneura as the commonest chironomid, but larvae of Larsia, Rheotanytarsus and Tanytarsus were recorded as well. This study included Corydalus and Protochauliodes as hosts for Temnocephala, which might be important for this worm dispersion and population dynamics.

Identification and reassessment of the specific status of some tropical freshwater midges (Diptera: Chironomidae) using DNA barcode data.

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Pramual, Pairot; Simwisat, Kusumart; Martin, Jon

2016-01-28

Chironomidae are a highly diverse group of insects. Members of this family are often included in programs monitoring the health of freshwater ecosystems. However, a difficulty in morphological identification, particularly of larval stages is the major obstacle to this application. In this study, we tested the efficiency of mitochondrial cytochrome c oxidase I (COI) sequences as the DNA barcoding region for species identification of Chironomidae in Thailand. The results revealed 14 species with a high success rate (>90%) for the correct species identification, which suggests the potential usefulness of the technique. However, some morphological species possess high (>3%) intraspecific genetic divergence that suggests these species could be species complexes and need further morphological or cytological examination. Sequence-based species delimitation analyses indicated that most specimens identified as Chironomus kiiensis, Tokunaga 1936, in Japan are conspecific with C. striatipennis, Kieffer 1912, although a small number form a separate cluster. A review of the descriptions of Kiefferulus tainanus (Kieffer 1912) and its junior synonym, K. biroi (Kieffer 1918), following our results, suggests that this synonymy is probably not correct and that K. tainanus occurs in Japan, China and Singapore, while K. biroi occurs in India and Thailand. Our results therefore revealed the usefulness of DNA barcoding for correct species identification of Chironomidae, particularly the immature stages. In addition, DNA barcodes could also uncover hidden diversity that can guide further taxonomic study, and offer a more efficient way to identify species than morphological analysis where large numbers of specimens are involved, provided the identifications of DNA barcodes in the databases are correct. Our studies indicate that this is not the case, and we identify cases of misidentifications for C. flaviplumus, Tokunaga 1940 and K. tainanus.

The influence of supplement feed preparation on the fatty acid composition of carp and Chironomidae larvae in a semi-intensive production system

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Živić Ivana

2013-01-01

Full Text Available In order to examine how extruded and pelleted feed affects the fatty acid composition of carp meat and Chironomidae larvae, two-month-old carp specimens were set in two fishponds (L1 and L2. The fatty acid composition of extruded and pelleted feed is characterized by a significantly higher content of ω-3 fatty acids and higher ω-3 to ω-6 fatty acids ratio (ω-3/ω-6 in extruded (11.34±0.12% and 0.315±0.005, respectively compared to pelleted feed (7.72±0.08%, 0.180±0.001, respectively. The fatty acid composition of carp meat is characterized by higher ω-3 fatty acid content and ω-3/ω-6 in carp fed with extruded feed (L1, 6.98±0.53% and 0.295±0.022, respectively compared to carp fed with extruded feed (L2, 5.46±0.07% and 0.232±0.009, respectively. Chironomidae larvae from the fishpond L2 had significantly higher ω-3 fatty acid content (8.22±0.89%, and therefore higher ω-3/ω-6 (0.81±0.09 in comparison to Chironomidae from the L1 fishpond where these parameters were 4.48±0.06% and 0.21±0.01, respectively. [Projekat Ministarstva nauke Republike Srbije, br. TR 31075 i br. 173040

The Use of the Developmental Rate of the Aquatic Midge Chironomus riparius (Diptera, Chironomidae) in the Assessment of the Postsubmersion Interval.

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González Medina, Alejandro; Soriano Hernando, Óscar; Jiménez Ríos, Gilberto

2015-05-01

Nonbiting midges (Diptera, Chironomidae) are the most abundant members of the fauna associated with submerged carcasses, but their use in the medicolegal context is very restricted because of their complex ontogeny. In this case, the corpse of a woman was recovered in late spring from a river in Granada (Iberian Peninsula). It showed obvious signs of long permanence in the aquatic environment and, along with pulmonary and microscopical analyses, led to the conclusion that the cause of death was drowning. Several larvae-like specimens were sampled from the scalp and later identified by morphological external features as IV instar larvae of Chironomus riparius Meigen, 1804 (Diptera, Chironomidae). Sequencing of cytochrome oxidase subunit I was performed to confirm the identification. The knowledge of the biology of C. riparius at low temperatures was critical to assess a postsubmersion interval of 16-17 days. © 2015 American Academy of Forensic Sciences.

Chironomidae Fauna (Diptera-Insecta) of Gümüldür Stream (İzmir)

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USTAOĞLU, Mustafa Ruşen; BALIK, Süleyman; TAŞDEMİR, Ayşe

2014-01-01

Samples were collected monthly from 10 different stations between April, 1993, and March, 1994, in order to determine the Chironomidae fauna of Gümüldür Stream in İzmir, Turkey. Ten species were found in the stream as determined from qualitative analyses of the samples. Of these, 5 species belong to the subfamily Orthocladiinae and the remaining 5 belong to the subfamily Chironominae. This is the first study reporting the existence of these species in Gümüldür Stream.

Chironomidae of semiaquatic lake shore habitats in the Karelian Isthmus (northwestern Russia

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Andrey Przhiboro

2012-10-01

Full Text Available Shores of lentic waters are poorly studied as habitats of Chironomidae. We investigated floating shore marsh surrounding the lakes Bol’shoe Rakovoe (Äyräpäänjärvi or Eteläjärvi and Okhotnich’e (Muolaanlampi, shallow mesotrophic wetlands in the Karelian Isthmus. Our research aimed to identify species structure of immature chironomid assemblages in this peculiar habitat and to provide their quantitative assessment. Five sites of the water margin zone (a 20-m part of floating marsh adjoining the lake littoral were studied using two techniques, quantitative samples taken with a grab-net and laboratory rearings of adults from substrata. Thirty-two samples were taken in July and October; 2970 emerging chironomid adults were identified. Nineteen species were found, 3 of Tanypodinae, 10 of Orthocladiinae and 6 of Chironominae. Tavastia yggdrasilia, Thienemanniella minuscula and Polypedilum trigonus are first recorded from Russia, and 8 more species, from NW Russia. Orthocladiinae accounted for over 99% emerging adults, with 3 species predominant and numerous on all sites, Paraphaenocladius impensus, Limnophyes minimus and L. natalensis. Species structure is discussed and compared with the data on similar habitats. Chironomid larvae were most numerous macroinvertebrates. Mean abundance of chironomid immatures varied from 1246 to 32060 ind./m2, mean biomass, 0.104 to 3.591 g(wet weight/m2, depending on site and season. In July, Chironomidae comprised 3-15% of Diptera biomass and 1-5% of macroinvertebrates biomass; in October, 13-49% and 7-20%, respectively.doi: 10.5324/fn.v31i0.1410.Published online: 17 October 2012.

Structure and Spatial Distribution of the Chironomidae Community in Mesohabitats in a First Order Stream at the Poço D'Anta Municipal Biological Reserve in Brazil

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Vescovi Rosa, Beatriz Figueiraujo Jabour; de Oliveira, Vívian Campos; Alves, Roberto da Gama

2011-01-01

The Chironomidae occupy different habitats along the lotic system with their distribution determined by different factors such as the substrate characteristics and water speed. The input of vegetable material from the riparian forest allows a higher habitat diversity and food to the benthic fauna. The main aim of this paper is to verify the structure and spatial distribution of the Chironomidae fauna in different mesohabitats in a first order stream located at a Biological Reserve in the southeast of Brazil. In the months of July, August, and September 2007, and in January, February, and March 2008, samples were collected with a hand net (250 µm) in the following mesohabitats: litter from riffles, litter from pools, and sediment from pools. The community structure of each mesohabitat was analyzed through the abundance of organisms, taxa richness, Pielou's evenness, Shannon's diversity, and taxa dominance. Similarity among the mesohabitats was obtained by Cluster analysis, and Chironomidae larvae distribution through the Correspondence analysis. Indicator species analysis was used to identify possible taxa preference for a determined mesohabitat. The analyzed mesohabitats showed high species richness and diversity favored by the large environmental heterogeneity. Some taxa were indicators of the type of mesohabitat. The substrate was the main factor that determined taxa distribution in relation to water flow differences (riffle and pool). Stream characteristics such as low water speed and the presence of natural mechanisms of retention may have provided a higher faunistic similarity between the areas with different flows. The results showed that the physical characteristics of each environment presented a close relationship with the structure and spatial distribution of the Chironomidae fauna in lotic systems. PMID:21529258

Madicolous Chironomidae from the Brazilian Atlantic Forest: a checklist with notes on altitudinal distributions (Diptera, Insecta)

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Shimabukuro, Erika Mayumi; Trivinho-Strixino, Susana

2018-01-01

Abstract Thin layers of water running over rocky surfaces are characteristic of madicolous habitats, which harbor a peculiar Chironomidae community. However, information on the identity, distribution, and ecology of madicolous chironomids in the Neotropical region are still sparse. The main purpose of this research is to reveal and contribute to the ecology of madicolous Chironomidae species, especially regarding their altitudinal distribution in the Atlantic Forest. Sampling was performed using our own designed emergence traps deployed from 0 to 2700 m a.s.l. in 70 sites in three mountains in southeastern Brazil. Sixty taxa of chironomids were collected and identified, of which only 22 are known to science. Most of the species showed a wider distribution than previously known, both in terms of geographic and altitudinal ranges, while others showed significant association with particular altitudinal bands (as evidenced by the indicator species analysis). Atlantic Forest mountainous regions are known to harbor one of the richest fauna in the world and have been suffering from several types of environmental impacts, including climate change, which will especially affect taxa living in specialized habitats. The narrow range of tolerance to environmental conditions verified for mountain species, and the fact that many of them are rare and endemic, make the conservation efforts in these areas indispensable. PMID:29706784

On the biology of Symbiocladius rhithrogenae (ZAVREL, 1924) (Diptera: Chironomidae) from the Chornohora Mts., Ukraine

Czech Academy of Sciences Publication Activity Database

Gilka, W.; Klonowska-Olejnik, M.; Godunko, Roman J.

2007-01-01

Roč. 76, - (2007), s. 285-291 ISSN 0032-3780 R&D Projects: GA AV ČR 1QS500070505 Grant - others:Institute of Environmental Sciences(PL) BW/V/INOS/4/06; Institute of Environmental Sciences(PL) DS/WBiNoZ/INoS/756/06; INTAS Fellowship Grant for Young Scientists(BE) 05-109-4162 Institutional research plan: CEZ:AV0Z50070508 Source of funding: R - rámcový projekt EK Keywords : Diptera * Chironomidae * Symbiocladius rhithrogenae Subject RIV: EG - Zoology

Two new species of Stenochironomus Kieffer (Diptera, Chironomidae) from Zhejiang, China

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Qi, Xin; Lin, Xiaolong; Liu, Yuedan; Wang, Xinhua

2015-01-01

Abstract Two new species of Stenochironomus Kieffer (Diptera: Chironomidae: Chironominae), Stenochironomus brevissimus sp. n. and Stenochironomus linanensis sp. n., are described from China and the male imagines are illustrated. Stenochironomus brevissimus sp. n. can be separated from the so far known species by having very short and small, spatulate superior volsella with two long setae, whereas Stenochironomus linanensis sp. n. is easily separated from the other species of Stenochironomus by the following characters: wings transparent, body yellow, superior volsella finger-like, with nine long setae, elongated inferior volsella with four long setae and one well developed terminal spine; tergite IX with 10−15 long setae medially. A key to the males of Stenochironomus occurring in China is given. PMID:25685018

An assessment of Chironomidae as quantitative indicators of past climatic change

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Walker, I.R.; Smol, J.P.; Engstrom, D.R.; Birks, H.J.B. (Queen' s University, Kingston, ON (Canada). Dept. of Biology)

1991-06-01

The distribution among Labrador (Canada) lakes of remains from 21 chironomid taxa (aquatic midges) was analysed by means of canonical correspondence analysis (CCA). Tests with partial CCA of three hypotheses revealed that the distributions of chironomid taxa were significantly correlated with summer surface-water temperature and maximum lake depth, but not sediment organic content. In addition, an exploratory CCA revealed possible relationships of chironomid fauna with residual longitude and Fe concentration. A weighted-averaging-regression/calibration model of the chironomid-temperature relationship (derived from a temperature-constrained CCA) allowed the summer surface-water temperature of lakes to be inferred from chironomid remains. Accurate quantitative reconstructions of late glacial and Holocene temperature variations should be possible from fossil Chironomidae. 60 refs., 7 figs., 6 tabs.

A Guide to Basic Taxonomic Literature for the Genera of North American Chironomidae (Diptera) - Adults, Pupae, and Larvae. Bulletin No. 447.

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Simpson, Karl W.

A generic list of North American Chironomidae (Diptera) is presented to help aquatic biologists quickly locate important taxonomic references for the adults, larvae, and pupae of each genus. The list (in chart format) includes literature published through 1981. When recent literature is available, older references are omitted, since the purpose of…

Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies.

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Kranzfelder, Petra; Anderson, Alyssa M; Egan, Alexander T; Mazack, Jane E; Bouchard, R William; Rufer, Moriya M; Ferrington, Leonard C

2015-07-24

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. Unfortunately, traditional benthic larval sampling methods, such as the dip-net, can be time-consuming and expensive. An alternative protocol involves collection of Chironomidae surface-floating pupal exuviae (SFPE). Chironomidae is a species-rich family of flies (Diptera) whose immature stages typically occur in aquatic habitats. Adult chironomids emerge from the water, leaving their pupal skins, or exuviae, floating on the water's surface. Exuviae often accumulate along banks or behind obstructions by action of the wind or water current, where they can be collected to assess chironomid diversity and richness. Chironomids can be used as important biological indicators, since some species are more tolerant to pollution than others. Therefore, the relative abundance and species composition of collected SFPE reflect changes in water quality. Here, methods associated with field collection, laboratory processing, slide mounting, and identification of chironomid SFPE are described in detail. Advantages of the SFPE method include minimal disturbance at a sampling area, efficient and economical sample collection and laboratory processing, ease of identification, applicability in nearly all aquatic environments, and a potentially more sensitive measure of ecosystem stress. Limitations include the inability to determine larval microhabitat use and inability to identify pupal exuviae to species if they have not been associated with adult males.

Benthic communities in inland salinized waters with different salinities and nutrient concentrations and the ecology of Chironomus aprilinus (Diptera: Chironomidae) in the Czech Republic.

Czech Academy of Sciences Publication Activity Database

Matěna, Josef; Šímová, I.; Brom, J.; Novotná, K.

2016-01-01

Roč. 113, January (2016), s. 122-129 E-ISSN 1802-8829 Institutional support: RVO:60077344 Keywords : Diptera * Chironomidae * Chironomus aprilinus * coal mining * hydric restoration * saline inland waters * fertilization Subject RIV: EH - Ecology, Behaviour Impact factor: 1.167, year: 2016

Cytogenetics of a parthenogenetic Arctic species of Micropsectra (Diptera, Chironomidae)

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Porter, David L.; Martin, Jon

2011-01-01

Abstract Micropsectra sedna (Oliver, 1976) is a parthenogenetic midge from the Canadian Arctic. The parthenogenetic mechanism is apomictic thelytoky, with a restitutional division during oogenesis, as found in other parthenogenetic Chironomidae. It is triploid, with two similar chromosome sets, and the third is relatively dissimilar, pairing little with the diploid set. Two karyotypes were observed: a single individual with eight polytene elements in the salivary glands (3n=12), considered standard, while the majority of larvae showed only seven polytene chromosomes (3n=11). Hybrid speciation is considered likely, although chromosomal recombination following the origin of thelytoky has played some part in karyotype evolution. A single morphologically distinct larva was also found, which might be the donor of the haploid chromosome set. The apomictic restitutional system is compared to that of the other, independently derived, parthenogenetic Chironomids to assess the extent of similarity between species. PMID:24260638

Additions to the aquatic diptera (Chaoboridae, Chironomidae, Culicidae, Tabanidae, Tipulidae) fauna of the White River National Wildlife Refuge, Arkansas

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Chordas, Stephen W.; Hudson, Patrick L.; Chapman, Eric G.

2004-01-01

The dipteran fauna of Arkansas is generally poorly known. A previous study of the Aquatic macroinvertebrates of the White River National Wildlife Refuge, the largest refuge in Arkansas, reported only 12 diptera taxa out of 219 taxa collected (Chordas et al., 1996). Most of the dipterans from this study were identified only to the family level. The family Chironomidae is a large, diverse group and was predicted to be much more diverse in the refuge than indicated by previous studies. In this study, Chironomidae were targeted, with other aquatic or semiaquatic dipterans also retained, in collections designed to better define the dipteran fauna of the White River National Wildlife Refuge. Adult dipterans were collected from 22 sites within the refuge using sweep-nets, two types of blacklight traps, and lighted fan traps in June of 2001. Specimens from previous studies were retrieved and identified to the lowest possible taxonomic level. A total of 4,917 specimens representing 122 taxa was collected. The 122 taxa were comprised of the following: two chaoborids, 83 chironomids, 15 culicids, nine tabanids, and 13 tipulids. Of these, 46 species are new state records for Arkansas. Nine undescribed species of chironomids were collected, and eight species records represent significant range extensions.

THE CHIRONOMIDAE ASSEMBLAGES IN SOMESUL MIC RIVER (ROMANIA DURING 1996 AND 1997

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Maria-Monica Tudorancea

2001-01-01

Full Text Available The communities of Chironomidae larvae in the Gilau – Gherla sector of the Somesul Mic River (Transylvania, Romania were studied during 1996 and 1997 in order to compare their species composition and to see if their component species could be good indicators for water quality deterioration. A total of 102 species were recorded, out of which 12 are new records for the Romanian fauna. Four of these species are known only from East Asia and from the North America. Some species such as Chironomus thumi, Microcricotopus bicolor, Dicrotendipes nervosus and Dicrotendipes notatus occurred in organically enriched waters. Other species, such as Cricotopus algarum, Cricotopus bicinctus, Cricotopus tremulus and Cricotopus trifasciatus occurred in both clean and organically polluted water which indicate they are not good bioindicators for water quality deterioration.

Observations of cocooned Hydrobaenus (Diptera: Chironomidae) larvae in Lake Michigan

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Tucker, Taaja R.; Hudson, Patrick L.; Riley, Stephen

2016-01-01

Larvae of the family Chironomidae have developed a variety of ways to tolerate environmental stress, including the formation of cocoons, which allows larvae to avoid unfavorable temperature conditions, drought, or competition with other chironomids. Summer cocoon formation by younger instars of the genus Hydrobaenus Fries allows persistence through increased temperatures and/or intermittent dry periods in arid regions or temporary habitats, but this behavior was not observed in the Great Lakes until the current study. Cocoon-aestivating Hydrobaenus sp. larvae were found in benthic grab samples collected in 2010–2013 near Sleeping Bear Dunes National Lakeshore in northern Lake Michigan with densities up to 7329/m2. The aestivating species was identified as Hydrobaenus johannseni (Sublette, 1967), and the associated chironomid community was typical for an oligotrophic nearshore system. Hydrobaenus cocoon formation in the Great Lakes was likely previously unnoticed due to the discrepancies between the genus' life history and typical benthos sampling procedures which has consequences for describing chironomid communities where Hydrobaenus is present.

The direct and indirect effects of a glyphosate-based herbicide and nutrients on Chironomidae (Diptera) emerging from small wetlands.

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Baker, Leanne F; Mudge, Joseph F; Houlahan, Jeff E; Thompson, Dean G; Kidd, Karen A

2014-09-01

Laboratory and mesocosm experiments have demonstrated that some glyphosate-based herbicides can have negative effects on benthic invertebrate species. Although these herbicides are among the most widely used in agriculture, there have been few multiple-stressor, natural system-based investigations of the impacts of glyphosate-based herbicides in combination with fertilizers on the emergence patterns of chironomids from wetlands. Using a replicated, split-wetland experiment, the authors examined the effects of 2 nominal concentrations (2.88 mg acid equivalents/L and 0.21 mg acid equivalents/L) of the glyphosate herbicide Roundup WeatherMax, alone or in combination with nutrient additions, on the emergence of Chironomidae (Diptera) before and after herbicide-induced damage to macrophytes. There were no direct effects of treatment on the structure of the Chironomidae community or on the overall emergence rates. However, after macrophyte cover declined as a result of herbicide application, there were statistically significant increases in emergence in all but the highest herbicide treatment, which had also received no nutrients. There was a negative relationship between chironomid abundance and macrophyte cover on the treated sides of wetlands. Fertilizer application did not appear to compound the effects of the herbicide treatments. Although direct toxicity of Roundup WeatherMax was not apparent, the authors observed longer-term impacts, suggesting that the indirect effects of this herbicide deserve more consideration when assessing the ecological risk of using herbicides in proximity to wetlands. © 2014 SETAC.

Cytogenetic comparison of chironomid midge Glyptotendipes glaucus (Meigen, 1818 (Diptera, Chironomidae populations from Northwest Russia and Ukraine (Chernobyl zone

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- -

2012-06-01

Full Text Available Functional characters of polythene chromosomes and chromosomal rearrangements in salivary glands of 177 larvae of Glyptotendipes glaucus (Diptera, Chironomidae from reservoirs of Russia and Ukraine (Chernobyl have been analysed. Similarity of the populations studied based on a pool of chromosomal reorganizations has been established. The general types of inversions in chromosomal arms A, B, D and E have been detected. Influence of radioactive pollution (Chernobyl on functional changes of a nucleus, Balbiani rings, puffs, morphology of disks and interdisks is revealed.

Chironomidae larvae (Diptera) of Neotropical floodplain: overlap niche in different habitats.

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Butakka, C M M; Ragonha, F H; Takeda, A M

2014-05-01

The niche overlap between trophic groups of Chironomidae larvae in different habitats was observed between trophic groups and between different environments in Neotropical floodplain. For the evaluation we used the index of niche overlap (CXY) and analysis of trophic networks, both from the types and amount of food items identified in the larval alimentary canal. In all environments, the larvae fed on mainly organic matter such as plants fragments and algae, but there were many omnivore larvae. Species that have high values of food items occurred in diverse environments as generalists with great overlap niche and those with a low amount of food items with less overlap niche were classified as specialists. The largest number of trophic niche overlap was observed among collector-gatherers in connected floodplain lakes. The lower values of index niche overlap were predators. The similarity in the diet of different taxa in the same niche does not necessarily imply competition between them, but coexistence when the food resource is not scarce in the environment even in partially overlapping niches.

Integrating DNA barcodes and morphology for species delimitation in the Corynoneura group (Diptera: Chironomidae: Orthocladiinae).

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Silva, F L; Wiedenbrug, S

2014-02-01

In this study, we use DNA barcodes for species delimitation to solve taxonomic conflicts in 86 specimens of 14 species belonging to the Corynoneura group (Diptera: Chironomidae: Orthocladiinae), from the Atlantic Forest, Brazil. Molecular analysis of cytochrome c-oxidase subunit I (COI) gene sequences supported 14 cohesive species groups, of which two similar groups were subsequently associated with morphological variation at the pupal stage. Eleven species previously described based on morphological criteria were linked to DNA markers. Furthermore, there is the possibility that there may be cryptic species within the Corynoneura group, since one group of species presented internal grouping, although no morphological divergence was observed. Our results support DNA-barcoding as an excellent tool for species delimitation in groups where taxonomy by means of morphology is difficult or even impossible.

Taxonomic review of the chironomid genus Cricotopus v.d. Wulp (Diptera: Chironomidae) from Australia: keys to males, females, pupae and larvae, description of ten new species and comments on Paratrichocladius Santos Abreu.

Science.gov (United States)

Drayson, Nick; Cranston, Peter S; Krosch, Matt N

2015-02-16

The Australian species of the Orthocladiinae genus Cricotopus Wulp (Diptera: Chironomidae) are revised for larval, pupal, adult male and female life stages. Eleven species, ten of which are new, are recognised and keyed, namely Cricotopus acornis Drayson & Cranston sp. nov., Cricotopus albitarsis Hergstrom sp. nov., Cricotopus annuliventris (Skuse), Cricotopus brevicornis Drayson & Cranston sp. nov., Cricotopus conicornis Drayson & Cranston sp. nov., Cricotopus hillmani Drayson & Cranston, sp. nov., Cricotopus howensis Cranston sp. nov., Cricotopus parbicinctus Hergstrom sp. nov., Cricotopus tasmania Drayson & Cranston sp. nov., Cricotopus varicornis Drayson & Cranston sp. nov. and Cricotopus wangi Cranston & Krosch sp. nov. Using data from this study, we consider the wider utility of morphological and molecular diagnostic tools in untangling species diversity in the Chironomidae. Morphological support for distinguishing Cricotopus from Paratrichocladius Santo-Abreu in larval and pupal stages appears lacking for Australian taxa and brief notes are provided concerning this matter.

Larval gut pH profile in pestiferous .i.Chironomus crassicaudatus./i. and .i.Glyptotendipes paripes./i. (Chironomidae: Diptera) in reference to the toxicity potential of .i.Bacillus thuringiensis./i. serovar .i.israelensis./i

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Lobinske, R.J.; Yaqub, A.; Ali, A.

2007-01-01

Roč. 23, č. 3 (2007), s. 355-358 ISSN 8756-971X Institutional research plan: CEZ:AV0Z60660521 Keywords : chironomidae larvae * gut pH * Bacillus thuringiensis serovar israelensis Subject RIV: EH - Ecology, Behaviour Impact factor: 0.706, year: 2007

Genetic architecture of local adaptation in lunar and diurnal emergence times of the marine midge Clunio marinus (Chironomidae, Diptera).

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Kaiser, Tobias S; Heckel, David G

2012-01-01

Circadian rhythms pre-adapt the physiology of most organisms to predictable daily changes in the environment. Some marine organisms also show endogenous circalunar rhythms. The genetic basis of the circalunar clock and its interaction with the circadian clock is unknown. Both clocks can be studied in the marine midge Clunio marinus (Chironomidae, Diptera), as different populations have different local adaptations in their lunar and diurnal rhythms of adult emergence, which can be analyzed by crossing experiments. We investigated the genetic basis of population variation in clock properties by constructing the first genetic linkage map for this species, and performing quantitative trait locus (QTL) analysis on variation in both lunar and diurnal timing. The genome has a genetic length of 167-193 centimorgans based on a linkage map using 344 markers, and a physical size of 95-140 megabases estimated by flow cytometry. Mapping the sex determining locus shows that females are the heterogametic sex, unlike most other Chironomidae. We identified two QTL each for lunar emergence time and diurnal emergence time. The distribution of QTL confirms a previously hypothesized genetic basis to a correlation of lunar and diurnal emergence times in natural populations. Mapping of clock genes and light receptors identified ciliary opsin 2 (cOps2) as a candidate to be involved in both lunar and diurnal timing; cryptochrome 1 (cry1) as a candidate gene for lunar timing; and two timeless (tim2, tim3) genes as candidate genes for diurnal timing. This QTL analysis of lunar rhythmicity, the first in any species, provides a unique entree into the molecular analysis of the lunar clock.

Chironomid (Diptera, Chironomidae species assemblages in northeastern Algerian hydrosystems

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N. Chaib

2013-04-01

Full Text Available The aim of this paper was to analyze the distribution of chironomids (Diptera, Chironomidae, and determine their substrate preferences, from two hydrosystems located in northeastern Algeria: the Kebir-East and the Seybouse wadis. Sixty-five species were recorded in 49 sampling sites distributed along the main courses of the two hydrographic nets and their tributaries. The majority of taxa comprised cosmopolitan species widely distributed along these two hydrosystems. Cricotopus (Cricotopus bicinctus showed the highest abundance and frequency of occurrence (29.52% and was widespread in almost all the sampling sites. Species richness ranged from 4 to 23, Shannon diversity between 0.15 and 0.90, Evenness from 0.23 to 1. A cluster analysis was carried out to represent the different groups of sites sharing similar species composition. Agglomerative cluster analysis grouped the sampling sites into four clusters according to the community data. An Indval analysis was then carried out to detect indicator species for each group of the sampling sites. Cricotopus (Isocladius sylvestris was indicator of the first group of the sampling sites. Orthocladius pedestris, Rheocricotopus chalybeatus and C. bicinctus were indicators of the second group, and Polypedilum cultellatum of the third group. The fourth group was not characterized by any species. Indval analysis allowed also to determine species preferences for substrate size: Corynoneura scutellata and Dicrotendipes nervosus emphasized a preference to fine gravel, and Glyptotendipes pallens to fine sand.

Variación espacio-temporal de Chironomidae (Diptera bentónicos y derivantes en un arroyo serrano en Córdoba, Argentina

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Juan P. Zanotto-Arpellino

2015-03-01

Full Text Available Chironomidae es una de las familias más abundantes y diversas en los ecosistemas de agua dulce, sin embargo su complejidad sistemática ha sido motivo de su escaso desarrollo en muchos estudios limnológicos. El objetivo de este estudio fue analizar los ensambles de Chironomidae bentónicos y derivantes de un arroyo serrano de la región central de Argentina evaluando abundancia, diversidad y composición de especies en diferentes hábitats fluviales y distintas estaciones del año. Se tomaron muestras cuantitativas de bentos y deriva en el arroyo Achiras (Córdoba, Argentina en hábitats de rabión y corredera, y se registraron variables ambientales en las cuatro estaciones del año, entre 2007 y 2008. Se registró un total de 25 taxones pertenecientes a cuatro subfamilias. Los quironómidos bentónicos constituyeron el 19% de la comunidad de macroinvertebrados, mientras que en deriva representaron el 33%. En el bentos dominó Thienemannimyia sp. y en la deriva, Corynoneura sp. De acuerdo con los resultados de ANOVAs de dos vías, los mayores valores de riqueza taxonómica y densidad bentónica se registraron en el periodo de aguas bajas (otoño e invierno y la diversidad de quirónomidos bentónicos fue mayor en rabión. Por el contrario, para el ensamble de derivantes sólo la equitatividad fue diferente entre hábitats y entre estaciones. El análisis TWINSPAN mostró una separación espacio-temporal de las muestras de bentos, mientras que las muestras de deriva se segregaron sólo temporalmente lo que sugiere que el transporte aguas abajo de los invertebrados homogeniza la variación espacial observada en el bentos. La densidad de bentos y deriva varió de manera similar a través de las estaciones del año y el coeficiente de Jaccard presentó un alto índice de similitud entre bentos y deriva (86%. Este trabajo posibilitó conocer la dinámica temporal y espacial de los quironómidos bentónicos y derivantes en un arroyo serrano. La

Estrutura da comunidade das larvas de Chironomidae (Insecta: Diptera, em diferentes substratos artificiais e fases hídricas, no trecho superior do rio Paraná, Estado do Paraná, Brasil = Community structure of Chironomidae larvae (Insecta: Diptera, in different artificial substrates and during distinct hydrological phases, in the upper stretch of the Paraná river, Paraná State, Brazil

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Adriana Felix dos Anjos

2010-04-01

Full Text Available Este estudo teve como objetivo verificar a influência das fases hídricas sobre a composição, a densidade e a dominância das larvas de Chironomidae em diferentes tipos de substratos artificiais. As coletas foram realizadas quinzenalmente, entre os meses de agosto de2004 e dezembro de 2005. A análise de agrupamento revelou diferenças na composição e densidade das morfoespécies entre as fases hídricas e, de acordo com o índice de dominância de Kownacki, Cricotopus sp. foi dominante ou subdominante em todos os substratos e fases hídricas.Na fase de águas baixas, a maior similaridade foi observada entre os substratos de mesma forma. Nesse período, os maiores valores de riqueza e densidade das larvas foram registrados nos substratos em forma de X. Na fase de águas altas, o aumento no nível do rio Paraná influenciou na redução da densidade média das larvas e somente nos substratos de madeira em forma de X e PVC em forma de tubo, cujos materiais favoreceram a melhor fixação das larvas, foramregistrados maiores valores de densidade.This study investigated the influence of hydrological phases on species composition, density and dominance of Chironomidae larvae indifferent types of artificial substrates. Samplings were undertaken fortnightly, between August 2004 and December 2005. Cluster analysis evidenced differences in the species composition and density of Chironomidae morphospecies among hydrological phases; according to the Kownacki dominance index, Cricotopus sp. was dominant or subdominant in all substrates and hydrological phases. During the low water phase, the greatest similarity was observed among the substrateswith the same shape. In this period, the highest values of species richness and density of larvae were registered in X-shaped substrates. During the high water phase, the rise in the level of the Paraná River influenced on the reduction of mean larvae density, and only in wooden X-shaped and tube-shaped PVC

Cytogenetic characteristics of Chironomus balatonicus Devai, Wulker, Scholl (Diptera, Chironomidae) from the Chernobyl region

International Nuclear Information System (INIS)

Michailova, P.; Petrova, N.

1994-01-01

A cytogenetic analysis was carried out on a population of Chironomus balatonicus (Chironomidae, Diptera) from Chernobyl, a highly radioactive area of the Kiev region. Several chromosomal aberrations were established unique to a population of Chironomus balatonicus living in an area contaminated by radioactive waste. Five new heterozygous inversions, deficiencies in arms C, D, E, F and chromatid breaks were found in the irradiated population but not in nonirradiated populations. A pericentric inversion in chromosome AB occurred at a relatively high frequency. Genome aberrations expressed by a heterochromatized 'B' chromosome were evident. In the irradiated and nonirradiated populations common inversions occurred showing variation in their frequency depending on specific environmental conditions. The somatic and also the germ cells were characterized by a number of heteropycnotic nuclei and vacuolized chromosomes. Both the somatic and germ cells showed changes in the structural and functional organization of heterochromatin and this was particularly marked in the telomeric sectors of the chromosomes. The heterochromatin which is extremely sensitive to radioactivity appears to protect euchromatin from adverse environmental conditions

Mentum deformities in Chironomidae communities as indicators of anthropogenic impacts in Swartkops River

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Odume, O. N.; Muller, W. J.; Palmer, C. G.; Arimoro, F. O.

Swartkops River is located in Eastern Cape of South Africa and drains a heavily industrialised catchment and has suffered deterioration in water quality due to pollution. Water quality impairment in the Swartkops River has impacted on its biota. Deformities in the mouth parts of larval Chironomidae, particularly of the mentum, represent sub-lethal effects of exposure to pollutants, and were therefore employed as indictors of pollution in the Swartkops River. Chironomid larvae were collected using the South African Scoring System version 5 (SASS5) protocol. A total of 4838 larvae, representing 26 taxa from four sampling sites during four seasons were screened for mentum deformities. The community incidences of mentum deformity were consistently higher than 8% at Sites 2-4, indicating pollution stress in the river. Analysis of variance (ANOVA) conducted on arcsine transformed data revealed that the mean community incidence of mentum deformity was significantly higher (p 0.05) between seasons across sites. Severe deformities were consistently higher at Site 3. Strong correlations were found between deformity indices and the concentrations of dissolved oxygen (DO), total inorganic nitrogen (TIN), orthophosphate-phosphorus (PO4-P), electrical conductivity (EC) and turbidity.

Distribución espacio-temporal de larvas de Chironomidae (Diptera en un arroyo andino (Uspallata, Mendoza, Argentina Spatial and temporal distribution of larvae of Chironomidae (Diptera in an Andean stream (Uspallata, Mendoza, Argentina

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Erica E. Scheibler

2008-12-01

Full Text Available Se realizó un estudio sobre la composición larval de la familia Chironomidae en un arroyo andino en la localidad de Uspallata (Mendoza, Argentina. Se realizaron muestreos estacionales durante un ciclo anual completo (2001/2002 en tres sitios, siguiendo un gradiente altitudinal. Se midieron variables físico-químicas en campo y laboratorio. La relación entre presencia y abundancia de quironómidos y parámetros ambientales se exploró mediante un análisis de Correspondencia Canónica. Se identificaron siete géneros pertenecientes a cuatro subfamilias: Chironominae, Orthocladiinae, Podonominae y Tanypodinae. Orthocladiinae fue la subfamilia que tuvo mayor riqueza genérica (Cricotopus van der Wulp, Onconeura Andersen & Saether y Parametriocnemus Goetghebuer, densidad y frecuencia de aparición a nivel estacional y espacial. Podonominae (Podonomus Philippi y Podonomopsis Brundin se halló únicamente en SA mientras que Chironominae (Polypedilum Kieffer estuvo presente en UD. Tanypodinae (Pentaneura Philippi se encontró en los tres sitios de muestreo aunque con una densidad menor. Se detectó incremento de la conductividad y temperatura del agua, y disminución del tamaño del sustrato desde SA a UD, lo que coincide con la desaparición de Podonomus y Podonomopsis y la aparición de Polypedilum hacia UD. De este estudio se concluye que el sistema presenta baja riqueza genérica comparada con otros sistemas montañosos de Argentina.A study was conducted on the larval composition of the family Chironomidae in an Andean stream in Uspallata locality (Mendoza, Argentina. Seasonal samplings were performed over a full annual cycle (2001/2002 at three sites, along an altitudinal gradient. Physical and chemical variables were measured in both the field and the laboratory. Relationship between presence and abundance of chironomids and environmental parameters was explored using a Canonical Correspondence analysis. Seven genera were identified

Chironomus larvae (Chironomidae: Diptera as water quality indicators along an environmental gradient in a neotropical urban stream

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Nadja Gomes Machado

2015-04-01

Full Text Available Anthropogenic interference in urban lotic systems is a factor affecting the biota of waterbodies. Aquatic macro invertebrates are an important food source for fish and are valuable indicators of water quality. The objective of this work was to study Chironomus larvae (Chironomidae: Diptera distribution along an environmental gradient in Barbado Stream, Cuiabá, MT, Brazil. No individual Chironomus was found in the springs of Barbado Stream, which may indicate preservation of the area. During the study period, we found 40.3 and 94.4 individuals/m2 at points 3 and 4 (low course, respectively. There is eutrophication in these sites due to domestic sewage discharges, indicating low quality water. The Barbado Stream needs restoration projects that include an awareness of the residents of their neighborhood’s environmental importance, and investments in the sanitation sector to prioritize the collection and treatment of wastewater and solid waste collection.

A DNA Barcode Library for Korean Chironomidae (Insecta: Diptera) and Indexes for Defining Barcode Gap

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Kim, Sungmin; Song, Kyo-Hong; Ree, Han-Il; Kim, Won

2012-01-01

Non-biting midges (Diptera: Chironomidae) are a diverse population that commonly causes respiratory allergies in humans. Chironomid larvae can be used to indicate freshwater pollution, but accurate identification on the basis of morphological characteristics is difficult. In this study, we constructed a mitochondrial cytochrome c oxidase subunit I (COI)-based DNA barcode library for Korean chironomids. This library consists of 211 specimens from 49 species, including adults and unidentified larvae. The interspecies and intraspecies COI sequence variations were analyzed. Sophisticated indexes were developed in order to properly evaluate indistinct barcode gaps that are created by insufficient sampling on both the interspecies and intraspecies levels and by variable mutation rates across taxa. In a variety of insect datasets, these indexes were useful for re-evaluating large barcode datasets and for defining COI barcode gaps. The COI-based DNA barcode library will provide a rapid and reliable tool for the molecular identification of Korean chironomid species. Furthermore, this reverse-taxonomic approach will be improved by the continuous addition of other speceis’ sequences to the library. PMID:22138764

Taxonomic and numeric structure of Chironomidae (Diptera in different habitats of a Neotropical floodplain

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Cristina Márcia de Menezes Butakka

2014-09-01

Full Text Available We characterized the local benthic Chironomidae by analyzing the numerical density, biomass, diversity index of Shannon-Wiener and dominance of larvae in the main channel of the Ivinhema River, in a secondary channel, in five lakes connected to the main channel and in five lakes without connection. Of the 68 taxa identified, Aedokritus sp., Tanytarsus sp., Chironomus strenzkei Fittkau, 1968 and Procladius sp.1 were found in all sampling sites and were considered morphospecies with greater of greatest ecological plasticity. Chironomus strenzkei Fittkau, 1968, contributed with the greatest biomass in the central region of lakes without connection, whereas Aedokritus sp. dominated in the littoral of lakes. The greater values of diversity indices in the littoral region of channels were due to the greater water flow and to the higher food availability in these areas. The dominance indices, by contrast, were greater on the central region of these environments. The littoral region has exclusive characteristics, representing habitats that could play important controlling in the numerical density and index diversity on the ecosystem, whereas that the biomass of benthic invertebrates in the central region in some biotopes would have different spatial probably according organisms drift.

Clave para la determinación de exuvias pupales de los quironómidos (Diptera: Chironomidae de ríos altoandinos tropicales

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Narcís Prat

2014-12-01

Full Text Available Chironomidae es una familia cosmopolita de dípteros nematóceros que comprende más de 20 000 especies descritas. Sin embargo, la diversidad de géneros y especies presentes en la región andina del Neotrópico es poco conocida. Por tal motivo se desarrolló una clave taxonómica para identificar las pupas y exuvias pupales de 46 géneros de la familia Chironomidae presentes en ríos de alta montaña ubicados en la cordillera de los Andes por encima de los 2 000msnm. Se utilizó material de colección obtenido de levantamientos faunísticos y estudios de biomonitoreo en diferentes ríos y quebradas de Colombia, Ecuador y Perú. La clave incluye ilustraciones y breves descripciones taxonómicas de todos los géneros incluyendo algunos que aún no han sido descritos formalmente. Para estos últimos se siguió la nomenclatura usada por Roback & Coffman (1983. Para los géneros Cricotopus y Género 1 se incluyen claves para la determinación de las morfoespecies más comunes. En el ensamblaje de quironómidos de la región altoandina domina la subfamilia Orthocladiinae (22 géneros seguida por Chironominae (13 géneros, patrón que contrasta con la dominancia de Chironominae en las zonas de menor altura de la región Neotropical. Se encontraron seis géneros pertenecientes a la subfamilia Tanypodinae, mientras que para Podonominae y Diamesinae estuvieron presentes tres y dos géneros respectivamente. Esta clave podría llegar a ser muy útil en estudios de la deriva y programas de biomonitoreo de los ríos altoandinos neotropicales.

Conochironomus (Diptera: Chironomidae) in Asia: new and redescribed species and vouchering issues.

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Cranston, Peter S

2016-05-09

The presence of the Afro-Australian genus Conochironomus Freeman, 1961 (Diptera: Chironomidae) in Asia has been recognised only informally. An unpublished thesis included Conochironomus from Singapore, and the genus has been keyed from Malaysia without named species. Here, the Sumatran Conochironomus tobaterdecimus (Kikuchi & Sasa, 1980) comb. n. is recorded from Singapore and Thailand. The species is transferred from Sumatendipes Kikuchi & Sasa, 1980, rendering the latter a junior synonym (syn. n.) of Conochironomus Freeman. Conochironomus nuengthai sp. n. and Conochironomus sawngthai sp. n. are described as new to science, based on adult males from Chiang Mai, Thailand. All species conform to existing generic diagnoses for all life stages, with features from male and female genitalia, pupal cephalic tubercles and posterolateral 'spurs' of tergite VIII providing evidence for species distinction. Some larvae are linked to C. tobaterdecimus through molecular barcoding. Variation in other larvae, which clearly belong to Conochironomus and are common throughout Thailand, means that they cannot be segregated to species. Larval habitats include pools in river beds, urban storage reservoirs, drains with moderately high nutrient loadings, and peat swamps. Endochironomus effusus Dutta, 1994 from north-eastern India may be a congener but may differ in adult morphology, thereby precluding formal new combination until discrepancies can be reconciled. Many problems with vouchering taxonomic and molecular material are identified that need to be rectified in the future.

Exploring the utility of DNA barcoding in species delimitation of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae).

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Song, Chao; Wang, Qian; Zhang, Ruilei; Sun, Bingjiao; Wang, Xinhua

2016-02-16

In this study, we tested the utility of the mitochondrial gene cytochrome c oxidase subunit 1 (CO1) as the barcode region to deal with taxonomical problems of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae). The 114 DNA barcodes representing 27 morphospecies are divided into 33 well separated clusters based on both Neighbor Joining and Maximum Likelihood methods. DNA barcodes revealed an 82% success rate in matching with morphospecies. The selected DNA barcode data support 37-64 operational taxonomic units (OTUs) based on the methods of Automatic Barcode Gap Discovery (ABGD) and Poisson Tree Process (PTP). Furthermore, a priori species based on consistent phenotypic variations were attested by molecular analysis, and a taxonomical misidentification of barcode sequences from GenBank was found. We could not observe a distinct barcode gap but an overlap ranged from 9-12%. Our results supported DNA barcoding as an ideal method to detect cryptic species, delimit sibling species, and associate different life stages in non-biting midges.

Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

International Nuclear Information System (INIS)

Doi, Hideyuki; Kikuchi, Eisuke; Shikano, Shuichi

2001-01-01

The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. δ 13 C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

Leaf litter as a possible food source for chironomids (Diptera in Brazilian and Portuguese headwater streams Detritos foliares como possível fonte de alimento para Chironomidae (Diptera em riachos de cabeceira brasileiros e portugueses

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Marcos Callisto

2007-06-01

Full Text Available Our objective was to evaluate the potential use of leaf detritus by chironomid larvae. Field and laboratory experiments were performed using leaves and chironomid species collected in Portugal and Brazil. Laboratory experiments under controlled conditions were done using microbial conditioned senescent leaves of Alnus glutinosa (L. Gaertn, Neriumoleander L., Protium heptaphilum (Aubl. March, Protium brasiliense (Spreng Engl., Myrcia guyanensis(Aubl. DC and Miconia chartacea Triana. Laboratory experiments were performed using specimens collected from leaf litter in local streams. Whenever possible, after the experiments, chironomids were allowed to emerge as adults and identified. In Portugal the following taxa were identified: Micropsectra apposita (Walker, 1856, Polypedilum albicorne (Meigen, 1838,Eukiefferiella claripennis Lundbeck (1898, Rheocricotopus (Psilocricotopus atripes Rempel (1937 and Ablabesmyia Johannsen (1905 (Diptera, Chironomidae. Consumption rates ranged from 0.15 ± 0.10 mg (AFDM of leaf animal-1 day-1 (Micropsectra apposita feeding on Alnus glutinosa up to 0.85 ± 0.33 mg (AFDM of leaf animal-1 day-1 (Polypedilum albicorne feeding on Miconia chartacea. In Brazil, the following taxa were identified from leaves: Phaenopsectra sp., Chironomus spp. and Polypedilum sp. and maximum consumption rates reached 0.47 ± 0.28 (AFDM of leaf mg.animal-1.day-1 (Chironomus Meigen (1803 feeding on Protium heptaphilum. Feeding experiments with laboratory cultured specimens, revealed that some chironomids were unable to feed on decomposing leaves (e.g., C. xanthus Rempel (1939 on P.brasiliensis and M.guyanensis. Our results suggest that some stream chironomids (not typical shredders can use leaf litter of riparian vegetation as a complementary food source.O objetivo foi avaliar o potencial uso de detritos foliares por larvas de Chironomidae. Foram realizados experimentos em campo e em laboratório utilizando folhas e larvas de Chironomidae

Clarification of Einfeldia Kieffer, 1922 (Diptera: Chironomidae) with E. australiensis (Freeman, 1961), comb. n. based on immature stages.

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Cranston, Peter S; Martin, Jon; Mulder, Monica; Spies, Martin

2016-08-31

The immature stages are described for the first time for Chironomus (Xenochironomus) australiensis Freeman (Diptera: Chironomidae) and the adult male is redescribed including from type specimens. The species does not belong to Chironomus Meigen or Xenochironomus Kieffer, but is best placed in a modestly expanded Einfeldia Kieffer. Application of this genus name is clarified, including by a lectotype fixation for its type species, E. pectoralis Kieffer, 1924. Einfeldia australiensis (Freeman) comb. n. provides the first record of the genus from Australia; otherwise the genus is reported confidently only from North America, Central America and western Europe to Japan. The immature stages of E. australiensis occur in relatively shallow mesotrophic to eutrophic dune lakes and maars with circum-neutral pH and high conductivity, from southeastern Queensland to southern Australia. The cytology is described briefly from larval salivary glands. Alternative genus placements for the species are discussed, and problems with Einfeldia and connected systematics in the tribe Chironomini are addressed.

Carbon and nitrogen stable isotope ratios analysis of food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) in strongly acidic lake Katanuma

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Doi, Hideyuki [Tohoku Univ., Sendai (Japan). Graduate School of Science; Kikuchi, Eisuke; Shikano, Shuichi

2001-12-01

The food sources for Chironomus acerbiphilus larvae (Diptera Chironomidae) were analyzed using carbon and nitrogen stable isotope ratios in Lake Katanuma. Lake Katanuma is a volcanic and strongly acidic lake (average pH 2.2). In Lake Katanuma, potential sources of diets for the chironomid larvae are limited including a benthic diatom (Pinnularia braunii), a phytoplankton (Chlamydomonas acidophila), sulfate oxidizing bacteria, and vascular plants supplied from vegetation surrounding the lake. Based on the average carbon and nitrogen isotope ratios among these potential sources and sediment, benthic diatoms were considered to be most probable food source of the chironomid larvae. {delta}{sup 13}C values of the chironomid were significantly different among seasons and habitat depths, suggesting that diet of C. acerbiphilus changed seasonally and with habitat depth. (author)

A new genus and species of Australian Tanypodinae (Diptera: Chironomidae) tolerant to mine waste.

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Cranston, Peter S

2017-05-09

For over 25 years an undescribed Tanypodinae (Diptera: Chironomidae) has been known to dominate the lotic invertebrate assemblage associated with long-term polluting mine adits in Captains Flat, on the Molonglo River, southern New South Wales, Australia. Although known in all life stages, it has been impossible to allocate the species to any described genus. Renewed interest in the taxonomy of the Tanypodinae, particularly associated with molecular investigations and pollution indicator status warrants formal description. All stages conform to tribe Pentaneurini, but each life stage differs in morphological resemblance. Yarrhpelopia Cranston gen. n. is proposed for the taxon previously referred to under the informal code name of 'genus A'. The genus name derives from south-east Australian aboriginal word yarrh, in recognition of its core distribution and presence in flowing waters. A single species, A. norrisi Cranston sp. n., is described, acknowledging the late Professor Richard Norris, an influential Australian limnologist. Larvae dominate the benthos immediately adjacent to mine adits that continue to leach heavy metals (zinc, cadmium, copper and lead) into downstream sediments. A wider distribution includes cleaner near pristine, eastern Australian rivers between 30° and 42°S, but these records are excluded from the type series pending molecular insights into species limits.

A revised annotated checklist of the Chironomidae (Insecta: Diptera) of the southeastern United States

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Caldwell, Broughton A.; Hudson, Patrick L.; Lenat, David R.; Smith, David

1997-01-01

A revised annotated checklist for the chironomid midges (Diptera: Chironomidae) of the southeastern United States is presented that includes the states of Alabama, Florida, Georgia, North Carolina, South Carolina, and Tennessee. Much of the information concerns occurrence and habitat preference records based upon the authors' data, as well as published and unpublished data. Some information is also presented that includes aspects of biology, habitat preference, bibliographic sources, and nomenclatorial changes. Based upon the present work, the chironomid fauna of the southeastern states is comprised of 189 genera (172 described, 17 informally or unofficially described) and 754 species (505 described, 17 informally or unofficially described, 33 that are assumed for generic or subgeneric presence only, 197 estimated species, and 2 species groups). Several new species synonyms and generic placements are recognized. Thirty-eight genera known from the Nearctic region remain unknown from the southeastern states. Diversity of species was greatest in the subfamily Chironominae, considering named as well as unnamed and estimated species. There were no significant changes in overall regional distribution patterns of subfamilies or habitat preferences form that which has been previously reported. The greatest totals for regional records, habitat types, and state occurrences were the Coastal Plain (378), streams (271), and North Carolina (373), respectively.

Setting the reference for the use of Chironomus sancticaroli (Diptera: Chironomidae as bioindicator: Ontogenetic pattern of larval head structures

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Débora Rebechi

2012-04-01

Full Text Available Species of Chironomidae are widely used as bioindicators of water quality, since their larvae undergo morphological deformities when in contact with sediment contaminated with chemicals. In this work we endeavored to study the morphology of head structures (antennae, mandible, mentum, pecten epipharyngis, ventromental plate and premandible throughout the development of the four larval instars of Chironomus sancticaroli Strixino & Strixino, 1981, which can be used in environmental impact analyses. Our results show that it is possible to differentiate among larval instars by doing a quantitative analysis on the number of striae on the ventromental plates. The six structures analyzed changed during larval ontogeny. These changes are part of the ontogeny of the immature stages not exposed to xenobiotics. We believe that the morphological pattern defined in this work can be used for comparisons with ontogenetic changes observed in field studies conducted in polluted environments.

[Chromosomal variation in Chironomus plumosus L. (Diptera, Chironomidae) from populations of Bryansk region, Saratov region (Russia), and Gomel region (Belarus)].

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Belyanina, S I

2015-02-01

Cytogenetic analysis was performed on samples of Chironomus plumosus L. (Diptera, Chironomidae) taken from waterbodies of various types in Bryansk region (Russia) and Gomel region (Belarus). Karyotypes of specimens taken from stream pools of the Volga were used as reference samples. The populations of Bryansk and Gomel regions (except for a population of Lake Strativa in Starodubskii district, Bryansk region) exhibit broad structural variation, including somatic mosaicism for morphotypes of the salivary gland chromosome set, decondensation of telomeric sites, and the presence of small structural changes, as opposed to populations of Saratov region. As compared with Saratov and Bryansk regions, the Balbiani ring in the B-arm of chromosome I is repressed in populations of Gomel region. It is concluded that the chromosome set of Ch. plumosus in a range of waterbodies of Bryansk and Gomel regions is unstable.

Does Nature and Persistence of Substrate at a Mesohabitat Scale Matter for Chironomidae Assemblages? a Study of Two Perennial Mountain Streams in Patagonia, Argentina

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Epele, Luis Beltrán; Miserendino, María Laura; Brand, Cecilia

2012-01-01

Chironomid substrate—specific associations regarding the nature (organic—inorganic) and stability (stable—unstable) of different habitats were investigated at two low order Patagonian streams, during high and low water periods. Nant y Fall and Glyn rivers were visited twice (October 2007 and March 2008) and seven different habitat types were identified. A total of 60 samples were collected using a Surber sampler (0.09 m -2 and 250 µm) and a set of 23 environmental descriptors including physicochemical parameters and different fractions of particulate organic matter were assessed. 35 Chironomidae taxa were recorded with Orthocladiinae (20), Chironominae (7), and Podonominae (4) being the most well—represented subfamilies. Paratrichocladius sp. 1, Parapsectrocladius sp. 2, Parametriocnemus sp. 1, Pseudochironomus sp., and Rheotanytarsus sp. were the most abundant taxa. According to the relative preference index, at least 14 taxa showed strong affinity for a particular substrate. The structurally complex macrophyte Myriophyllum quitense supported 11 taxa compared with only five taxa found on the less complex Isoetes savatieri. Generally, stable substrates (boulders, cobbles, and rooted plants) supported significantly higher chironomids richness, abundance, and diversity than unstable ones (gravel—sand). Canonical correspondence analysis revealed that detritus (leaves, seeds, and biomass), macrophyte biomass, and secondarily hydraulic variables had high explanatory power on chironomids species composition and structure. This work suggests that more complex substrates showing persistence in the temporal dimension supported a diverse array of chironomids, meaning that the maintenance of natural habitat heterogeneity is essential for the community. Land—use practices having significant effects on ecological stream attributes such as increased turbidity, sediment deposition, and runoff patterns will alter assemblages. Understanding environmental associations

Does nature and persistence of substrate at a mesohabitat scale matter for Chironomidae assemblages? A study of two perennial mountain streams in Patagonia, Argentina.

Science.gov (United States)

Epele, Luis Beltrán; Miserendino, María Laura; Brand, Cecilia

2012-01-01

Chironomid substrate-specific associations regarding the nature (organic-inorganic) and stability (stable-unstable) of different habitats were investigated at two low order Patagonian streams, during high and low water periods. Nant y Fall and Glyn rivers were visited twice (October 2007 and March 2008) and seven different habitat types were identified. A total of 60 samples were collected using a Surber sampler (0.09 m(-2) and 250 µm) and a set of 23 environmental descriptors including physicochemical parameters and different fractions of particulate organic matter were assessed. 35 Chironomidae taxa were recorded with Orthocladiinae (20), Chironominae (7), and Podonominae (4) being the most well-represented subfamilies. Paratrichocladius sp. 1, Parapsectrocladius sp. 2, Parametriocnemus sp. 1, Pseudochironomus sp., and Rheotanytarsus sp. were the most abundant taxa. According to the relative preference index, at least 14 taxa showed strong affinity for a particular substrate. The structurally complex macrophyte Myriophyllum quitense supported 11 taxa compared with only five taxa found on the less complex Isoetes savatieri. Generally, stable substrates (boulders, cobbles, and rooted plants) supported significantly higher chironomids richness, abundance, and diversity than unstable ones (gravel-sand). Canonical correspondence analysis revealed that detritus (leaves, seeds, and biomass), macrophyte biomass, and secondarily hydraulic variables had high explanatory power on chironomids species composition and structure. This work suggests that more complex substrates showing persistence in the temporal dimension supported a diverse array of chironomids, meaning that the maintenance of natural habitat heterogeneity is essential for the community. Land-use practices having significant effects on ecological stream attributes such as increased turbidity, sediment deposition, and runoff patterns will alter assemblages. Understanding environmental associations of the

Emergence, growth, and dispersal of Chironomidae in reclaimed wetlands in the Athabasca oil sands region of Alberta

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Kennedy, K.; Ciborowski, J. [Windsor Univ., ON (Canada)

2010-07-01

Concerns over the environmental impacts of oil sands extraction in northeastern Alberta has increased as the industry continues to expand. This study examined if the emergence, growth, and dispersal of Chironomidae differ in reclaimed wetlands constructed with oil sands process materials (OSPM) when compared with growth in reference wetlands. Five floating 30 cm diameter halo traps were deployed in various wetlands for a 24 hour period. Exuviae trapped in the surface water film were then collected, identified, and counted. Chironomids grown in laboratories from egg masses collected from 2 OSPM-affected wetlands and 2 reference wetlands were paired according to geographic proximity under controlled conditions for 1 generation. Chironomid larval growth was quantified in situ in the wetlands by reciprocally transferring second instar, second generation culture larva. The dispersal of the larvae was quantified by tabulating the number of adults caught in sticky insect traps located along 3 radially-arranged transects in each wetland. A preliminary analysis has suggested that fewer chironomids emerged from the OSPM-affected wetlands. No differences in dispersal distance between the OSPM-affected and reference wetlands were observed.

Emergence, growth, and dispersal of Chironomidae in reclaimed wetlands in the Athabasca oil sands region of Alberta

International Nuclear Information System (INIS)

Kennedy, K.; Ciborowski, J.

2010-01-01

Concerns over the environmental impacts of oil sands extraction in northeastern Alberta has increased as the industry continues to expand. This study examined if the emergence, growth, and dispersal of Chironomidae differ in reclaimed wetlands constructed with oil sands process materials (OSPM) when compared with growth in reference wetlands. Five floating 30 cm diameter halo traps were deployed in various wetlands for a 24 hour period. Exuviae trapped in the surface water film were then collected, identified, and counted. Chironomids grown in laboratories from egg masses collected from 2 OSPM-affected wetlands and 2 reference wetlands were paired according to geographic proximity under controlled conditions for 1 generation. Chironomid larval growth was quantified in situ in the wetlands by reciprocally transferring second instar, second generation culture larva. The dispersal of the larvae was quantified by tabulating the number of adults caught in sticky insect traps located along 3 radially-arranged transects in each wetland. A preliminary analysis has suggested that fewer chironomids emerged from the OSPM-affected wetlands. No differences in dispersal distance between the OSPM-affected and reference wetlands were observed.

Does predator benefits prey? Commensalism between Corynoneura Winnertz (Diptera, Chironomidae and Corydalus Latreille (Megaloptera, Corydalidae in Southeastern Brazil O predador beneficia sua presa? Comensalismo entre Corynoneura Winnertz (Diptera, Chironomidae e Corydalus Latreille (Megaloptera, Corydalidae no Sudeste do Brasil

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Marcos Callisto

2006-06-01

Full Text Available Commensalism between Corydalus Latreille, 1802 (Megaloptera, Corydalidae and Corynoneura Winnertz, 1846 (Diptera, Chironomidae, Orthocladiinae larvae was recorded in Indaiá stream, at 1,380 m a.s.l. (Parque Nacional da Serra do Cipó, 19º-20ºS, 43º-44ºW and in the headwaters of São Francisco river, at 1,300-1,700 m a.s.l. (Parque Nacional da Serra da Canastra, 20º00'-20º30'S, 46º15'-47º00'W, in Minas Gerais state, Brazil. Seventy eight Corydalus larvae (range 22-88 mm were sampled: 61 in the Indaiá stream and 17 in other two streams. Twelve Corydalus larvae (22-79 mm in the Indaiá stream and three out of 15 larvae in the headwaters of São Francisco river (38-50 mm had Corynoneura, larvae and pupae on their gills (3rd to 6th and a few larvae attached to the abdominal segments of larger Corydalus larvae (> 25 mm. Sixty-nine larvae of Corynoneura were found in the regurgitated material from Corydalus. It is remarkable that by attaching to larger body size predators, prey could become free from predator bouts and could also be transported by them.Comensalismo entre Corydalus Latreille, 1802 (Insecta, Megaloptera, Corydalidae e Corynoneura Winnertz, 1846 (Insecta, Diptera, Chironomidae, Orthocladiinae foi registrado no córrego Indaiá situado a 1.380 m de altitude no Parque Nacional da Serra do Cipó (19-20ºS, 43-44ºW e nas nascentes do rio São Francisco a 1.300-1.700 m de altitude no Parque Nacional da Serra da Canastra (20º00'-20º30'S, 46º15'-47º00'W, Minas Gerais, Brasil. Setenta e oito larvas de Corydalus (tamanhos: 22-88 mm foram coletadas: 61 no córrego Indaiá e 17 em outros córregos. Doze larvas de Corydalus (tamanhos: 22-79 mm no córrego Indaiá e três encontradas nas nascentes do rio São Francisco (tamanhos: 38-50 mm apresentaram larvas e pupas de Corynoneura em suas brânquias (3ª a 6ª e algumas larvas fixadas nos segmentos abdominais de grandes Corydalus (> 25 mm. Sessenta e nove larvas de Corynoneura foram

Investigation of heavy metals (Cadmium, Lead in Chironomidae and Gammarus pulex Namrood River – Tehran Province

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Rezaei M. Kamali A. and Shapoori M.

2012-01-01

Full Text Available Marine ecosystem pollution is one of the important problems of today environment. In this study the existence of heavy metal in the Namrood River, situated in Firoozkooh in Tehran province, Iran has been investigated. The Namrood River is located near Firoozkooh route, and is affected by pollutant from tourist centers, entertainment, gas stations, nearby villages’ sewage systems, farming effluent, and hatchery farms. In some areas, its water is heavily polluted possibly by heavy metals. After selecting two stations in upstream and downstream of the river, they were sampled three times in both cold and hot seasons of year (mid-March, and June for Chironomidae, and Gammarus plux sediments. The measured heavy metals were cadmium and lead. The results showed that the concentration of cadmium in measured samples varied from 0.010-0.2033 ppm. The concentration of lead in samples varied from 0.11-2.16 ppm. The results also indicated that sediments of samples taken from the upper station in the cold season had a higher proportion of cadmium and a higher concentration of lead  than  sediments in the lower station during the hot season.

Low malathion concentrations influence metabolism in Chironomus sancticaroli (Diptera, Chironomidae in acute and chronic toxicity tests

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Débora Rebechi

2014-09-01

Full Text Available Low malathion concentrations influence metabolism in Chironomus sancticaroli (Diptera, Chironomidae in acute and chronic toxicity tests. Organophosphate compounds are used in agro-systems, and in programs to control pathogen vectors. Because they are continuously applied, organophosphates often reach water sources and may have an impact on aquatic life. The effects of acute and chronic exposure to the organophosphate insecticide malathion on the midge Chironomus sancticaroli are evaluated. To that end, three biochemical biomarkers, acetylcholinesterase (AChE, alpha (EST-α and beta (EST-β esterase were used. Acute bioassays with five concentrations of malathion, and chronic bioassays with two concentrations of malathion were carried out. In the acute exposure test, AChE, EST-α and EST-β activities declined by 66, 40 and 37%, respectively, at 0.251 µg L-1 and more than 80% at 1.37, 1.96 and 2.51 µg L-1. In chronic exposure tests, AChE and EST-α activities declined by 28 and 15% at 0.251 µg L-1. Results of the present study show that low concentrations of malathion can influence larval metabolism, indicating high toxicity for Chironomus sancticaroli and environmental risk associated with the use of organophosphates.

DNA Barcoding for Species Identification of Insect Skins: A Test on Chironomidae (Diptera) Pupal Exuviae

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Ekrem, Torbjørn; Stur, Elisabeth

2017-01-01

Abstract Chironomidae (Diptera) pupal exuviae samples are commonly used for biological monitoring of aquatic habitats. DNA barcoding has proved useful for species identification of chironomid life stages containing cellular tissue, but the barcoding success of chironomid pupal exuviae is unknown. We assessed whether standard DNA barcoding could be efficiently used for species identification of chironomid pupal exuviae when compared with morphological techniques and if there were differences in performance between temperate and tropical ecosystems, subfamilies, and tribes. PCR, sequence, and identification success differed significantly between geographic regions and taxonomic groups. For Norway, 27 out of 190 (14.2%) of pupal exuviae resulted in high-quality chironomid sequences that match species. For Costa Rica, 69 out of 190 (36.3%) Costa Rican pupal exuviae resulted in high-quality sequences, but none matched known species. Standard DNA barcoding of chironomid pupal exuviae had limited success in species identification of unknown specimens due to contaminations and lack of matching references in available barcode libraries, especially from Costa Rica. Therefore, we recommend future biodiversity studies that focus their efforts on understudied regions, to simultaneously use morphological and molecular identification techniques to identify all life stages of chironomids and populate the barcode reference library with identified sequences.

Larva of Glyptotendipes (Glyptotendipes) glaucus (Meigen 1818) (Chironomidae, Diptera)-morphology by Scanning Electron Microscope (SEM), karyotype, and biology in laboratory conditions.

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Kownacki, Andrzej; Woznicka, Olga; Szarek-Gwiazda, Ewa; Michailova, Paraskeva

2016-09-21

Larvae belonging to the family Chironomidae are difficult to identify. The aim of the present study was to describe the larval morphology of G. (G.) glaucus with the aid of a Scanning Electron Microscope (SEM), the karyotype and biology based on materials obtained from laboratory culture. Describing the morphology of larvae, special attention was paid to rarely or never described structures like the maxilla (lacinia and maxillary palp), the long plate situated below the ventromental plate, and plate X situated between lacinia and mentum. The use of SEM allowed also to obtain better images of labrum and ventromental plate. Morphological features of this species have been supplemented by karyotype and biology of larvae in laboratory conditions. Under controlled experimental conditions we found non-synchronous development of G. (G.) glaucus larvae hatched from one egg mass reflected in different lengths of larvae and emerged imagoes.

Fossil Chironomidae (Insecta: Diptera) as Paleothermometers in the African Tropics

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Eggermont, H.; Heiri, O.; Russell, J.; Vuille, M.; Audenaert, L.; Klaassen, G.; Verschuren, D.

2008-12-01

Reconstruction of Africa's temperature history from natural climate archives such as lake sediments is essential to amend the current scarcity of information on natural tropical climate and ecosystem variability. Chironomids are well-established paleothermometers in north-temperate/boreal regions, but their potential in tropical lakes has never before been assessed. We surveyed sub-fossil chironomid assemblages in surface sediments from 65 lakes and permanent pools in southwestern Uganda and central/southern Kenya, spanning elevations between 489 and 4575 m asl. Using various subsets of lakes and corresponding Surface-Water Temperatures (SWTemp) and Mean Annual Air Temperatures (MATemp), we developed a series of inference models for quantitative paleotemperature reconstruction. Models using both low-, mid- and high-elevation sites suffer to some extent from the small number of samples between 2500 and 3500 m asl, and from the presence of ecologically distinct but morphologically indistinguishable taxa. Models confined to mountain sites produce poorer error statistics, but are less prone to the biogeographical and taxonomic complexities associated with long climatic gradients. Overall, error statistics compare favourably with those of inference models developed for temperate regions, indicating that fossil assemblages of African Chironomidae can be valuable indicators of past temperature change. We subsequently used these models to evaluate whether high-elevation lakes in the Rwenzori Mountains (>3000 m asl) have been impacted by climate warming in recent centuries by comparing temperatures inferred from chironomid assemblages in modern sediments with those derived from chironomid assemblages in sediments deposited within or briefly after the Little Ice Age (1270-1850 AD). Depending on the model used, between 44 and 63% of the 16 lakes studied indicate significantly warmer temperatures in recent times (corresponding with an average MATemp rise of 0.88 ° C, and

Integrated Taxonomy and DNA Barcoding of Alpine Midges (Diptera: Chironomidae).

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Montagna, Matteo; Mereghetti, Valeria; Lencioni, Valeria; Rossaro, Bruno

2016-01-01

Rapid and efficient DNA-based tools are recommended for the evaluation of the insect biodiversity of high-altitude streams. In the present study, focused principally on larvae of the genus Diamesa Meigen 1835 (Diptera: Chironomidae), the congruence between morphological/molecular delimitation of species as well as performances in taxonomic assignments were evaluated. A fragment of the mitochondrial cox1 gene was obtained from 112 larvae, pupae and adults (Diamesinae, Orthocladiinae and Tanypodinae) that were collected in different mountain regions of the Alps and Apennines. On the basis of morphological characters 102 specimens were attributed to 16 species, and the remaining ten specimens were identified to the genus level. Molecular species delimitation was performed using: i) distance-based Automatic Barcode Gap Discovery (ABGD), with no a priori assumptions on species identification; and ii) coalescent tree-based approaches as the Generalized Mixed Yule Coalescent model, its Bayesian implementation and Bayesian Poisson Tree Processes. The ABGD analysis, estimating an optimal intra/interspecific nucleotide distance threshold of 0.7%-1.4%, identified 23 putative species; the tree-based approaches, identified between 25-26 entities, provided nearly identical results. All species belonging to zernyi, steinboecki, latitarsis, bertrami, dampfi and incallida groups, as well as outgroup species, are recovered as separate entities, perfectly matching the identified morphospecies. In contrast, within the cinerella group, cases of discrepancy arose: i) the two morphologically separate species D. cinerella and D. tonsa are neither monophyletic nor diagnosable exhibiting low values of between-taxa nucleotide mean divergence (0.94%); ii) few cases of larvae morphological misidentification were observed. Head capsule color is confirmed to be a valid character able to discriminate larvae of D. zernyi, D. tonsa and D. cinerella, but it is here better defined as a color gradient

Using various lines of evidence to identify Chironomus species (Diptera: Chironomidae) in eastern Canadian lakes.

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Proulx, Isabelle; Martin, Jon; Carew, Melissa; Hare, Landis

2013-11-29

Chironomus Meigen (Diptera, Chironomidae) larvae are usually the largest sediment-burrowing chironomids, and as such often constitute a major part of the freshwater infaunal biomass. However, use of this genus in ecological, environmental and paleoecological studies is hampered by the fact that Chironomus larvae are difficult to identify to species because the larvae of many species are morphologically similar. We used a combination of morphological, cytological and genetic techniques to distinguish Chironomus larvae collected from 31 water bodies located in eastern Canada, producing 17 distinguishable groupings. These groups of larvae were ultimately identified as belonging to 14 known species (C. anthracinus, C. bifurcatus, C. cucini, C. decorus-group sp. 2, C. dilutus, C. entis, C. frommeri, C. harpi, C. maturus, C. nr. atroviridis (sp. 2i), C. ochreatus, C. plumosus, C. staegeri and C. 'tigris') and three other species that remain unidentified (C. sp. NAI-III). No single approach served to delimit and identify larvae of all 17 Chironomus species that we collected. Although we expected that morphological criteria alone would be insufficient, our results suggest that DNA barcoding, using either the mitochondrial cox1 or the nuclear gb2β gene, was also inadequate for separating some Chironomus species. Thus we suggest that multiple approaches will often be needed to correctly identify Chironomus larvae to species.

Cardiocladius oliffi (Diptera: Chironomidae as a potential biological control agent against Simulium squamosum (Diptera: Simuliidae

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Wilson Michael D

2009-04-01

Full Text Available Abstract Background The control of onchocerciasis in the African region is currently based mainly on the mass drug administration of ivermectin. Whilst this has been found to limit morbidity, it does not stop transmission. In the absence of a macrofilaricide, there is a need for an integrated approach for disease management, which includes vector control. Vector control using chemical insecticides is expensive to apply, and therefore the use of other measures such as biological control agents is needed. Immature stages of Simulium squamosum, reared in the laboratory from egg masses collected from the field at Boti Falls and Huhunya (River Pawnpawn in Ghana, were observed to be attacked and fed upon by larvae of the chironomid Cardiocladius oliffi Freeman, 1956 (Diptera: Chironomidae. Methods Cardiocladius oliffi was successfully reared in the rearing system developed for S. damnosum s.l. and evaluated for its importance as a biological control agent in the laboratory. Results Even at a ratio of one C. oliffi to five S. squamosum, they caused a significant decrease in the number of adult S. squamosum emerging from the systems (treatments. Predation was confirmed by the amplification of Simulium DNA from C. oliffi observed to have fed on S. squamosum pupae. The study also established that the chironomid flies could successfully complete their development on a fish food diet only. Conclusion Cardiocladius oliffi has been demonstrated as potential biological control agent against S. squamosum.

Cryptic species in the nuisance midge Polypedilum nubifer (Skuse (Diptera: Chironomidae) and the status of Tripedilum Kieffer.

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Cranston, Peter S; Martin, Jon; Spies, Martin

2016-02-15

Polypedilum nubifer (Skuse, 1889), originally described from Australia, is an apparently widespread species of Chironomidae (Diptera) that can attain nuisance densities in some eutrophic water bodies. Appropriate management depends upon the identity and ability to distinguish from potential cryptic taxa. A morphological study of larvae, pupae and adults of both sexes confirmed P. nubifer as widely distributed and frequently abundant, but also revealed two previously cryptic species of limited distribution in northern Australia. These species are described as new and illustrated in all stages here. Polypedilum quasinubifer Cranston sp. n. is described from north-west Queensland, Australia and also from Thailand and Singapore. Polypedilum paranubifer Cranston sp. n. is known only from retention ponds of a uranium mine in Northern Territory, Australia. Unusual morphological features of P. nubifer including alternate Lauterborn organs on the larval antenna, cephalic tubules on the pupa and frontal tubercles on the adult head are present in both new species as well. Newly slide-mounted types of Polypedilum pelostolum Kieffer, 1912 (lectotype designated here) confirm synonymy to Chironomus nubifer Skuse, 1889, examined also as newly-slide mounted types. Reviewed plus new evidence does not support recognition of Tripedilum Kieffer, 1921 as a separate taxon; therefore, Tripedilum is returned to junior synonymy with Polypedilum s. str.

Why on the snow? Winter emergence strategies of snow-active Chironomidae (Diptera) in Poland.

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Soszyńska-Maj, Agnieszka; Paasivirta, Lauri; Giłka, Wojciech

2016-10-01

A long-term study of adult non-biting midges (Chironomidae) active in winter on the snow in mountain areas and lowlands in Poland yielded 35 species. The lowland and mountain communities differed significantly in their specific composition. The mountain assemblage was found to be more diverse and abundant, with a substantial contribution from the subfamily Diamesinae, whereas Orthocladiinae predominated in the lowlands. Orthocladius wetterensis Brundin was the most characteristic and superdominant species in the winter-active chironomid communities in both areas. Only a few specimens and species of snow-active chironomids were recorded in late autumn and early winter. The abundance of chironomids peaked in late February in the mountain and lowland areas with an additional peak in the mountain areas in early April. However, this second peak of activity consisted mainly of Orthocladiinae, as Diamesinae emerged earliest in the season. Most snow-active species emerged in mid- and late winter, but their seasonal patterns differed between the 2 regions as a result of the different species composition and the duration of snow cover in these regions. Spearman's rank correlation coefficient tests yielded positive results between each season and the number of chironomid individuals recorded in the mountain area. A positive correlation between air temperature, rising to +3.5 °C, and the number of specimens recorded on the snow in the mountain community was statistically significant. The winter emergence and mate-searching strategies of chironomids are discussed in the light of global warming, and a brief compilation of most important published data on the phenomena studied is provided. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Influence of antifouling paint on freshwater invertebrates (Mytilidae, Chironomidae and Naididae): density, richness and composition.

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Fujita, D S; Takeda, A M; Coutinho, R; Fernandes, F C

2015-11-01

We conducted a study about invertebrates on artificial substrates with different antifouling paints in order to answer the following questions 1) is there lower accumulation of organic matter on substrates with antifouling paints, 2) is invertebrate colonization influenced by the release of biocides from antifouling paints, 3) is the colonization of aquatic invertebrates positively influenced by the material accumulated upon the substrate surface and 4) is the assemblage composition of invertebrates similar among the different antifouling paints? To answer these questions, four structures were installed in the Baía River in February 1st, 2007. Each structure was composed of 7 wood boards: 5 boards painted with each type of antifouling paints (T1, T2, T3, T4 and T5), one painted only with the primer (Pr) and the other without any paint (Cn). After 365 days, we observed a greater accumulation of organic matter in the substrates with T2 and T3 paint coatings. Limnoperna fortunei was recorded in all tested paints, with higher densities in the control, primer, T2 and T3. The colonization of Chironomidae and Naididae on the substrate was positively influenced by L. fortunei density. The non-metric multidimensional scaling (NMDS) of the invertebrate community provided evidence of the clear distinction of invertebrate assemblages among the paints. Paints T2 and T3 were the most similar to the control and primer. Our results suggest that antifouling paints applied on substrates hinder invertebrate colonization by decreasing the density and richness of invertebrates.

Annual Survey of Horsehair Worm Cysts in Northern Taiwan, with Notes on a Single Seasonal Infection Peak in Chironomid Larvae (Diptera: Chironomidae).

Science.gov (United States)

Chiu, Ming-Chung; Huang, Chin-Gi; Wu, Wen-Jer; Shiao, Shiuh-Feng

2016-06-01

The life cycle of the freshwater horsehair worm typically includes a free-living phase (adult, egg, larva) and a multiple-host parasitic phase (aquatic paratenic host, terrestrial definitive host). Such a life cycle involving water and land can improve energy flow in riparian ecosystems; however, its temporal dynamics in nature have rarely been investigated. This study examined seasonal infection with cysts in larval Chironominae (Diptera: Chironomidae) in northern Taiwan. In the larval chironomids, cysts of 3 horsehair worm species were identified. The cysts of the dominant species were morphologically similar to those of Chordodes formosanus. Infection with these cysts increased suddenly and peaked 2 mo after the reproductive season of the adult horsehair worms. Although adult C. formosanus emerged several times in a year, only 1 distinct infection peak was detected in September in the chironomid larvae. Compared with the subfamily Chironominae, samples from the subfamilies Tanypodinae and Orthocladiinae were less parasitized. This indicates that the feeding behavior of the chironomid host likely affects horsehair worm cyst infections; however, bioconcentration in predatory chironomids was not detected.

Genome Instability of Chironomus riparius Mg. (Diptera, Chironomidae from Polluted Water Basins in Bulgaria

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Julia Ilkova

2014-04-01

Full Text Available Larvae of Chironomus riparius Mg. (Chironomidae, Diptera collected from two polluted water basins in Bulgaria, the Maritsa and Chaya Rivers (adjacent to Plovdiv and Asenovgrad respectively, a small pool (near Plovdiv plus controls reared in the laboratory were studied. High concentrations of the heavy metals Pb, Cu and Cd were recorded in the sediments of the polluted stations. Marked somatic structural chromosome aberrations were found in C. riparius salivary polytene chromosomes from the field stations and their frequency was significantly higher (p<0.01 compared to the control. The observed somatic chromosome changes are discussed as a response of the chironomid genome to aquatic pollution. A new cytogenetic index based on the number of aberrations found in larvae from polluted regions in comparison with the control was applied to the data to more easily evaluate the degree of heavy metal pollution in aquatic ecosystems. Our study of a polluted site near the River Chaya showed that the somatic index was very high at 3.35 for 2010 and 11.66 for 2013 compared to 0.5 in the control. The cytogenetic index was effective in showing that all studied sites were highly polluted in comparison with the control. To determine the mechanism involved in the concentration of aberration breakpoints within specific regions of the chironomid polytene chromosome the FISH method was applied. The localization of a transposable element TFB1 along the polytene chromosomes of C. riparius was analyzed and the sites of localization were compared with breakpoints of chromosome aberrations. A significant correlation (p<0.05 was found which shows that most of the aberrations do not appear randomly but are concentrated in sites rich in transposable elements.

Temperature-dependent development, cold tolerance, and potential distribution of Cricotopus lebetis (Diptera: Chironomidae), a tip miner of Hydrilla verticillata (Hydrocharitaceae).

Science.gov (United States)

Stratman, Karen N; Overholt, William A; Cuda, James P; Mukherjee, A; Diaz, R; Netherland, Michael D; Wilson, Patrick C

2014-10-15

A chironomid midge, Cricotopus lebetis (Sublette) (Diptera: Chironomidae), was discovered attacking the apical meristems of Hydrilla verticillata (L.f. Royle) in Crystal River, Citrus Co., Florida in 1992. The larvae mine the stems of H. verticillata and cause basal branching and stunting of the plant. Temperature-dependent development, cold tolerance, and the potential distribution of the midge were investigated. The results of the temperature-dependent development study showed that optimal temperatures for larval development were between 20 and 30°C, and these data were used to construct a map of the potential number of generations per year of C. lebetis in Florida. Data from the cold tolerance study, in conjunction with historical weather data, were used to generate a predicted distribution of C. lebetis in the United States. A distribution was also predicted using an ecological niche modeling approach by characterizing the climate at locations where C. lebetis is known to occur and then finding other locations with similar climate. The distributions predicted using the two modeling approaches were not significantly different and suggested that much of the southeastern United States was climatically suitable for C. lebetis. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Time-Efficiency of Sorting Chironomidae Surface-Floating Pupal Exuviae Samples from Urban Trout Streams in Northeast Minnesota, USA

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Alyssa M Anderson

2012-10-01

Full Text Available Collections of Chironomidae surface-floating pupal exuviae (SFPE provide an effective means of assessing water quality in streams. Although not widely used in the United States, the technique is not new and has been shown to be more cost-efficient than traditional dip-net sampling techniques in organically enriched stream in an urban landscape. The intent of this research was to document the efficiency of sorting SFPE samples relative to dip-net samples in trout streams with catchments varying in amount of urbanization and differences in impervious surface. Samples of both SFPE and dip-nets were collected from 17 sample sites located on 12 trout streams in Duluth, MN, USA. We quantified time needed to sort subsamples of 100 macroinvertebrates from dip-net samples, and less than or greater than 100 chironomid exuviae from SFPE samples. For larger samples of SFPE, the time required to subsample up to 300 exuviae was also recorded. The average time to sort subsamples of 100 specimens was 22.5 minutes for SFPE samples, compared to 32.7 minutes for 100 macroinvertebrates in dip-net samples. Average time to sort up to 300 exuviae was 37.7 minutes. These results indicate that sorting SFPE samples is more time-efficient than traditional dip-net techniques in trout streams with varying catchment characteristics.doi: 10.5324/fn.v31i0.1380.Published online: 17 October 2012.

WATER QUALITY ANALYSIS OF LOTIC ECOSYSTEMS FROM UPPER MUREŞ RIVER CATCHMENT AREA USING DIFFERENT BIOTIC INDICES

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Milca PETROVICI

2012-01-01

Full Text Available Present paper approach the issue of assessing the water quality of tributaries located in the upper basin of the river Mureş, taking into account changes in the value of biotic indices. In this sense, have been selected the next five biotic indices: Ephemeroptera Plecoptera Trichoptera index (EPT, Total Invertebrates index (T, Chironomidae index (Ch, EPT / Total invertebrates index (EPT / T, EPT / Chironomidae index (EPT / Ch and % Chironomidae index (% Chironomidae. Considering all these indices, it was found existence of a medium to best quality water in Mureş tributaries from Harghita Mountains and a good quality water which comes from the Maramureş Mountains and Transylvania Plateau.

A new record of Chironomus (Chironomus) acidophilus Keyl (Diptera, Chironomidae) from the Uzon volcanic caldera (Kronotsky Reserve, Kamchatka Peninsula, Russia), its karyotype, ecology and biology.

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Orel, Oksana V; Lobkova, Ludmila E; Zhirov, Sergey V; Petrova, Ninel A

2015-07-03

Morphology, cytology, ecology and biology of Holarctic Chironomus (Chironomus) acidophilus Keyl, 1960 (Diptera, Chironomidae) was examined from material collected in the geothermal Vosmerka Lake (pH=2.0-2.5). An illustrated redescription of C. acidophilus is given on the basis of adult males reared from field-collected pupae, and of simultaneously collected larvae. Additional larvae belonging to the pseudothummi-complex were identified as C. acidophilus on the basis of their karyotype. The karyotype of C. acidophilus (2n=8) and detailed mapping of the 4 chromosome arms A, E, D and F are provided. The population of C. acidophilus from Kamchatka was found to be karyologically monomorphic. Information on distribution and ecology of C. acidophilus from Vosmerka Lake (total mineralization 1583.5 mg/l) is also given. Chironomus acidophilus is the only species of aquatic insects recorded in this lake. Lack of competition and a richness of food resources contribute to the high abundance (35161 ind./m2) and biomass (11.342 g/m2) of the larvae of C. acidophilus in Vosmerka Lake.

Comparison of the behavioural effects of pharmaceuticals and pesticides on Diamesa zernyi larvae (Chironomidae).

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Villa, Sara; Di Nica, Valeria; Pescatore, Tanita; Bellamoli, Francesco; Miari, Francesco; Finizio, Antonio; Lencioni, Valeria

2018-07-01

Several studies have indicated the presence of contaminants in Alpine aquatic ecosystems. Even if measured concentrations are far below those that cause acute effects, continuous exposure to sub-lethal concentrations may have detrimental effects on the aquatic species present in these remote environments. This may lead to a cascade of indirect effects at higher levels of the ecological hierarchy (i.e., the community). To improve the determination of ecologically relevant risk endpoints, behavioural alterations in organisms due to pollutants are increasingly studied in ecotoxicology. In fact, behaviour links physiological function with ecological processes, and can be very sensitive to environmental stimuli and chemical exposure. This is the first study on behavioural alteration in a wild population of an Alpine species. In the present study, a video tracking system was standardized and subsequently used to identify contaminant-induced behavioural alterations in Diamesa zernyi larvae (Diptera, Chironomidae). Diamesa zernyi larvae, collected in an Italian Alpine stream (Rio Presena, Trentino Region), were acclimated for 24 h and successively exposed to several aquatic contaminants (pesticides: chlorpyrifos, metolachlor, boscalid, captan; pharmaceuticals: ibuprofen, furosemide, trimethoprim) at concentrations corresponding to their Lowest Observed Effect Concentration (LOEC). After 24, 48, 72, and 96 h of exposure, changes in the distance moved, the average speed, and the frequency of body bends were taken to reflect contaminant- and time-dependent effects on larval behaviour. In general, metolachlor, captan, and trimethoprim tended to reduce all the endpoints under consideration, whereas chlorpyrifos, boscalid, ibuprofen, and furosemide seemed to increase the distances moved by the larvae. This could be related to the different mechanisms of action of the investigated chemicals. Independently of the contaminant, after 72 h a general slowing down of all the

Diversity and structure of Chironomidae communities in relation to water quality differences in the Swartkops River

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Odume, O. N.; Muller, W. J.

. Results revealed that the family Chironomidae, identified to species or genus, can be use to assess environmental water quality status in South African freshwater ecosystems.

Habitats and trophic relationships of Chironomidae insect larvae from the Sepotuba River basin, Pantanal of Mato Grosso, Brazil.

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Butakka, C M M; Grzybkowska, M; Pinha, G D; Takeda, A M

2014-05-01

Benthic habitats are linked by physical processes and are essential elements in assessing of the distribution dynamics of Chironomidae dipteran insects and their role in aquatic ecosystems. This work presents results of distribution patterns of chironomids larvae in 38 sites that are abundant in the study site, inhabiting the substrate of the main river channel, rapids, tributary brook, floodplain lakes and reservoir along the Sepotuba River from its mouth at the Paraguay River to the headwater region. A total of 1,247 larvae was registered. The most abundant taxa were Polypedilum (Tripodura) sp. (25.2%), Cricotopus sp.3 (23.0%) and Tanytarsus sp. (15.0%). Fissimentum desiccatum were found only in the reservoir; Fissimentum sp.2 and Tanytarsus cf. T. obiriciae sp.2 in floodplain lakes, and Goeldichironomus sp. in the main channel. The low diversity of the sites S06 and S35 is caused by the near-exclusive presence of the species Cricotopus sp.3, alone or together with one or another taxon (Tanytarsus sp., Djalmabatista sp.3). Collectors-filterers represent 16%, collectors-gatherers 15%, predators 11% and scrapers only 1%. The predators dominated in the secondary channel (±88 ind/m2), corresponding to 40% of the total of this group. Cryptochironomus sp.2 (34%) and Ablasbemyia gr. annulata (26%) were the most abundant among the predators. The differences along the river course are decisive for the formation of distinct or discontinuous communities and the limits become obvious though the interrelations between the populations in the community, as for instance, competition for food and habitats.

Análise da dieta das larvas de 4º estádio de Cricotopus sp. (Diptera: Chironomidae, em diferentes substratos artificiais e fases hídricas, no trecho superior do rio Paraná = Diet analysis of Cricotopus sp. larvae (Diptera: Chironomidae, fourth stage, in different artificial substrates and hydrological phases, in the upper Paraná river

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Adriana Felix dos Anjos

2009-10-01

Full Text Available No Brasil, estudos sobre hábitos alimentares das larvas de Chironomidae ainda são escassos e estas informações são importantes para entender a estrutura trófica e a organização dos ecossistemas aquáticos. Neste estudo, teve-se como objetivo identificar osprincipais itens alimentares ingeridos por Cricotopus sp. e comparar as possíveis diferenças na dieta das larvas em diferentes substratos artificiais e fases hídricas. Foram utilizados quatro tipos de substratos artificiais: madeira em forma de X (MADX, placas de nitacetal em forma de X (NITX, PVC em forma de tubo (PVCT e metal galvanizado em forma de tubo (METT, cada um com três réplicas. As coletas foram realizadas quinzenalmente, entre os meses de agosto de 2004 e dezembro de 2005. A dieta de Cricotopus sp. foi constituída por detritos, algas e hifas de fungos. Detrito foi o principal item alimentar, com valores superiores a 50% do total consumido. Os resultados indicaram que Cricotopus sp. é uma espécie coletora e, independentemente do substrato, as larvas alimentam-se dos recursos disponíveis no ambiente. Entretanto, mudanças no regime hidrológico do rio Paraná podem influenciar a disponibilidade de alimento, principalmente algumas diatomaceas como Melosira sp., consumidas em maior quantidade apenas na fase de águas baixas.In Brazil, studies on the diet of Chironomidae larvae are still scarce and these data are important to understand the trophic structure and organization of aquatic ecosystems. In this study, we identified the main food items consumed by Cricotopus sp. and compared possible differences in the larval diet at different artificial substrates and hydrological phases. We used four types of artificial substrates: X-shaped wood (MADX; X-shaped nitacetal plates (NITX; tube-shaped PVC (PVCT and tube-shaped galvanizedmetal (METT, each with three replicates. Samplings were undertaken fortnightly, between August 2004 and December 2005. Cricotopus sp. diet was

Widespread IgE-mediated hypersensitivity in the Sudan to the 'green nimitti' midge, Cladotanytarsus lewisi (Diptera: Chironomidae) II. Identification of a major allergen.

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Gad El Rab, M O; Thatcher, D R; Kay, A B

1980-01-01

A major allergen has been identified in an aqueous extract of the 'green nimitti' midge, Cladotanytarsus lewisi (Diptera: Chironomidae). Following chromatography on Sephadex G-100 allergenic activity, as assessed by skin ('prick') testing, eluted as two closely related peaks (pools I and II) at about 50% bed volume. When these pools were applied separately to columns of CM-cellulose, activity in each eluted with 0 . 05 M NaCl. Isoelectric focusing of the unfractionated allergen gave a single peak of activity at pI 4 . 3. By SDS--PAGE, biological activity in the whole 'green nimitti' extract and the material eluting from both pools I and II of the Sephadex G-100 column migrated to the same positions and were associated with a molecular size of 15,000--20,000 daltons. Skin test reactivity of the unfractionated material and the Sephadex G-100 pool I and II eluates were all destroyed following incubation with trypsin, chymotrypsin, thermolysin and neuraminidase. These experiments indicate that a major allergen derived from the 'green nimitti' midge, a cause of widespread and severe immediate-type allergy in the Sudan, is an acidic glycoprotein of 15,000--20,000 molecular weight. Images Fig. 3 PMID:7438559

Laboratory and field investigations of pestiferous Chironomidae (Diptera) in some man-made wetlands in central Florida, USA.

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Ali, Arshad; Leckel, Robert J; Jahan, Nusrad; Al-Shami, Salman A; Rawi, Che Salmah Md

2009-03-01

A 1-year larval and adult population survey of pestiferous chironomids was conducted in 4 man-made wetlands in a resort area of central Florida, USA. Benthic samples were randomly collected from each wetland at least once every month. Geocoordinates, water depth, and physical composition of substrates at each larval sample location were noted. Adult midge populations were sampled weekly around the wetlands by employing 10 New Jersey light traps permanently placed in the area. Chironominae and Tanypodinae midges occurred in the larval and adult samples; a few Orthocladiinae were also taken. Among Chironominae, Chironomini (mostly Polypedilum spp., Cryptochironomus spp., Glyptotendipes paripes, and Goeldichironomus carus) and Tanytarsini (mostly Tanytarsus spp.), and some other Chironomidae were recorded. Tanypodinae were quantitatively not important. Monthly mean number of total adults per trap-night ranged from 23 in February to 211 in October. Annual mean larval density and range of total chironomids in the study wetlands amounted to 1,128/m2, range: 0-12,332/m2. The total larvae were most abundant in May. Tanytarsus spp. and Polypedilum spp. were numerically the most predominant spatially as well as temporally. Mean water depth at the sampled locations was 1.83 m (range: 1-m-deep water. Of all sampled locations, substrates such as sand, mixed substrates, and muck were respectively encountered at 656, 371, and 299 locations. The predominance of sand and mixed substrates was conducive to supporting the numerically dominant Tanytarsus spp. and Polypedilum spp. In laboratory bioassays, Tanytarsus spp., Polypedilum spp., Glyptotendipes paripes, and Goeldichironomus carus were highly susceptible to temephos, as well as to s-methoprene. Bacillus thuringiensis serovar. israelensis was most effective against Tanytarsus spp. and least against Goeldichironomus carus.

African Journal of Science and Technology (AJST) DIVERSITY OF ...

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NORBERT OPIYO AKECH

ABSTRACT: This paper presents the first results on the water quality of the River Niger at Niamey based on the Chironomidae ... Key words: Chironomidae, River Niger, Niamey, water quality ...... of macroinvertebrates assemblages in the Azul-.

Zoobenthic fauna and seasonal changes of mamasin dam lake ...

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STORAGESEVER

2009-09-15

Sep 15, 2009 ... Psammoryctides deserticula (Grimm, 1877). 14. Procladius (Holotanypus) sp. 15. Chironomus plumosus (Linnaeus, 1758). 16. C. anthracinus (Zetterstedt, 1860). Insecta. Chironomidae. 17. Polypedilum nubeculosum (Meigen, 1804). Figure 2. Average numbers (BS/m2) of chironomidae, oligochaeta and ...

Karyotype characteristics, larval morphology and chromosomal polymorphism peculiarities of Glyptotendipes salinus Michailova, 1983 (Diptera, Chironomidae) from Tambukan Lake, Central Caucasus

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Karmokov, Mukhamed Kh.; Akkizov, Azamat Y.

2016-01-01

Abstract Data on the karyotype characteristics, larval morphology and features of chromosomal polymorphism of a population of Glyptotendipes salinus Michailova, 1983 (Diptera, Chironomidae) from Tambukan Lake (on the northern macroslope of the central Caucasus) are presented. It was found that diagnostic larval characters of Glyptotendipes salinus from Caucasus in general are similar to those described in previous studies, but with some significant differences. By some morphological characteristics Caucasian larvae appeared to be closer to Glyptotendipes barbipes than to ones provided for European larvae of Glyptotendipes salinus by Contreras-Lichtenberg (1999). Obtained morphological data make possible to conclude that Caucasian population of Glyptotendipes salinus can be a markedly diverged population of the species, probably even subspecies. In the Caucasian population 12 banding sequences were found: two in arms A, B, C, E, and G, and one in arms D and F. Eight of these are already known for this species, and four, salA2, salB2, salEX, and salG3, are described for the first time. Genetic distances between all the previously studied populations of Glyptotendipes salinus were measured using Nei criteria (1972). The population of the central Caucasus occupies a distinct position on the dendrogram compared with populations from Altai and Kazakhstan. All the obtained morphological and cytogenetic data can indicate the plausible relative isolation and complexity of the Caucasus from the viewpoint of microevolution. More researches are required in other parts of Caucasus and other geographically distant regions for more specific allegations. PMID:28123679

Karyotype characteristics, larval morphology and chromosomal polymorphism peculiarities of Glyptotendipes salinus Michailova, 1983 (Diptera, Chironomidae from Tambukan Lake, Central Caucasus

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Mukhamed Karmokov

2016-11-01

Full Text Available Data on the karyotype characteristics, larval morphology and features of chromosomal polymorphism of a population of Glyptotendipes salinus Michailova, 1983 (Diptera, Chironomidae from Tambukan Lake (on the northern macroslope of the central Caucasus are presented. It was found that diagnostic larval characters of G. salinus from Caucasus in general are similar to those described in previous studies, but with some significant differences. By some morphological characteristics Caucasian larvae appeared to be closer to G. barbipes than to ones provided for European larvae of G. salinus by Contreras-Lichtenberg (1999. Obtained morphological data make possible to conclude that Caucasian population of G. salinus can be a markedly diverged population of the species, probably even subspecies. In the Caucasian population 12 banding sequences were found: two in arms A, B, C, E, and G, and one in arms D and F. Eight of these are already known for this species, and four, salA2, salB2, salEX, and salG3, are described for the first time. Genetic distances between all the previously studied populations of G. salinus were measured using Nei criteria (1972. The population of the central Caucasus occupies a distinct position on the dendrogram compared with populations from Altai and Kazakhstan. All the obtained morphological and cytogenetic data can indicate the plausible relative isolation and complexity of the Caucasus from the viewpoint of microevolution. More researches are required in other parts of Caucasus and other geographically distant regions for more specific allegations.

Study of Chironomidae Natural Populations of the Former Semipalatinsk Test Site Water Bodies

International Nuclear Information System (INIS)

Aimanova, K.G.; Blinov, A.G.; Kiknadze, I.I.; Bakhtin, M.M.; Seisebaev, A.T.; Rakhimbaeva, K.T.

1998-01-01

The open water bodies as a component of the biosphere serve as the accumulators of artificial radionuclides generated during the nuclear explosions; therefore their radioactive contamination needs to be registered. The assessment of the environmental radioactive contamination consequences for the natural populations of organisms living in water bodies is of particular importance. Chironomini (Diptera, Chironomidae) play an important role as they are a significant component of water and air biocenoses and provide the self-cleaning of water bodies and food chains of industrial fish and bird. Chironomini have been chosen to be a model for the UNESCO International Program titled 'Man and Biosphere' and are used as the biologic indicator for ecological studies of anthropogenic influence on water bodies. The study of Chironomini natural mutagenic process and its alteration due to the radioactive contamination of water bodies is of extreme scientific interest and can serve as the indicator of the scale of genetic damage of water organisms. This work presents the data on natural populations of Chironomini of former STS water bodies: Shagan Lake, Balapan Lake, the artificial water body on the Karazhyra Coal Field, the backwater near the Shagan River, Balykty col Lake, etc. The analysis of morphology and caryotype of Camptochironomus sp. S (S - larvae have been sampled from the Semipalatinsk Test Site) showed that this is a new species as compared to studied species (C. tentans, C. pallidivittatus) of Camptochironomus subfamily. The caryotype Camptochironomus sp. S differs sharply from the caryotypes of other Camptochironomus species due to its strong hetero chromatization of centromeric discs. The immediate molecular analysis of genome DNA of Camptochironomus sp. S larvae sampled from Shagan Lake was performed: the total DNA of larvae of this species was obtained, nucleonic sequences of genes of cytochrome B (Cyt B) and cytochrome I (COI) were determined using methods of

Guía para la identificación genérica de larvas de quironómidos (Diptera: Chironomidae de la Sabana de Bogotá. III subfamilias Tanypodinae, Podonominae y Diamesinae

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Ruiz Moreno Jeanet Liliana

2000-07-01

Full Text Available A diagnosis of larvae in the subfamilies Tanypodinae and Podonominae (Chironomidae is provided, based on macroscopic and microscopic characters. A key to the genera recorded in streams of the Sabana de Bogotá and surrounding mountains is presented. Additionally, diagnoses are given for the genera Podonomus and Parochlus of the subfamily Podonominae and the genus araheptagyia, of the subfamily Diamesinae.Se presentan diagnosis de las subfamilias Tanypodinae y Podonominae (Diptera: Chironomidael, incluyendo características macroscópicas que diferencian las larvas de la subfamilia y microscópicas que permiten diferenciar los géneros, que hasta el momento se han encontrado en las aguas corrientes de la sabana de Bogotá y sus montañas circundantes. Además, se presenta una clave para la identificación de los diez géneros registrados para la subfamilia Tanypodinae, así como una diagnosis de los géneros: Podonomus y Parochlus, de la subfamilia Podominae y el género Paraheptagyia, de la subfamilia Diamesinae.

Effects of impoundment and regulation upon the stomach contents of fish at Cow Green, Upper Teesdale

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Crisp, D.T.; Mann, R.H.K.; McCormack, J.C.

1978-04-01

The stomach contents of 1003 brown trout, 1551 bullheads and 800 minnows taken from the reservoir basin and below the dam, before and after impoundment of the river Tees, were examined. Their composition reflected observations by other workers on river and reservoir benthos, except for the increase in numbers of Hydra and Nais below the dam, and Mollusca, Hirudinea and oligochaetes in the reservoir. Trout below the dam ate more Ephemeroptera nymphs and Chironomidae larvae but fewer terrestrial casualties after river regulation, whereas bullheads ate more Mollusca but fewer Plecoptera nymphs. In both species Baetidae nymphs increased in numerical importance relative to Ecdyonuridae. Trout, but not bullheads, took zooplankton discharged from the reservoir. Before impoundment, trout within the reservoir basin ate chiefly benthic organisms and terrestrial casualties. Inundated terrestrial material, mainly earthworms, formed the bulk of their food for at least three years after impoundment, whilst from the second year onwards Chironomidae and, in some years, Gammarus became increasingly important. Zooplankton was taken by all sizes of reservoir trout. Bullheads within the reservoir basin ate chiefly river benthos before impoundment, with Ephemeroptera and Plecoptera nymphs predominant in older fish, and aquatic Diptera and Coleoptera also important in the fry. After impoundment, Chironomidae and Gammarus were the main items taken by older bullheads, and Chironomidae and micro-crustacea by the fry. Among all sizes of minnow, Chironomidae, micro-crustacea and detritus increased in numerical importance after impoundment.

Karyotype characteristics and polymorphism peculiarities of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae) from the Central Caucasus and Ciscaucasia

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Karmokov, Mukhamed Kh.; Polukonova, Natalia V.; Sinichkina, Olga V.

2015-01-01

Abstract Data about the karyotype characteristics, features of chromosomal polymorphism and larval morphology of populations of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae) from the Central Caucasus (the northern macroslope) and Ciscaucasia are presented. The characteristics of the pericentromeric regions of the long chromosomes of this species from Caucasian populations were very similar to the ones from some European populations (from Poland and Italy), but differed from Swiss and Siberian populations. In the North Caucasian populations 10 banding sequences were found: two in arms A, C, and E, and one in arms B, D, F, and G. Nine of them were already known for this species, and one, berC2, is described for the first time. Cytogenetic distances between all the studied populations of Chironomus bernensis show that close geographical location of all studied populations from the Central Caucasus and Ciscaucasia is reflected in their similar cytogenetic structure, but on the other hand, that they are more closely related to populations from Europe than to populations from Western Siberia. At the same time, all studied larvae from Caucasian populations have a four-bladed premandible, instead of a two-bladed one, as in the description of Chironomus bernensis from Switzerland (Wülker and Klötzli 1973, Polukonova 2005c). These peculiarities may indicate the relative isolation of the Caucasus from the viewpoint of microevolution. Further research on karyological and morphological characteristics of Chironomus bernensis from geographically distant regions is necessary as there is a possibility that the presently known species is actually polytypic and consists of several sibling species. PMID:26312128

Karyotype characteristics and polymorphism peculiarities of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae from the Central Caucasus and Ciscaucasia

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Mukhamed Kh. Karmokov

2015-06-01

Full Text Available Data about the karyotype characteristics, features of chromosomal polymorphism and larval morphology of populations of Chironomus bernensis Wülker & Klötzli, 1973 (Diptera, Chironomidae from the Central Caucasus (the northern macroslope and Ciscaucasia are presented. The characteristics of the pericentromeric regions of the long chromosomes of this species from Caucasian populations were very similar to the ones from some European populations (from Poland and Italy, but differed from Swiss and Siberian populations. In the North Caucasian populations 10 banding sequences were found: two in arms A, C, and E, and one in arms B, D, F, and G. Nine of them were already known for this species, and one, berC2, is described for the first time. Cytogenetic distances between all the studied populations of Ch. bernensis show that close geographical location of all studied populations from the Central Caucasus and Ciscaucasia is reflected in their similar cytogenetic structure, but on the other hand, that they are more closely related to populations from Europe than to populations from Western Siberia. At the same time, all studied larvae from Caucasian populations have a four-bladed premandible, instead of a two-bladed one, as in the description of Ch. bernensis from Switzerland (Wülker and Klötzli 1973, Polukonova 2005c. These peculiarities may indicate the relative isolation of the Caucasus from the viewpoint of microevolution. Further research on karyological and morphological characteristics of Chironomus bernensis from geographically distant regions is necessary as there is a possibility that the presently known species is actually polytypic and consists of several sibling species.

Effects of Bacillus thuringiensis israelensis and spinosad on adult emergence of the non-biting midges Polypedilum nubifer (Skuse) and Tanytarsus curticornis Kieffer (Diptera: Chironomidae) in coastal wetlands.

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Duchet, Claire; Franquet, Evelyne; Lagadic, Laurent; Lagneau, Christophe

2015-05-01

To optimize their efficacy, some insecticides used for mosquito control are introduced into aquatic ecosystems where mosquito larvae develop (marshes, ponds, sanitation devices) and cannot escape from the treated water. However, this raises the question of possible effects of mosquito larvicides on non-target aquatic species. Bacillus thuringiensis var. israelensis (Bti), which is well-known for its selectivity for Nematocera dipterans, is widely used for mosquito control all over the world. Spinosad, a mixture of spinosyns A and D known as fermentation products of a soil actinomycete (Saccharopolyspora spinosa), is a biological neurotoxic insecticide with a broader action spectrum. It is a candidate larvicide for mosquito control, but some studies showed that it may be toxic to beneficial or non-target species, including non-biting midges. The present study was therefore undertaken to assess the impact of Bti and spinosad on natural populations of Polypedilum nubifer (Skuse) and Tanytarsus curticornis Kieffer (Diptera: Chironomidae) in field enclosures implemented in Mediterranean coastal wetlands. Unlike Bti, spinosad had a strong lethal effect on P. nubifer and seems to affect T. curticornis at presumed recommended rates for field application. Differences in the sensitivity of these two species to spinosad confirm that population dynamics need to be known for a proper assessment of the risk encountered by chironomids in wetlands where larvicide-based mosquito control occurs. Copyright © 2015 Elsevier Inc. All rights reserved.

Associação forética entre larvas de Rheotanytarsus (Chironomidae, Tanytarsini e adultos de Elmidae (Coleoptera, coletados em córregos no Parque Estadual de Campos do Jordão, São Paulo, Brasil Phoretic association between larvae of Rheotanytarsus and adult of Coleoptera, collected from State Park Campos do Jordão, São Paulo State, Brazil

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Melissa O. Segura

2007-06-01

Full Text Available Esta nota registra a ocorrência de foresia entre larvas de Rheotanytarsus Thienemann & Bause, 1913 (Chironomidae, Tanytarsini e adultos de Hexacylloepus Hinton, 1940 e Microcylloepus Hinton, 1935 (Coleoptera, Elmidae. Os exemplares foram obtidos em córregos no Parque Estadual de Campos de Jordão, Estado de São Paulo, Brasil.This note reports phoresy between larvae of Rheotanytarsus Thienemann & Bause, 1913 (Chironominae, Tanytarsini and adult of Hexacylloepus Hinton, 1940 and Microcylloepus Hinton, 1935 (Coleoptera, Elmidae. The specimens had been collected in streams from State Park Campos do Jordão, São Paulo State, Brazil.

Quantitative Temperature Reconstructions from Holocene and Late Glacial Lake Sediments in the Tropical Andes using Chironomidae (non-biting midges)

Science.gov (United States)

Matthews-Bird, F.; Gosling, W. D.; Brooks, S. J.; Montoya, E.; Coe, A. L.

2014-12-01

Chironomidae (non-biting midges) is a family of two-winged aquatic insects of the order Diptera. They are globally distributed and one of the most diverse families within aquatic ecosystems. The insects are stenotopic, and the rapid turnover of species and their ability to colonise quickly favourable habitats means chironomids are extremely sensitive to environmental change, notably temperature. Through the development of quantitative temperature inference models chironomids have become important palaeoecological tools. Proxies capable of generating independent estimates of past climate are crucial to disentangling climate signals and ecosystem response in the palaeoecological record. This project has developed the first modern environmental calibration data set in order to use chironomids from the Tropical Andes as quantitative climate proxies. Using surface sediments from c. 60 lakes from Bolivia, Peru and Ecuador we have developed an inference model capable of reconstructing temperatures, with a prediction error of 1-2°C, from fossil assemblages. Here we present the first Lateglacial and Holocene chironomid-inferred temperature reconstructions from two sites in the tropical Andes. The first record, from a high elevation (4153 m asl) lake in the Bolivian Andes, shows persistently cool temperatures for the past 15 kyr, punctuated by warm episodes in the early Holocene (9-10 kyr BP). The chironomid-inferred Holocene temperature trends from a lake sediment record on the eastern Andean flank of Ecuador (1248 m asl) spanning the last 5 millennia are synchronous with temperature changes in the NGRIP ice core record. The temperature estimates suggest along the eastern flank of the Andes, at lower latitudes (~1°S), climate closely resemble the well-established fluctuations of the Northern Hemisphere for this time period. Late-glacial climate fluctuations across South America are still disputed with some palaeoecological records suggesting evidence for Younger Dryas

Análise da dieta das larvas de 4º estádio de Cricotopus sp. (Diptera: Chironomidae, em diferentes substratos artificiais e fases hídricas, no trecho superior do rio Paraná - DOI: 10.4025/actascibiolsci.v31i4.3522 Diet analysis of Cricotopus sp. larvae (Diptera: Chironomidae, fourth stage, in different artificial substrates and hydrological phases, in the upper Paraná river - DOI: 10.4025/actascibiolsci.v31i4.3522

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Alice Michiyo Takeda

2009-08-01

Full Text Available No Brasil, estudos sobre hábitos alimentares das larvas de Chironomidae ainda são escassos e estas informações são importantes para entender a estrutura trófica e a organização dos ecossistemas aquáticos. Neste estudo, teve-se como objetivo identificar os principais itens alimentares ingeridos por Cricotopus sp. e comparar as possíveis diferenças na dieta das larvas em diferentes substratos artificiais e fases hídricas. Foram utilizados quatro tipos de substratos artificiais: madeira em forma de X (MADX, placas de nitacetal em forma de X (NITX, PVC em forma de tubo (PVCT e metal galvanizado em forma de tubo (METT, cada um com três réplicas. As coletas foram realizadas quinzenalmente, entre os meses de agosto de 2004 e dezembro de 2005. A dieta de Cricotopus sp. foi constituída por detritos, algas e hifas de fungos. Detrito foi o principal item alimentar, com valores superiores a 50% do total consumido. Os resultados indicaram que Cricotopus sp. é uma espécie coletora e, independentemente do substrato, as larvas alimentam-se dos recursos disponíveis no ambiente. Entretanto, mudanças no regime hidrológico do rio Paraná podem influenciar a disponibilidade de alimento, principalmente algumas diatomaceas como Melosira sp., consumidas em maior quantidade apenas na fase de águas baixasIn Brazil, studies on the diet of Chironomidae larvae are still scarce and these data are important to understand the trophic structure and organization of aquatic ecosystems. In this study, we identified the main food items consumed by Cricotopus sp. and compared possible differences in the larval diet at different artificial substrates and hydrological phases. We used four types of artificial substrates: X-shaped wood (MADX; X-shaped nitacetal plates (NITX; tube-shaped PVC (PVCT and tube-shaped galvanized metal (METT, each with three replicates. Samplings were undertaken fortnightly, between August 2004 and December 2005. Cricotopus sp. diet was

Analysis of an alternative method for the study of bromeliad-associated fauna in plants with different foliar organization

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Gerson A. Müller

2010-12-01

Full Text Available The efficiency of an alternative method of collection (by suction of water for the study of Culicidae and Chironomidae (Diptera, Scirtidae (Coleoptera and Coenagrionidae (Odonata in bromeliads with different foliar architecture in a restinga at Florianópolis, SC, Brazil, was studied. The alternative method was less efficient to collect Culicidae and Chironomidae (Wilcoxon test p 0.05 from Aechmea lindenii. This method was less efficient to collect insects of all groups from Vriesea friburgensis (Wilcoxon test p A eficiência do método alternativo de coleta (por sucção da água para o estudo de Culicidae e Chironomidae (Diptera, Scirtidae (Coleoptera e Coenagrionidae (Odonata em bromélias com diferentes estruturas foliares de restinga em Florianópolis, SC, Brasil, foi estudada. O método alternativo foi menos eficiente para coletar Culicidae e Chironomidae (teste de Wilcoxon p 0, 05 a partir de Aechmea lindenii. Esse foi menos eficiente para coletar insetos de todos os grupos a partir de Vriesea friburgensis (teste de Wilcoxon p < 0,05. O método alternativo se mostrou eficiente em estimar a diversidade desses insetos nas duas espécies de bromélias. A alta mobilidade das formas imaturas dos coleópteros e libélulas e a disponibilidade de apenas um tanque em Aechea lindenii, em contraste com as várias axilas e Vriesea friburgensis, facilitando a sucção destas formas imaturas provavelmente influenciaram os resultados. Os resultados indicam que o método de sucção não deve substituir o desmanche no estudo de Culicidae e Chironomidae; ele pode ser útil para a obtenção de formas imaturas de Scirtidae e Coenagrionidae em bromélias de um só tanque.

Biological and genetic characteristics of Glyptotendipes tokunagai (Diptera: Chironomidae) on the basis of successive rearing of forty-two generations over seven years under laboratory conditions.

Science.gov (United States)

Baek, Min Jeong; Yoon, Tae Joong; Kang, Hyo Jeong; Bae, Yeon Jae

2014-10-01

Members of the nonbiting midge family Chironomidae have been used worldwide as water-quality indicators or toxicity test organisms. The purpose of this study was to establish the chironomid Glyptotendipes tokunagai Sasa as a new test species by conducting successive rearing under laboratory conditions. We monitored biological and genetic aspects of >42 successive generations over 7 yr, and also compared the development of the 39th generation with the fourth generation under five constant temperatures of 15, 20, 25, 30, and 35°C. We observed that the number of eggs in an egg mass and the adult body sizes decreased rapidly in the early generations, and thereafter tended to stabilize from the fifth generation to the 42nd generation. In all generations, the mean hatching rate was >75%. Males were predominant in the early generations, but the sex ratio increased to 0.5 (ranged 0.24-0.61) in later generations. The genetic divergence of the reared generations, analyzed by using the mitochondrial cytochrome c oxidase subunit I gene, decreased from 0.0049 to 0.0004 as the generations progressed. In comparison with the fourth generation, the mortality and developmental time of the 39th generation were generally greater, and the adult body sizes were generally smaller. The estimated low developmental threshold temperatures of eggs, male larvae to male adults, and female larvae to female adults were 9.6, 11.3, and 9.7°C, respectively. The optimal rearing temperature was determined to be 25°C. This is the first record of domesticated rearing of a wild chironomid species under laboratory conditions for >7 yr.

Using δ15N of Chironomidae as an index of nitrogen sources and processing within watersheds as part of EPA's National Aquatic Resource Surveys

Science.gov (United States)

Brooks, J. R.; Compton, J.; Herlihy, A.; Sobota, D. J.; Stoddard, J.; Weber, M.

2014-12-01

Nitrogen (N) removal in watersheds is an important regulating ecosystem service that can help reduce N pollution in the nation's waterways. However, processes that remove N such as denitrification are generally determined at point locations. Measures that integrate N processing within watersheds and over time would be particularly useful for assessing the degree of this vital service. Because most N removal processes isotopically enrich the N remaining, δ15N from basal food-chain organisms in aquatic ecosystems can provide information on watershed N processing. As part of EPA's National Aquatic Resource Surveys (NARS), we measured δ15N of Chironomidae in lakes, rivers and streams because these larval aquatic insects were found in abundance in almost every lake and stream in the U.S. Using information on nitrogen loading to the watershed, and total N concentrations within the water, we assessed when elevated chironomid δ15N would indicate N removal rather than possible enriched sources of N. Chironomid δ15N values ranged from -4 to +20 ‰, and were higher in rivers and streams than in lakes (median = 7.6 ‰ vs. 4.8 ‰, respectively), indicating that N was processed to a greater degree in lotic chironomids than in lentic ones. For both, δ15N increased with watershed-level agricultural land cover and N loading, and decreased as precipitation increased. In rivers and streams with high synthetic N loading, we found lower N concentrations in streams with higher chironomid δ15N values, suggesting greater N removal. At low levels of synthetic N loading, the pattern reversed, and streams with enriched chironomid δ15N had higher N concentrations, suggesting enriched sources such as manure or sewage. Our results indicate that chironomid δ15N values can provide valuable information about watershed-level N inputs and processing for national water quality monitoring efforts.

Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates.

Science.gov (United States)

De Jonge, M; Belpaire, C; Geeraerts, C; De Cooman, W; Blust, R; Bervoets, L

2012-12-01

The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Inversion polymorphism of the nonbiting midges Camptochironomus pallidivittatus Edwards, 1929 (Diptera, Chironomidae) from populations of the Lower Volga region and Central Caucasus].

Science.gov (United States)

Polukonova, N V; Karmokov, M Kh; Shaternikov, A N

2015-02-01

The karyotype of Camptochironomus pallidivittatus Edwards, 1929 (Diptera, Chironomidae) from five populations of the Lower Volga region and Central Caucasus (the northern macroslope) has been studied. In populations of S. pallidivittatus from the Central Caucasus, 11 banding sequences (BS) were found; one sequence, pal B10, was new to the species. In the Saratov population, 11 BS were also found, three of which were new for the species-pal A3, pal B11, and pal B12. The banding sequences detected for the first time have not yet been found in other parts of the habitat of this species and may be endemic to these regions. In the studied populations ofS. pallidivittatus, banding sequences were found that were nonstandard but fixed in the karyotype. This is indicative of some degree of chromosomal divergence. These banding sequences include pal A2.2 in arm A and pal B10.10 in arm B in the Central Caucasus region, as well as pal B2.2 and pal G2.2 in the Lower Volga region. Arms A, B, D, and G in the Central Caucasian populations and A, B, and D in the Saratov oblast were polymorphic. The composition of heterozygous sequences between populations from different regions coincided only in arm D (pal D 1.2). In arms A and B, the set of heterozygous BS was different: pal A1.2 and pal B1.10 sequences were found in the Central Caucasian populations, and pal A1.3 and B11.12 were found in Saratov oblast. The number of genotypic combinations of S. pallidivittatus was higher in the Central Caucasus region, whereas the number of zygotic combinations was higher in the Saratov population. The percentage of heterozygous larvae in the Central Caucasian populations varied from 20 to 80, whereas all individuals in the Saratov population had heterozygous inversions. Zygotic combinations of larvae in all the studied populations were different.

FAMILY CHIRONOMIDAE.

Science.gov (United States)

Mendes, Humberto Fonseca; Pinho, Luiz Carlos

2016-06-14

Only 30 chironomid species distributed in 16 genera and three subfamilies are formally recorded to Colombia. Another 32 genera and two subfamilies have been recorded on larval stage, with no identification at species level. Many new records, genera and species are expected when focusing on systematics of chironomids from Colombia.

Ecological impact assessment of sediment remediation in a metal-contaminated lowland river using translocated zebra mussels and resident macroinvertebrates

International Nuclear Information System (INIS)

De Jonge, M.; Belpaire, C.; Geeraerts, C.; De Cooman, W.; Blust, R.; Bervoets, L.

2012-01-01

The present study investigated to what extent accumulated metal levels in aquatic invertebrates can reflect environmental contamination and how these tissue levels can be related to alterations in macroinvertebrate communities in the dredged River Dommel. Metal accumulation was measured in translocated zebra mussels (Dreissena polymorpha) and resident Chironomidae. Furthermore, macroinvertebrate community composition was assessed. Our results indicated that trends of total metal concentrations in surface water of the Dommel in time are reflected well by metal levels in tissue of D. polymorpha. In contrast, sediment-bound metals were the most dominant exposure route for Chironomidae. Alterations in macroinvertebrate community composition were observed during dredging and significant relations between metal levels in invertebrate tissues and ecological responses were found. Our results demonstrated that metal accumulation in both zebra mussels and Chironomidae can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity on macroinvertebrate communities. - Highlights: ► The use of tissue concentrations to assess environmental metal pollution was studied. ► Metal accumulation was measured in caged zebra mussels and resident Chironomidae. ► Shell condition of mussels and macroinvertebrate taxa distribution was assessed. ► Different accumulation between biota and relations with community level were found. ► Bioaccumulation is an integrated measure of metal toxicity in aquatic communities. - Metal accumulation in selected aquatic invertebrates can be used as an integrated measure of metal bioavailability and to predict ecological effects of metal toxicity.

Evaluation of long term effects of thermal effluents on stream biota

International Nuclear Information System (INIS)

Sublette, J.E.

1980-10-01

In order to evaluate the effects of energy related developments in aquatic ecosystems, a normal water data base must be established. One approach used is the selection of indicator communities on species with fairly well known environmental tolerances and requirements. The Chironomidae (Order Diptera) dominate the macrobenthic assemblages of many streams. The group offers great potential for water quality assessment. The studies in this report determine the species composition of Chironomidae at stream sites in New Mexico, across the relationship of species composition to water quality parameters, and map karyotypes for the chironomus decorus group

DEFORMITAS LIGULA LARVA TANYPODINAE SEBAGAI INDIKATOR PENCEMARAN LOGAM BERAT DI DANAU LIDO, JAWA BARAT

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Tyas Dita Pramesthy

2014-08-01

Full Text Available As one group of Chironomidae Tanypodinae larvae can be used in biological assessment to detect the heavymetal pollution in aquatic environment, because they could show morphological changes due to the pollution. Thestudy was aimed to describe ligula deformities in Tanypodinae larvae in a heavy metal polluted lake. The study wasconducted in Mei to June 2014 at Lake Lido, West Java. The results showed that lead (Pb concentration in LidoLake was quaite high, i.e. 0.08 0.19 mg/L. Ten of fifty-five collected Tanypodinae larve exhibited deformation in theirligulae. Index of severity of ligula deformation (ILSD was 4.4 indicating the response of the Chironomidae larvae tolead pollution.

Temporal Analyses of Select Macroinvertebrates in the Upper Mississippi River System, 1992-1995

National Research Council Canada - National Science Library

Sauer, Jennifer

1998-01-01

The annual variability in mayflies (Ephemeroptera), fingernail clams (Sphaeriidae), and midges (chironomidae) in six study areas of the Upper Mississippi River System from 1992 to 1995 was examined...

Similarity and diversity between aquatic insect populations in streams of first and second order, south of Brazil Diversidade e similaridade entre populações de insetos aquáticos em riachos de primeira e segunda ordem, sul do Brasil

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Cibele Bender Raio

2011-06-01

Full Text Available Aquatic communities of macroinvertebrates are influencied by rapid velocity, habitat heterogeneity and other characteristics. This study examined a relationship between aquatic insects diversity with hydrologic order of two streams. We tested following hypothesis: diversity of insects associated with the same substrate in equal parts of streams, classified in different orders, are similar. Samples of litter were collected in middle stretches of stream Cascatinha (first order and stream João Pinheiro (second order, Tibagi river basin, Telêmaco Borba, Paraná, Brazil. Diversity of each stream was obtained by Shannon index. Diversity values were low for both streams (0.8 for the first order stream and 0.89 for the second order stream with no statistical difference (t = -1.12; p = 0. 27. Similarity between the streams was 0.51. These results allowed us to verify that, to studied streams, hydrological order has no effect on aquatic insects diversity (F= 0.14, p= 0.71, so the hypothesis was accepted. The most abundant taxon in both streams was Chironomidae (Diptera, representing 82.7% of total collected. However when Chironomidae was removed from analysis, the hypotesis was refused. An high abundance of Chironomidae individuals had influenced values of local diversity. A estrutura das comunidades de macroinvertebrados aquáticos é influenciada pela velocidade da correnteza do curso d’água e da heterogeneidade de habitats entre outras características. Este trabalho verificou a relação da diversidade de insetos aquáticos com a ordem hidrológica de dois riachos. Para isso, foi testada a seguinte hipótese: a diversidade de insetos associados ao mesmo substrato em trechos equivalentes de riachos classificados em diferentes ordens é semelhante. Amostras de folhiço foram coletas nos trechos médios do riacho Cascatinha (primeira ordem e do riacho João Pinheiro (segunda ordem, pertencentes à bacia do rio Tibagi, Telêmaco Borba, Paran

Impact of routine Bacillus thuringiensis israelensis (Bti) treatment on the availability of flying insects as prey for aerial feeding predators.

Science.gov (United States)

Timmermann, Ute; Becker, Norbert

2017-12-01

Since 1980, mosquito breeding habitats in the Upper Rhine Valley were routinely treated with Bacillus thuringiensis var. israelensis (Bti). Bti is considered to significantly reduce the number of mosquitoes, and - especially when used in higher dosages - to be toxic to other Nematocera species, e.g. Chironomidae, which could be food sources for aerial feeding predators. To investigate direct and indirect effects of routine Bti treatment on food sources for aerial feeding predators, the availability of flying insects in treated and untreated areas was compared. A car trap was used for insect collection, which allowed their exact spatiotemporal assignment. The statistical analysis revealed that insect taxa abundance was influenced differently by the factors season, temperature and time of day. Nematocera (Diptera) were the most frequently collected insects in all areas. Chironomidae were the predominant aquatic Nematocera. The comparison of treated and untreated sites did not show significant differences that would indicate any direct or indirect effect of routine Bti treatment on the availability of flying insects. Additional to food availability, food selection must be considered when investigating food resources for aerial feeding predators. In this study, food selection of Delichon urbicum (House Martin) as an example was investigated with the help of neck ring samples. The preferred prey of the investigated D. urbicum colony consisted of diurnal insects with terrestrial larvae (Aphidina, Brachycera, Coleoptera). Chironomidae were consumed, but not preferred.

Efeito de metais Cobre (Cu e Zinco (Zn sobre a comunidade de macroinvertebrados bentônicos em riachos do sul do Brasil - DOI: 10.4025/actascibiolsci.v30i3.677 The effect of metals (Cu and Zn on the benthic macroinvertebrate community in streams in southern Brazil - DOI: 10.4025/actascibiolsci.v30i3.677

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Luiz Ubiratan Hepp

2008-10-01

Full Text Available O objetivo deste estudo foi avaliar os efeitos de metais (Cu e Zn sobre a comunidade de macroinverterados bentônicos. Foram amostrados, trimestralmente, entre setembro de 2006 e junho de 2007, organismos e água em oito trechos de riachos de duas bacias hidrográficas influenciadas por urbanização e agricultura. Foram estimados os valores de densidade de organismos, riqueza taxonômica e diversidade de Shannon. Para avaliação dos dados, foram utilizados testes de variância e regressão linear simples. Os resultados demonstraram variabilidade das concentrações dos metais e da macrofauna entre as estações do ano e riachos estudados. O metal Cobre (Cu apresentou influência apenas sobre a densidade Chironomidae e o metal Zinco (Zn apresentou efeito sobre a densidade total da macrofauna bentônica e de Chironomidae. Nenhum dos metais apresentou efeitos sobre a riqueza e diversidade de macroinvertebrados. Os resultados indicam potencial bioindicador da comunidade bentônica na avaliação da qualidade integrada do ambiente.The aim of this study was to evaluate the effect of metals (Cu and Zn on the benthic macroinvertebrate community. The organisms and water were collected quarterly between September 2006 and June 2007, in eight sites in streams of two hydrographic basins, influenced by urbanization and agriculture. The values of organism density, taxonomic richness and the Shannon diversity index were calculated. For data evaluation, tests of variance and simple linear regression were used. The results showed variability in the metal concentration and benthic community among seasons and studied streams. Cu showed influence only on Chironomidae density. Zn demonstrated effect on the benthic community and Chironomidae density. None of the metals presented effect on the macroinvertebrate richness and diversity. The results indicate a bioindicator potential of the benthic community in the evaluation of integral quality of the environment.

Natural diet of three species of shrimp in a tropical coastal lagoon

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Albertoni Edélti Faria

2003-01-01

Full Text Available The gut content of 495 specimens of Farfantepenaeus brasiliensis, 131 of F. paulensis (Penaeidae and 102 of Macrobrachium acanthurus (Palaemonidae were analyzed to establish the composition of their diets F. brasiliensis had as the most important feeding items in its diet larvae of Chironomidae, Polychaeta and Heleobia australis (Mollusca. For F. paulensis, the most important items were the same as for F. brasiliensis, but the order of importance of H. australis and Polychaeta was inverted. M. acanthurus had detritus as the most important item, followed by Chironomidae larvae, Odonata nymphs, and fragments of the macroalgae Chara. The results showed that the three species were omnivorous, with a varied diet including both components of macrofauna of benthos and associated to the macroalgae Chara and plant fragments and detritus.

Algal food selection and digestion by larvae of the pestiferous chironomid Chironomus crassicaudatus under laboratory conditions

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Ali, A.; Lobinske, R. J.

2004-01-01

Roč. 20, č. 4 (2004), s. 458-461 ISSN 8756-971X Institutional research plan: CEZ:AV0Z6066911 Keywords : Chironomidae * nuisance midge * cyanobacteria Subject RIV: EH - Ecology, Behaviour Impact factor: 0.691, year: 2004

Diptera Community In The Littoral Zone Of A North East Arid Zone ...

African Journals Online (AJOL)

Maiduguri, Nigeria, were studied between January and June 2002. Dipteran samples were collected every 2 weeks from five different stations. Five groups of diptera organisms simulidae, chironomidae, centrapogo nidae, culicidae and chaoboridae were found in analyzable numbers. The diptera assemblage was ...

Assessment of oil sand process water toxicity in wetlands of northern Alberta using Chironomid mentum deformities

Energy Technology Data Exchange (ETDEWEB)

Whelly, M. P.; Ciborowski, J. J. H. [Windsor, Univ., Windsor, ON (Canada)

1998-07-01

The effects of oil sands process water (OSPW) on aquatic invertebrates in wetlands near Fort McMurray, Alberta, are assessed. Principal components analysis and cluster analysis of environmental characteristics of 15 wetlands were used to identify three pairs of environmentally similar wetlands that differed mainly in exposure to or absence of OSPW. Large larvae of Chironomidae were collected and examined for mentum deformities (missing or extra teeth) for use as a biomarker. Invertebrate taxa richness and abundance was only moderately lower at OSPW -affected sites than at corresponding reference sites. The incidence of teeth deformities in midges (Chironomidae spp.) from OSPW-affected and corresponding reference wetlands was found to be moderate, and homogeneous among sites and between paired reference and OSPW-affected wetlands. This finding led to the conclusion that the suspected trace metals and PAHs may not be bioavailable in these highly humic wetlands.

Assessment of oil sand process water toxicity in wetlands of northern Alberta using Chironomid mentum deformities

Energy Technology Data Exchange (ETDEWEB)

Whelly, M. P.; Ciborowski, J. J. H. [Windsor, Univ., Windsor, ON (Canada)

1998-12-31

The effects of oil sands process water (OSPW) on aquatic invertebrates in wetlands near Fort McMurray, Alberta, are assessed. Principal components analysis and cluster analysis of environmental characteristics of 15 wetlands were used to identify three pairs of environmentally similar wetlands that differed mainly in exposure to or absence of OSPW. Large larvae of Chironomidae were collected and examined for mentum deformities (missing or extra teeth) for use as a biomarker. Invertebrate taxa richness and abundance was only moderately lower at OSPW -affected sites than at corresponding reference sites. The incidence of teeth deformities in midges (Chironomidae spp.) from OSPW-affected and corresponding reference wetlands was found to be moderate, and homogeneous among sites and between paired reference and OSPW-affected wetlands. This finding led to the conclusion that the suspected trace metals and PAHs may not be bioavailable in these highly humic wetlands.

Assessment of oil sand process water toxicity in wetlands of northern Alberta using Chironomid mentum deformities

International Nuclear Information System (INIS)

Whelly, M. P.; Ciborowski, J. J. H.

1998-01-01

The effects of oil sands process water (OSPW) on aquatic invertebrates in wetlands near Fort McMurray, Alberta, are assessed. Principal components analysis and cluster analysis of environmental characteristics of 15 wetlands were used to identify three pairs of environmentally similar wetlands that differed mainly in exposure to or absence of OSPW. Large larvae of Chironomidae were collected and examined for mentum deformities (missing or extra teeth) for use as a biomarker. Invertebrate taxa richness and abundance was only moderately lower at OSPW -affected sites than at corresponding reference sites. The incidence of teeth deformities in midges (Chironomidae spp.) from OSPW-affected and corresponding reference wetlands was found to be moderate, and homogeneous among sites and between paired reference and OSPW-affected wetlands. This finding led to the conclusion that the suspected trace metals and PAHs may not be bioavailable in these highly humic wetlands

Estrutura da comunidade de macroinvertebrados bentônicos de um riacho de serra em Itatinga, São Paulo, Brasil Structure of a benthic macroinvertebrates community in a mountain stream in Itatinga, São Paulo, Brazil

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Ludmilla O. Ribeiro

2005-09-01

Full Text Available A comunidade de macroinvertebrados bentônicos de um riacho de terceira ordem foi analisada em duas estações do ano, chuvosa e seca. Substratos artificiais foram amostrados semanalmente, ao longo de 56 dias para a coleta de macroinvertebrados, nas duas estações do ano. A composição da comunidade foi caracterizada por uma baixa diversidade, ou seja, presença de muitas espécies raras e poucas espécies abundantes nas duas estações do ano. Uma alta dominância de Chironomidae (Diptera nas duas estações, seguida de Baetidae (Ephemeroptera e Ancylidae (Mollusca, respectivamente nas estações chuvosa e seca, foi característico. Os resultados obtidos reforçam a grande importância de Chironomidae na comunidade bentônica de riachos e salientam a influência da sazonalidade sobre a estruturação destes organismos.The benthic macroinvertebrates community of a third order stream was studied during the wet and dry seasons. The community was analyzed using artificial substrates sampled weekly during 56 days in each season. The community composition was characterized by low species diversity, with high number of rare species and few abundant species for both seasons. A high dominance of Chinonomidae (Diptera for both seasons, followed by Baetidae (Ephemeroptera and Ancylidae (Mollusca, respectively for the wet and dry seasons, was found. The results reinforced the high importance of Chironomidae and the seasonal effect determining the stream benthic community structure.

Long-term resource limitation reduces insect detritivore growth in a headwater stream

Science.gov (United States)

Brent R. Johnson; Wyatt F. Cross; J. Bruce Wallace

2003-01-01

We measured larval growth rates of 2 dominant stream detritivore groups to assess the mechanism underlying declines in invertebrate production following exclusion of terrestrial litter inputs to a forested headwater stream. Larval Tallaperla spp. (P1ecoptera:Peltoperlidae) were chosen as representative shredders and non-Tanypodinae Chironomidae (...

Trophic state changes can affect the importance of methane-derived carbon in aquatic food webs

NARCIS (Netherlands)

Schilder, Jos; Van Hardenbroek, M.; Bodelier, P.L.E.; Kirilova, Emiliya P.; Leuenberger, Markus; Lotter, A.F.; Heiri, O.

2017-01-01

Methane-derived carbon, incorporated by methane-oxidizing bacteria, has been identified as a significant source of carbon in food webs of many lakes. By measuring the stable carbon isotopic composition (δ13C values) of particulate organic matter, Chironomidae and Daphnia spp. and their resting eggs

An assessment of Environmental Conditions and the Benthic Fauna ...

African Journals Online (AJOL)

Sensitive taxa of Dytiscidae, Hydropsychidae and Libellulidae were found only upstream from Obommirem to Buade. The mid portion of the Odaw catchment area were dominated by Oligochaeta, Naedidae and Lymnaea while the lower portion was dominated by the Chironomidae. There was no seasonal variation in the ...

Feeding habits of an endemic fish, Oxygymnocypris stewartii, in the Yarlung Zangbo River in Tibet, China

Science.gov (United States)

Huo, Bin; Xie, Cong Xin; Madenjian, Charles P.; Ma, Bao Shan; Yang, Xue Feng; Huang, Hai Ping

2014-01-01

Feeding habits of Oxygymnocypris stewartii were investigated based on monthly sampling in the Yarlung Zangbo River from August 2008 to August 2009. The gut contents of 194 individuals were analysed and quantified with numerical and gravimetric methods. This species can be considered a generalized and opportunistic predator feeding both on teleosts and aquatic insects. A multivariate analysis revealed noticeable variation in O. stewartii diet composition with fish size and season. The smaller specimens fed primarily on Cobitidae and Hydropsychidae. As they grew, Cyprinidae and Chironomidae larvae became important prey. The preferred food items were teleosts in summer and autumn. For winter and spring, the predominant prey switched to chironomidae larvae. Diet composition did not significantly vary between the sexes. Finally, a significant and positive correlation between predator and prey length was found. These findings provide the fundamental information better understanding the role of this important endemic species in the Yarlung Zangbo River food web.

Fish on the roof of the world

DEFF Research Database (Denmark)

Jacobsen, Dean; Laursen, Søren Kock; Hamerlik, Ladislav

2017-01-01

, but the composition of the stomach contents varied greatly between sites and among individuals. Algal matter was ingested at most sites, but macroinvertebrates (Chironomidae, Baetidae and Simuliidae) dominated the ingestion (average 50–100. The trophic position of Triplophysa, identified from δ15N (‰) of the biota...

Morphology and anatomy of leaf miners in two species of Commelinaceae (Commelina diffusa Burm. f. and Floscopa glabrata (Kunth Hassk Morfologia e anatomia de minas foliares em duas espécies de Commelinaceae Commelina diffusa Burm. f. e Floscopa glabrata (Kunth Hassk

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Paula Maria Elb

2010-03-01

Full Text Available In specialized literature, reports on anatomy of miners in host plants are few in number. These agents trigger excavations, or paths, by consumption of plant inner tissues by larvae of several insects. The aim of this work was to investigate leaf miner occurrence in Commelina diffusa (a cosmopolitan plant and Floscopa glabrata (an amphibious plant using anatomical techniques. The place where the plants were collected is subjected to seasonal floods, consequently both the species were exposed to the same weather conditions and seasonal floods. This study showed that members of Agromyzidae and Chironomidae families, which are Diptera endophytophagous larvae types, were responsible for the tunnels. Moreover, in Commelina diffusa Agromyzidae larvae were found, while in Floscopa glabrata three Chironomidae cephalic exuviae were found. The miners, as can be seen from anatomical studies, used only mesophyll parenchyma tissues for feeding, causing the formation of linear mines. In addition, in both the species, the epidermis and the medium-sized vascular units were kept intact, showing no structural modification, such as neoformation of tissues.Existem poucos relatos na literatura sobre anatomia de plantas parasitadas por agentes minadores, os quais promovem escavações ou caminhos através do consumo dos tecidos internos das plantas por larvas de diversos insetos. A proposta deste trabalho foi analisar anatomicamente a ocorrência de minas foliares em Commelina diffusa (planta cosmopolita e Floscopa glabrata (planta anfíbia causadas por espécies de larvas endofitófagas de dípteros, pertencentes a duas famílias: Agromyzidae e Chironomidae. O local onde as plantas foram coletas está sujeito a inundações sazonais, e as duas espécies foram submetidas às mesmas condições climáticas. Em Commelina diffusa foram encontradas larvas da família Agromyzidae e, em Floscopa glabrata observaram-se três exuvias cefálicas de Chironomidae. Os dados anat

Distribution and abundance of the main insect families in the MUDA area

International Nuclear Information System (INIS)

Maimon Abdullah; Azura Zainal Ratin; Noraini Dan

2002-01-01

Periodic sampling of invertebrates by the Sweeping Method was carried out in the Muda rice area. Two plots with three subplots were chosen incorporating both the recycled and non-recycled irrigation systems. Our results showed that there was a significant difference in abundance and diversity of insect families sampled within plots and between visits undertaken from 19 to 89 days after seeding (DAS). Plot comparison between the two irrigated systems shows that the recycled system supports a higher diversity of insects and arachnids compared to the non-recycled system. From a total of 2418 individuals analysed, some 87.43% was from the recycled plots. Of the four dominant families captured from both types of plots, the most abundant comprised Pyralidae, followed by Chironomidae, Coenagrionidae and Tetragnathidae families for the non-recycled plots, whilst ranking for the recycled plots was Chironomidae followed by Acrididae, Coenagrionidae and Cicadellidae families, respectively. The relative abundance and diversity of the various orders and families are also related to abiotic parameters and planting stage of rice. (Author)

MACROZOOBENTHOS IN CARP FISH FRY

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Ljubica Debeljak

1996-12-01

Full Text Available Qualitative and quantitative components of macrozoobenthos was investigated on six fish farms with 8-10 ha-1 each at "Donji Miholjac". The ponds were stocked with 200,000 individuals per ha! of three-day-old carp larvae. The fry were fed with animal protein throughout the culturing season. The qualitative and quabtitative macrozoobenthos components formed mainly due to systematic groups of Oligochaeta and Chironomidae. The average size of Oligohaeta varied in each pond from 119 to 944 individuals per m-2 and from 2.18 to 14.09 g per m-2, and the larvae of Chironomidae from 174 to 1086 ind. per m-2 and from 2.66 to 14.09 g per m-2. Variation s of the total macrozoobenthos was within the amplitude of from 28 to 5805 ind. per m-2 and from 0.11 to 73.72 g. per m-2. In mid summer it was determined that there was a fall in the amount of macrozoobenthos in all fish ponds (Table 6.

Spatial variability in macroinvertebrate assemblages along and among neighbouring equatorial glacier-fed streams

DEFF Research Database (Denmark)

Kuhn, J.; Andino, P.; Calvez, R.

2011-01-01

, the three sites were placed at comparable distances from the glacier and were grouped as ‘upper’ (50–200 m), ‘middle’ (1.5 km) and ‘lower’ sites (3.5–5.6 km). 3. In total, 2200 individuals (64% chironomids) were collected and 47 taxa (30 dipterans, 18 of these Chironomidae) identified. Density ranged from...

A tale of two fjords – en analyse af bundfauna samfund i Odense og Roskilde Fjord

DEFF Research Database (Denmark)

Banta, Gary Thomas; Delefosse, Matthieu; Canal Vergés, Paula

gravende muslinger (f.eks. Cerastoderma spp.) mens Odense Fjord (OF) havde flere orme. Ligeledes så vi mange tubificide orme i den indre del af OF. I den indre del af RF så vi i stedet mange dansemyggelarver (Chironomidae). Af de undersøgte miljøvariable var vanddybde og salinitet (både niveauet og...

Controlling factors of benthic macroinvertebrates distribution in a small tropical pond, lateral to the Paranapanema River (São Paulo, Brazil Macroinvertebrados bentônicos e fatores controladores de sua distribuição em uma pequena lagoa tropical adjacente ao rio Paranapanema (São Paulo, Brasil

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Erika Mayumi Shimabukuro

2011-06-01

Full Text Available AIM: The aim of the present study was to examine the benthic fauna in a marginal pond lateral to the Paranapanema River and to identify the main controlling factors of its distribution. Considering the small size of the lacustrine ecosystem, we expected that seasonal variations of the benthic community attributes are more important than spatial variations; METHODS: Two samplings, one in March and another in August, were carried out at nine sites in the pond. Sediment samples were obtained through a Van Veen grab for invertebrate sorting, granulometric analysis, and for quantification of organic matter in sediment. Other abiotic factors were measured, such as water transparency, dissolved oxygen, pH, electric conductivity, temperature, and depth of sediment sampling sites. Regarding the comparative analysis at spatial scale, no significant variations in density of the benthic invertebrate community were found. RESULTS: In relation to the studied abiotic factors, only depth presented significant differences among sampling sites; All the measured environmental parameters presented significant differences among sampling months, except depth and the physical and chemical characteristics of the sediment. The abundance of Chaoboridae and Chironomidae was the unique attribute with a significant difference in comparing the two months. A higher abundance of taxa occurred in August, especially for Oligochaeta, Nematoda, Chaoboridae, and Chironomidae; CONCLUSIONS: Because of the low structural complexity of the studied pond, we concluded that the changes in benthic macroinvertebrate community attributes were mainly due to seasonal effects.OBJETIVO: O presente estudo tem por objetivo examinar a fauna bentônica em lagoa marginal ao rio Paranapanema e os principais fatores reguladores da sua distribuição. Devido ao pequeno tamanho do ambiente lacustre, procurou-se mostrar que as variações sazonais dos atributos da comunidade bentônica são mais

Preimpoundment Water Quality Study

Science.gov (United States)

1981-12-01

American Elm U. americana Americrn Holly Ilex opaca Persirmnr~ Diospyros virginiana Tulip Rbplar Liriodexniron tul-ipifera Basswoo Tilia americana...Brown Company, Dubuque, Iowa. 977 pp. Roback, S.S. 1963. The genus Xenochironomus (Diptera: Tendipedidae) Kieffer, taxonomy and immature stages...Transactions of the American Entomological Society 88:235-245. Roback, S.S. 1969. The immature stages of the genus Tanypus Meigen (Diptera: Chironomidae

Screening for deformed teeth; Screening for saere taender

Energy Technology Data Exchange (ETDEWEB)

Vermeulen, A.; Dall, P.C.; Hansen, F.G.

1996-04-01

Water pollution by pesticides and heavy metals causes sublethal effects in larvae of the Chironomidae midges. These effects are particularly noticeable in the deformities of the oral parts and antennae. Possibilities of using these deformities for the purpose of water/sediment biomonitoring are very promising. Here the first results of screening in a Danish stream are presented. (EG) 9 refs.

Comparison of the abiotic preferences of macroinvertebrates in tropical river basins.

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Gert Everaert

Full Text Available We assessed and compared abiotic preferences of aquatic macroinvertebrates in three river basins located in Ecuador, Ethiopia and Vietnam. Upon using logistic regression models we analyzed the relationship between the probability of occurrence of five macroinvertebrate families, ranging from pollution tolerant to pollution sensitive, (Chironomidae, Baetidae, Hydroptilidae, Libellulidae and Leptophlebiidae and physical-chemical water quality conditions. Within the investigated physical-chemical ranges, nine out of twenty-five interaction effects were significant. Our analyses suggested river basin dependent associations between the macroinvertebrate families and the corresponding physical-chemical conditions. It was found that pollution tolerant families showed no clear abiotic preference and occurred at most sampling locations, i.e. Chironomidae were present in 91%, 84% and 93% of the samples taken in Ecuador, Ethiopia and Vietnam. Pollution sensitive families were strongly associated with dissolved oxygen and stream velocity, e.g. Leptophlebiidae were only present in 48%, 2% and 18% of the samples in Ecuador, Ethiopia and Vietnam. Despite some limitations in the study design, we concluded that associations between macroinvertebrates and abiotic conditions can be river basin-specific and hence are not automatically transferable across river basins in the tropics.

Stonlach content analyses of Gilchristella aestuarius and Hepsetia ...

African Journals Online (AJOL)

Apseudes digitalis. 80 2,2. 6. 5. Decapoda. Zoea larvae. 6 1,0. 3. 2. Unidentified larvae. 0,3. 2. 0. Insecta. Chironomidae larvae. 810 8,1. 67. 0. 13,5. 65. 13. Terrestrial insects. 2 0,4. 4. 0. Pupae. 22 1,1. 4. 2. Arachnida. Araneida. <0,05. 2. 0. Mollusca. Lamellibranch veligers. 9 <0,05. 8. 0 2240 7,5. 69. 6. Gastropod veligers.

An evaluation of invertebrate dynamics in a drinking water distribution system: a South African perspective

OpenAIRE

2008-01-01

M.Sc. The occurrence of invertebrates in drinking water supplies is a common consumer complaint with studies showing that very few drinking water distribution networks are totally free of organisms. A detailed investigation of different types of metazoan animals in the drinking water supply networks of South Africa has not been undertaken. In limited worldwide studies, invertebrates (mainly Amphipoda, Chironomidae, Cladocera, Copepoda and Ostracoda) have been detected in produced drinking ...

Evaluation of the impact of Bacillus thuringiensis serovar israelensis and Temephos, used for the control of Simulium (Chirostilbia pertinax Kollar, 1832 (Diptera, Simuliidae on the associated entomofauna, Paraty, state of Rio de Janeiro, Brazil

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Araújo-Coutinho Carlos José Pereira da Cunha de

2003-01-01

Full Text Available The study was set up to evaluate the impact of two commercial larvicide formulations, Bacillus thuringiensis serovar israelensis base (Bti at 15 ppm/1 min and temephos at 0.03 ppm of active ingredient, used to control Simulium pertinax populations, on associated non-target entomofauna occupying the same breeding sites. The experiments were carried out on the Pedra Branca and Muricana rivers, on the slopes of Serra do Mar massif, municipality of Paraty, state of Rio de Janeiro, Brazil. Bti was applied to the river Pedra Branca and temephosto theriver Muricana. On both rivers, treatment and control sections were labeled as such, each one with two observation posts: slow moving water and fast water regions respectively. Artificial substrata was used to evaluate the abundance of associated entomofauna. Attached immature stages of arthropods were removed from both of its surfaces fortnightly. Were collected, from the two rivers, 28 477 specimens of the entomofauna associated with S. pertinax. The families Hydropsychidae, Chironomidae, Bactidae, Simuliidae, Blephariceridae and Megapodagrionidae were represented. These was an impact of temephos on the entomofauna associated with S. pertinax only in Simuliidae and Chironomidae, and to Bti only in Simuliidae. However, the reduction in their numbers was not statistically significant.

Evaluation of the impact of Bacillus thuringiensis serovar israelensis and Temephos, used for the control of Simulium (Chirostilbia) pertinax Kollar, 1832 (Diptera, Simuliidae) on the associated entomofauna, Paraty, state of Rio de Janeiro, Brazil.

Science.gov (United States)

de Araújo-Coutinho, Carlos José Pereira da Cunha; Cunha, Andrea de Barros Pinto Viviani; Serra-Freire, Nicolau Maués; de Mello, Rubens Pinto

2003-07-01

The study was set up to evaluate the impact of two commercial larvicide formulations, Bacillus thuringiensis serovar israelensis base (Bti) at 15 ppm/1 min and temephos at 0.03 ppm of active ingredient, used to control Simulium pertinax populations, on associated non-target entomofauna occupying the same breeding sites. The experiments were carried out on the Pedra Branca and Muricana rivers, on the slopes of Serra do Mar massif, municipality of Paraty, state of Rio de Janeiro, Brazil. Bti was applied to the river Pedra Branca and temephosto theriver Muricana. On both rivers, treatment and control sections were labeled as such, each one with two observation posts: slow moving water and fast water regions respectively. Artificial substrata was used to evaluate the abundance of associated entomofauna. Attached immature stages of arthropods were removed from both of its surfaces fortnightly. Were collected, from the two rivers, 28 477 specimens of the entomofauna associated with S. pertinax. The families Hydropsychidae, Chironomidae, Bactidae, Simuliidae, Blephariceridae and Megapodagrionidae were represented. These was an impact of temephos on the entomofauna associated with S. pertinax only in Simuliidae and Chironomidae, and to Bti only in Simuliidae. However, the reduction in their numbers was not statistically significant.

Relations Between the Structure of Benthic Macro-Invertebrates and the Composition of Adult Water Beetle Diets from the Dytiscidae Family.

Science.gov (United States)

Frelik, Anna; Pakulnicka, Joanna

2015-10-01

This paper investigates the relations between the diet structure of predaceous adult water beetles from the Dytiscidae family and the structure of macrofauna inhabiting the same environments. The field studies were carried out from April until September in 2012 and 2013 in 1-mo intervals. In total, >1,000 water beetles and 5,115 benthic macro-invertebrates were collected during the whole period of the study. Subsequently, 784 specimens of adult water beetles (70.6% out of the total sampled) with benthic macro-invertebrates found in their proventriculi, were subject to analysis. The predators were divided into three categories depending on their body size: small beetles (2.3-5.0 mm), medium-sized beetles (13-15 mm), and large beetles (27-37 mm). All adult Dytiscidae consumed primarily Ephemeroptera and Chironomidae larvae. Although Asellidae were numerically dominant inhabitants of the sites, the adult water beetles did not feed on them. The analysis of feeding relations between predators and their prey revealed that abundance of Ephemeroptera, Chironomidae, and larval Dytiscidae between the environment and the diet of adult Dytiscidae were strongly correlated. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Chironomidae (Insecta: Diptera) Collected from Hydrilla Verticillata ...

African Journals Online (AJOL)

A survey of the aquatic weed Hydrilla verticillata was conducted in selected Kenyan and Ugandan lakes, and emerging chironomid adults were collected from samples of Hydrilla and seven other aquatic macrophytes. Hydrilla was absent from Lake Victoria, in sites where it previously occurred. Hydrilla was found in four of ...

O regime hidrológico do rio Ivinhema (Estado do Mato Grosso do Sul e sua influência na assembléia zoobentônica=Hydrologic regime of the Ivinhema river (Mato Grosso do Sul, State and its influence on zoobenthic assemblage

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José Antonio Arenas-Ibarra

2012-01-01

Full Text Available O estudo foi realizado em diferentes ambientes da várzea do rio Ivinhema com o intuito de analisar a variação espacial e temporal da assembléia de invertebrados bentônicos, bem como sua relação com as variáveis físicas e químicas e o nível hidrométrico. Foram estudados quatro ambientes, o canal principal do rio, o canal Ipoitã, a lagoa Ventura (sem comunicação e a lagoa dos Patos (com comunicação. As coletas foram realizadas trimestralmente de fevereiro a novembro de 2002. O sistema rio Ivinhema foi caracterizado por um regime de potamofase bimodal com intensidades moderadas e grandes amplitudes, permanecendo em potamofase 184 dias em 2001 e 67 dias em 2002. Foram observadas as variações espacial e temporal, quanto às variáveis físicas e químicas, sumarizadas em uma PCA. Dos 37 táxons registrados, Nematoda, Corbiculidae, Oligochaeta, Acari, Ostracoda e Chironomidae foram os mais abundantes, sendo as larvas de Chironomidae o táxon predominante no canal Ipoitã e na lagoa Ventura. Entretanto, a análise da estrutura da assembléia (CA demonstrou que a assembléia bentônica do rio Ivinhema é dissimilar a das lagoas. A relação entre PCA e CA não foi significativa, indicando que no sistema Ivinhema há uma estrutura complexa e que a uniformidade espacial da densidade e temporal da assembléia bentônica deve-se à maior conectividade entre os ambientes.This study was developed in different environments of the Ivinhema river floodplain in order to analyze the spatial and temporal variation of benthic assemblages and their relationship with physical and chemical variables and water level. Samples were taken quarterly between February and November 2002 in four environments: Ivinhema main channel, Ipoitã channel, Patos lake (with direct connectivity and Ventura lake (without connectivity. The system was characterized by a bimodal potamophase cycle with moderate intensities and large amplitudes, remaining in potamophase for

Cladocera from bottom deposits as an indicator of changes in climate and ecological conditions

Science.gov (United States)

Frolova, L. A.

2018-01-01

Diatoms, pollen, and remains of higher vegetation are used as indicator groups in paleoecological studies. Using certain groups of zoological indicators such as planktonic and benthic organisms (Ostracoda, Cladocera, Chironomidae) has recently become popular in paleolimnology and paleoecology. This study aims to estimate the possibilities, benefits, problems and prospects of Cladocera use in the composition of zoothanatocoenosis of lakes’ sediments as one of the biological indicators in paleoenvironmental studies and paleoreconstructions of abiotic conditions of the past.

An Investigation into the Physico-chemical Factors Affecting the Abundance and Diversity of Aquatic Insects in Organically Manured Aquadams and Their Utilization by Oreochromis mossambicus (Perciformes: Cichlidae).

Science.gov (United States)

Rapatsa, M M; Moyo, N A G

2015-08-01

The interaction between the fish Oreochromis mossambicus (Percifomes: Cichlidae) and aquatic insects after application of chicken, cow, and pig manure was studied in 7,000-liter plastic aquadams. Principal component analysis showed that most of the variation in water quality after application of manure was accounted for by potassium, nitrogen, dissolved oxygen, phosphate, and alkalinity. Canonical correspondence analysis showed that Gyrinidae, Elminidae, Hydrophilidae, Hydraenidae, and Athericidae were associated with high nutrient levels (nitrogen, phosphorus, and potassium) characteristic of the chicken manure. However, the most abundant aquatic insects Gerridae, Notonectidae, and Culicidae were close to the centre of the ordination and not defined by any nutrient gradient. The Shannon-Wiener diversity was highest in the aquadams treated with chicken manure. The most frequently occurring aquatic insects in the diet of O. mossambicus were culicid mosquitoes in all the treatments. However, in the laboratory, Chironomidae were the most preferred because they lacked refuge. Notonectidae and Gerridae were not recorded in the diet of O. mossambicus despite their abundance. This may be because of their anti-predation strategies. Laboratory experiments showed that Notonectidae, Gyrinidae, and Gerridae fed on Chironomidae and Culicidae. This implies that aquatic predatory insects competed for food with O. mossambicus. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of Didymosphenia geminata blooms on prey composition and associated diet and growth of Brown Trout

Science.gov (United States)

James, Daniel A.; Chipps, Steven R.

2016-01-01

We compared diet, stomach fullness, condition, and growth of Brown Trout Salmo trutta among streams with or without blooms of the benthic diatom Didymosphenia geminata in the Black Hills, South Dakota. In Rapid Creek, where D. geminata blooms covered ∼30% of the stream bottom, Brown Trout consumed fewer ephemeropterans (6–8% by weight) than individuals from two stream sections that have not had D. geminatablooms (Castle and Spearfish creeks; 13–39% by weight). In contrast, dipterans (primarily Chironomidae) represented a larger percentage of Brown Trout diets from Rapid Creek (D. geminata blooms present; 16–28% dry weight) compared with diets of trout from streams without D. geminata blooms (6–19% dry weight). Diets of small Brown Trout (100–199 mm TL) reflected the invertebrate species composition in benthic stream samples; in Rapid Creek, ephemeropterans were less abundant whereas dipterans were more abundant than in streams without D. geminata blooms. Stomach fullness and condition of Brown Trout from Rapid Creek were generally greater than those of Brown Trout from other populations. Linkages among invertebrate availability, diet composition, and condition of Brown Trout support the hypothesis that changes in invertebrate assemblages associated with D. geminata (i.e., more Chironomidae) could be contributing to high recruitment success for small Brown Trout in Rapid Creek.

Cytogenetic study of natural chironomini (diptera, chiromedae) populations from open water bodies of former Semipalatinsk test site

International Nuclear Information System (INIS)

Seysebaev, A.T.; Rakhimbaeva, K. T.; Bakhtin, M.M.

2002-01-01

In the paper genetic variability of natural population of chironomidae inhabiting in waters on the territory of Semipalatinsk test site (STS) is studied. Ten Chironomini species of Chironomidae subfamily and one species of Tanypodinae subfamily were identified using cyto-taxonomic methods of analysis. Cytophotomap of polythene chromosomes of salivary glands were established for four species: Glyptotendipes salinus, Captochironomus setivalva, Camptochriomonus tentas and Chironomus plumosus. For the first time a new previously unknown species of Chironomus gender, and namely C, genelenus 1. sp. n. was described and a cytophotomap of its polythene chromosomes was established. A detailed quantative and qualitative analysis of chromosome polymorphism was carried out and the spectrum and frequency of the disk sequences and genotypic combination were identified. New evidence on change in the polythene chromosomes structure were revealed in certain Chironomini species dwelling in the radioactively contaminated water bodies of STS: rare, unique disk sequences of chromosomes were found, a series of specific homo zygote and heterozygote inversions were observed, which evidently resulted from long-term adaptive selection under conditions of the chronic ionizing radiation. Increase of in frequency of structural mutations of chromosomes was found in mitotic cells of imago disk of Chironomini larvae is revealed. This increase indicates that at the STS many population of benthos organisms are directly affected by the ionizing radiation

Biota and biological principles of the aquatic environment

International Nuclear Information System (INIS)

Greeson, P.E.

1982-01-01

The first of several compilations of briefing papers on water quality prepared by the U.S. Geological Survey is presented. Each briefing paper is prepared in a simple, nontechnical, easy to understand manner. This U.S. Geological Survey Circular contains papers on selected biota and biological principles of the aquatic environment. Briefing papers are included on Why biology in water quality studies , Stream biology, Phytoplankton, Periphyton, Drift organisms in streams, Family Chironomidae (Diptera), Influences of water temperature on aquatic biota, and Stream channelization: Effects on stream fauna

Parachironomus lenz from china and Japan (Diptera, chironomidae).

Science.gov (United States)

Yan, Chun-Cai; Yan, Jiao; Jiang, Li; Guo, Qin; Liu, Ting; Ge, Xin-Yu; Wang, Xin-Hua; Pan, Bao-Ping

2015-01-01

Members of the genus Parachironomus Lenz known from China and Japan are revised, and a key to their male adults is given. Parachironomuspoyangensis sp. n. is described in this life stage. Parachironomusfrequens (Johannsen) and Parachironomusmonochromus (van der Wulp) are recorded from China for the first time, thus are redescribed from Chinese specimens. Parachironomuskamaabeus Sasa & Tanaka and Parachironomustoneabeus Sasa & Tanaka are new junior synonyms of Parachironomusfrequens. Three Chinese or Japanese species formerly placed in Parachironomus are transferred to other genera, resulting in the new combinations Cryptochironomusinafegeus (Sasa, Kitami & Suzuki), Demicryptochironomus (Irmakia) lobus (Yan, Sæther, Jin & Wang), and Microchironomuslacteipennis (Kieffer). Chironomussauteri Kieffer, Parachironomuskisobilobalis Sasa & Kondo and Parachironomuskuramaexpandus Sasa are removed from Parachironomus; the last of these three denotes a valid species of uncertain generic placement, the first two are nomina dubia.

VALORACIÓN DE LA CALIDAD DEL AGUA DE TRES CIÉNAGAS DEL DEPARTAMENTO DE CESAR MEDIANTE MACROINVERTEBRADOS ASOCIADOS A EICHHORNIA CRASSIPES (PONTEDERIACEAE

Directory of Open Access Journals (Sweden)

MARÍA DEL ÁNGEL MARTÍNEZ-RODRÍGUEZ

2014-12-01

Full Text Available Se evalúo la calidad de agua de tres ciénagas del departamento del Cesar (Zapatosa, Mata de Palma y La Pachita mediante la caracterización de la comunidad de macroinvertebrados acuáticos asociados a la planta acuática-flotante Eichhornia crassipes (taruya, buchón. Se realizaron dos muestreos en época de aguas altas y dos en el periodo de aguas bajas. Para determinar la calidad del agua se midieron variables fisicoquímicas y se utilizaron el Índice Biótico de Polución (IBP y el Índice de Integridad Biótica de Macroinvertebrados (IIBM, este último desarrollado específicamente para las ciénagas estudiadas. Los individuos encontrados pertenecen a 15 órdenes, 34 familias y 87 morfotipos, y de ellos el orden Coleoptera fue el más diverso con 49 morfotipos (56% del total. Las familias Hydrophilidae y Dytiscidae (Coleptera, Cyclestheriidae (Branchiopoda, Chironomidae (Diptera y Planorbidae (Basommatophora fueron las más representativas en cuanto a la abundancia. Las abundancias por área fluctuaron entre 3130 ind.m-2 en Mata de Palma (27% Conchostraca y 190686 ind.m-2 en La Pachita (95% Chironomidae. El IBP presentó las mayores correlaciones con las variables fisicoquímicas, pero el IIBM fue más flexible y sensible, por lo que se recomienda su utilización.

Hydrobiological survey of some surface waters in the area of Mochovce nuclear power plant and their saprobiological assessment

International Nuclear Information System (INIS)

Kovacik, L.

1987-01-01

The results are presented of a hydrobiological study of three flows and one retention reservoir in the surroundings of the Mochovce nuclear power plant (Western Slovakia) performed in June 1982 and May 1983. The research was aimed at obtaining necessary information on the species composition of the algal flora (include blue-green algae) and selected groups of invertebrate hydrofauna (Sarcodina, Rotatoria, Cladocera, Copepoda, Oligochaeta and Chironomidae) in this territory. Natural waters were classified on the basis of the species composition of water organisms according to saprobiological criteria. (author). 4 refs

Occurence of larval Culicidae (Diptera in water retained in Aquascypha hydrophora (Fungus: Stereaceae in Central Amazônia, Brazil

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Ruth LM Ferreira

2001-11-01

Full Text Available The community structure of insects, especially mosquito larvae, in water held in the fungus Aquascypha hydrophora (Berk. Reid (Stereaceae is reported. The study was done in the Adolpho Ducke Forest Reserve, 26 km east of Manaus, AM, Brazil, from September 1998 through November 1999. The most abundant entomofauna were immature Culicidae (n = 121 91.7%, followed by adult Dytiscidae (n = 3 2.3%, immature Chironomidae (n = 5 3.8% and immature Tipulidae (n = 3 2.3%. Culicidae associated with A. hydrophora comprised species of the subfamilies Anophelinae and Culicinae.

Sewage input effects on the macroinvertebrate community associated to Typha domingensis Pers in a coastal lagoon in southeastern Brazil Efeitos do aporte de esgotos sobre a comunidade de macroinvertebrados associada à Typha domingensis Pers em uma lagoa costeira no Sudeste do Brasil

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C. Henriques-de-Oliveira

2007-02-01

Full Text Available This study was carried out at Imboassica Lagoon, located in an urban zone in the municipality of Macaé, Rio de Janeiro state, Brazil. This lagoon has been subject to anthropogenic impacts due to the increasing city population, such as the input of sewage. Areas of variable degree of anthropogenic influence in the lagoon were compared regarding the structure of the macroinvertebrate community associated to Typha domingensis leaves. For sampling, we used 35 x 20 cm net plastic bags, with 6.8 mm mesh containing T. domingensis leaves for colonization. Two different sampling stations were selected: station A, under direct input of sewage; and station B with lesser sewage influence. The bags were removed after 20, 40 and 75 days of colonization. For each sample the Shannon-Wiever Diversity, Pielou Evenness, Jaccard Similarity Indices, Correspondence Analysis and taxonomic richness were calculated. A total of 31,874 individuals were sampled, belonging to 34 taxa. The main taxonomical groups were: Oligochaeta (41%, Chironomidae (40%, Ancylidae (4.6%, Polymitarcyidae (4% and Thiaridae (3%. At station A, the taxonomic richness, the Evenness and Diversity values were lower than in station B. On the other hand, the total density was three times higher in station A than in B. It was already possible to discriminate the community structure of each sampling station in the first sampling. Trichoptera and Ephemeroptera were the main exclusive groups of station B and are considered good water quality indicators due to their high sensibility to contamination. The major contribution to discriminate between the macroinvertebrate communities of the two sample stations came from Chironomidae, Oligochaeta and Ephemeroptera.O presente estudo foi realizado na Lagoa Imboassica, localizada no perímetro urbano da cidade de Macaé, RJ, Brasil. Esta lagoa vem sofrendo impactos antrópicos com o aumento da cidade, como o aporte de esgotos sem tratamento. Áreas com

Macroinvertebrate fauna associated with Pistia stratiotes and Nymphoides indica in subtropical lakes (south Brazil

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EF. Albertoni

Full Text Available This study was carried out at the Biguás and Polegar lakes, both small environments but at different successional stages. The main objective was to characterize the macroinvertebrate community associated to the aquatic macrophyte stand in each lake in order for this community, the environmental conditions and their water quality to interact. The samples were taken in 2003. The abiotic variables of N and P totals, the temperature, electrical conductivity, pH and dissolved oxygen, as well as the determined clorophyll a concentration were measured. Macroinvertebrates were sampled with a 500 µ mesh size net, separated under a stereomicroscope and identified at the lowest possible taxonomic level, and their densities were shown as the number of individuals per 100 g of macrophyte dry weight. The Shannon-Wiener Diversity Index (H', Pielou evenness (J, frequency of occurrence, abundance and taxa richness were calculated for each invertebrate community. The Lago dos Biguás is undergoing a process of eutrophication and during the study presented a large Pistia stratiotes stand. The Lago Polegar is oligotrophic and had only a small Nymphoides indica bankwe. The macrophyte associated invertebrate communities in each lake were considered significantly different (p < 0.05. Sixty seven taxa were found for the Lago dos Biguás and 32 for the Lago Polegar. For both lakes, most of the taxa were considered rare, with a low dominance in a few months. The taxa with highest densities at Lago dos Biguás were Chironomidae, Daphniidae and Cyclopidae, and Oligochaeta, Chironomidae and Coenagrionidae for Lago Polegar.

Quantifying climate changes of the Common Era for Finland

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Luoto, Tomi P.; Nevalainen, Liisa

2017-10-01

In this study, we aim to quantify summer air temperatures from sediment records from Southern, Central and Northern Finland over the past 2000 years. We use lake sediment archives to estimate paleotemperatures applying fossil Chironomidae assemblages and the transfer function approach. The used enhanced Chironomidae-based temperature calibration set was validated in a 70-year high-resolution sediment record against instrumentally measured temperatures. Since the inferred and observed temperatures showed close correlation, we deduced that the new calibration model is reliable for reconstructions beyond the monitoring records. The 700-year long temperature reconstructions from three sites at multi-decadal temporal resolution showed similar trends, although they had differences in timing of the cold Little Ice Age (LIA) and the initiation of recent warming. The 2000-year multi-centennial reconstructions from three different sites showed resemblance with each other having clear signals of the Medieval Climate Anomaly (MCA) and LIA, but with differences in their timing. The influence of external forcing on climate of the southern and central sites appeared to be complex at the decadal scale, but the North Atlantic Oscillation (NAO) was closely linked to the temperature development of the northern site. Solar activity appears to be synchronous with the temperature fluctuations at the multi-centennial scale in all the sites. The present study provides new insights into centennial and decadal variability in air temperature dynamics in Northern Europe and on the external forcing behind these trends. These results are particularly useful in comparing regional responses and lags of temperature trends between different parts of Scandinavia.

Kuş Gölü (Bandırma Makrobentik Omurgasız Faunası Hakkında Bir Ön Araştırma.

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Süleyman Balık

2015-12-01

Full Text Available Kuş Gölü’nün makrobentik omurgasız faunasını belirlemek amacıyla 1987 ve 1988 yılları arasında aylık periyotlar halinde, bir yıl süre ile 5 istasyonda arazi çalışması yapılmıştır. Ekman grab ile alınan çamur örnekleri 500 μm göz açıklığındaki elekten geçirilmiş ve örnekler %4’lük formaldehit solüsyonunda tespit edilmiştir. Araştırma sonucunda, Oligochaeta sınıfından 10, Chironomidae familyasından 5 ve Ceratopogonidae familyasından 1 olmak üzere toplam 16 takson tespit edilmiştir. Kuş gölü’nde metrekarede ortalama 6759 birey tespit edilmiş, grupların oransal dağılımında %81,94 ile Oligochaeta bireylerinin en baskın grubu oluşturduğu, bu grubu Chironomidae (%17,90 ve Ceratopogonidae (%0,16 larvalarının takip ettiği saptanmıştır. Tespit edilen grupların istasyonlara göre oransal dağılımlarında ise, 1. istasyonun en zengin (%28,71, 4. istasyonun en fakir (%12,77 istasyon olduğu gözlenmiştir

The influence of Eucalyptus plantations on the macrofauna associated with Salvinia auriculata in Southeast Brazil

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M. CALLISTO

Full Text Available The influence of Eucalyptus plantations on the structure and composition of macroinvertebrate communities associated with the aquatic fern Salvinia auriculata Aublet were investigated in a high altitude lake bordered by either secondary Atlantic forest or Eucalyptus plantations. Comparisons of the diversity of Chironomidae (Diptera, Insecta larvae in the littoral zone between these two vegetation types showed higher diversity of larvae in waters bordered by Eucalyptus. The results demonstrated that the predominance of carnivorous taxa among the macroinvertebrate fauna appears to be the major controlling factor for limiting diversity in lake areas bordered by Eucalyptus.

The influence of Eucalyptus plantations on the macrofauna associated with Salvinia auriculata in Southeast Brazil

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CALLISTO M.

2002-01-01

Full Text Available The influence of Eucalyptus plantations on the structure and composition of macroinvertebrate communities associated with the aquatic fern Salvinia auriculata Aublet were investigated in a high altitude lake bordered by either secondary Atlantic forest or Eucalyptus plantations. Comparisons of the diversity of Chironomidae (Diptera, Insecta larvae in the littoral zone between these two vegetation types showed higher diversity of larvae in waters bordered by Eucalyptus. The results demonstrated that the predominance of carnivorous taxa among the macroinvertebrate fauna appears to be the major controlling factor for limiting diversity in lake areas bordered by Eucalyptus.

Metriocnemus carmencitabertarum, een nieuwe dansmug voor Nederland (Diptera: Chironomidae)

NARCIS (Netherlands)

Kuper, J.T.; Moller Pillot, H.K.M.

2012-01-01

In augustus 2011 werd een larve van een dansmug gevonden in een emmer onder een dakgoot in Appingedam. Na uitkweken bleek het te gaan om Metriocnemus carmencitabertarum, een nieuwe soort voor Nederland. In het buitenland komt deze soort voor in met water gevulde natuurlijke kommen in rotsen en

Chironomus polonicus sp. n. (Diptera: Chironomidae) from southern Poland.

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Michailova, Paraskeva; Kownacki, Andrzej; Langton, Peter H

2013-01-10

The paper describes larval, pupal and adult morphology as well as the karyotype of Chironomus polonicus sp. n. from southern Poland. The material has been obtained from reared egg masses collected in Bolesław pool, near Kraków. The species belongs to the pseudothummi cytocomplex with 2n = 8 and chromosome arm combinations AE, BF, CD, G. Several homozygous inversions distinguish arm A of the new species from that of C. pseudothummi Strenzke. Arm F is similar to that of C. aprilinus Meigen and differs from it by few steps of homozygous inversions. Few morphological differences in the pupa and adult are also presented.

A new species of Dicrotendipes (Diptera: Chironomidae) from Florida.

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Epler, J H

2016-12-14

A new species of Dicrotendipes is described in all life stages from Florida. Adults of this new species are nearly identical to D. modestus (Say); pupae are similar to D. modestus, D. neomodestus (Malloch) and D. tritomus (Kieffer); while the larvae are unique and were keyed by Epler (1992, 1995, 2001) as Dicrotendipes sp. A. The taxonomic status of D. modestus and D. pulsus (Walker) is discussed.

Karyotype and chromosomal polymorphism of Camptochironomous tentans (diptera, chironomidae)

International Nuclear Information System (INIS)

Sejsebaev, A.T.; Bakhtin, M.M.; Rakhimbaeva, K.T.

2000-01-01

Particular features of chromosomal polymorphism and cytogenetic differentiations have been studied in three natural populations of Camptochironomous tentans affecting the Semipalatinsk test site. For the first time C. tentans population from water-bodies of the Degelen mountain massif was found to contain a unique rarely observed inverse sequence of chromosomal disks (p'ten B85, p'ten D3, p'ten Ck, p'ten FK) and a series of special homozygous (p'ten C1.1; p'ten D2.2) and heterozygous (p'ten B1.5; p'ten D1.2; p'ten D1.3; p'ten F1.3; p'ten F1K) inversions which could be the result of Chironomini adaptation to the radioactive environment. (author)

The rainy season increases the abundance and richness of the aquatic insect community in a Neotropical reservoir

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HS Santana

Full Text Available Alterations in aquatic systems and changes in water levels, whether due to rains or dam-mediated control can cause changes in community structure, forcing the community to readjust to the new environment. This study tested the hypothesis that there is an increase in the richness and abundance of aquatic insects during the rainy season in the Serra da Mesa Reservoir, with the premise that increasing the reservoir level provides greater external material input and habitat diversity, and, therefore, conditions that promote colonization by more species. We used the paired t test to test the differences in richness, beta diversity, and abundance, and a Non-metric Multidimensional Scaling (NMDS was performed to identify patterns in the community under study. Additionally, Pearson correlations were analyzed between the richness, abundance, and beta diversity and the level of the reservoir. We collected 35,028 aquatic insect larvae (9,513 in dry period and 25,515 in the rainy season, predominantly of the Chironomidae family, followed by orders Ephemeroptera, Trichoptera, and Odonata. Among the 33 families collected, only 12 occurred in the dry season, while all occurred in the rainy season. These families are common in lentic environments, and the dominance of Chironomidae was associated with its fast colonization, their behavior of living at high densities and the great tolerance to low levels of oxygen in the environment. The hypothesis was confirmed, as the richness, beta diversity, and abundance were positively affected by the increase in water levels due to the rainy season, which most likely led to greater external material input, greater heterogeneity of habitat, and better conditions for colonization by several families.

The rainy season increases the abundance and richness of the aquatic insect community in a Neotropical reservoir.

Science.gov (United States)

Santana, H S; Silva, L C F; Pereira, C L; Simião-Ferreira, J; Angelini, R

2015-01-01

Alterations in aquatic systems and changes in water levels, whether due to rains or dam-mediated control can cause changes in community structure, forcing the community to readjust to the new environment. This study tested the hypothesis that there is an increase in the richness and abundance of aquatic insects during the rainy season in the Serra da Mesa Reservoir, with the premise that increasing the reservoir level provides greater external material input and habitat diversity, and, therefore, conditions that promote colonization by more species. We used the paired t test to test the differences in richness, beta diversity, and abundance, and a Non-metric Multidimensional Scaling (NMDS) was performed to identify patterns in the community under study. Additionally, Pearson correlations were analyzed between the richness, abundance, and beta diversity and the level of the reservoir. We collected 35,028 aquatic insect larvae (9,513 in dry period and 25,515 in the rainy season), predominantly of the Chironomidae family, followed by orders Ephemeroptera, Trichoptera, and Odonata. Among the 33 families collected, only 12 occurred in the dry season, while all occurred in the rainy season. These families are common in lentic environments, and the dominance of Chironomidae was associated with its fast colonization, their behavior of living at high densities and the great tolerance to low levels of oxygen in the environment. The hypothesis was confirmed, as the richness, beta diversity, and abundance were positively affected by the increase in water levels due to the rainy season, which most likely led to greater external material input, greater heterogeneity of habitat, and better conditions for colonization by several families.

Chironomus alchichica sp. n. (Diptera: Chironomidae) from Lake Alchichica, Mexico.

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Acosta, Raúl; Prat, Narcís; Ribera, Carles; Michailova, Paraskeva; Hernández-Fonseca, María Del Carmen; Alcocer, Javier

2017-12-15

Morphological analysis of all developmental stages (except female), mitochondrial DNA sequences from cytochrome c oxidase subunit I (cox1) and cytological analysis of the polytene chromosomes were used to describe a new species of Chironomus found in the littoral and profundal zones of an endorheic, warm-monomictic lake in Mexico. Male imago is distinguished by the shape of superior volsella and by an antennal and bristle ratio lower than two. The pupa is characterized by the spur morphology of abdominal segment VIII. There is also a continuous row of hooklets on abdominal segment II. The larva is distinguished by a combination of antenna, mentum, mandible, and pecten epipharyngis characteristics, and abdominal ventral tubules. Molecular and cytological analysis supported the morphological differences found. The maximum likelihood tree obtained shows that Chironomus alchichica sp. n. clusters together with Chironomus decorus-group sp. 2 Butler et al. (1995) (bootstrap support = 92%), but genetic p-distances within C. alchichica sp. n. (0.004) were lower than the p-distances between other species of the decorus-group (C. decorus-group sp. 2, Chironomus bifurcatus Wülker et al., 2009 and Chironomus maturus Johannsen, 1908) confirming that it is a different species. The new species belongs to thummi cytocomplex, (decorus-group), with chromosome set- 2n = 8 and chromosome arm combinations: AB CD EF G. Karyologically, the species is closest to Chironomus riihimaekiensis Wülker (1973). This species has very compact salivary gland chromosomes with well heterochromatinized centromere regions in chromosomes AB CD G. Several fixed homozygous inversions distinguish arm A of the species from that of C. riihimaekiensis. Arm E differs from that of C. riihimaekiensis by simple fixed homozygous inversion. Some similarities in band sequences of this arm were found with species from the decorus-group as Chironomus blaylocki Wülker et al., 2009 and C. bifurcatus (decorus-group). The position of the key constrictions in chromosome G: Nucleolar organizer (NOR) and Balbiani rings (BRs) is similar to the species of decorus-group. C. alchichica sp. n. has been found in soft sediments rich in organic matter in well mineralized waters (where conductivity >10 mS cm-1) and with a high pH (≥9). The profundal zone is inhabited only during the mixing period, when dissolved oxygen is present.

Review of genus Pseudorthocladius Goetghebuer, 1943 (Diptera, Chironomidae from China

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Jing Ren

2014-03-01

Full Text Available The genus Pseudorthocladius Goetghebuer, 1943 from China, including 12 species, is reviewed. Five new species, P. (P. binarius sp. n., P. (P. cylindratus sp. n., P. (P. digitus sp. n., P. (P. ovatus sp. n. and P. (P. paucus sp. n. are described and illustrated as adult males. P. (P. cristagus Stur & Sæther, 2004, P. (P. jintutridecima (Sasa, 1996, P. (P. macrovirgatus Sæther & Sublette, 1983, P. (P. morsei Sæther & Sublette, 1983, P. (P. uniserratus Sæther & Sublette, 1983, P. (L. wingoi Sæther & Sublette, 1983 are newly recorded in Oriental Region. A key to the males of Pseudorthocladius in China is presented.

Evaluación de la calidad de las aguas del estero Limache (Chile central, mediante bioindicadores y bioensayos Water quality assessment in the Limache stream (central Chile, using bioindicators and bioassays

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Salomé Córdova

2009-01-01

Full Text Available Se evaluó la calidad de las aguas del estero Limache en cinco estaciones de muestreo en el período de bajo caudal. En cada estación se colectaron macroinvertebrados acuáticos, se midió in situ pH, conductividad, oxígeno disuelto, y sólidos disueltos totales. En el laboratorio se determinó la demanda biológica de oxígeno (DBO, fósforo total y nitrógeno total. También se determinó la toxicidad del agua mediante bioensayos con la microalga Pseudokirchrneriella subcapitata. Se determinaron 33 familias de macroinvertebrados, los taxa dominantes fueron Dugessidae, Oligochaeta y Chironomidae. Se encontró correlación significativa entre el índice biótico de familias (ChIBF, la conductividad eléctrica y los sólidos disueltos totales (r = 0,92; p The water quality in the Limache stream was evaluated at five sampling stations during the pe-riod of low water flow. At each station, aquatic macroinvertebrates were collected and the following parame-ters were measured in situ: pH, conductivity, dissolved oxygen, and total dissolved solids. The biological oxy-gen demand, total phosphorus, and total nitrogen were determined in the laboratory. Water toxicity was deter-mined through toxicity bioassays with the microalga Pseudokirchrneriella subcapitata. Thirty-three macroin-vertebrate families were found and the dominant taxa were Dugessidae, Oligochaeta and Chironomidae. A significant correlation was found among the Family Biotic índex ChFBI, conductivity, and total dissolved solids (r = 0.92; p < 0.05. Species diversity was lowest, as was the growth rate of P. subcapitata, at the stations with the greatest anthropogenic activity and in the discharge zone of a domestic wastewater treatment plant.

Macrozoobenthos in the subarctic river Tenojoki as an environmental indicator. Tenojoen pohjaelaeimistoe ympaeristoen laadun kuvaajana

Energy Technology Data Exchange (ETDEWEB)

Lax, H.G.; Koskenniemi, E.; Sevola, P.; Bagge, P.

1993-01-01

The macrozoobenthos of the subarctic river Tenojoki and some of its tributaries was studied in June and September 1989 as a part of the environmental monitoring programme. The river (F = 16 386 km[sup 2], length 300 km, L = 2.4 %, Q varies between 30-400 m[sup 3]/s) is situated on the Finnish-Norwegian border and is characterized by sand bottoms interrupted by shorter reaches of gravel and stone bottoms. The water is usually clear (colour < 40 mg Pt/l) and oligotrophic (tot-P < 10 [mu]g/l). The bottom fauna was sampled from 9 stations in the main river and from one station in each of the 5 major tributaries. The sampling methods used were: kick-sampling and imago hand netting from all stations, colonization substrates (stone baskets and bricks) at 9 stations in the main river. The tax a number of the kick-samples varied from 10-15/station in spring (totally 51 taxa) and from 15-25/station in autumn (totally 69 taxa). In spring the river margin (depth 0-25 cm) seemed to be an important habitat for many species especially in the upper parts of the river. In autumn most of the species occurred on deeper bottoms (depth 50-100 cm). The most common feeding types in spring were the collectors (Amaletus inopinatus, Chironomidae) and in autumn the scrapers (Elmidae, Baetidae, Hydroptllidae) and collectors (Chironomidae). The pollution index (LongScoreSystem) indicated that the conditions in the lower part of the main river was more stressing for the bottom fauna than in the upper part. But up to now it seems as if the organic pollution from settlements have had only positive effects on the benthic community

Sphagnum mosses as a microhabitat for invertebrates in acidified lakes and the colour adaptation and substrate preference in Leucorrhinia dubia (Odonata, Anisoptera)

Energy Technology Data Exchange (ETDEWEB)

Henrikson, B.-I. (Dept. of Zoology, Sect. of Animal Ecology, Univ. of Goeteborg, Goeteborg (Sweden))

1993-01-01

The increase of peat mosses, Sphagnum spp., in acidified lakes leads to a changed microhabitat structure for benthic invertebrates. The importance of this change was investigated for some benthic invertebrates. Comparisons between quantitative samples of Sphagnum and debris within the acidified Lake Stora Haestevatten, in the Lake Gaardsjoen catchment of SW Sweden, showed significantly higher abundances of Chironomidae, Ceratopogonidae, Odonata, Trichoptera, Cladocera and Argyroneta aquatica (Araneae) in Sphagnum. For chironomidae and Cladocera the differences were tenfold. Special reference was made to the libellulid Leucorrhinia dubia which is common in acid lakes. In a laboratory test, late instar larvae of L. dubia were shown to change colour to correspond to the brown and green colour of Sphagnum. This result was completed with a field test where larvae of L. dubia were significantly more common in Sphagnum of the same colour as the larvae. The ability to change colour may have an adaptive value when coexisting with visual predators. Small larvae were more prevalent in Sphagnum and they also showed a preference for this substrate in the laboratory test. Laboratory tests showed mediumsized larvae preferred Sphagnum. Larvae of L. dubia were more successful as predators on Asellus aquaticus in Sphagnum substrate than in debris in the laboratory test. Laboratory predation tests with notonecta glauca, Corixa dentipes, Acilius sulcatus, Hyphydrus ovatus and L. dubia showed that they could all feed on larvae of L. dubia. The complex habitat structure of Sphagnum is probably the reason for the high abundance of invertebrates since it may serve as both shelter against predation and as foraging sites. it is probably important as a key habitat for young instars of, for example, L. dubia. In lakes with large Sphagnum mats, L. dubia can coexist with fish. The expansion of Sphagnum due to acidification will probably benefit many acid-tolerant invertebrate species. (au)

DIET OF DIRECT-DEVELOPING FROGS (ANURA: CRAUGASTORIDAE: Pristimantis FROM THE ANDES OF WESTERN COLOMBIA

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Juan Carlos GARCIA-R

2015-01-01

Estudiamos la dieta de 15 especies de ranas montanas del género Pristimantis (Craugastoridae en la Cordillera Occidental de Colombia para determinar su variación, amplitud y traslape de nicho. En los contenidos estomacales e intestinales de 154 especímenes se identificaron 499 presas que fueron organizadas en 74 categorías diferentes. Las 15 categorías de presas más comunes representaron el 65 % de la dieta. Las familias de invertebrados Isotomidae, Chironomidae, Formicidae y Tipulidae fueron las más abundantes, representando el 32 % de la dieta de las ranas. Diez de las 15 especies de ranas presentaron al menos un ítem de Araneae. Coleoptera y Tipulidae fueron otras categorías frecuentemente encontradas en los tractos digestivos de las ranas (nueve especies de ranas presentaron estos ítems,  seguidas de Acari y Carabidae (ocho especies. En general, los escarabajos fueron encontrados en los tractos gastrointestinales de todas las especies, excepto en P. quantus, pero este resultado debe tratarse con precaución porque solo un individuo de esta especie fue capturado. Pristimantis hectus mostró una dieta especializada consumiendo principalmente dípteros de la familia Chironomidae, mientras que las especies restantes mostraron una dieta generalista. Pristimantis palmeri presentó superposiciones de nicho con P. erythropleura (Фjk = 0,69, P. myops (Фjk = 0,64, y P. orpacobates (Фjk = 0,64. Nuestros resultados sugieren que la mayoría de las especies estudiadas son generalistas que se alimentan de manera oportunista de dípteros, arácnidos, colémbolos, coleópteros e himenópteros. Aquí, reportamos la dieta de especies montanas de Pristimantis y discutimos los resultados con datos de otros estudios en especies relacionadas de regiones montanas y tierras bajas

Feeding ecology of arctic-nesting sandpipers during spring migration through the prairie pothole region

Science.gov (United States)

Eldridge, J.L.; Krapu, G.L.; Johnson, D.H.

2009-01-01

We evaluated food habits of 4 species of spring-migrant calidrid sandpipers in the Prairie Pothole Region (PPR) of North Dakota. Sandpipers foraged in several wetland classes and fed primarily on aquatic dipterans, mostly larvae, and the midge family Chironomidae was the primary food eaten. Larger sandpiper species foraged in deeper water and took larger larvae than did smaller sandpipers. The diverse wetland habitats that migrant shorebirds use in the PPR suggest a landscape-level approach be applied to wetland conservation efforts. We recommend that managers use livestock grazing and other tools, where applicable, to keep shallow, freshwater wetlands from becoming choked with emergent vegetation limiting chironomid production and preventing shorebird use.

Aquatic insect populations in the MUDA rice agroecosystem

International Nuclear Information System (INIS)

Rozilah Ismail; Ahyaudin Ali

2002-01-01

Periodic sampling of aquatic insects was carried out in an experimental plot of the Muda rice agroecosystem. The study which was conducted from August to December 1995, investigated the impact of the pesticides Broadox and Trebon on aquatic insect populations during the rice growing period. The results indicated that there was no significant difference in abundance and diversity of aquatic insects between the treated and non-treated area. The four dominant aquatic insects were from the families; Chironomidae, Dysticidae, Corixidae and Belostomatidae. Water temperature and dissolved oxygen showed changes throughout the rice growing season and the values of these parameters decreased gradually towards the end of the rice growing season in January when the rice plants were maturing. (Author)

Feeding ecology of waterfowl wintering on evaporation ponds in California

Science.gov (United States)

Euliss, N.H.; Jarvis, R.L.; Gilmer, D.S.

1991-01-01

We examined the feeding ecology of Northern Pintails (Anas acuta), Northern Shovelers (A. clypeata), and Ruddy Ducks (Oxyura jamaicensis) wintering on drainwater evaporation ponds in California from 1982 through 1984. Pintails primarily consumed midges (Chironomidae) (39.3%) and widegeongrass (Ruppia maritima) nutlets (34.6%). Shovelers and Ruddy Ducks consumed 92.5% and 90.1% animal matter, respectively. Water boatmen (Corixidae) (51.6%), rotifers (Rotatoria) (20.4%), and copepods (Copepoda) (15.2%) were the most important Shoveler foods, and midges (49.7%) and water boatmen (36.0%) were the most important foods of Ruddy Ducks. All three species were opportunistic foragers, shifting their diets seasonally to the most abundant foods given their behavioral and morphological attributes.

Sobre um novo gênero neotrópico da subfamília Tanypodinae (Diptera, Chironomidae On a new neotropical genus of the subfamily Tanypodinae (Diptera, Chironomidae

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Sebastião José de Oliveira

1992-01-01

Full Text Available A new neotropical genus and a new species of a non-biting midge for the subfamily Tanypodinae from Brazil are described. The new genus is near Tanypus Meigen, 1803 and Procladius Skuse, 1889, but differs of both by wings and male terminalia.

Contamination of harbor sediments in the eastern Gulf of Finland (Neva Bay), Baltic Sea

Energy Technology Data Exchange (ETDEWEB)

Ussenkov, S.M. [Dept. of Lithology and Marine Geology, Faculty of Geology, St. Petersburg State Univ. (Russian Federation)

1997-11-01

The areal distribution of oil products and various trace metals have been studied in bottom surface deposits from the harbors of Neva Bay. The data of contents were normalized to natural background concentrations. Also the size and biomass of benthos groups were analyzed. The results show clearly that industrial discharges have elevated levels of contamination in the sediments. Few efficient measures against environmental contamination have been taken. The sediments contain very high concentrations of oil products and such heavy metals as Hg, Pb, Cu, and Zn. The benthic organisms most sensitive to heavy metal contamination are Chironomidae. The dredging and dumping of the contaminated deposits can lead to secondary contamination of the Gulf of Finland and the Baltic proper. (orig.)

MACROZOOBENTHIC COMMUNITIES STRUCTURE CHARACTERISTIC OF CERTAIN TRIBUTARIES OF THE SIRET RIVER FROM HARGHITA, MARAMUREŞ AND VRANCEA MOUNTAINS AND MOLDOVEI PLATEAU

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Elena-Andreea GHIBUŞI

2012-01-01

Full Text Available 35 qualitative macrozoobentonic samples were collected in 2011 from many Siret river tributaries coming from the Harghita Mountains (5 stations, Maramureş Mountains (14 stations, Moldavian Plateau (4 stations and Vrancea Mountains (12 stations. Laboratory analysis of samples revealed the existence of the following 15 groups of benthic invertebrates: Ephemeroptera, Plecoptera, Trichoptera, Oligochaeta, Diptera (Chironomidae, Simuliidae, Ceratopogonidae, Limoniidae, Gastropoda, Bivalva, Coleoptera, Acarina, Odonata, Hirudinea, Isopoda, Heteroptera, Turbellariata and Collembola. Groups that have the highest frequencies were mayflies and dipterans (each with a frequency of 97.1%, followed by caddisflies (80%, amphipods (68.6%, oligochaetes (57.1% and stoneflies (54.3%. Presence of sensitive groups to water quality degradation (Ephemeroptera, Trichoptera and Plecoptera with high frequency shows good quality water at most stations investigated.

Feeding of two Cichlidae species (Perciformes in an hypertrophic urban lake

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Yafe Alejandro

2002-01-01

Full Text Available Diet of two cichlid species, Cichlasoma facetum (Jenyns, 1842, and Gymnogeophagus rhabdotus Hensel, 1870, was studied in Rodó Lake, an urban hypertrophic lake in Uruguay. The stomach contents from 192 individuals of C. facetum and 202 of G. rhabdotus, obtained through seasonal sampling in the year 2000, were analyzed. The occurrence frequency and the alimentary importance index of each food item were calculated for each season and size class in both species. Cichlasoma facetum fed upon insects (mainly chironomid larvae and pupae, fish (Cnesterodon decemmaculatus Jenyns, 1842, and vegetals (algae, periphyton and macrophytes debris; large individuals also fed upon the freshwater shrimp Palaemonetes argentinus Nobili, 1901. Gymnogeophagus rhabdotus consumed zooplankton (mainly copepods, vegetals (algae and detritus and Chironomidae larvae in a lesser extent.

Invertebrate communities associated with Bangia atropurpurea and Cladophora glomerata in western Lake Erie

Science.gov (United States)

Chilton, E.W.; Lowe, R.L.; Schurr, K.M.

1986-01-01

The appearance of the marine alga Bangia atropurpurea (Rhodophyta) in Lake Erie has been followed by its rapid dispersal throughout the eulittoral zone of the lake. Bangia was extensively sampled to determine its suitability as a habitat for littoral organisms. Present data indicate that the only organisms capable of maintaining populations on Bangia filaments are larval Chironomidae. Cladophora supports a larger and more diverse community. It is concluded that the mucilaginous cell wall of Bangia provides a less stable substrate for attached or clinging organisms than does the cellulose cell wall of Cladophora. The presence of Bangia in the littoral zone of Lake Erie results in a reduction of the quantity and diversity of algal epiphytes and may negatively impact the littoral food web.

Radioactive background in principal components of the Jihlava River ecosystem

International Nuclear Information System (INIS)

Stanek, Z.; Penaz, M.; Trnkova, J.; Wohlgemuth, E.

1980-01-01

In 1976 through to 1978, the radioactive background was investigated in the various components of the Jihlava River ecosystem. The investigations involved total β-activity, 40 K, residual β-activity, sup(nat)U, 226 Ra and, in some of the samples, also 210 Pb, 90 Sr and 137 Cs. The analyses included water, bottom sediments, samples of aquatic macrophytes (Batrachium fluitans), samples of aquatic invertebrates (Herpobdella octoculata, Anodonta cygnea, Asellus aquaticus, larval Ephemeroptera, larval Trichoptera, exuviae of pupae of Chironomidae) and samples of the tissues of 8 species of fishes (Salmo trutta m. fario, Cyprinus carpio, Rutilus rutilus, Leuciscus cephalus, Leuciscus leuciscus, Chondrostoma nasus, Gobio gobio, Barbus barbus). The activity of the radionuclides under study corresponded to the values reported for uncontaminated streams. (author)

Diversity of the chironomidae (diptera) of river Niger related to water ...

African Journals Online (AJOL)

Organic pollution and nutrients loading were the main factors explaining the differences in spatial distribution. Some taxa, e.g. Chironomus gr. plumosus and Microchironomus sp. are positively correlated to those factors, while others as Tanytarsini, Nilodosis sp., Micropelopinae and Procladius sp. are negatively correlated.

Diplosmittia caribensis, a new Orthocladiinae (Diptera: Chironomidae) from the Dominican Republic.

Science.gov (United States)

Wiedenbrug, Sofia; Silva, Fabio Laurindo Da

2016-04-11

The genus Diplosmittia was erected by Sæther (1981) based on Diplosmittia harrisoni from St. Lucia and St. Vincent in the British West Indies. Prior to the present study the genus comprised nine species, all except D. carinata Sæther were known only from Neotropical Region (Ashe & O'Connor, 2012). During sampling in the surroundings of a highly organic polluted river, in the National Botanical Garden in Santo Domingo, Dominican Republic, the present second author collected several imagines of Diplosmittia that did not fit any taxon treated in the recent review of the genus (Pinho et al. 2009). In the present paper, the male of this new species is described and illustrated.

De larven der Nederlandse Chironomidae (Diptera) Deel C: Autoekologie en verspreiding

NARCIS (Netherlands)

Moller Pillot, H.K.M.; Buskens, R.F.M.

1990-01-01

Chironomid larvae occur in nearly all kinds of fresh and brackish waters as well as in semiterrestrial environments. The authors treat the autecology and the distribution of more than 200 taxa in the Netherlands. Except for the tribe Tanytarsini (Chironominae) all the subfamilies occurring in the

New gnat-midge species chironomus degelenus i sp. n. (diptera chironomidae)

International Nuclear Information System (INIS)

Sejsebaev, A.T.; Bakhtin, M.M.; Siirin, M.T.

2001-01-01

For the first time the morphology of larvae, pupae, imago and karyotype of Chironomus degelenus I Sp. n. collected from Water-Body D-3-3 of the Degelen Mountain Massif has been described. The larvae have a species-specific structure and color of the head capsule, ventral-mental blades, and mandibula hamuli. The male gnat is characterized for grid structure in IX tergite. The karyotype of C. degelenus I Sp. n. has the following combination of chromosome arms: AB, CD, EF, and G (thummi complex), which is typical for Chironomus species. It was concluded that the origin of the new species of Chironomus degelenus I Sp. N. is related to the long-term genetic processes of Chironomini adaptation to the elevated radiation background level. (author)

Some new records of chironomids (Diptera: Chironomidae from the Czech Republic

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Bitušík Peter

2016-09-01

Full Text Available Six chironomid species: Paraboreochlus minutissimus (Strobl, 1894, Trissopelopia longimanus (Staeger 1839, Boreoheptagyia monticola (Serra-Tosio, 1964, Cricotopus (s.str. similis Goetghebuer 1921, Heleniella serratosioi Ringe, 1976, Krenosmittia camptophleps (Edwards, 1929, were recorded in Czech Republic for the first time. The pupal exuviae were collected in July 2009 from Otava River in the vicinity of Rejštejn village in the central part of the Bohemian Forest. The notes on known distribution and ecology of the species are presented.

Two New and Four Unrecorded Species of Chironomidae (Diptera in Korea

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Han-Il Ree

2012-01-01

Full Text Available Chironomid adults attracted to the light were collected at Dangsan-ri, Muju-eup, Muju-gun, Jeollabuk-do in 2008-2009. Two new species, Lymnophyes parakitanaides sp. nov. and Parakiefferiella mujuensis sp. nov., and four unrecorded species, Cardiolcladius capusinus, Thienemanniella vittata, Conchapelopia pallidula, and Nilotanypus dubius were found and are described with illustrations. The genera Thienemanniella and Nilotanypus have not been previously reported in Korea. The genus Thienemanniella which belongs to Orthocladiinae is characterized by the radial sector retracted and apically fused with the costa, and the genus Nilotanypus which belongs to Tanypodinae is characterized by the absence of R2+3, pubescent eyes and lack of the gonocoxal lobes.

Feeding and trophic ecomorphology of Satanoperca pappaterra (Pisces, Cichlidae in the Manso Reservoir, Mato Grosso State, Brazil

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Norma Segatti Hahn

2005-11-01

Full Text Available The aim of this work was to evaluate the relationship between diet and features of the trophic ecomorphology of Satanoperca pappaterra (Heckel, 1840 in an impacted environment. Samples were collected from March 2000 to February 2003 in Manso Reservoir, Cuiabá River, Mato Grosso State. Analysis of 93 stomachs contents showed that food resources associated with the substrate, such as plant remains, detritus, fish scales and Chironomidae larvae, dominated the diet. Consequently this species was characterized as a detritivorous-invertivorous. However, individuals collected in 2003 showed a greater selection of benthic organisms in relation to previous periods. Morphological structures such as position of the mouth, form of the lips, gill rakers and pharyngeal teeth, in addition to the length of the intestine, showed specializations correlated with the diet. However, as long as the food was associated with the substrate, it seemed to be selected according to its abundance in the environment.O objetivo deste estudo foi descrever e avaliar as relações entre dieta e traços da ecomorfologia trófica de Satanoperca pappaterra (Heckel, 1840 em ambiente impactado. As coletas foram realizadas no reservatório de Manso, MT., entre março/2000 a fevereiro/2003. A análise de 93 estômagos, mostrou que recursos alimentares associados ao substrato, tais como restos vegetais, detritos, escamas e larvas de Chironomidae, predominaram na dieta, caracterizando esta espécie como detritívora-invertívora. Entretanto, indivíduos coletados em 2003 mostraram maior seleção de organismos bentônicos em relação aos períodos anteriores. As estruturas morfológicas, como posição da boca, forma dos lábios, rastros branquiais e dentes faríngeos, além do comprimento do intestino mostram um certo grau de especialização ao tipo de dieta. No entanto, o alimento, desde que associado ao substrato, parece ser selecionado de acordo com sua abundância no ambiente.

An Asiatic Chironomid in Brazil: morphology, DNA barcode and bionomics

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Gizelle Amora

2015-07-01

Full Text Available In most freshwater ecosystems, aquatic insects are dominant in terms of diversity; however, there is a disproportionately low number of records of alien species when compared to other freshwater organisms. The Chironomidae is one aquatic insect family that includes some examples of alien species around the world. During a study on aquatic insects in Amazonas state (Brazil, we collected specimens of Chironomidae that are similar, at the morphological level, to Chironomus kiiensis Tokunaga and Chironomus striatipennis Kieffer, both with distributions restricted to Asia. The objectives of this study were to provide morphological information on this Chironomus population, to investigate its identity using DNA barcoding and, to provide bionomic information about this species. Chironomus DNA barcode data were obtained from GenBank and Barcode of Life Data Systems (BOLD and, together with our data, were analyzed using the neighbor-joining method with 1000 bootstrap replicates and the genetic distances were estimated using the Kimura-2-parameter. At the morphological level, the Brazilian population cannot be distinguished either from C. striatipennis or C. kiiensis, configuring a species complex but, at the molecular level our studied population is placed in a clade together with C. striatipennis, from South Korea. Bionomic characteristics of the Brazilian Chironomus population differ from the ones of C. kiiensis from Japan, the only species in this species complex with bionomic information available. The Brazilian Chironomus population has a smaller size, the double of the number of eggs and inhabits oligotrophic water, in artificial container. In the molecular analysis, populations of C. striatipennis and C. kiiensis are placed in a clade, formed by two groups: Group A (which includes populations from both named species, from different Asiatic regions and our Brazilian population and Group B (with populations of C. kiiensis from Japan and South Korea

Sucessão de invertebrados durante o processo de decomposição de duas plantas aquáticas (Eichhornia azurea e Polygonum ferrugineum - DOI: 10.4025/actascibiolsci.v28i2.1017 Succession of invertebrates during the decomposition process of two aquatic plants (Eichhornia azurea and Polygonum ferrugineum - DOI: 10.4025/actascibiolsci.v28i2.1017

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Alexandre Monkolski

2006-03-01

Full Text Available A colonização de invertebrados durante o período de 56 dias de decomposição de duas espécies de plantas aquáticas (Eichhornia azurea e Polygonum ferrugineum foi investigada para determinar o papel de macroinvertebrados no processo de fragmentação da folha. Durante a análise do material, foi constatado um total de 2096 invertebrados, associados a E.azurea e 6154 invertebrados associados a P. ferrugineum, identificados dentro de 18 táxons, com predominância de larvas de Diptera da família Chironomidae, seguido por espécimes de Oligochaeta, microcrustáceos como Cladocera e Copepoda. Em ambas as plantas, os macroinvertebrados mostraram um aumento significativo de densidade ao longo do processo de decomposição, o que provavelmente está associado à perda de compostos fenólicos. Os resultados sugerem que as espécies de macrófitas apresentam associações específicas com seus consumidores, ou seja, o processo de sucessão da colonização torna-se diferenciado de acordo com as características fenológicas da planta.The invertebrate colonization was investigated during 56-day decomposition of two macrophytes species (Eichhornia azurea and Polygonum ferrugineum. The aim was to determine the role of macroinvertebrates in the process of leaf fragmentation. During material analysis, 2096 invertebrates were associated with E.azurea and 6154 were associated with P. ferrugineum, identified in 18 taxons, with predominance of Diptera larvae (Chironomidae family specially, followed by Oligochaeta species and microcrustaceans such as Cladocera and Copepoda. In both macrophytes the macroinvertebrates showed a significant increase of density through the process of decomposition, which is probably associated with the loss of phenolic compounds. Results suggest that macrophytes specimens show specific associations with their consumers, i.e., the succession process of colonization becomes singular according to the phenolic characteristics of the

Some aspects of the distribution and dynamics of the benthic macroinvertebrate groups from Nimăieşti valley river

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CUPŞA Diana

2005-09-01

Full Text Available In the Nimăieşti Valley river we found in a number of four sample sites a community of benthic macroinvertebrates represented by Oligochaeta, Ephemeroptera larva, Trichoptera larva, Chironomida larva and Hidracarina species. The communities structure vary depending on season and the sampling site acording to the water quality and trophic condition of the substrate. The greatest diversity was recorded during the summer months (may-august and comparing the sample sites, we found that the first three sampling sites are very similar from the point of view of the macroinvertebrate community, but the fourth sampling site the community is different because the river pases through the town of Beiuş and as a consequence the water quality is lower that at the other three sample sites.

New records of non-biting midges (Diptera: Chironomidae, Orthocladiinae from Mallorca, Spain

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Viktor Baranov

2016-09-01

Full Text Available Ten species of non-biting midges belonging to the subfamily Orthocladiinae were found in samples from predominantly madicolous habitats in Mallorca, Spain. One species, Bryophaenocladius nidorum (Edwards, 1929, has not previously been recorded from Spain, while Smittia pratorum (Goetghebuer, 1927, Bryophaenocladius inconstans (Brundin, 1947, Orthocladius (O. maius Goetghebuer, 1942, Paracladius conversus (Walker, 1856 and Paraphaenocladius impensus (Walker, 1856 are recorded for the first time from the Balearic Islands.

Inconsistency in the analysis of morphological deformities in chironomidae (Insecta: Diptera) larvae.

Science.gov (United States)

Salmelin, Johanna; Vuori, Kari-Matti; Hämäläinen, Heikki

2015-08-01

The incidence of morphological deformities of chironomid larvae as an indicator of sediment toxicity has been studied for decades. However, standards for deformity analysis are lacking. The authors evaluated whether 25 experts diagnosed larval deformities in a similar manner. Based on high-quality digital images, the experts rated 211 menta of Chironomus spp. larvae as normal or deformed. The larvae were from a site with polluted sediments or from a reference site. The authors revealed this to a random half of the experts, and the rest conducted the assessment blind. The authors quantified the interrater agreement by kappa coefficient, tested whether open and blind assessments differed in deformity incidence and in differentiation between the sites, and identified those deformity types rated most consistently or inconsistently. The total deformity incidence varied greatly, from 10.9% to 66.4% among experts. Kappa coefficient across rater pairs averaged 0.52, indicating insufficient agreement. The deformity types rated most consistently were those missing teeth or with extra teeth. The open and blind assessments did not differ, but differentiation between sites was clearest for raters who counted primarily absolute deformities such as missing and extra teeth and excluded apparent mechanical aberrations or deviations in tooth size or symmetry. The highly differing criteria in deformity assignment have likely led to inconsistent results in midge larval deformity studies and indicate an urgent need for standardization of the analysis. © 2015 SETAC.

A generic guide to the larvae of the Nearctic Tanytarsini, (Chironomidae:diptera)

Science.gov (United States)

Steiner, J.W.; Doughman, J.S.; Moore, C.R.

1982-01-01

Larvae of the tribe Tanytarsini occur in nearly every aquatic habitat in North America where they act as primary consumers in the food chain. This new taxonomic guide overcomes some deficiencies in existing keys to this tribe and the reviewed and updated taxonomy enables identification of the larvae that may be useful as ecological indicators. Over 2,000 specimens from 26 states were examined, identified and measured in this study. The following genera were included: Stempellinell, Zavrelia, Stempellina, Constempellina, Corynocera, Cladotanytarsus,.. Paratanytarsus, Rheotanytarsus,. Micropsectra, Lauterbornia, Nimbocera, Tanytarsus and Neozavrelia. Photographs illustrate mature larvae of these genera with the exception of Zavrelia and Neozavrelia which are not known to exist in North America. The morphological data, Which are summarized in a table of distinctive characteristics and the dichotomous key, enable identification to genus. Notes on range, habitat and food preference are included, and species identifications are presented where applicable.

A New Species of Corynoneura Winnertz from Oriental China (Diptera: Chironomidae: Orthocladiinae).

Science.gov (United States)

Fang, Xiangliang; Wang, Xinhua; Fu, Yue

2014-11-19

A new species of Corynoneura Winnertz (1846) from Oriental China, C. ecphora sp. n. is described and illustrated as male. A distribution map of adult males in Oriental China is given. A key to known males of Oriental China is provided.

A new species of Parapsectrocladius Cranston (Diptera: Chironomidae: Orthocladiinae) from Patagonia, Argentina.

Science.gov (United States)

Donato, Mariano; Mauad, Melina; Fuentes, María Cecilia

2015-01-21

Parapsectrocladius setosus sp. n. is described and figured as pupa and male imago, based on material collected in Patagonia, Argentina. The male of the new species groups with P. escondido Cranston & Añón Suárez by having the anal point tapering triangular; inferior volsella simple, rounded, without any dorsal ridge and apically blunt. It can be distinguished from P. escondido by the possession of strong setae on the inner margin of inferior volsella. New material of Parapsectrocladius belonging from several localities allows us to emend the generic diagnosis of the adult male, female and larva of Parapsectrocladius, discuss its phylogenetic position and to expand the geographic distribution of P. acuminatus Cranston, P. escondido and P. reissi. Cranston. 

Life-cycle effects of sediment-associated uranium on Chironomus riparius (diptera: chironomidae)

Energy Technology Data Exchange (ETDEWEB)

Dias, V.; Ksas, B.; Camilleri, V.; Bonzom, J.M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

2004-07-01

In aquatic ecosystems, sediments function as reservoir for many of the more persistent chemicals that are introduced into surface waters. Sediments provide a habitat for various benthic macro-invertebrates, which are exposed to sediment-associated chemicals both directly and via food intake. These chemicals may be directly toxic to benthic macro-invertebrates and can be integrated into food chain. Benthic macro-invertebrates play an important role in the ecosystem structure and functioning. In particular, they represent an important component of aquatic food chains. Among the non biologically essential metals, data concerning uranium fate and effects on freshwater benthic invertebrates are sparse. The present study aimed to estimate effects of a chronic uranium exposure on life-cycle traits of Chironomus riparius. To achieve this goal, (i) first instar larvae were exposed to a series of concentrations of uranium via the sediment, and (ii) a number of developmental (e.g. growth) and reproductive (e.g. emergence, fecundity, viability) endpoints, through parental and into F1 generations, were evaluated. Within the framework of ecological risk assessment, these data will help the derivation of a sediment guideline value for uranium that does not currently exist in France or elsewhere due to a lack of toxicity data. (author)

Genotoxic effects of vinclozolin on the aquatic insect Chironomus riparius (Diptera, Chironomidae).

Science.gov (United States)

Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis

2018-01-01

Vinclozolin (Vz) is a pollutant found in aquatic environments whose antiandrogenic effects in reproduction are well known in mammals. Although its reproductive effects have been less studied in invertebrates, other effects, including genotoxicity, have been described. Therefore, in this work, we studied the genotoxic effects of Vz in the freshwater benthic invertebrate Chironomus riparius. DNA damage was evaluated with the comet assay (tail area, olive moment, tail moment and % DNA in tail), and the transcriptional levels of different genes involved in DNA repair (ATM, NLK and XRCC1) and apoptosis (DECAY) were measured by RT-PCR. Fourth instar larvae of C. riparius, were exposed to Vz for 24 h at 20 and 200 μg/L. The Vz exposures affected the DNA integrity in this organism, since a dose-response relationship occurred, with DNA strand breaks significantly increased with increased dose for tail area, olive moment and tail moment parameters. Additionally, the lower concentration of Vz produced a significant induction of the transcripts of three genes under study (ATM, NLK and XRCC1) showing the activation of the cellular repair mechanism. In contrast, the expression of these genes with the highest concentration were downregulated, indicating failure of the cellular repair mechanism, which would explain the higher DNA damage. These data report for the first time the alterations of Vz on gene transcription of an insect and confirm the potential genotoxicity of this compound on freshwater invertebrates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Photoreactivation of RNA in UV-irradiated insect eggs (Smittia SP., Chironomidae, Diptera)

International Nuclear Information System (INIS)

Kalthoff, K.; Urban, K.; Jaeckle, H.

1978-01-01

Two biological effects of UV radiation upon Smittia eggs are observed, both of which seem to be associated with the formation of pyrimidine dimers in the RNA (largely ribosomal) of the eggs. While irradiation of the anterior pole region causes the formation of an aberrant segment pattern (double abdomen induction), irradiation of entire eggs leads to an arrest of their development (inactivation). Both UV effects are photoreversible with different action spectra of the photoreactivating light. A dose rate dependence of the photoreactivation can be observed after both UV effects. The saturating dose rate is about 6 W/m 2 (at 440 nm) after UV induction of double abdomens. Upon UV inactivation, the saturating dose rate level for the photoreactivating light is much higher, and a single light flash causes both a considerable biological reactivation and the disappearance of about 7 x 10 9 pyrimidine dimers from the total RNA per egg. The results indicate the presence of heterogeneous light-dependent repair activities acting upon UV induced pyrimidine dimers in the RNA of the eggs. (author)

Photoreactivation of RNA in UV-irradiated insect eggs (Smittia SP., Chironomidae, Diptera)

International Nuclear Information System (INIS)

Jaeckle, H.; Kalthoff, K.

1978-01-01

Irradiation of Smittia eggs with UV during intravitelline cleavage causes the formation of pyrimidine dimers in the (largely ribosomal) RNA of the eggs. The yield of dimers is wavelength-dependent in a way that strongly suggests the involvement of photosensitizing egg components. Illumination of UV-irradiated eggs with light (380 or 400 nm) causes both photoreactivation of the eggs and monomerization of the pyrimidine dimers in their RNA. The photoreactivable sector of the biological damage is correlated with the amount of pyrimidine dimers present in the RNA after inactivation of the eggs with UV of different wavelengths. The data are regarded as the first direct evidence that the photoreactivation of a eukaryotic organism is correlated with the light-dependent (and apparently enzymatic) monomerization of pyrimidine dimers in RNA. (author)

Life-cycle effects of sediment-associated uranium on Chironomus riparius (diptera: chironomidae)

International Nuclear Information System (INIS)

Dias, V.; Ksas, B.; Camilleri, V.; Bonzom, J.M.

2004-01-01

In aquatic ecosystems, sediments function as reservoir for many of the more persistent chemicals that are introduced into surface waters. Sediments provide a habitat for various benthic macro-invertebrates, which are exposed to sediment-associated chemicals both directly and via food intake. These chemicals may be directly toxic to benthic macro-invertebrates and can be integrated into food chain. Benthic macro-invertebrates play an important role in the ecosystem structure and functioning. In particular, they represent an important component of aquatic food chains. Among the non biologically essential metals, data concerning uranium fate and effects on freshwater benthic invertebrates are sparse. The present study aimed to estimate effects of a chronic uranium exposure on life-cycle traits of Chironomus riparius. To achieve this goal, (i) first instar larvae were exposed to a series of concentrations of uranium via the sediment, and (ii) a number of developmental (e.g. growth) and reproductive (e.g. emergence, fecundity, viability) endpoints, through parental and into F1 generations, were evaluated. Within the framework of ecological risk assessment, these data will help the derivation of a sediment guideline value for uranium that does not currently exist in France or elsewhere due to a lack of toxicity data. (author)

Survival strategies of chironomids (Diptera: Chironomidae) living in temporary habitats: a review

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Matěna, Josef; Ali, A.

2003-01-01

Roč. 100, - (2003), s. 459-465 ISSN 1210-5759 R&D Projects: GA ČR GA526/98/P156; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6066911; CEZ:AV0Z6017912; CEZ:MSM 124100001 Keywords : insect ecology * midges * colonization Subject RIV: EH - Ecology, Behaviour Impact factor: 0.741, year: 2003

THE STUDY OF WATER QUALITY USING BENTHIC MACROINVERTEBRATES AS BIOINDICATORS IN THE CATCHMENT AREAS OF THE RIVERS JIU, OLT AND IALOMIŢA

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Elena Daniela MITITELU

2012-01-01

Full Text Available The wide distribution of benthic invertebrates and their different sensitivity shown upon modifying the qualitative parameters of aquatic ecosystems led to a frequent use of these group as bioindicators in different studies. The present study aims at presenting a list concerning the different macroinvertebrates identified in the larva stage in three watersheds (Jiu, Olt, Ialomiţa and establishing the water quality of the monitored sections using this benthic macroinvertebrates. The sample collecting points were represented by 23 stations. The abundance and frequency values recorded for benthic communities varied according to the physical-chemical conditions specific to each sample collecting station. There were identified 15 groups in total. The most frequent were Ephemeroptera, Plecoptera, Trichoptera, Diptera (Chironomidae and others. The deterioration of water quality is marked by the decrease in the biotic index EPT/Ch value.

The macroinvertebrates of Magela Creek, Northern Territory

International Nuclear Information System (INIS)

Marchant, R.

1982-04-01

The littoral zones of five permanent billabongs in Magela Creek were sampled monthly for macroinvertebrates. Greatest numbers of taxa and individuals were caught in the late wet season and early dry season in the shallow billabongs; in the deep billabongs, seasonal variations were not so marked. These changes appeared to be associated with the development of macrophytes, which offered food and shelter to the invertebrate fauna. The dominant groups were the Chironomidae, Oligochaetae and Ephemeroptera. The seasonal patterns of the catches were sufficiently consistent for future samples to be able to be compared with these initial ones with some confidence that any changes are real. This work is part of a larger study into the biota and water quality of Magela Creek designed to provide data on aquatic communities before mining of the Ranger uranium deposit starts

A review of necrophagous insects colonising human and animal cadavers in south-east Queensland, Australia.

Science.gov (United States)

Farrell, Julianne F; Whittington, Andrew E; Zalucki, Myron P

2015-12-01

A review of insects collected from decomposing human remains in south-east Queensland yielded 32 species in three orders (Diptera, Coleoptera, Hymenoptera) and 11 families (Calliphoridae, Sarcophagidae, Muscidae, Phoridae, Sepsidae, Chironomidae, Dermestidae, Cleridae, Histeridae, Staphylinidae, Encyrtidae). There were 15 cases where remains were located indoors and five cases where remains were outdoors, in both terrestrial and aquatic environments. Coleoptera were strongly associated with outdoors remains, while dipteran species composition was similar in both indoor and outdoor habitats. Some Diptera were only associated with indoors remains, while others were similarly restricted to remains recovered outdoors. Hymenopteran parasitoids were active in both habitats. Comparative collections were made from other vertebrate remains, including road-kill and farmed animals throughout south-east Queensland (Qld) and northern New South Wales (NSW) during the same period. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Feeding of Eigenmannia trilineata (Pisces, Sternopygidae (Lopez & Castello, 1966, in the upper Paraná River floodplain, Brazil

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Danielle Peretti

1999-01-01

Full Text Available Studies were performed on various aspects related to the feeding of Eigenmannia trilineata in the upper Paraná River floodplain, from June 1993 to July 1994, at four places with different types of bottom and waters speed. A number of 279 fish had its stomachal contents analyzed by occurence and point methods in which it was applied on its frequencies the feeding index. Two hundred an sixty two specimens were utilized to the analysis of the feeding activity that it was based on frequency and middle degree of stomach repletion. For the morfological analyse utilized 12 individuals. It was verified fourteen items on species diet which it was found chiefly Chironomidae (Diptera and detritus. Seasonal, area variations were verified in feeding activity and the participation of constituent items in diet. The results showed that the species presents nightly and benthophagous habits, with morfological characters of the carnivorous species.Os estudos foram realizados sob vários aspectos relacionados à alimentação de Eigenmannia trilineata na planície de inundação do alto rio Paraná, de junho de 1993 a julho de 1994 em quatro locais com diferentes tipos de fundo e velocidade de águas. Um número de 279 peixes tiveram seus estômagos analisados pelos métodos de ocorrência e pontos sendo aplicado sobre suas frequências o índice alimentar. Duzentos e sessenta e dois indivíduos foram utilizados para a análise da atividade alimentar, a qual foi baseada sobre a freqüência e grau de repleção médio dos estômagos. Para a análise morfológica foram utilizados 12 indivíduos. Foi verificado 14 itens na dieta da espécie, encontrando-se principalmente Chironomidae (Diptera e detritos. Variações sazonais e de área foram verificados na atividade alimentar e na participação dos itens constituintes da dieta. Os resultados mostraram que a espécie apresenta hábitos noturno e bentófago, com características morfológicas de espécies carnívoras.

OIL DECONTAMINATION OF BOTTOM SEDIMENTS EXPERIMENTAL WORK RESULTS

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Lushnikov Sergey V.

2006-08-01

Full Text Available This article presents the results of experimental work during 2004-2005 on oil decontamination of bottom sediments of Lake Schuchye, situated in the Komi Republic (Northern Russia. The cause of thecontamination were huge oil spills occurred after a series of accidental ruptures on the Harjaga-Usinsk and Vozej-Usinsk oil-pipe lines in 1994. Flotation technology was used for the cleaning of bottom sediments.157 tons of crude oil were removed during the course of 2-year experimental work from an area of 4,1 ha.The content of aliphatic and alicyclic oil hydrocarbons was reduced from 53,3 g/kg to 2,2 g/kg, on average.Hydrobiological investigations revealed that bottom sediments started to be inhabited by benthos organisms, dominantly Oligochaeta. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected. Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality.

Habitat preference and reproductive traits in the Antarctic midge Parochlus steinenii (Diptera: Chironomidae)

NARCIS (Netherlands)

Hahn, S.M.; Reinhardt, K.

2006-01-01

We provide the first comprehensive account of habitat preference, mating, oviposition and developmental stages of Parochlus steinenii. There are eight records from the South Shetland Islands. On King George Island, none out of 40 temporary ponds and 9% out of 44 lakes with variable water levels were

Two new species of genus Hydrosmittia Ferrington & Sæther (Diptera: Chironomidae) from China.

Science.gov (United States)

Zhang, Ruilei; Liu, Wenbin; Ferrington, Leonard C Jr; Wang, Xinhua

2016-06-08

The genus Hydrosmittia from China is reviewed. Two new species H. continalinea sp. n. and H. sipinata sp. n. are described and illustrated based on male imagines. Key to known male imagines of genus Hydrosmittia worldwide is provided.

Cytological and cytochemical characterization of the polytene chromosomes of Chironomus sancticaroli (Diptera: chironomidae)

International Nuclear Information System (INIS)

Freitas, F. de; Leoncini, O.

1985-01-01

The chromosome complement of a Brazilian Chironomus Species, C. Sancticaroli, was analyzed cytochemically. The polytene Chromosomes were identified and characterized and the nucleolus organizer regions (NORs) were located by a technique of in situ hybridization and immunofluorescence. Constitutive heterochromatin and its distribution in relation to the NORs were studied. (Author) [pt

Limnophyes guarani sp. n., a new hygropetric Orthocladiinae from southern Brazil (Diptera: Chironomidae).

Science.gov (United States)

Pinho, Luiz Carlos; Andersen, Trond

2015-04-20

A new species of Limnophyes Eaton collected in the Corvo Branco Mountains in Santa Catarina State is described and figured, based on male and female adults, larva and pupa. The species groups with L. griseata (Edwards) and L. bidumus Sæther as the adults have a pronounced humeral pit with lanceolate setae and an additional group of lanceolate setae just posterior to antepronotum. The adults are, however, distinctly smaller, have a lower AR and have more lanceolate setae in the group just posterior to antepronotum than the two other species. The pupa can easily be separated from the pupa of L. bidumus as the anal macroseta is longer than the anal lobe. The larva lives hygropetric on vertical rock surfaces. A key to male adults of Neotropical Limnophyes is given.

New species and records of Goeldichironomus Fittkau, 1965 from Brazil (Diptera: Chironomidae).

Science.gov (United States)

Amora, Gizelle; Hamada, Neusa; Pinho, Luiz Carlos

2015-12-22

One new species named Goeldichironomus adhaerens sp. n. is described from urban area in Manaus, Brazilian Amazon, based on male adult, pupa and larva. New records of G. neopictus Trivinho-Strixino & Strixino, G. maculatus Trivinho-Strixino & Strixino, G. pictus Reiss and G. fluctuans Reiss are also provided.

Eonandeva gen. nov., a new distinctive genus from Eocene Baltic amber (Diptera: Chironomidae).

Science.gov (United States)

Zakrzewska, Marta; Giłka, Wojciech

2015-11-20

A new fossil genus, Eonandeva gen. nov., with two new species: E. helva sp. nov. (type for the genus) and E. latistyla sp. nov., is described from Eocene Baltic amber (~45-40 Ma). Adult males of both new species show the wing venation pattern, shape and chaetotaxy typical for the tribe Tanytarsini. The characters defined as prior apomorphies for the new genus--the gonostylus with a subapical flattened lobe and the stout, strongly elongated superior volsella--separate Eonandeva from the closely related extant genus Nandeva Wiedenbrug, Reiss et Fittkau, 1998.

A new species of Metapelopia Silva, Oliveira & Trivinho-Strixino (Diptera: Chironomidae) from Peru.

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Dantas, Galileu P S; Hamada, Neusa; Araujo, Ana A Huamantinco

2016-07-08

A new species of the monotypic genus Metapelopia is described and illustrated based on all life stages. Adults of the Metapelopia peruensis sp. n. can be easily distinguished from those of M. corbii by the color pattern of the legs and abdomen. Larvae and pupae were collected associated with algae accumulated on rocks.

Stenochironomus munteanpurin sp. n., a new leaf-mining species from Brazil (Diptera: Chironomidae).

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Amora, Gizelle; Hamada, Neusa; Pinho, Luiz C

2018-02-21

Stenochironomus munteanpurin sp. n. is described and illustrated in all life stages, except eggs, from Brazil. The male is very similar to Stenochironomus quadrinotatus Borkent, 1984 due to same overall pattern of pigmentation. The new species can be distinguished from the other related species principally in immature stages: larva with labral lamella arranged in two groups with one or two conical-shaped teeth, spicules of pecten epipharyngis arranged in a row, unequal and irregularly distributed sizes, SI bifurcated, SII pinnate, SIII pinnate setae and, larval exuviae is compacted; pupa with shagreens being in all TI, less number of hooklets in TII, TVII without shagreens and presence of shagreen in conjunctive III/IV and IV/V. Adult male is very similar to the one of S. quadrinotatus but can be distinguished by combination of the TIX with more than 25 setae medially and phallapodeme curved anteriorly. The new species were collected in the following Brazilian states: Rio de Janeiro, Santa Catarina, Bahia and Acre.

Intraspecific competition of .i.Glyptotendipes paripes./i. (Diptera: Chironomidae) larvae under laboratory conditions

Czech Academy of Sciences Publication Activity Database

Frouz, Jan; Lobinske, R.J.; Ali, A.

2009-01-01

Roč. 43, č. 2 (2009), s. 487-500 ISSN 1386-2588 Institutional research plan: CEZ:AV0Z60660521; CEZ:AV0Z6066911 Keywords : food availability * Glyptotendipes paripes * larval density Subject RIV: EH - Ecology, Behaviour Impact factor: 1.549, year: 2009

Chromosomal organization of the ribosomal RNA genes in the genus Chironomus (Diptera, Chironomidae

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Larisa Gunderina

2015-05-01

Full Text Available Chromosomal localization of ribosomal RNA coding genes has been studied by using FISH (fluorescence in situ hybridization in 21 species from the genus Chironomus Meigen, 1803. Analysis of the data has shown intra- and interspecific variation in number and location of 5.8S rDNA hybridization sites in 17 species from the subgenus Chironomus and 4 species from the subgenus Camptochironomus Kieffer, 1914. In the majority of studied species the location of rDNA sites coincided with the sites where active NORs (nucleolus organizer regions were found. The number of hybridization sites in karyotypes of studied chironomids varied from 1 to 6. More than half of the species possessed only one NOR (12 out of 21. Two rDNA hybridization sites were found in karyotypes of five species, three – in two species, and five and six sites – in one species each. NORs were found in all chromosomal arms of species from the subgenus Chironomus with one of them always located on arm G. On the other hand, no hybridization sites were found on arm G in four studied species from the subgenus Camptochironomus. Two species from the subgenus Chironomus – Ch. balatonicus Devai, Wuelker & Scholl, 1983 and Ch. “annularius” sensu Strenzke, 1959 – showed intraspecific variability in the number of hybridization signals. Possible mechanisms of origin of variability in number and location of rRNA genes in the karyotypes of species from the genus Chironomus are discussed.

Cytological and cytochemical characterization of the polytene chromosomes of Chironomus sancticaroli (Diptera: chironomidae)

Energy Technology Data Exchange (ETDEWEB)

Freitas, F. de; Leoncini, O.; Floeter-Winter, L.M.

1985-03-01

The chromosome complement of a Brazilian Chironomus Species, C. Sancticaroli, was analyzed cytochemically. The polytene Chromosomes were identified and characterized and the nucleolus organizer regions (NORs) were located by a technique of in situ hybridization and immunofluorescence. Constitutive heterochromatin and its distribution in relation to the NORs were studied.

New species and records of Zavreliella Kieffer, 1920 from Neotropical region (Diptera: Chironomidae).

Science.gov (United States)

Fusari, Lívia Maria; Pinho, Luiz Carlos; Lamas, Carlos José Einicker

2017-01-19

A new species of Zavreliella Kieffer, Zavreliella kambeba sp. n., is described, based on male adults collected in the Amazon rainforest, Brazil. Further seven Zavreliella species are recorded for new localities in Brazil, with the first Neotropical record of Z. marmorata (van der Wulp). The genus Zavreliella is now composed of 15 species, of which adult males are reviewed in a key to their identification.

Copper, cadmium, and zinc concentrations in aquatic food chains from the Upper Sacramento River (California) and selected tributaries

Science.gov (United States)

Saiki, M.K.; Castleberry, D. T.; May, T. W.; Martin, B.A.; Bullard, F. N.

1995-01-01

Metals enter the Upper Sacramento River above Redding, California, primarily through Spring Creek, a tributary that receives acid-mine drainage from a US EPA Superfund site known locally as Iron Mountain Mine. Waterweed (Elodea canadensis) and aquatic insects (midge larvae, Chironomidae; and mayfly nymphs, Ephemeroptera) from the Sacramento River downstream from Spring Creek contained much higher concentrations of copper (Cu), cadmium (Cd), and zinc (Zn) than did similar taxa from nearby reference tributaries not exposed to acid-mine drainage. Aquatic insects from the Sacramento River contained especially high maximum concentrations of Cu (200 mg/kg dry weight in midge larvae), Cd (23 mg/kg dry weight in mayfly nymphs), and Zn (1,700 mg/kg dry weight in mayfly nymphs). Although not always statistically significant, whole-body concentrations of Cu, Cd, and Zn in fishes (threespine stickleback, Gasterosteus aculeatus; Sacramento sucker, Catostomus occidentalis; Sacramento squawfish, Ptychocheilus grandis; and chinook salmon, Oncorhynchus tshawytasch) from the Sacramento River were generally higher than in fishes from the reference tributaries.

Mortality of nontarget arthropods from an aerial application of pyrethrins.

Science.gov (United States)

Kwan, Jonathan A; Novak, Mark G; Hyles, Timothy S; Niemela, Michael K

2009-06-01

Mortality of nontarget organisms from an ultra-low volume (ULV) aerial application of pyrethrins (Evergreen EC 60-6) was monitored by collecting arthropods from ground tarps placed at the interface of open and canopy areas. A larger number and greater diversity of arthropods were recovered from tarps in the ULV spray area. The observed mortality was approximately 10-fold greater than in the control area. Kruskal-Wallis tests revealed a significant difference in the abundance and diversity of arthropods collected at treatment and control sites at 1 and 12 h postspray. Arthropods, primarily insects, from the treatment area included representatives from 12 orders and > or = 34 families, as compared to 7 orders and 12 families in the control area. Chironomidae (midges) and Formicidae (ants) were the most commonly represented families, accounting for 61% of the arthropods collected from the treatment area; no large-bodied insects (>8 mm) were recovered. Mortality of sentinel mosquitoes in the treatment and control areas averaged 96% and arthropods.

What is the diet of Palaemon elegans Rathke, 1837 (Crustacea, Decapoda, a non-indigenous species in the Gulf of Gdańsk (southern Baltic Sea?

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Urszula Janas

2008-06-01

Full Text Available Palaemon elegans, a new component of the Gulf of Gdańsk macrozoobenthos,colonised the southern Baltic coastal zone in the late 20th and early 21stcentury. Analysis of the stomach contents of P. elegans revealed 16plant and animal taxa that these prawns had fed on. The principal dietarycomponent was detritus, with a mean frequency of occurrence in stomachs of > 80%.The most frequently occurring plant components in the diet were algaefrom the genus Cladophora and the family Ectocarpaceae, while the mostsignificant animal components were Harpacticoida, Chironomidae, Ostracoda andGammarus spp. The results of the study show that the dietary composition ofP. elegans differed significantly between stations and months. The foraging area consisted of two distinctive regions - the Inner Puck Bay, and the Outer Puck Bay together with the Dead Vistula River; two of the stations - Gdynia and Sopot - were distinctfrom all the others. However, no obvious seasonality in the food compositioncould be demonstrated.

Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2007

Science.gov (United States)

May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

2007-01-01

This report presents the results for two sampling periods during a 4-year monitoring survey to provide a characterization of selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species, and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species-western mosquitofish (Gambusia affinis), and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Total selenium concentrations in water for both sampling periods ranged from 1.43 to 47.1 micrograms per liter, predominately as selenate, which is typical of waters leached out of selenium-contaminated marine shales under alkaline and oxidizing conditions. Total selenium concentrations ranged from 0.88 to 20.2 micrograms per gram in biota, and from 0.15 to 28.9 micrograms per gram in detritus and sediment.

Midges (Diptera:Chironomidae) as indicators of wetland viability in the Alberta Oil Sands region

Energy Technology Data Exchange (ETDEWEB)

Ciborowski, J. J. H.; Whelly, M. P.; Leonhardt, C.; Laing, D. [Windsor Univ., Dept. of Biological Sciences, ON (Canada)

1999-07-01

Thirty-three wetlands northeast of Fort McMurray, Alberta, ten of which are receiving oil sands mine process-affected water (OSPW), have been examined to assess their biological integrity. Physico-chemical and environmental attributes were measured, sediment, zoobenthic, plankton and chlorophyll samples were analyzed. Results of principal component analysis indicated that the wetlands could be categorized into three classes on the basis of three independent combinations of environmental features, namely pH/size/dissolved oxygen; conductivity; and sediment composition. Cluster analysis identified four groups of wetlands. High conductivity wetlands were found to support greater density but reduced richness of benthic population, irrespective of the presence of OSPW. To evaluate OSPW wetland ability to support and maintain benthic populations chironomid larval morphology, density, adult emergence, flight activity, egg-laying behaviour and the ability of eggs to hatch in OSPW were monitored. Results indicated no inhibition of adult chironomid flight activity, egg-laying or hatching by OSPW, although there was some evidence of OSPW reducing chironomid density, diversity and secondary production.

To systematics of the genus Saetheria Jackson (Diptera, Chironomidae) from the Russian Far East.

Science.gov (United States)

Orel, Oksana V

2014-05-23

The genus Saetheria Jackson from the Russian Far East is reviewed. The males of S. reissi Jackson, 1977, S. tamanipparai (Sasa, 1983) and S. tylus (Townes, 1945) are redescribed and figured. The pupa of S. reissi is redescribed and illustrated. The larva of S. reissi Jackson is described for the first time. Comments on the systematics and distribution of each species are provided. Paracladopelma kisopediformis Sasa, Kondo, 1993 is designated a new junior synonym of S. reissi Jackson, 1977. Keys to the males, pupae and larvae of the Russian Saetheria are given.

The response of chironomidae (Diptera) to a long-term exclusion of terrestrial organic matter

Science.gov (United States)

Sally A. Entrekin; J. Bruce Wallace; Susan L. Eggert

2007-01-01

We examined the effects of a seven-year detrital exclusion on chironomid assemblages in an Appalachian headwater stream. We hypothesized that litter exclusion would lead to a reduction in all chironomids at both the subfamily and generic levels because organic matter serves as both food and habitat in these headwater streams. Tanytarsini total abundance and biomass...

Photoreversible UV-inactivation of messenger RNA in an insect embryo (Smittia spec., chironomidae, diptera)

International Nuclear Information System (INIS)

Jaeckle, H.; Kalthoff, K.

1980-01-01

Smittia embryos were UV-irradiated during intravitelline cleavage while nuclei are heavily shielded by yolk-rich cytoplasm and do not synthesize detectable amounts of RNA. Irradiation at 265, 285 and 295 nm wavelength caused biological inactivation, and pyrimidine dimer formation in maternal RNA. Marked effects on protein synthesis were also observed: (1) the overall rate of 35 S-methionine incorporation in vivo was reduced to less than half of the normal rate, (2) two dimensional gel electrophoresis revealed quantitative variations in the synthetic rate of some polypeptides and the appearance of new ones in UV-irradiated embryos, (3) translation of polyadenylated RNA from Smittia embryos in a cell-free system was inhibited by UV-irradiation in vivo, (4) the apparent degradation during early embryogenesis, of maternal polyadenylated RNA was retarded in UV-irradiated embryos. Exposure to light (400 nm) after UV caused partial photoreversal of all UV effects observed. This is the first data showing that animal mRNA, after UV-irradiation, can be photoreactivated in vivo. The results also strongly suggest that the photorepairable lesions consist of pyrimidine dimers generated in a photosensitized reaction. (author)

New species and records of Oukuriella Epler, 1986 from the Neotropical region (Diptera: Chironomidae).

Science.gov (United States)

Bellodi, Carolina Ferraz; Fusari, Lívia Maria; Roque, Fabio De Oliveira

2016-02-09

Two new species of Oukuriella, O. angelomachadoi sp. nov. (Holotype male deposited in MZUSP: BRAZIL, Paraná State) and O. plumaterata sp. nov. (Holotype male deposited in MZUSP: BRAZIL, São Paulo State), and the immatures stages of O. sublettei are described and figured. The larvae of O. sublettei were collected from submerged woods in low-order streams in the Atlantic Forest. In addition new records of several described species, including the first records of Oukuriella from Mexico and Bolivia are given.

Factors that alter the biochemical biomarkers of environmental contamination in Chironomus sancticaroli (Diptera, Chironomidae

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Débora Rebechi-Baggio

Full Text Available ABSTRACT Changes in physiology of the nervous system and metabolism can be detected through the activity of acetylcholinesterase (AChE, alpha esterase (EST-a and beta esterase (EST-ß in chironomids exposed to pollutants. However, to understand the real effect of xenobiotics on organisms, it is important to investigate how certain factors can interfere with enzyme activity. We investigated the effects of different temperatures, food stress and two steps of the enzymatic protocol on the activity of AChE, EST-a and EST-ß in Chironomus sancticaroli. In experiment of thermal stress individuals from the egg stage to the fourth larval instar were exposed to different temperatures (20, 25 and 30 °C. In food stress experiment, larvae were reared until IV instar in a standard setting (25 °C and 0.9 g weekly ration, but from fourth instar on they were divided into groups and offered different feeding regimes (24, 48 and 72 h with/without food. In sample freezing experiment, a group of samples was processed immediately after homogenization and another after freezing for 30 days. To test the effect of centrifugation on samples, enzyme activity was quantified from centrifuged and non-centrifuged samples. The activity of each enzyme reached an optimum at a different temperature. The absence of food triggered different changes in enzyme activity depending on the period of starvation. Freezing and centrifugation of the samples significantly reduced the activity of three enzymes. Based on these results we conclude that the four factors studied had an influence on AChE, EST-a and EST-ß and this influence should be considered in ecotoxicological approaches.

A new species of the genus Microtendipes Kieffer, 1915 (Diptera, Chironomidae from Oriental China

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Xin Qi

2012-07-01

Full Text Available A new species of the genus Microtendipes Kieffer, 1915, M. zhejiangensis sp.n., is described, and its morphological description and illustrations are given. A catalogue of the genus in Oriental Region is provided and a key to the males of Microtendipes in the Oriental Region is given.

Polypedilum nubifer, a Chironomid Midge (Diptera: Chironomidae) new to Florida that has nuisance potential

International Nuclear Information System (INIS)

Jacobsen, R.E.; Perry, S.A.

2007-01-01

We document the first record of Polypedilum nubifer in Pan-America. This eurytopic species often reaches severe nuisance population sizes in Australia, Asia, and Hawaii in warm, shallow, eutrophic waters subject to drying. A large population was discovered in newly-constructed infiltration basins and neighboring marshes along the eastern boundary of Everglades National Park. Presently, this population appears minimally invasive to Park marshes and is far removed from urban areas. However, we anticipate this species could disperse and attain nuisance population sizes in suitable urban and agricultural habitats in south Florida. (author)

Macroinvertebrados bentónicos del humedal de Palo Verde, Costa Rica

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F.A Trama

2009-11-01

Full Text Available El humedal de Palo Verde es uno de los más importantes de Centro America para aves acuáticas. Durante el período 2002 y 2005, se llevaron a cabo actividades de manejo para controlar la invasión de Typha domingensis. Con el fin de establecer una línea base para monitoreos futuros, en el 2003 se realizó una evaluación de macroinvertebrados acuáticos. Se efectuó un muestreo mensual durante un año, usando el método de sustratos artificiales. Se identificaron 116 táxones pertenecientes a 47 familias y a 18 órdenes. La mayor abundancia se encontró en la clase Conchostraca y la familia Chironomidae que juntas representaron casi la mitad de todos los individuos colectados. En contraste, el 97% de los táxones tuvieron, cada uno, menos del 1% del total de la abundancia. La diversidad de táxones, así como la abundancia de individuos y el número de especies, fueron mayores en la época seca que en la lluviosa. La curva acumulada de especies indicó que se hubiera registrado una mayor cantidad de táxones si los muestreos se hubieran extendido por más tiempo. Con este trabajo damos a conocer la primera lista de macroinvertebrados para el humedal de Palo Verde.Benthic macroinvertebrates of the Palo Verde wetland, Costa Rica. Palo Verde, Costa Rica, is one of the most important wetlands in the region now recovering from some invasive plants, especially Typha domingensis, and monitoring programs were started, including studies on the aquatic macoinvertebrate fauna. We sampled benthic macroinvertebrates monthly for more than a year with artificial substrates, and identified 116 taxa from 57 families and 18 orders, with 90 morfospecies of insects. The highest abundances were in the class Conchostraca (typical in seasonal wetlands and in the family Chironomidae (Diptera, Insecta, which together represent almost half of all individuals collected. In contrast, 97 taxa were less than 1% of total abundance each. Number of individuals and number of

Effects of carbofuran and metsulfuron-methyl on the benthic macroinvertebrate community in flooded ricefields Efeito do carbofurano e metsulfuron-methyl sobre a comunidade de macroinvertebrados bentônicos de lavoura de arroz irrigado

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Joele Baumart

2011-06-01

Full Text Available AIM: This study evaluated the effect of the insecticide carbofuran and the herbicide metsulfuron-methyl on the abundance and diversity of benthic macroinvertebrates in a paddy ricefield. METHODS: To achieve this goal, two pesticide treatments [the insecticide carbofuran (IC and the herbicide metsulfuron-methyl (HM] and a control (Co treatment with no added pesticide were established in an experimental area of the Plant Science Department of the Federal University of Santa Maria. Soil samples were collected in triplicate from each treatment 30 days before and 1, 10, and 51 days after the pesticide application, for macrofauna identification. RESULTS: Among the 21 taxa identified, Trichoceridae was present only in Co, Hydroptilidae was recorded only in IC, and Corixidae in HM. In Co, the most abundant group was Annelida, while in IC and HM Diptera (Chironomidae was dominant. Significant differences were observed between Co and IC, in the density of Odontoceridae (Control>IC and Hydrophilidae (ControlHM and Hirudinea (ControlOBJETIVO: O objetivo desse estudo foi avaliar o efeito do inseticida carbofurano e do herbicida metsulfuron-methyl na abundância e diversidade de macroinvertebrados bentônicos em campo de arroz irrigado. MÉTODOS: Para isto, dois tratamentos com agrotóxicos [o inseticida carbofurano (IC e o herbicida metsulfuron-methyl (HM] e um controle (Co, tratamento sem pesticida, foram aplicados em uma área experimental no Departamento de Fitotecnia da Universidade Federal de Santa Maria. Amostras de solo foram coletadas em triplicatas em cada tratamento 30 dias antes (DBA e 1, 10 e 51 dias após a aplicação dos pesticidas, posteriormente a macrofauna foi identificada. RESULTADOS: Vinte e um (21 taxa foram identificados, entre esses Trichoceridae esteve presente apenas em Co, enquanto que Hydroptilidae foi coletado apenas em IC, e Corixidae em HM. Em Co e IC, o grupo mais abundante foi Annelida, e em HM foi Diptera (Chironomidae que

Macroinvertebrates associated with bryophyta in a first-order Atlantic Forest stream

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Beatriz F. J. V. Rosa

2011-06-01

Full Text Available This study describes the composition and structure of the benthic community associated with bryophytes in a first-order stream, located in a biological reserve of the Atlantic Forest, during two seasons. During three months of the dry season of 2007 and three months of the rainy season of 2008, samples of bryophytes attached to stones were collected randomly, along a 100 m stream reach. The structure of the community was analyzed through the mean density of individuals, Shannon's diversity index, Pielou's evenness, family richness, dominance index, and the percentage of Ephemeroptera, Plecoptera and Trichoptera (% EPT. Chironomidae larvae were dominant in the two periods of study, followed by Ceratopogonidae in the rainy season, and Naididae in the dry season. The orders EPT contributed 14 families. The results showed that bryophytes constitute suitable habitat which is able to shelter an abundant and diversified benthic fauna in a small extension of the stream. This habitat provides refuge during spates, and thus minimizes downstream transport of the macroinvertebrate fauna.

Effect of habitat improvement on Atlantic salmon in the regulated river Suldalslaagen

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Raastad, J.E.; Lillehammer, A.; Lillehammer, L.; Eie, J.A.

1993-01-01

The River Suldaalslagen, which holds a population of large Atlantic salmon, has been regulated twice for hydropower production. The first regulation occurred in 1968 and the second in 1980. Present problems include the reduced density of benthic fauna, the reduced growth rate of young salmon, the low survival of 0 + fish and the increased time required for smoltification. A programme of habitat restoration includes building a rearing channel system where water flow and the substrate can be controlled. The salmon fry are stocked in the rearing channel and in an adjacent tributary stream. The effects on macrobenthos of introduced dead organic material were also studied. Improvement of physical habitat increased the density of benthic animals, and the survival of 1 + salmon was about 30%. Experiments that included adding 115 g wheat/m 2 resulted in a threefold increase in benthic fauna compared with a control area. The largest increase in numbers was Chironomidae in August-September, when benthic Crustacea also showed a significant increase. An increase in macrobenthos is expected to increase the growth and survival of young salmon fry. (Author)

Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina

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María V. López van Oosterom

2013-03-01

Full Text Available The diet and trophic relationships between the macroinvertebrates Phyllogomphoides joaquini Rodrigues Capítulo, 1992 and Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, and Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae and the fishes Pimelodella laticeps Eigenmann, 1917 (Heptapteridae and Bryconamericus iheringii (Boulenger, 1887 (Characidae in a temperate lowland lotic system in Argentina were assessed on the basis of gut contents and stable-isotope analyses. The feeding strategies were analyzed by the AMUNDSEN method. Relative food items contribution for the taxa studied indicated a generalist-type trophic strategy. In macroinvertebrates, in general, the values of stable isotope confirmed the result of the analysis of gut contents. With the fish, stable-isotope analysis demonstrated that both species are predators, although B. iheringii exhibited a more omnivorous behaviour. These feeding studies allowed us to determine the trophic relationships among taxa studied. Detritus and diatoms were a principal source of food for all the macroinvertebrates studied. In La Choza stream the particulate organic matter is a major no limited food resource, has a significant influence upon the community.

How are macroinvertebrates of slow flowing lotic systems directly affected by suspended and deposited sediments?

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Kefford, Ben J., E-mail: ben.kefford@rmit.edu.a [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Zalizniak, Liliana [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Dunlop, Jason E. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia); Smart Water Research Facility, Griffith University, Queensland (Australia); Nugegoda, Dayanthi [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083 (Australia); Choy, Satish C. [Department of Environment and Resource Management (DERM), 120 Meiers Rd, Indooroopilly, Queensland 4068 (Australia)

2010-02-15

The effects of suspended and deposited sediments on the macroinvertebrates are well documented in upland streams but not in slower flowing lowland rivers. Using species found in lowland lotic environments, we experimentally evaluate mechanisms for sediments to affect macroinvertebrates, and in one experiment whether salinity alters the effect of suspended sediments. Suspended kaolin clay reduced feeding of Ischnura heterosticta (Odonata: Coenagrionidae) at high turbidity (1000-1500 NTU) but had no effects on feeding of Hemianax papuensis (Odonata: Aeshnidae) and Micronecta australiensis (Hemiptera: Corixidae). In freshwater (0.1 mS/cm), survival of Ischnura aurora was poor in clear water, but improved with suspended kaolin. Growth and feeding of I. aurora were unaffected by suspended sediments and salinity. Burial (1-5 mm) of eggs with kaolin or sand reduced hatching in Physa acuta (Gastropoda: Physidae), Gyraulus tasmanica (Gastropoda: Planorbidae) and Chironomus cloacalis (Diptera: Chironomidae). Settling sediments may pose greater risk to lowland lotic invertebrates than suspended sediments. - Sediment deposition may be more directly detrimental to macroinvertebrates of lowland rivers than suspended sediments.

Biodiversity of Aquatic Insects of Zayandeh Roud River and Its Branches, Isfahan Province, Iran.

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Mansoreh Shayeghi

2014-12-01

Full Text Available Aquatic insects are the major groups of arthropods that spend some parts of their life cycle in the water. These insects play an important role for transmission of some human and animal diseases. There is few information about the aquatic insects fauna of Iran.To study the aquatic insects fauna, adult, nymphal and larval collections were carried out from different habitats using the standard technique in Zayandeh Roud River, Isfahan Province,central Iran, during summer 2011.In total, 741 speimens of aquatic insects were collected and morphologically identified. They include 7 families and 12 genera representing 2 Orders. The order of Diptera (92.31% and Coleoptera (7.69%. The families Culicidae, Syrphidae and Chironomidae from Diptera order, Gyrinidae, Dytiscidae, Haliplidae, Hydrophilidae from Coleoptera order were identified.Some aquatic insects play an important role for transmission of human and animal diseases. These insects also are important for biological control. Therefore ecological study on aquatic insects can provide information about ecology of insects in an area for any decision making.

Low species richness of non-biting midges (Diptera: Chironomidae) in Neotropical artificial urban water bodies

DEFF Research Database (Denmark)

Hamerlik, Ladislav; Jacobsen, Dean; Brodersen, Klaus Peter

2011-01-01

Chironomid assemblages of 22 artificial water bodies, mainly fountains, in two South American cities were surveyed. We found surprisingly low diversities, with a total of 11 taxa, averaging two taxa per site. The typical fountain assemblages mainly consisted of common species that have a wide...... distribution pattern and are tolerant to organic pollution. Also taxa independent of the natural aquatic sources, such as tap-water and semi-terrestrial species were represented. There was no significant difference between the taxa richness of the two S. American regions, however, the assemblage structures...

Experimental acidification of a poor fen in northwestern Ontario: Effects on emergence of Chironomidae (Diptera)

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Rosenberg, D.M.; Wiens, A.P.; Bilyj, B. [Department of Fisheries and Oceans, Winnipeg, MB (Canada). Central and Arctic Region; Armstrong, L. [Department of Fisheries and Oceans, Winnipeg, MB (Canada). Central and Arctic Region

1995-10-01

The effects of experimental acidification and N fertilization on chironomid emergence from a poor fen in northwestern Ontario were studied from 1984 to 1989. Experimental treatments did not affect the numbers of chironomids emerging weekly, the timing of emergence, or the species composition of emergence during the study period. Weekly emergence counts were higher (P<0.05) from the periphery of the fen than the central part. Total seasonal emergence was higher from an area that was previously burned than from the rest of that swamp, though the difference was not statistically significant. Stability of species composition, despite experimental treatments and physiographic differences in the fen, may be a widespread characteristic of Canadian acidic peatlands. 7 tabs., 4 figs., 23 refs.

A new record and two new species of Cryptochironomus Kieffer, 1918 from China (Diptera, Chironomidae).

Science.gov (United States)

Yan, Chuncai; Zhao, Guangjun; Liu, Ting; Guo, Qin; Hou, Ziyuan; Wang, Xinhua; Pan, Baoping

2016-12-19

Two new species of the genus Cryptochironomus Kieffer, C. maculus Yan & Wang sp. n. and C. protuberans Yan & Wang sp. n. are described and illustrated as adult males. C. albofasciatus (Staeger) is recorded from China for the first time. A key to the males of Cryptochironomus in China is presented and generic diagnosis is emended.

Chaudhuriomyia, a new tanypod genus of Macropelopiini (Diptera: Chironomidae: Tanypodinae) from the Eastern Himalaya.

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Paul, Nilotpol; Mazumdar, Abhijit

2015-05-06

A new genus, Chaudhuriomyia in the tribe Macropelopiini belonging to subfamily Tanypodinae is described and illustrated in all life stages. The genus can be distinguished from all the other known Macropelopiini by the presence of a blunt claw on fore leg and a smooth surface of tibial spur in adult male, seminal capsules without proper neck in adult female, round anal lobe in pupa, and slightly inwardly bent inner tooth of ligula in larva. Generic diagnoses for larva, pupa and adult are provided. Taxonomic position and distribution of the genus are discussed along with a new adult key of tribe Macropelopiini. The specimens were collected from a stream in Indo-Bhutan border area of Eastern Himalaya in Indian Subcontinent. A note on the ecology and biology of the new genus is included.

Redescription of 13 holotypes of Rheocricotopus Brundin, 1956 (Diptera: Chironomidae) from the Sino-Indian Region.

Science.gov (United States)

Fu, Yue; Huang, Jingli; Liu, Wenbin; Fang, Xiangliang; Wang, Xinhua

2016-05-24

Thirteen holotypes of the orthoclad genus Rheocricotopus from Sino-Indian Region: R. (Psilocricotopus) hidakadeeus Sasa & Suzuki, R. (P.) isigadeeus Sasa & Suzuki, R. (P.) kurocedeus Sasa, R. (P.) tokarakeleus Sasa & Suzuki, R. (P.) tobatervicesimus Kikuchi & Sasa, R. (Rheocricotopus) inaquereus Sasa, Kitami & Suzuki, R. (R.) inaxeyeus Sasa, Kitami & Suzuki, R. (R.) shoufukusecundus Sasa, R. (R.) tamahumeralis Sasa, R. (R.) tatequintus Sasa, R. (R.) tedorisecundus Sasa, R. (R.) togapeniculus Sasa & Okazawa and R. (R.) yakulemeus Sasa & Suzuki are re-examined and illustrated, Some additional descriptions, corrections and a key of these thirteen holotypes are given.

Alimentação e fator de condição de peixes characidiíneos no sistema do Ribeirão Grande, Sudeste do Brasil - DOI: 10.4025/actascibiolsci.v27i3.1336 Feeding and condition factor of characidiin fish in Ribeirão Grande system, Southeastern Brazil - DOI: 10.4025/actascibiolsci.v27i3.1336

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Francisco Manoel de Souza Braga

2005-03-01

Full Text Available Os peixes foram amostrados quatro vezes em cada local, de julho de 2001 a abril de 2002: inverno (julho de 2001, primavera (outubro de 2001, verão (fevereiro de 2002 e outono (abril de 2002. Foram amostrados segmentos de cinco riachos no sistema do Ribeirão Grande (22o 47’ 08’’ S, 45o 28’ 17’’W. Coletas quantitativas foram feitas com um aparelho de pesca-elétrica ligado a um gerador com capacidade máxima de 1.500 V e 8,7 A de 600 Hz de corrente alternada. Alimentação, mudanças na gordura visceral e fator de condição foram comparados em duas espécies de characidiíneos, Characidium lauroi e C. Alipioi do sistema do Ribeirão Grande, sudeste do Brasil. Nas dietas das duas espécies ninfas de Ephemeroptera, foram registradas larvas de Diptera (Chironomidae, Simuliidae, ninfas de Plecoptera, larvas de Trichoptera (Hydroptilidae, Psychoyiidae, insetos terrestres (Coleoptera, Isoptera, Hemiptera [Heteroptera, Homoptera], larvas de Megaloptera (Corydalidae, Arachnida, Ostracoda e restos vegetais. A gordura visceral decresceu em fevereiro, coincidindo com o declínio do fator de condição em ambas as espécies. O aumento da atividade alimentar durante o verão proporciona o acúmulo de gordura. Durante as estações seguintes, esses peixes devem utilizar as reservas de gordura visceral para manutenção e reproduçãoFeeding, seasonal changes in visceral fat and condition factor were compared in two species of characidiin fishes, Characidium lauroi and C. alipioi from Ribeirão Grande system, southeastern Brazil. Five streams of Ribeirão Grande system were sampled (22o 47’ 08’’ S, 45o 28’ 17’’W. The samples were taken four times per site, from July, 2001 to April, 2002: winter (July 2001, spring (October 2001, summer (February 2002 and autumn (April 2002. Quantitative collections were made with an electro-fishing device powered by a generator with maximum capacity of 1,500 V and 8.7 A of 60 Hz alternating current

Assessment of disturbance at three spatial scales in two large tropical reservoirs

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Letícia de Morais

2016-12-01

Full Text Available Large reservoirs are an increasingly common feature across tropical landscapes because of their importance for water supply, flood control and hydropower, but their ecological conditions are infrequently evaluated. Our objective was to assess the range of disturbances for two large tropical reservoirs and their influences on benthic macroinvertebrates. We tested three hypotheses: i a wide variation in the level of environmental disturbance can be observed among sites in the reservoirs; ii the two reservoirs would exhibit a different degree of disturbance level; and iii the magnitude of disturbance would influence the structure and composition of benthic assemblages. For each reservoir, we assessed land use (macroscale, physical habitat structure (mesoscale, and water quality (microscale. We sampled 40 sites in the littoral zones of both Três Marias and São Simão Reservoirs (Minas Gerais, Brazil. At the macroscale, we measured cover percentages of land use categories in buffer areas at each site, where each buffer was a circular arc of 250 m. At the mesoscale, we assessed the presence of human disturbances in the riparian and drawdown zones at the local (site scale. At the microscale, we assessed water quality at each macroinvertebrate sampling station using the Micro Disturbance Index (MDI. To evaluate anthropogenic disturbance of each site, we calculated an integrated disturbance index (IDI from a buffer disturbance index (BDI and a local disturbance index (LDI. For each site, we calculated richness and abundance of benthic macroinvertebrates, Chironomidae genera richness, abundance and percent Chironomidae individuals, abundance and percent EPT individuals, richness and percent EPT taxa, abundance and percent resistant individuals, and abundance and percent non-native individuals. We also evaluated the influence of disturbance on benthic macroinvertebrate assemblages at the entire-reservoir scale. The BDI, LDI and IDI had significantly

Phototaxis of Propsilocerus akamusi (Diptera: Chironomidae) From a Shallow Eutrophic Lake in Response to Led Lamps.

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Hirabayashi, Kimio; Nagai, Yoshinari; Mushya, Tetsuya; Higashino, Makoto; Taniguchi, Yoshio

2017-06-01

A study on the attraction of adult Propsilocerus akamusi midges to different-colored light traps was carried out from October 21 to November 15, 2013. The 6 colored lights used in light-emitting diode (LED) lamps were white, green, red, blue, amber, and ultraviolet (UV). The UV lamp attracted the most P. akamusi, followed by green, white, blue, amber, and red. A white pulsed LED light attracted only half the number of midges as did a continuous-emission white LED light. The result indicated that manipulation of light color, considering that the red LED light and/or pulsed LED light are not as attractive as the other colors, may be appropriate for the development of an overall integrated strategy to control nuisance P. akamusi in the Lake Suwa area.

Monopelopia mongpuense sp. n., a phytotelmata midge from sub-Himalayan region of India (Diptera: Chironomidae: Tanypodinae).

Science.gov (United States)

Paul, Nilotpol; Hazra, Niladri; Mazumdar, Abhijit

2014-05-23

Immature and adult stages of Monopelopia mongpuense sp. n. from phytotelmata of Cedrus deodara (Lamb.) in Darjeeling are described along with biological notes. Key to the adult males of all species of the genus Monopelopia Fittkau is also presented. This genus is recorded for the first from Indian subcontinent.

A contribution to the systematics of Australasian Tanytarsini (Diptera: Chironomidae): first descriptions from New Caledonia.

Science.gov (United States)

Giłka, Wojciech; Dobosz, Roland

2015-06-26

First specific records of chironomids of the tribe Tanytarsini from New Caledonia based on detailed descriptions of new species are presented. Cladotanytarsus (Cladotanytarsus) stylifer sp. nov. and its closest relatives, i.a. Cladotanytarsus (C.) isigacedeus (Sasa et Suzuki, 2000), comb. nov., known from males bearing extraordinarily elongate hypopygial anal points are diagnosed. Paratanytarsus mirificus sp. nov. is described as adult male with unique structure of its hypopygium and shortened antennae. Diagnostic description of Tanytarsus fuscithorax Skuse, 1889 is also complemented.

Genotoxic effect of copper on salivary gland polytene chromosomes of Chironomus riparius Meigen 1804 (Diptera, Chironomidae)

Energy Technology Data Exchange (ETDEWEB)

Michailova, P. [Institute of Zoology, Bulgarian Academy of Sciences, 1 Tzar Osvoboditel boul., Sofia 1000 (Bulgaria)]. E-mail: michailova@zoology.bas.bg; Petrova, N. [Institute of Zoology, Russian Academy of Sciences, St. Petersburg, 199034, Universit. nab. 1, Russia (Russian Federation); Ilkova, J. [Institute of Zoology, Bulgarian Academy of Sciences, 1 Tzar Osvoboditel boul., Sofia 1000 (Bulgaria); Bovero, S. [Department of Animal Biology, University of Turin, via Albertina 13, Turin (Italy); Brunetti, S. [Department of Animal Biology, University of Turin, via Albertina 13, Turin (Italy); White, K. [School of Biological Sciences, University of Manchester, Manchester M13 9PT (United Kingdom); Sella, G. [Department of Animal Biology, University of Turin, via Albertina 13, Turin (Italy)

2006-11-15

The genotoxic action of copper (Cu) on the polytene chromosomes of Chironomus riparius was investigated by analysing structural and functional chromosome aberrations of fourth instars larvae hatched from eggs subject to acute (48 h) exposure with three environmentally relevant concentrations of aqueous Cu (0.005, 0.01, 0.05 mg/l). A dose dependent relationship was observed between Cu concentration and frequency of chromosomal aberrations. A significantly higher frequency of functional alterations, specifically decondensed centromeres and telomeres, and reduction in activity of Balbiani rings, was observed in treated material compared to control. A comparison of breakpoints resulting from treatment with chromium and lead from earlier studies with those Cu-induced identified a series of chromosomal weak points particularly vulnerable to trace metals. We also show that the appearance of structural and functional chromosome aberrations are more sensitive indicators of acute Cu toxicity in chironomid larvae than changes in external morphology. - Acute exposure of Chironomus eggs to copper resulted in changes in chromosome structure and function.

Blind Flight? A New Troglobiotic Orthoclad (Diptera, Chironomidae from the Lukina Jama - Trojama Cave in Croatia.

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Trond Andersen

Full Text Available The genus Troglocladius Andersen, Baranov et Hagenlund, gen. n. is erected based on T. hajdi Andersen, Baranov et Hagenlund, sp. n. collected at 980 m depth in the Lukina jama-Trojama cave system in Croatia. Morphological features such as pale color, strongly reduced eyes and very long legs make it a typical cave animal. Surprisingly, it has also retained large wings and appears to be capable of flight which would make T. hajdi the first flying troglobiont worldwide, disproving previous beliefs that bats are the only animals capable of flying in complete darkness. Morphologically the new species does not readily fit within any described genus, but shares characteristics with genera both in the tribes "Metriocnemini" and "Orthocladiini". Bayesian molecular phylogenetic analysis using the markers COI, 18S rDNAs, 28S rDNA, CADI, and CADIV groups it with the genera Tvetenia, Cardiocladius and Eukiefferiella in the tribe "Metriocnemini". Troglocladius hajdi may be parthenogenetic, as only females were collected. The discovery confirms the position of the Dinaric arch as a highly important hotspot of subterranean biodiversity.

Survivorship and longevity of adult Diamesa mendotae Muttkowski, 1915 (Diptera: Chironomidae) at controlled, sub-freezing temperatures

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Mazack, Jane E.; Kranzfelder, Petra; Anderson, Alyssa M.; Bouchard, William; Perry, James; Vondracek, Bruce C.; Ferrington, Leonard C.

2014-01-01

Diamesa mendotae Muttkowski, 1915 is a winter-active species common in groundwater-buffered streams of Minnesota and Wisconsin. This species is capable of surviving under snow cover for at least 28 days. Field collections of adult D. mendotae were used to determine survivorship under long-term exposure to controlled sub-freezing conditions. Specimens were placed into a controlled temperature chamber at −5 °C, batches removed at weekly intervals, and subsequently held at 6 °C to determine survivorship and longevity. Our results indicate that overall survivorship is negatively related to treatment duration of sub-freezing treatment, individuals can survive sub-freezing temperatures for at least 70 days, with total longevity of 92 days. Additionally, males had a significantly higher rate of survivorship than females within treatments. Total longevity increased with treatment time, suggesting adult D. mendotae may survive long periods of below-freezing temperatures under natural conditions before mating, which may convey population-level advantages.

Two species of Nilothauma Kieffer (Diptera, Chironomidae) from Japan, with description of a new species.

Science.gov (United States)

Niitsuma, Hiromi

2016-02-16

The male and female adults and pupa of Nilothauma niidaense n. sp. are described and illustrated on the basis of the material collected from a fontal stream in Fukushima Prefecture, Japan. N. sasai Adam & Sæther is treated as a junior synonym of N. hibaratertium Sasa, of which the male is redescribed. The Adam & Sæther key to Nilothauma males is revised.

A Key to the Pupal Exuviae of the Midges (Diptera: Chironomidae) of Everglades National Park, Florida

Science.gov (United States)

Jacobsen, Richard E.

2008-01-01

A key has been developed for identifying the pupal exuviae of 132 taxa of chironomid midges collected in Everglades National Park, as well as 18 additional species from freshwater habitats adjacent to the Park. Descriptions and illustrations are based upon voucher specimens from extensive collections of chironomid pupal exuviae for faunal surveys and biomonitoring research conducted in ENP and surrounding freshwater areas from 1998 to 2007. The key includes taxonomic comments for confirming identifications, as well as brief summaries of the distribution and ecology of each species in southern Florida waters. Information is also provided on the morphology of chironomid pupal exuviae, recommended references for identifying pupal exuviae, techniques for making slides, and methods to confirm proper identification.

Blind Flight? A New Troglobiotic Orthoclad (Diptera, Chironomidae) from the Lukina Jama - Trojama Cave in Croatia.

Science.gov (United States)

Andersen, Trond; Baranov, Viktor; Hagenlund, Linn Katrine; Ivković, Marija; Kvifte, Gunnar Mikalsen; Pavlek, Martina

2016-01-01

The genus Troglocladius Andersen, Baranov et Hagenlund, gen. n. is erected based on T. hajdi Andersen, Baranov et Hagenlund, sp. n. collected at 980 m depth in the Lukina jama-Trojama cave system in Croatia. Morphological features such as pale color, strongly reduced eyes and very long legs make it a typical cave animal. Surprisingly, it has also retained large wings and appears to be capable of flight which would make T. hajdi the first flying troglobiont worldwide, disproving previous beliefs that bats are the only animals capable of flying in complete darkness. Morphologically the new species does not readily fit within any described genus, but shares characteristics with genera both in the tribes "Metriocnemini" and "Orthocladiini". Bayesian molecular phylogenetic analysis using the markers COI, 18S rDNAs, 28S rDNA, CADI, and CADIV groups it with the genera Tvetenia, Cardiocladius and Eukiefferiella in the tribe "Metriocnemini". Troglocladius hajdi may be parthenogenetic, as only females were collected. The discovery confirms the position of the Dinaric arch as a highly important hotspot of subterranean biodiversity.

The immature stages of Polypedilum (Pentapedilum) nodosum (Johannsen) and Polypedilum (Tripodura) masudai (Tokunaga) (Diptera, Chironomidae, Chironominae).

Science.gov (United States)

Tang, Hong-Qu; Cranston, Peter S; Zhao, Jian-Gang; Lok, Chan-Wa; Wong, Kai-Chin; Li, Zhi-Qiang

2014-12-09

Based on associated material collected from Macau and Guangxi, the pupae and larvae of Polypedilum (Pentapedilum) nodosum Johannsen and P. (Tripodura) masudai Tokunaga are described completely for the first time. Both species are newly recorded from China. Characters for distinguishing the immature stage of these species from other allied Polypedilum species are noted. The previously recorded Polypedilum (Pentapedilum) 'K1' of Cranston  (1996) is shown to be P. nodosum. Information is provided on distribution and ecological tolerances. 

Genotoxic effect of copper on salivary gland polytene chromosomes of Chironomus riparius Meigen 1804 (Diptera, Chironomidae)

International Nuclear Information System (INIS)

Michailova, P.; Petrova, N.; Ilkova, J.; Bovero, S.; Brunetti, S.; White, K.; Sella, G.

2006-01-01

The genotoxic action of copper (Cu) on the polytene chromosomes of Chironomus riparius was investigated by analysing structural and functional chromosome aberrations of fourth instars larvae hatched from eggs subject to acute (48 h) exposure with three environmentally relevant concentrations of aqueous Cu (0.005, 0.01, 0.05 mg/l). A dose dependent relationship was observed between Cu concentration and frequency of chromosomal aberrations. A significantly higher frequency of functional alterations, specifically decondensed centromeres and telomeres, and reduction in activity of Balbiani rings, was observed in treated material compared to control. A comparison of breakpoints resulting from treatment with chromium and lead from earlier studies with those Cu-induced identified a series of chromosomal weak points particularly vulnerable to trace metals. We also show that the appearance of structural and functional chromosome aberrations are more sensitive indicators of acute Cu toxicity in chironomid larvae than changes in external morphology. - Acute exposure of Chironomus eggs to copper resulted in changes in chromosome structure and function

A new invasive weed-feeding species of Polypedilum (Pentapedilum) Kieffer from South Africa (Diptera: Chironomidae, Chironominae).

Science.gov (United States)

Andersen, Trond; González, Orestes C Bello; Baars, Jan-Robert; Earle, William

2015-08-19

Polypedilum (Pentapedilum) tuburcinatum Andersen et Bello González sp. n. is described and figured as male, female, pupa and larva based on material collected in the Eastern Cape Province in South Africa, imported into quarantine in Ireland and reared in the laboratory. The species feeds on the aquatic weed Lagarosiphon major (Ridl.) Moss ex Wager and is regarded as a promising candidate agent for biological control of this invasive weed.

Response of chironomid species (Diptera, Chironomidae to water temperature: effects on species distribution in specific habitats

Directory of Open Access Journals (Sweden)

L. Marziali

2013-09-01

Full Text Available The response of 443 chironomid species to water temperature was analyzed, with the aim of defining their thermal optimum, tolerance limits and thermal habitat. The database included 4442 samples mainly from Italian river catchments collected from the 1950s up to date. Thermal preferences were calculated separately for larval and pupal specimens and for different habitats: high altitude and lowland lakes in the Alpine ecoregion; lowland lakes in the Mediterranean ecoregion; heavily modified water bodies; kryal, krenal, rhithral and potamal in running waters. Optimum response was calculated as mean water temperature, weighted by species abundances; tolerance as weighted standard deviation; skewness and kurtosis as 3rd and 4th moment statistics. The responses were fitted to normal uni- or plurimodal Gaussian models. Cold stenothermal species showed: i unimodal response, ii tolerance for a narrow temperature range, iii optima closed to their minimum temperature values, iv leptokurtic response. Thermophilous species showed: i optima at different temperature values, ii wider tolerance, iii optima near their maximum temperature values, iv platikurtic response, often fitting a plurimodal model. As expected, lower optima values and narrower tolerance were obtained for kryal and krenal, than for rhithral, potamal and lakes. Thermal response curves were produced for each species and were discussed according to species distribution (i.e. altitudinal range in running water and water depth in lakes, voltinism and phylogeny. Thermal optimum and tolerance limits and the definition of the thermal habitat of species can help predicting the impact of global warming on freshwater ecosystems.

Taxonomic notes on Chironomidae (Diptera from Okinawa Island, Japan, with the description of three new species

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Masaru Yamamoto

2015-07-01

Full Text Available Three new species: Ionthosmittia cuneipenne sp. nov., Orthocladius (Euorthocladius okinawanus sp. nov. and Parakiefferiella semiovata sp. nov., are described from Okinawa Island, Ryukyus, Japan. In addition to these species, twelve species are newly recorded from this island. Diagnostic characters of Tokyobrillia tamamegaseta (Kobayashi et Sasa are emended. Pentapedilum yakuabeum Sasa et Suzuki syn. nov. and Polypedilum yakucedeum Sasa et Suizuki syn. nov. are junior synonyms of Ainuyusurika tuberculatum (Tokunaga. Einfeldia kanazawai (Yamamoto is transferred to the genus Chironomus Meigen and its systematic position is discussed.

Paleoecología: el uso de los quironómidos fósiles (Diptera: Chironomidae en reconstrucciones paleoambientales durante el Cuaternario en la Patagonia Paleoecology: the use of fossil chironomids (Diptera: Chironomidae for paleoenvironmental reconstructions in Patagonia

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Julieta Massaferro

2009-06-01

Full Text Available Entre los indicadores biológicos lacustres más utilizados en las reconstrucciones ambientales, se encuentran el polen, los ostrácodos y las diatomeas, y entre los insectos, los coleópteros y los quironómidos. Este grupo ha cobrado gran importancia en los últimos tiempos, debido a los resultados prometedores que se han obtenido en reconstrucciones climáticas realizadas en América del Norte y Europa. En América del Sur, el uso de los quironómidos fósiles en estudios cuaternarios es relativamente limitado, principalmente por su escaso conocimiento taxonómico regional. La mayor parte de estos estudios fueron realizados en lagos glaciares patagónicos de Argentina y Chile. Las larvas de quironómidos constituyen una valiosa herramienta paleolimnológica, por ser un grupo de organismos altamente sensible a cambios ambientales, tanto naturales como artificiales. Además, es un grupo de insectos ampliamente distribuido y con una abundancia y diversidad relativamente altas. Sus cápsulas cefálicas se preservan en los sedimentos lacustres y poseen caracteres importantes que permiten identificar géneros y muchas veces especies. El estudio de los ensambles de quironómidos en sedimentos lacustres puede ser utilizado con distintos objetivos, por ejemplo, para estudios de eutrofización, ya que responden rápidamente a cambios en la concentración de nutrientes, materia orgánica y otros elementos, como metales pesados. No obstante, uno de los potenciales más importantes de este grupo de insectos es su sensibilidad a los cambios de temperatura, por este motivo, la aplicación más importante de su estudio en sedimentos se centra en las reconstrucciones climáticas. Esta contribución es una síntesis de los resultados de los trabajos publicados en la Patagonia argentina y chilena, sobre la base del uso de los quironómidos fósiles en reconstrucciones paleoambientales.Pollen, ostracods, diatoms and insects such as beetles and chironomids are the biological indicators from lake sediments more useful in environmental reconstructions. Chironomids have recently acquired great importance due to the promising results obtained regarding climatic reconstructions mainly in Europe and North America. In South America, the use of fossil chironomids in Quaternary studies is still limited and the reason for that is the little regional taxonomic knowledge. Most of these studies were developed in glacial lakes in Patagonia both in Argentina and Chile. The larvae of chironomids are an invaluable paleolimnological tool due to the sensitiveness of these insects to natural and non-natural environmental changes. In addition to that, this group of insects is widely distributed with a high abundance and diversity. Their head capsules can preserve in sediments holding characters which allow their generic and sometimes specific identification. The study of chironomid assemblages can be used with different goals, for instance, to study eutrofication due to their quick response to changes in organic matter, nutrients and heavy metals. However, one of the most significant potentials of this group is its sensitivity to temperature variations, which is why the most important implementation of their study in sediments is centered in climatic reconstructions. This article is a review of the studies developed in Argentinean and Chilean Patagonia, using fossil chironomids for paleoenvironmental reconstructions.

Macroinvertebrate assemblages in agricultural, mining, and urban tropical streams: implications for conservation and management.

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Mwedzi, Tongayi; Bere, Taurai; Mangadze, Tinotenda

2016-06-01

The study evaluated the response of macroinvertebrate assemblages to changes in water quality in different land-use settings in Manyame catchment, Zimbabwe. Four land-use categories were identified: forested commercial farming, communal farming, Great Dyke mining (GDM) and urban areas. Macroinvertebrate community structure and physicochemical variables data were collected in two seasons from 41 sites following standard methods. Although not environmentally threatening, urban and GDM areas were characterised by higher conductivity, total dissolved solids, salinity, magnesium and hardness. Chlorides, total phosphates, total nitrogen, calcium, potassium and sodium were significantly highest in urban sites whilst dissolved oxygen (DO) was significantly higher in the forested commercial faming and GDM sites. Macroinvertebrate communities followed the observed changes in water quality. Macroinvertebrates in urban sites indicated severe pollution (e.g. Chironomidae) whilst those in forested commercial farming sites and GDM sites indicated relatively clean water (e.g. Notonemouridae). Forested watersheds together with good farm management practices are important in mitigating impacts of urbanisation and agriculture. Strategies that reduce oxygen-depleting substances must be devised to protect the health of Zimbabwean streams. The study affirms the wider applicability of the South African Scoring System in different land uses.

Biology and chemistry of three Pennsylvania lakes: responses to acid precipitation

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Bradt, P.T.; Dudley, J.L.; Berg, M.B.; Barrasso, D.S.

1986-09-01

The biology and chemistry of three northeastern Pennsylvania lakes was studied from summer 1981 through summer 1983 to evaluate lakes with different sensitivities to acidification. At the acidified lake there were fewer phytoplankton and zooplankton species than at the moderately sensitive lakes. The most numerous plankton species in all three lakes are reportedly acid tolerant. Among the benthic macro-invertebrates (BMI) there were more acid tolerant Chironomidae at the acidified lake, but more acid intolerant Ephemeroptera and Mollusca and a higher wet weight at the least sensitive lake. There were no differences among the lakes' BMI mean total numbers or mean number of taxa. The fish community at the acidified lake was dominated by stunted Lepomis gibbosus, but L. machrochirous were most abundant in the other lakes. Principal component analysis suggested a shift in all three lakes over the sampling period toward combined lower pH, alkalinity, specific conductance, Ca and Mg and higher Al and Mn. Such chemical changes have been associated with acidification. The rate and extent of acidification appeared to be controlled by geological and hydrological characteristics of the drainage basins. 38 refs.

Responses of a macroinvertebrate community from a pristine, southern British Columbia, Canada, stream to metals in experimental mesocosms

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Richardson, J.S.; Kiffney, P.M.

2000-03-01

Metal contamination is one of the most widespread impacts on surface waters. Experimental flumes receiving water and aquatic invertebrates from an undisturbed, forested stream were used to determine the impact of metals in a low-conductivity stream. The experimental flumes were exposed to a gradient of doses maintaining a constant ratio of metals (1995: Cu, Zn, Mn, and Pb; 1996: Cu and Zn) for 6 d. Benthos and emigration were sampled from each of the 16 troughs. The overall densities of benthos declined, but not significantly, as the dose of metals increased. On the basis of the slopes of the concentration-response curve, Baetis, Ameletus, and Paraleptophlebia were the most sensitive taxa present. Other taxa (e.g., Nemouridae and Oligochaeta) were mildly affected by high metal concentrations. Chironomidae showed no significant decrease in densities with increasing dose. Chironomids made up >80% of the benthos and is the primary reason for no significant dose effect on overall densities. No treatment effect was observed on either algal standing crop or bacterial respiration rates. The invertebrate genera most affected by exposure to metals in this study were also absent or rare in nearby urban streams with high metal concentrations.

RESEARCH ON THE ENVIRONMENTAL QUALITY IN BRATIA RIVER

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Alina - Mihaela Truţă

2017-12-01

Full Text Available The main purpose of the study was to determine the quality of Bratia River. The present paper was based on the bibliographic material as well as the field research carried out during 2016-2017. The research objectives were the following: identification of qualitative and quantitative structure of phytobenthic biocenoses in the established monitoring points; determination of the phytoplankton algae families in the monitoring stations; identification of the structure of benthic biocenoses in the monitoring points; establishing saprobity indices for each species identified and incorporation of the monitoring sections into the appropriate saprobity class; determining the quality of Bratia River according to the Water Framework Directive 2000/60/EU. We have identified 54 species in the phytobenthonic samples, grouped in three phyla: Cyanobacteria, Bacillariophyta and Chlorophyta. We have also identified 47 species in the structure of benthic zoocenosis belonging to 25 families from 8 genera. The main benthic invertebrate groups in the Bratia River were: Ephemeroptera, Plecoptera, Chironomidae, Trichoptera, and Gammaridae. Oboarele Mari and Gămăceşti recorded a high quality ecological status, while Berevoiesti station had a good ecological status.

Effect of habitat improvement on Atlantic salmon in the regulated river Suldalslaagen

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Raastad, J.E.; Lillehammer, A.; Lillehammer, L. (Oslo Univ. (Norway). Zoological Museum); Kaasa, H. (Statkraft, Hoevik (Norway)); Eie, J.A. (Norwegian Water Resources and Energy Administration, Oslo (Norway))

1993-05-01

The River Suldaalslagen, which holds a population of large Atlantic salmon, has been regulated twice for hydropower production. The first regulation occurred in 1968 and the second in 1980. Present problems include the reduced density of benthic fauna, the reduced growth rate of young salmon, the low survival of 0[sup +] fish and the increased time required for smoltification. A programme of habitat restoration includes building a rearing channel system where water flow and the substrate can be controlled. The salmon fry are stocked in the rearing channel and in an adjacent tributary stream. The effects on macrobenthos of introduced dead organic material were also studied. Improvement of physical habitat increased the density of benthic animals, and the survival of 1[sup +] salmon was about 30%. Experiments that included adding 115 g wheat/m[sup 2] resulted in a threefold increase in benthic fauna compared with a control area. The largest increase in numbers was Chironomidae in August-September, when benthic Crustacea also showed a significant increase. An increase in macrobenthos is expected to increase the growth and survival of young salmon fry. (Author)

Benthic communities on hard substrates covered by Limnoperna fortunei Dunker (Bivalvia, Mytilidae at an estuarine beach (Río de la Plata, Argentina

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Fernando G. Spaccesi

2012-01-01

Full Text Available The structure and composition of benthic communities on hard substrates covered by the nonindigenous bivalve Limnoperna fortunei Dunker, the golden mussel, were quantified in the middle zone of the Río de la Plata Estuary (Argentina from April 2001 through March 2002. A total of 26 taxa were recorded. L. fortunei and Nematoda were the central and dominant groups, with a prodigious abundance of over 80%. The prevalence of L. fortunei, rather than the environmental variables, regulated the dynamics of the associated invertebrate fauna. The golden mussel alters both the structure and function of benthic native communities on hard substrates, allows a higher surface available for colonization and refuge, and provides food source to deposit-feeding organisms in the form of organic or residual material. The mussel also increases the abundance and diversity of taxa on hard substrata - such as Oligochaeta, Hirudinea, Tardigrada, Chironomidae, Copepoda, Tanaidacea, and Hydrachnidia. Similarities and nonparametric multidimensional-scaling analyses indicated that the benthic composition had a seasonal variation. L. fortunei has an environmental impact, an ability to invade new freshwater ambiences worldwide and ecological characteristic comparable to those of Dreissena polymorpha Pallas (the zebra mussel of North America and Europe.

Influence of acidification and aluminium on the density and biomass of lotic benthic invertebrates

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Allard, M.; Moreau, G.

1986-10-01

Experiments were carried out in plasticized wooden channels fed by a small creek in the Reserve des Laurentides, 80 km north of Quebec city. Channels were naturally colonized by invertebrates for 65 d before treatment. Treated channels were acidified in August with dilute H/sub 2/SO/sub 4/ only, or with acid plus a solution of Al sulfate (final concentration of 0.19 mg L/sup -1/). The control channel received creek water only (pH 6.3 to 6.9). The addition of Al had no effect on invertebrate density and biomass. After 73 d of acidification, invertebrate densities were only one third the number found in the control channel. Invertebrate biomass was not different within channels, although biomass was generally higher in the two acidified channels. Difference in densities between acidified and non-acidified channels was attributed to lack of colonization and not to an increase in drift. Microtendipes, a large and resistant larva of Chironomidae constituted a large fraction of the biomass, largely outweighing numerous very small larvae. Effects on the density were attributed to the direct effect of low pH and not to indirect action through food limitations. 22 refs.

Biology and chemistry of tree Pennsylvania lakes: responses to acid precipitation. [Lepomis gibbosus; Lepomis machrochirous

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Bradt, P.T.; Dudley, J.L.; Berg, M.B.; Barrasso, D.S.

1986-01-01

The biology and chemistry of three northeastern Pennsylvania lakes was studied from summer 1981 through summer 1983 to evaluate lakes with different sensitivities to acidification. At the acidifies lake (total alkalinity par. delta 0.0 ..mu..eq L/sup -1/) there were fewer phytoplankton and zooplankton species than at the moderately sensitive lakes. The most numerous plankton species in all three lakes are reportedly acid tolerant. Among the benthic macro- invertebrates (BMI) there were more acid tolerant Chironomidae at the acidified lake, but more acid intolerant Ephemeroptera and Mollusca and a higher wet weight at the least sensitive lake. There were no differences among the lakes' BMI mean total numbers or mean number of taxa. The fish community at the acidified lake was dominated by stunted Lepomis gibbosus, but L. machrochirous were most abundant in the other lakes. Principal component analysis suggested a shift in all three lakes over the sampling period toward combined lower pH, alkalinity, specific conductance, Ca, and Mg and higher Al and Mn. Such chemical changes have been associated with acidification. The rate and extent of acidification appeared to be controlled by geological and hydrological characteristics of the drainage basins.

The opportunistic feeding and reproduction strategies of the annual fish Cynopoecilus melanotaenia (Cyprinodontiformes: Rivulidae inhabiting ephemeral habitats on southern Brazil

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Cristina da Silva Gonçalves

Full Text Available Most Rivulidae fishes are popularly known as annual fishes which live in ephemeral environments such as pools, that obligatorily dry out seasonally causing the death of adult individuals. They have unique biological characteristics such as small body size, early sexual maturation, continuous reproduction, an elaborated courtship behavior, and a great reproductive capacity among fishes. The rivulids are widely distributed in North, Central and South America. In this study, the diet and reproductive biology of Cynopoecilus melanotaenia was analyzed. A total of 263 specimens were collected and the analysis of 233 gastrointestinal contents revealed an invertivorous diet composed mainly of small crustaceans (Cladocera, Amphipoda, and Ostracoda and immature insects (Chaoboridae, Culicidae, Syrphidae, but mainly Chironomidae larvae. Lepidophagy on male's diet was also registered. Fecundity was estimated by analyzing 59 pairs of mature ovaries and ranged from 2 to 157 oocytes (mean, 19 ± 26[SD]. The species has fractional spawning, a strategy to increase the chance of survival to prolonged depletions. This study is the first to investigate the reproductive biology of C. melanotaenia. The results confirmed the opportunistic character of the rivulid C. melanotaenia and provided unreported reproductive information that may aid conservation of the species.

The Benthonic Macroinvertebrates of Pozo Azul (Gaira River Basin, Colombia and their Relationship with Water Quality

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Francisco Guerrero-Bolaño

2003-07-01

Full Text Available On July 2002, a study of some physicochemical parameters and their relationship with the benthonic macroinvertebrates community structure on four coriotypes: stone, trash, silt and macrophytes, was carried out in Pozo Azul (Gaira River basin, Magdalena, Colombia. The physicochemical parameters were determined, to a considerable extent, by the geographic characteristics of the system. The water was found to be oxygen saturated, and intermediate compounds of the organic matter stabilization, such as nitrites and ammonium, there were found 588 individuals distributed in 11 orders and 38 families. The most representative orders were Trichoptera, Coleoptera, Diptera and Ephemeroptera. The most representative families were Baetidae, Simullidae, Perlidae, Chironomidae, and Hydropsychidae, in this rank of abundance. The BMWP index for the relationship between the community structure and the water quality (adapted by Universidad del Valle, Cali, Colombia was calculated. According to this index the water quality was optimum. Also, given the general characteristics of the site studied, the water mass quality was classified as good and oligosaprobit, based on the saprobit ecology. It is possible that this state was reached due to stabilization after a small perturbation induced by coffee cultivation in the zone.

Effects of logging on macroinvertebrates in streams with and without buffer strips

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Newbold, J D; Erman, D C; Roby, K B

1980-01-01

The impact of logging with and without buffer strip protection on stream macroinvertebrates was examined through comparisons of community structure in commercially logged and control watersheds throughout northern California. A nonparametric test of community dissimilarities within matched blocks of two control and one or two treated stations showed significant (P < 0.05) logging effects on unprotected streams when Euclidean distance and mutual information were used as dissimilarity indices, but not when chord distance was used. Shannon diversity in unprotected streams was lower (P < 0.01) than in control (unlogged) streams; densities of total macroinvertebrate fauna and of Chironomidae, Baetis, and Nemoura were higher in unprotected streams than in controls (P <0.05). Streams with narrow buffer strips (<30 m) showed significant effects by the Euclidean distance test, but diversity varied widely and was not significantly different from that in either unprotected or control streams than in controls (P < 0.05). Macroinvertebrate communities in streams with wide buffers (greater than or equal to 30m) could not be distinguished from those of controls by either Euclidean distance or diversity; however, diversity in wide-buffered streams was significantly greater than in streams without buffer strips, indicating effective protection from logging effects.

Structure of the macrozoobenthos as an indicator of different types of pollution in running waters

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Simić Vladica M.

2002-01-01

Full Text Available Hydrobiological research on streams with different dominant forms of pollution (anthropogenic eutrophication, organic pollution, toxic pollution, trans-saprobic pollution in the central part of the Balkan Peninsula (territory of Serbia and Montenegro indicates that these different forms of pollution can be detected on the basis of structure of the macrozoobenthos community and individual indicator taxa. It is established from the obtained results that the greatest community diversity occurs in the case of anthropogenic eutrophication or weak organic pollution as a dominant process, where phytophilous and/or detritophagic forms (Cloeon, Polypedilum, Asellus, Stylaria, Erpobdella, Gammarus are dominant in the community. In the cases of very strong organic pollution, the macrozoobenthos community is characterized by mass development of certain taxa of the group Oligochaeta (Tubificidae and Chironomidae larvae {Chironomus gr. thummi. Depending on the strength and contribution of organic, toxic, and/or transsaprobic components, toxic pollution and mixed pollution arc characterized by a more or less heterogeneous and nonspecific population. However, a common feature is the presence of a small number of taxa with populations of a relatively low density, or the occurrence of individual specimens belonging to different groups of animals.

The benthonic macro invertebrates of Pozo Azul (Gaira River basin, Colombia) and their relationship with water quality

International Nuclear Information System (INIS)

Guerrero Bolano, Francisco; Manjares Hernandez, Ana; Nunez Padilla, Norbelis

2003-01-01

On July 2002, a study of some physicochemical parameters and their relationship with the benthonic macro invertebrates community structure on four coriotypes: stone, trash, silt and macrophytes, was carried out in Pozo Azul (Gaira River Basin, Magdalena, Colombia). The physicochemical parameters were determined, to a considerable extent, by the geographic characteristics of the system. The water was found to be oxygen saturated, and intermediate compounds of the organic matter stabilization, such as nitrites and ammonium, there were found 588 individuals distributed in 11 orders and 38 families. The most representative orders were trichoptera, coleoptera, diptera and ephemeroptera. The most representative families were baetidae, simullidae, perlidae, chironomidae, and hydropsychidae, in this rank of abundance. The BMWP index for the relationship between the community structure and the water quality (adapted by Universidad del Valle, Cali, Colombia) was calculated. According to this index the water quality was optimum. Also, given the general characteristics of the site studied, the water mass quality was classified as good and oligosaprobit, based on the saprobit ecology. It is possible that this state was reached due to stabilization after a small perturbation induced by coffee cultivation in the zone

Effects of sea lamprey substrate modification and carcass nutrients on macroinvertebrate assemblages in a small Atlantic coastal stream

Science.gov (United States)

Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.

2018-01-01

Aquatic macroinvertebrates respond to patch dynamics arising from interactions of physical and chemical disturbances across space and time. Anadromous fish, such as sea lamprey, Petromyzon marinus, migrate from the ocean and alter physical and chemical properties of recipient spawning streams. Sea lamprey disturb stream benthos physically through nest construction and spawning, and enrich food webs through nutrient deposition from decomposing carcasses. Sea lamprey spawning nests support greater macroinvertebrate abundance than adjacent reference areas, but concurrent effects of stream bed modification and nutrient supplementation have not been examined sequentially. We added carcasses and cleared substrate experimentally to mimic the physical disturbance and nutrient enrichment associated with lamprey spawning, and characterized effects on macroinvertebrate assemblage structure. We found that areas receiving cleared substrate and carcass nutrients were colonized largely by Simuliidae compared to upstream and downstream control areas that were colonized largely by Hydropsychidae, Philopotamidae, and Chironomidae. Environmental factors such as stream flow likely shape assemblages by physically constraining macroinvertebrate establishment and feeding. Our results indicate potential changes in macroinvertebrate assemblages from the physical and chemical changes to streams brought by spawning populations of sea lamprey.

Biodiversity of benthic macroinvertebrates in Air Terjun Asahan, Asahan, Melaka, Malaysia

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Nurhafizah-Azwa, S.; Ahmad A., K.

2016-11-01

A study on benthic macroinvertebrate diversity was conducted at Air Terjun Asahan, Asahan, Melaka. Five stations were selected with distance intervals of approximately 500 metres. Three replicates of benthic macroinvertebrate and water samples were taken. Results classified Air Terjun Asahan in class II, which indicated good water quality based on WQI recommended by the Department of Environment. A total of 1 phylum, 2 classes, 6 order, 30 families, and 2183 individuals were successfully sampled and recorded. The analysis showed that the average value of Shannon Diversity Index, H' (2.19), Pielou Evenness Index, J' (0.30), and Margaleff Richness Index, DMG (3.77) described that Air Terjun Asahan was in moderate condition and the distribution of macroinvertebrates was uniform between stations. Correlation test showed that the WQI had a strong relationship with the diversity indices involved. BMWP, and FBI showed that Air Terjun Asahan was in good water quality. CCA test was conducted to show environmental factors towards benthic macroinvertebrate distribution. The presence of Leptophlebiidae, Baetidae, Heptageniidae and Chironomidae with high abundance of the families showed the potential as biological indicators of a clean ecosystem.

Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2008 and January 2009

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May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

2009-01-01

This report presents the results for two sampling periods (October 2008 and January 2009) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples. Total selenium also was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.00 to 33.6 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 1.52 to 8.26; plankton, 0.79 to 3.66; midges, 2.68 to 50.6; fish, 3.09 to 30.4; detritus, 1.78 to 58.0; and sediment, 0.42 to 10.0.

Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2008

Science.gov (United States)

May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

2009-01-01

This report presents the results for two sampling periods (April 2008 and July 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples and total selenium was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species - western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.93 to 44.2 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.75 to 3.39; plankton, 0.88 to 4.03; midges, 2.52 to 44.3; fish, 3.37 to 18.9; detritus, 1.11 to 13.6; sediment, 0.11 to 8.93.

Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2007 and January 2008

Science.gov (United States)

May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

2008-01-01

This report presents the results for two sampling periods (October 2007 and January 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (selenite, selenate, organoselenium), and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species?western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 0.97 to 64.5 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.95 to 5.99; plankton, 0.15 to 19.3; midges, 1.39 to 15.4; fish, 3.71 to 25.1; detritus, 0.85 to 21.7; sediment, 0.32 to 7.28.

A biodiversidade bentônica em lagoa marginal ao rio Paranapanema na zona de sua desembocadura, na represa de Jurumirim - DOI: 10.4025/actascibiolsci.v28i4.166 The benthic biodiversity in a lake marginal to the Paranapanema river in its mouth zone into Jurumirim reservoir- DOI: 10.4025/actascibiolsci.166

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Rosemary Cristina Souza Davanso

2007-11-01

Full Text Available O presente trabalho teve como objetivo principal verificar a biodiversidade bentônica em áreas do fundo da lagoa do Coqueiral, zona de desembocadura do rio Paranapanema, na represa de Jurumirim, Estado de São Paulo. Foram selecionados dezoito pontos de amostragem, englobando áreas rasas e áreas profundas. As coletas foram feitas em intervalos trimestrais ao longo de um ano; também foram analisadas as variáveis físicas e químicas da água (nível, transparência, temperatura, oxigênio dissolvido, pH e condutividade elétrica. Amostras do sedimento, para análise da fauna e de fatores abióticos (granulometria e conteúdo orgânico, foram recolhidas em tréplicas, utilizando como coletor a draga de Petersen. O material foi triado e analisado sob microscópio estereoscópico. Contagem e identificação dos organismos foram realizadas, e densidade, abundância relativa, riqueza taxonômica e índice de dominância foram calculados. A análise revelou uma fauna com baixa diversidade e a dominância de Chironomidae e Ephemeroptera. Domínio de Ephemeroptera, constituído por Campsurus, ocorreu no período mais quente do ano e com baixa profundidade da lagoa. A distribuição dos organismos teve como principais fatores determinantes profundidade, transparência, pH e temperatura da água. Na comparação feita entre áreas rasas e profundas, foi observada uma menor densidade de organismos nas regiões profundas.Coqueiral lake is a marginal lake located at the southeast São Paulo State, in the mouth zone of the Paranapanema river into Jurumirim Reservoir and it has high connectivity with the Paranapanema river. This work aimed to verify the benthic biodiversity in areas of the lake bottom. 18 sampling sites in the lake were selected, including shallow and deep areas. The samples were taken every three months during one year. Physical and chemical water variables (level, transparency, dissolved oxygen, pH, and electric conductivity were

A biodiversidade bentônica em lagoa marginal ao rio Paranapanema na zona de sua desembocadura, na represa de Jurumirim = The benthic biodiversity in a lake marginal to the Paranapanema river in its mouth zone into Jurumirim reservoir

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Rosemary Cristina Souza Davanso

2006-10-01

Full Text Available O presente trabalho teve como objetivo principal verificar a biodiversidade bentônica em áreas do fundo da lagoa do Coqueiral, zona de desembocadura do rio Paranapanema, na represa de Jurumirim, Estado de São Paulo. Foram selecionados dezoito pontos de amostragem, englobando áreas rasas e áreas profundas. As coletas foram feitas emintervalos trimestrais ao longo de um ano; também foram analisadas as variáveis físicas e químicas da água (nível, transparência, temperatura, oxigênio dissolvido, pH e condutividade elétrica. Amostras do sedimento, para análise da fauna e de fatores abióticos(granulometria e conteúdo orgânico, foram recolhidas em tréplicas, utilizando como coletor a draga de Petersen. O material foi triado e analisado sob microscópio estereoscópico. Contagem e identificação dos organismos foram realizadas, e densidade, abundância relativa, riqueza taxonômica e índice de dominância foram calculados. A análiserevelou uma fauna com baixa diversidade e a dominância de Chironomidae e Ephemeroptera. Domínio de Ephemeroptera, constituído por Campsurus, ocorreu no período mais quente do ano e com baixa profundidade da lagoa. A distribuição dos organismos teve como principais fatores determinantes profundidade, transparência, pH etemperatura da água. Na comparação feita entre áreas rasas e profundas, foi observada uma menor densidade de organismos nas regiões profundas.Coqueiral lake is a marginal lake located at the southeast São Paulo State, in the mouth zone of the Paranapanema river into Jurumirim Reservoir and it has high connectivity with the Paranapanema river. This work aimed to verify the benthic biodiversity in areas of the lake bottom. 18 sampling sites in the lake were selected, including shallow and deep areas. The samples were taken every three months during one year. Physical and chemical water variables (level, transparency, dissolved oxygen, pH, and electric conductivity were analyzed

Records of the Genus Paramerina (Diptera: Chironomidae: Tanypodinae) from Eastern Himalaya and Satpura Hill Regions of India.

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Paul, N; Hazra, N; Mazumdar, A

2013-10-01

The pupa and the male imago of Paramerina valida n. sp. and the larva of Paramerina inficia Chaudhuri & Debnath are described and illustrated along with a brief re-description of the adult of P. inficia from the Eastern Himalaya and Satpura hill regions of India. A key to the adult males of the Indian species of the genus Paramerina Fittkau is provided. The notes on ecology of the two species are also provided.

A review of the genus Parorthocladius Thienemann, 1935 (Diptera: Chironomidae: Orthocladiinae) from the Russian Far East.

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Makarchenko, Eugenyi A; Makarchenko, Marina A

2015-06-23

Three new species of the genus Parorthocladius Thienemann, P. lazovskiensis sp. nov., P. plolabius sp. nov., and P. tyurkini sp. nov. from the Russian Far East are described and figured. Descriptions of pupae and larvae of one indeterminate species, Parorthocladius sp. 1, are also presented. Keys to determination of adult males, pupae and fourth instar larvae of Far-Eastern species Parorthocladius are provided.

Synthesis of a posterior indicator protein in normal embryos and double abdomens of Smittia sp. (Chironomidae, Diptera).

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Jäckle, H; Kalthoff, K

1980-01-01

In embryos of the chironomid midge Smittia, synthesis of a posterior indicator protein designated PI1 (Mr approximately 50,000; pI approximately 5.5) forecasts development of an abdomen as opposed to head and thorax. The protein is synthesized several hours before germ anlage formation. In normal embryos at early blastoderm stages, synthesis of PI1 is restricted to posterior embryonic fragments but not to pole cells. In "double-abdomen" embryos, a mirror-image duplication of the abdomen is formed by cells that would otherwise develop into head and thorax. Embryos were programmed for double-abdomen development by UV irradiation of the anterior pole, and half of them were reprogrammed for normal development by subsequent exposure to visible light (photoreversal). Correspondingly, PI1 was synthesized in anterior fragments of UV-irradiated embryos but not after photoreversal. In a control experiment, UV irradiation of the posterior pole caused neither double-abdomen formation nor PI1 synthesis in anterior fragments. The identity of PI1 formed in anterior fragments of prospective double abdomens with the protein found in posterior fragments was revealed by two-dimensional gel electrophoresis and limited proteolysis. Suppression of PI1 synthesis in anterior fragments of normal embryos is ascribed to the activity of cytoplasmic ribonucleoprotein particles thought to act as anterior determinants. Images PMID:6935679

A new species of Cladotanytarsus (Lenziella) from Oregon supports the systematic concept of the subgenus (Diptera: Chironomidae).

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Puchalski, Mateusz; Giłka, Wojciech

2017-05-18

A new species of the genus Cladotanytarsus Kieffer, 1921 and the small subgenus Lenziella Kieffer, 1922 is described from Southern Oregon, USA. The adult male of C. (L.) glaber Giłka et Puchalski, sp. nov., featuring tibial lobes armed with dense setae and a large globular swelling of the hypopygial inferior volsella, supports the recently defined systematic concept for Lenziella. This subgenus is known from seven species distributed in the Northern Hemisphere (1 European, 1 Palaearctic and 5 Nearctic), the males of which are included in an updated identification key.

Cladotanytarsus Kieffer (Diptera: Chironomidae): several distinctive species reviewed on the basis of records from Canada and USA.

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Puchalski, Mateusz; Giłka, Wojciech

2017-03-10

Two species of the genus Cladotanytarsus Kieffer, 1921 are described as adult males, both peculiar in having distinctively elongated hypopygial anal points. The male of Cladotanytarsus bilyji Giłka et Puchalski, sp. nov. (Canada, Manitoba; USA, Ohio) is presumed to be a close relative of C. nigrovittatus (Goetghebuer, 1922). Another unknown Cladotanytarsus species (USA, Illinois and Louisiana) keys with the European C. donmcbeani Langton et McBean, 2010. The intraspecific variability of the male C. acornutus Jacobsen et Bilyj, 2007 is also presented on the basis of new records (Canada, Ontario; USA, South Carolina). Cladotanytarsus males with similarly structured elongate anal points are reviewed, including C. tobaquardecimus Kikuchi et Sasa, 1990, considered a junior synonym (syn. nov.) of C. conversus (Johannsen, 1932). As a compilation of this study, a key to the identification of the adult males of 14 Cladotanytarsus species is provided.

Morphological identification and COI barcodes of adult flies help determine species identities of chironomid larvae (Diptera, Chironomidae).

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Failla, A J; Vasquez, A A; Hudson, P; Fujimoto, M; Ram, J L

2016-02-01

Establishing reliable methods for the identification of benthic chironomid communities is important due to their significant contribution to biomass, ecology and the aquatic food web. Immature larval specimens are more difficult to identify to species level by traditional morphological methods than their fully developed adult counterparts, and few keys are available to identify the larval species. In order to develop molecular criteria to identify species of chironomid larvae, larval and adult chironomids from Western Lake Erie were subjected to both molecular and morphological taxonomic analysis. Mitochondrial cytochrome c oxidase I (COI) barcode sequences of 33 adults that were identified to species level by morphological methods were grouped with COI sequences of 189 larvae in a neighbor-joining taxon-ID tree. Most of these larvae could be identified only to genus level by morphological taxonomy (only 22 of the 189 sequenced larvae could be identified to species level). The taxon-ID tree of larval sequences had 45 operational taxonomic units (OTUs, defined as clusters with >97% identity or individual sequences differing from nearest neighbors by >3%; supported by analysis of all larval pairwise differences), of which seven could be identified to species or 'species group' level by larval morphology. Reference sequences from the GenBank and BOLD databases assigned six larval OTUs with presumptive species level identifications and confirmed one previously assigned species level identification. Sequences from morphologically identified adults in the present study grouped with and further classified the identity of 13 larval OTUs. The use of morphological identification and subsequent DNA barcoding of adult chironomids proved to be beneficial in revealing possible species level identifications of larval specimens. Sequence data from this study also contribute to currently inadequate public databases relevant to the Great Lakes region, while the neighbor-joining analysis reported here describes the application and confirmation of a useful tool that can accelerate identification and bioassessment of chironomid communities.

Study of the role of biotic and abiotic factors in modifying metal accumulation by Chironomus (Diptera: Chironomidae)

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Krantzberg, G.B.

1987-01-01

The author examined the variability in metal bioaccumulation by chironomids collected from sites that differed in the extent of metal and acid loadings. Bioaccumulation by Chironomus was related to both biotic and abiotic factors. Metal accumulation was age and weight dependent. Aluminum, Ca, and Fe concentrations increased with age, Cd and Ni decreased, and Cu, Mn, Pb, and Zn remained constant with age. Calcium, Fe, and Ni concentration increased with weight, Cd decrease, and Cu, Mn, and Zn remained constant with weight. Age and weight effects on metal accumulation were identified as a potential source of spacial and temporal variability in tissue concentrations. Metal regulation differed between populations of Chironomus. Lead and Cd were not regulated, Zn was regulated, and larvae from a Cu and Ni contaminated system appeared to regulate Cu and Ni. X-ray probe microanalysis provided further support that metal metabolism differed between population, and results from laboratory experiments suggested that populations differed in relation to metal tolerance. There was evidence that pH modified metal accumulation.

Effects of exposure to azaarenes on emergence and mouthpart development in the midge Chironomus riparius (Diptera: Chironomidae)

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Bleeker, E.A.J.; Leslie, H.A.; Groenendijk, D.; Plans, M.; Admiraal, W.

1999-08-01

Adverse effects of azaarenes on emergence and mouthpart development of the midge Chironomus riparius were analyzed using six closely related three-ringed isomers and metabolites. Effects on growth rate were examined by comparing the average day of emergence of exposed midges with that of controls. Fluctuating asymmetry (FA) in the pecten epipharyngis was examined as a measure of developmental abnormality. Delayed emergence was found at concentrations as low as 2% of the acute LC50, so emergence day appears to be a useful sensitive parameter to quantity life cycle effects. No differences in FA were found between exposed and control larvae, although, in other studies, all compounds have been proven to be genotoxic. The differences in FA were found between exposed and control larvae, although, in other studies, all compounds have been proven to be genotoxic. The differences in the genotoxic and FA-inducing properties of these compounds indicate that different mechanisms are involved in expressing these adverse effects. This study also illustrates that the choice of the morphological parameter strongly influences the results of developmental disturbance analyses and thus the risk qualification of a potentially hazardous compound.

Blind Flight? A New Troglobiotic Orthoclad (Diptera, Chironomidae) from the Lukina Jama – Trojama Cave in Croatia

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Ivković, Marija; Kvifte, Gunnar Mikalsen; Pavlek, Martina

2016-01-01

The genus Troglocladius Andersen, Baranov et Hagenlund, gen. n. is erected based on T. hajdi Andersen, Baranov et Hagenlund, sp. n. collected at 980 m depth in the Lukina jama—Trojama cave system in Croatia. Morphological features such as pale color, strongly reduced eyes and very long legs make it a typical cave animal. Surprisingly, it has also retained large wings and appears to be capable of flight which would make T. hajdi the first flying troglobiont worldwide, disproving previous beliefs that bats are the only animals capable of flying in complete darkness. Morphologically the new species does not readily fit within any described genus, but shares characteristics with genera both in the tribes “Metriocnemini” and “Orthocladiini”. Bayesian molecular phylogenetic analysis using the markers COI, 18S rDNAs, 28S rDNA, CADI, and CADIV groups it with the genera Tvetenia, Cardiocladius and Eukiefferiella in the tribe “Metriocnemini”. Troglocladius hajdi may be parthenogenetic, as only females were collected. The discovery confirms the position of the Dinaric arch as a highly important hotspot of subterranean biodiversity. PMID:27119557

A new orthoclad species of Rheocricotopus Thienemann & Harnisch (Diptera, Chironomidae from the Darjeeling-Sikkim Himalayas in India

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Hazra, N.

2004-12-01

Full Text Available The adults and pupa of a new species, Rheocricotopus rarispina are described from the Darjeeling-Sikkim Himalayas in India. The species is distinguished by the few spines on the thoracic horn, anal lobe without fringe and bristle-like L setae and presence of ovoid humeral pit, nine squamal setae, structure of anal point and triangular and subterminal crista dorsalis in the adult male. With this new species, the number of Indian species of the genus rises to six.

Two new species of the acifer species group of Polypedilum subgenus Tripodura Townes from China (Diptera: Chironomidae).

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Zhang, Ruilei; Song, Chao; Wang, Liqing; Wang, Xinhua

2015-02-13

Polypedilum (Tripodura) falcatum sp. n. and P. (T.) procerum sp. n. of the acifer species group of Polypedilum subgenus Tripodura Townes are described and illustrated as male imagines from China. The male adult of P. (T.) falcatum sp. n. is distinguished by the presence of two faint markings on wing; short and interrupted abdominal tergite bands; the sickle-like superior volsella bearing 0-2 outer setae and a tuft of short setae on its apex. The male adult of P. (T.) procerum sp. n. differs in having short abdominal tergite bands; a long, slender and apically curved superior volsella; a high fore leg ratio (2.30-2.33). A key to known male imagines of Polypedilum subgenus Tripodura from China is presented.

Histopathological effects of cypermethrin and Bacillus thuringiensis var. israelensis on midgut of Chironomus calligraphus larvae (Diptera: Chironomidae).

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Lavarías, Sabrina; Arrighetti, Florencia; Siri, Augusto

2017-06-01

Pesticides are extensively used for the control of agricultural pests and disease vectors, but they also affect non-target organisms. Cypermethrin (CYP) is a synthetic pyrethroid used worldwide. Otherwise, bioinsecticides like Bacillus thuringiensis var. israelensis (Bti) have received great attention as an environmentally benign and desirable alternative. In order to evaluate the toxicity of those pesticides, Chironomus calligraphus was selected due to its high sensitivity to some toxicants. Third and fourth instars larvae were exposed to serial dilutions of CYP and Bti to determine LC 50 values. In order to evaluate the potentially histopathological alterations as biomarkers, after 96-h of exposure, live larvae were fixed for histological analysis of the mid region of digestive tract. The 96-h LC 50 values were 0.52 and 1.506μg/L for CYP and Bti, respectively. Midgut histological structure of the control group showed a single layer of cubical cells with microvilli in their apical surface and a big central nucleus. The midgut epithelium of larvae exposed to a low concentration of CYP (0.037μg/L) showed secretion activity and vacuolization while at high concentration (0.3μg/L) cells showed a greater disorganization and a more developed fat body. On the other hand, Bti caused progressive histological damage in this tissue. Chironomus calligraphus is sensitive to Bti and CYP toxicity like other Chironomus species. The histopathological alterations could be a valuable tool to assess toxicity mechanism of different pesticides. Copyright © 2017 Elsevier Inc. All rights reserved.

Patterns of Fluctuating Asymmetry and Shape Variation in Chironomus riparius (Diptera, Chironomidae) Exposed to Nonylphenol or Lead

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Arambourou, Hélène; Beisel, Jean-Nicolas; Branchu, Philippe; Debat, Vincent

2012-01-01

Deformities and fluctuating asymmetry in chironomid larvae have been proposed as sensitive indicators of biological stress and are commonly used to assess the ecological impact of human activities. In particular, they have been associated in Chironomus riparius, the most commonly used species, with heavy metal and pesticide river pollution. In this study, the effect of lead and 4-nonylphenol on mouthpart morphological variation of Chironomus riparius larvae was investigated by traditional and geometric morphometrics. For this purpose, first to fourth instar larvae were exposed to sediment spiked with lead (from 3.0 to 456.9 mg/kg dry weight) or 4-NP (from 0.1 to 198.8 mg/kg dry weight). Mentum phenotypic response to pollutants was assessed by four parameters: (1) the frequency of deformities, (2) fluctuating asymmetry of mentum length, (3) fluctuating asymmetry of mentum shape and (4) the mentum mean shape changes. Despite the bioaccumulation of pollutants in the chironomid’s body, no significant differences between control and stressed groups were found for mouthpart deformities and fluctuating asymmetry of mentum length. Slight effects on mentum shape fluctuating asymmetry were observed for two stressed groups. Significant mean shape changes, consisting of tooth size increase and tooth closing, were detected for lead and 4-NP exposure respectively. Those variations, however, were negligible in comparison to mentum shape changes due to genetic effects. These results suggest that the use of mentum variation as an indicator of toxic stress in Chironomus riparius should be considered cautiously. PMID:23133660

Quaternary paleoecology of aquatic Diptera in tropical and Southern Hemisphere regions, with special reference to the Chironomidae

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Verschuren, Dirk; Eggermont, Hilde

2006-08-01

Chironomid paleoecology in north-temperate regions has made tremendous progress over the past decade, but studies in tropical and Southern Hemisphere regions remain relatively scarce. Reasons for this imbalance are (1) incomplete taxonomic knowledge of chironomid faunas outside Europe and North America, (2) a scarcity of ecological data on local species and genera that might confer bio-indicator value to them, and (3) logistic difficulties hampering the lake surveying necessary to develop paleoenvironmental calibration data sets. Thus far, most chironomid paleoecology in tropical and Southern Hemisphere regions has relied on an indicator-species approach, combining autecological information on local species of which larval morphology is known with the traditional ecological typology of chironomid genera transferred from the Holarctic region. This paper reviews work accomplished to date in tropical and temperate South America, Australia, Africa, and New Zealand, including studies on various families of non-chironomid Diptera with diagnostic fossils. Research has focused mostly on late-Glacial and Holocene climate reconstruction, less on tracing past human disturbance of aquatic ecosystems and their drainage basins. Quantitative chironomid-based paleoenvironmental reconstruction has so far been done only in Australia and Africa. These studies compensated for the lack of traditional surface-sediment calibration data sets, nowadays often the main source of quantitative information on species ecological optima and tolerances, by maximally exploiting archival species-distribution data based on live collections of adult and/or larval midges. This stimulated efforts to achieve trustworthy species-level identification of fossil chironomid remains, and, as a result, the taxonomic resolution of paleoecological studies in Australia and Africa is higher on average than that achieved in European and North American studies.

Mouthpart deformities in Chironomidae (Diptera) as bioindicators of heavy metals pollution in Shiroro Lake, Niger State, Nigeria.

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Arimoro, Francis O; Auta, Yohanna I; Odume, Oghenekaro N; Keke, Unique N; Mohammed, Adamu Z

2018-03-01

In this study, mouthpart deformities in Chironomid larvae (Diptera) were investigated in relation to sediment contamination in the Shiroro Lake in Nigeria. Metals and chironomids were sampled monthly at three stations (A-C) between August 2013 and January 2014. Across the stations, zinc ranged (3.9-75mg/g), manganese (1.29-1.65mg/g), lead (0.00-0.10mg/g), iron (101-168mg/g) and copper (0.13-0.17mg/g). The metal ions did not differ significantly (P > 0.05) between the sampling stations. However, zinc and iron ions were significantly different between the sampling seasons (P < 0.05). Thirteen chironomid species were recorded, with Chironomus sp., Polypedilum sp. and Ablabesmyia sp. dominating the assemblage structure. Mouthpart deformities were significantly higher at Station A compared with Station C, and seasonally significantly higher during dry season compared with wet season. Elevated incidences of deformity were recorded in Chironomus spp larvae as compared to other genera therefore for further studies in this region assessments should be based solely on Chironomus species and ignoring the rest. Strategies need to be developed to reduce the contaminations and the biological effects. Copyright © 2017 Elsevier Inc. All rights reserved.

Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system

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M. Prus

2002-02-01

Full Text Available The cascade of Solina/Myczkowce dam reservoirs situated in the West Carpathian Mts was investigated. The cascade consists of two reservoirs, the upper one built 35 yr ago on the San and Solinka Rivers of 2100 ha area separated from another one, of 190 ha area, with hypolimnion cold water supplied from the upper one.

The offshore zone was investigated monthly (6 sites of upper, 3 sites of lower reservoir using a tube bottom sampler. Besides numbers, biomass and biodiversity indices, the proportion of predators, plant/detritus-feeders and filter-feeders was assessed.

In upper reservoir Solina, with a lack of filter-feeders, a clear preponderance of plant-detritus feeders was observed. Predators, consisting mostly of leeches and hydranchnellids were present. In lower reservoir Myczkowce, all three trophic classes were present in the first year of study in almost equal proportions and in 1998 with slight preponderance of plant/detritus feeders was observed.

The Oligochaeta/Chironomidae index in both reservoirs was low, indicating low degree of eutrophication. Only one site in Solina reservoir (near a fish culture and one in Myczkowce (influenced by tourist activity showed a high value of this index.

Macroinvertebrate Richness Importance in Coastal Tropical Streams of Esmeraldas (Ecuador and Its Use and Implications in Environmental Management Procedures

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Carlos Martínez-Sanz

2014-01-01

Full Text Available This study was aimed at determining the performance of some indices and community attributes frequently used to assess river quality and test the role of macroinvertebrate taxa richness as element of bioindication in several coastal tropical streams of western Esmeraldas (Ecuador. In addition, a macroinvertebrate taxon list of this region was provided for the first time. Thirteen sampled points distributed across nine streams were selected for this study and nineteen parameters and attributes of bioindication were tested. The differences between nonimpact and impact places were evaluated mainly using one-way analysis of variance. Jackknife 2 and Clench were used to estimate the regional richness and the quality of the inventory, respectively. Seventy taxa (principally genus and family of the main groups of macroinvertebrates were collected. Measured richness and family richness were the best metric followed by Biological Monitoring Working Party/Colombia (BMWP/Col, Odonata richness, Shannon-Weiner, and EPT richness (Ephemeroptera + Plecoptera + Trichoptera indices. Only a slight right trend (Ephemeroptera, Trichoptera, and Chironomidae attributes or incorrect performances (Average Score Per Taxon (ASPT and % EPT were showed by frequently used metrics. Finally, several recommendations were made about taxonomic level used, the ranks of quality of taxa richness, and the effort-results relationship in the field of bioindication.

Development of a benthic multimetric index for biomonitoring of a neotropical watershed

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WR. Ferreira

Full Text Available Biotic indices are important tools for evaluating water quality in Biomonitoring Programmes of river basins. The objective of this study was to develop a Benthic Multimetric Index (BMI to evaluate the water quality in a neotropical catchment in southeastern Brazil. Thirty metrics were evaluated and six were selected to calculate the BMI: family richness, % Oligochaeta, % Chironomidae + Oligochaeta (% CHOL, % EPT (Ephemeroptera, Plecoptera and Trichoptera, % Collector-gatherers, and BMWP-CETEC biotic index. Sampling was carried in triplicate at 21 sampling sites (8 in the river channel and 13 in the tributaries during 4 annual collecting trips from June 2004 to November 2007, making a total of 945 samples. Scores (5, 3 or 1 were attributed to each chosen metric and were added up to establish the water quality criteria (a score of 6-12 - poor; 13-18 - intermediate; 19-24 - good; and 25-30 - very good water quality. Our results indicated that 48% of the sampling sites analysed in the catchment basin presented very good water quality, 14% good quality, 19% regular, and 19% poor water quality. This methodology proved to be an efficient tool for evaluating water quality in the Biomonitoring Programme of the Velhas River basin, and that it may serve to evaluate water quality in other river basins in South America.

Biodiversity assessment of benthic macroinvertebrates along a reservoir cascade in the lower São Francisco river (northeastern Brazil

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M. Callisto

Full Text Available In order to verify the cascade-system effect in benthic macroinvertebrate communities, and the implications for policy making and proposals for conservation and sustainable use of the lower portion of São Francisco river basin (Bahia State, Brazil, a three-reservoir cascade system including two stretches downstream were studied during dry (June, 1997 and rainy (March, 1998 periods. The dominant groups found were Mollusca (Melanoides tuberculata, Oligochaeta, and Chironomidae larvae. Low Shannon-Wiener and Pielou index values were found, but with no significant difference between the sampling periods. However, density and taxonomic richness were significantly different (t(0.05; 31 = -2.1945; p < 0.05; e t(0.05; 31 = -3.0600; p < 0.01 between the sampling periods, with a reduction in the number of taxaand macroinvertebrate abundance during the rainy period. An increasing gradient in benthic macroinvertebrate community structures was noted along the reservoir cascade from the first reservoir (Apolônio Sales, followed by a decrease downstream from the third reservoir of the system (Xingó. Despite the negative consequences of rapid proliferation of dams, which have caused widespread loss of freshwater habitats, the reservoir cascade system promoted an increase in benthic macroinvertebrate diversity, due to water-quality improvement along the system.

Feeding of larvae of the hybrid surubim Pseudoplatystoma sp. under two conditions of food management - doi: 10.4025/actascibiolsci.v35i2.15359

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Aryadne Simões Rocha

2013-05-01

Full Text Available We evaluated the growth and diet composition of hybrid surubim larvae (Pseudoplatystoma corruscans x P. reticulatum produced in two fish farming by using different systems of feeding with natural plankton: M I, larvae are transferred to fertilized fish pond for being freely fed with natural plankton; M II, larvae are remained inside laboratory in glass fiber boxes and plankton are gathered with a plankton net and offered in a controlled way. It was collected 10 individuals daily during the feeding period with live plankton for 20 days. After the biometry, stomachs were opened and the food items identified and quantified by the volumetric method. The items were represented by algae, protozoa, microcrustacean, insect larvae and surubim fragments (cannibalism. The items with higher volumetric percentage were Chironomidae larvae (29.25% followed by surubim fragments (19.68% in M I, and surubim fragments (21.85% and Moina micrura (19.97% in MII. The items Chydorus sp., Diaphanosoma sp., sp. Macrothrix and Ephemeroptera larvae were found only in fish of M I, while algae Ulothrix sp., Oscillatoria sp. and the protozoa Difflugia sp were only found in stomachs of surubim from M II. Regarding the growth, the surubim had grown faster in M I.

Extraction of methylmercury from tissue and plant samples by acid leaching

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Hintelmann, Holger; Nguyen, Hong T. [Trent University, Chemistry Department, Peterborough, ON (Canada)

2005-01-01

A simple and efficient extraction method based on acidic leaching has been developed for measurement of methylmercury (MeHg) in benthic organisms and plant material. Methylmercury was measured by speciated isotope-dilution mass spectrometry (SIDMS), using gas chromatography interfaced with inductively coupled plasma mass spectrometry (GC-ICP-MS). Reagent concentration and digestion temperature were optimized for several alkaline and acidic extractants. Recovery was evaluated by addition of MeHg enriched with CH{sub 3}{sup 201}Hg{sup +}. Certified reference materials (CRM) were used to evaluate the efficiency of the procedure. The final digestion method used 5 mL of 4 mol L{sup -1} HNO{sub 3} at 55 C to leach MeHg from tissue and plant material. The digest was further processed by aqueous phase ethylation, without interference with the ethylation step, resulting in 96{+-}7% recovery of CH{sub 3}{sup 201}Hg{sup +} from oyster tissue and 93{+-}7% from pine needles. Methylmercury was stable in this solution for at least 1 week and measured concentrations of MeHg in CRM were statistically not different from certified values. The method was applied to real samples of benthic invertebrates and inter-laboratory comparisons were conducted using lyophilized zooplankton, chironomidae, and notonectidae samples. (orig.)

Numerical Response of Migratory Shorebirds to Prey Distribution in a Large Temperate Arid Wetland, China

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Yamian Zhang

2016-01-01

Full Text Available Wuliangsuhai Lake provides important breeding and stopover habitats for shorebirds. The health of this wetland ecosystem is rapidly deteriorating due to eutrophication and water pollution and environmental management is urgently needed. To explore the connections among ecosystem health, prey density, and shorebird populations, we conducted surveys of both the benthic macroinvertebrates and shorebirds in the shorebird habitat of the wetland during the 2011 autumn migration season. The abundance of both shorebirds and benthic macroinvertebrates varied significantly in both space and time. Our data showed a clear association between shorebird populations and the density of benthic macroinvertebrates, which explained 53.63% of the variation in shorebird abundance. The prey density was strongly affected by environmental factors, including water and sediment quality. Chironomidae were mainly found at sites with higher total phosphorus, but with lower sediment concentrations of Cu. Lymnaeidae were mainly found at sites with a higher pH, lower salinity, and lower concentrations of total phosphorus and Cu. Habitats with very high concentrations of total phosphorus, heavy metals, or salinity were not suitable for benthic macroinvertebrates. Our findings suggest that the reductions of nutrient and heavy metal loadings are crucial in maintaining the ecological function of Wuliangsuhai as a stopover habitat for migratory shorebirds.

Development of a benthic multimetric index for the Serra da Bocaina bioregion in Southeast Brazil

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DF. Baptista

Full Text Available Brazil faces a challenge to develop biomonitoring tools to be used in water quality assessment programs, but few multimetric indices were developed so far. This study is part of an effort to test and implement programs using benthic macroinvertebrates as bioindicators in Rio de Janeiro State. Our aim was first to test the Multimetric Index for Serra dos Órgãos (SOMI for a different area - Serra da Bocaina (SB - in the same ecoregion. We sampled 27 streams of different sizes and altitudes in the SB region. Despite the environmental similarities, results indicated biological differences between reference sites of the two regions. Considering these differences, we decided to develop an index specific for the SB region, the Serra da Bocaina Multimetric Index (MISB. We tested twenty-two metrics for sensitivity to impairment and redundancy, and six metrics were considered valid to integrate the MISB: Family Richness, Trichoptera Richness, % Coleoptera, % Diptera, IBE-IOC index, EPT / Chironomidae ratio. A test of the MISB in eleven sites indicated it was more related to land-use and water physico-chemical parameters than with altitude or stream width, being a useful tool for the monitoring and assessment of streams in the bioregion.

Influence of a trout farm on macrozoobenthos communities of the Trešnjica river, Serbia

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Živić Ivana

2009-01-01

Full Text Available Trout farming poses an increasing threat to quality of the water of clean highland streams. Research of this problem has focused primarily on changes in physico-chemical composition of the water and structure of the river bottom, and less on the effects on living organisms. In the present work, we investigated influence of the farm with the highest trout production in Serbia, the 'Riboteks' Trout Farm on the Trešnjica River, on its macrozoobenthos communities. Our investigations showed that the 'Riboteks' Trout Farm wastewaters caused a clear and statistically significant change of moderate intensity in all measured parameters describing the composition and structure of macrozoobenthos communities. These changes were most pronounced in the part of the watercourse closest to the influx of waste water (locality III but remained statistically significant even 500 m downstream (locality IV and were lost only about 3.5 km away from the influx of the farm's wastewater (locality V. The most pronounced were changes in the participation in total abundance of the Baetidae, Chironomidae, and Plecoptera. Additionally, results of the present work confirmed that the mass of fish on the trout farm is a parameter that adequately defines the strength of its action, above all the intensity of its influence on structure of the macrozoobenthos community.

Survey of arthropod assemblages responding to live yeasts in an organic apple orchard

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Stefanos S Andreadis

2015-10-01

Full Text Available Associations between yeasts and insect herbivores are widespread, and these inter-kingdom interactions play a crucial role in yeast and insect ecology and evolution. We report a survey of insect attraction to live yeast from a community ecology perspective. In the summer of 2013 we screened live yeast cultures of Metschnikowia pulcherrima, M. andauensis, M. hawaiiensis, M. lopburiensis, and Cryptococcus tephrensis in an organic apple orchard. More than 3,000 arthropods from 3 classes, 15 orders, and 93 species were trapped; ca. 79% of the trapped specimens were dipterans, of which 43% were hoverflies (Syrphidae, followed by Sarcophagidae, Phoridae, Lauxaniidae, Cecidomyidae, Drosophilidae, and Chironomidae. Traps baited with M. pulcherrima, M. andauensis, and C. tephrensis captured typically 2.4 times more specimens than control traps; traps baited with M. pulcherrima, M. hawaiiensis, M. andauensis, M. lopburiensis and C. tephrensis were more species-rich than unbaited control traps. We conclude that traps baited with live yeasts of the genera Metschnikowia and Cryprococcus are effective attractants and therefore of potential value for pest control. Yeast-based monitoring or attract-and-kill techniques could target pest insects or enhance the assemblage of beneficial insects. Manipulation of insect behavior through live yeast cultures should be further explored for the development of novel plant protection techniques.

Solar and atmospheric forcing on mountain lakes.

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Luoto, Tomi P; Nevalainen, Liisa

2016-10-01

We investigated the influence of long-term external forcing on aquatic communities in Alpine lakes. Fossil microcrustacean (Cladocera) and macrobenthos (Chironomidae) community variability in four Austrian high-altitude lakes, determined as ultra-sensitive to climate change, were compared against records of air temperature, North Atlantic Oscillation (NAO) and solar forcing over the past ~400years. Summer temperature variability affected both aquatic invertebrate groups in all study sites. The influence of NAO and solar forcing on aquatic invertebrates was also significant in the lakes except in the less transparent lake known to have remained uniformly cold during the past centuries due to summertime snowmelt input. The results suggest that external forcing plays an important role in these pristine ecosystems through their impacts on limnology of the lakes. Not only does the air temperature variability influence the communities but also larger-scale external factors related to atmospheric circulation patterns and solar activity cause long-term changes in high-altitude aquatic ecosystems, through their connections to hydroclimatic conditions and light environment. These findings are important in the assessment of climate change impacts on aquatic ecosystems and in greater understanding of the consequences of external forcing on lake ontogeny. Copyright © 2016 Elsevier B.V. All rights reserved.

Disturbance caused by freshwater releases of different magnitude on the aquatic macroinvertebrate communities of two coastal lagoons

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Cañedo-Argüelles, Miguel; Rieradevall, Maria

2010-06-01

The response of the aquatic macroinvertebrate communities to freshwater releases of different magnitude and persistence was investigated in two Mediterranean coastal lagoons (Ca l'Arana and Ricarda). The study was carried out during 14 months (June 2004-July 2005) in which different environmental variables and the macroinvertebrate communities associated with two different habitats, the Phragmites australis belt and the deep area of the lagoons, were sampled monthly. Additionally, potential colonizing sources were identified through the analysis of Chironomidae pupal exuviae. The initial response of the communities to the freshwater releases was similar, being characterized by a peak of opportunistic taxa (mainly Naididae), but the late response was different for each lagoon. In the Ca l'Arana, the magnitude of the freshwater release was higher (salinity dropped below five, which is the limit commonly established for most freshwater species) and its persistence was also higher, allowing the colonization of the lagoon by new insect taxa, which replaced the brackish water species. In the Ricarda, the salinity never dropped beyond five and pre-disturbance conditions were rapidly re-established. This, together with the acclimatizing mechanisms showed by the species Chironomus riparius and Hediste diversicolor, permitted the recovery of the pre-disturbance macroinvertebrate community.

Aquatic macroinvertebrates associated with roots of Eichhornia azuera (Swarts Kunth (Pontederiaceae in an oxbow lake in Pantanal, MS

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Hugo Henrique L. Saulino

2014-09-01

Full Text Available Macrophytes play an important role in the community structure of aquatic systems. In this study, we examined the macroinvertebrate communities within 20 Eichhornia azurea roots in an oxbow lake in Pantanal (MS during dry season. Species abundance and richness were compared via linear regression, and the mean relative proportion of macroinvertebrates among root samples was determined. Macroinvertebrates were identified to the lowest practical taxonomic level, and root volume was measured using the volume displacement method. We identified 371 specimens, belonging to 31 families and 21 taxonomic groups. Chironomus sp. (Chironomidae, Slavinia sp. and Dero sp. (Naididae, all detritivores, were most the represented taxon. Regression analysis indicated a positive correlation between root volume and the abundance and richness of the macroinvertebrate community. Analysis of variance showed no statistically significant differences between species abundance and richness among different E. azuera root volumes, however we did observe a trend toward a positive correlation of both variables with increasing root volume. We suspect that greater root volumes should increase microhabitat availability, which could explain this observed trend. Our results indicate that E. azurea roots may play an important ecologic role (e.g., by providing shelter, food stock in lake macroinvertebrate communities.

Differences found in the macroinvertebrate community composition in the presence or absence of the invasive alien crayfish, Orconectes hylas

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Freeland-Riggert, Brandye T.; Cairns, Stefan H.; Poulton, Barry C.; Riggert, Chris M.

2016-01-01

Introductions of alien species into aquatic ecosystems have been well documented, including invasions of crayfish species; however, little is known about the effects of these introductions on macroinvertebrate communities. The woodland crayfish (Orconectes hylas (Faxon)) has been introduced into the St. Francis River watershed in southeast Missouri and has displaced populations of native crayfish. The effects of O. hylas on macroinvertebrate community composition were investigated in a fourth-order Ozark stream at two locations, one with the presence of O. hylas and one without. Significant differences between sites and across four sampling periods and two habitats were found in five categories of benthic macroinvertebrate metrics: species richness, percent/composition, dominance/diversity, functional feeding groups, and biotic indices. In most seasons and habitat combinations, the invaded site had significantly higher relative abundance of riffle beetles (Coleoptera: Elmidae), and significantly lower Missouri biotic index values, total taxa richness, and both richness and relative abundance of midges (Diptera: Chironomidae). Overall study results indicate that some macroinvertebrate community differences due to the O. hylas invasion were not consistent between seasons and habitats, suggesting that further research on spatial and temporal habitat use and feeding ecology of Ozark crayfish species is needed to improve our understanding of the effects of these invasions on aquatic communities.

Diversity and spatial and temporal variation of benthic macroinvertebrates with respect to the trophic state of Lake Figueira in the South of Brazil

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Fernanda Blauth de Lima

2013-12-01

Full Text Available Benthic macroinvertebrates are widely used in evaluations of environmental impact and recommended in biomonitoring, but little used in Brazilian lentic environments. One of the main objectives has been to explain and predict the distribution of those species according to environmental characteristics. Thus, the study aims to characterize the predominant fauna of the Lake Figueira sediment and its relationship with organic matter and depth, analyzing seasonal variation in communities and aiming to select bioindicators of the trophic state. Sampling was carried out from January 2008 to January 2009, along the lagoon fetch, with an Ekmann-Birge dredge (area 225 cm². Taxon richness was not significantly related with depth and organic matter content, but those variables were highly correlated (r = 0.962; r² = 0.926 and p < 0.001. The constant oxygenation of the whole water column allows the occurrence of organisms, independent of depth and organic matter content. Chironomidae was the most abundant taxon and from the frequency of occurrence, abundance and clustering analysis it was possible to select Larsia sp. , Goeldichironomus maculatus, Xenochironomus sp. , Aedokritus sp. Cladopelma forcipis, Cryptochironomus brasiliensis, Nilothauma sp.1 and Caladomyia sp. C, Tanytarsus sp. , Tanytarsus rhabdomantis and Chironomus gr. salinarius as potential indicators related with the spatiotemporal faunal distribution of Lake Figueira.

Impact of heated waters on water quality and macroinvertebrate community in the Narew River (Poland

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Krolak Elzbieta

2017-07-01

Full Text Available The effect of heated waters from coal-burning power stations on the water parameters and the occurrence of macroinvertebrates depends on the individual characteristics of the river to which the heated waters are discharged. The objective of the study was to assess the impact of heated water from the Ostrołęka Power Station on selected water properties and the macroinvertebrate community in the Narew River. Samples were collected in years: 2013-2016 along two river stretches: upstream and downstream of the canal. The water temperature was higher and the oxygen concentrations were lower at the downstream sites compared to the upstream sites of the canal. The values of conductivity, concentrations of nitrates, phosphates, chlorides and calcium were similar at the sampling sites. A total of 33 families of macrozoobenthos were found. The numbers of families were positively correlated with the temperature and conductivity and negatively correlated with oxygen. The heated waters were found to have no effect on the Shannon-Wiener diversity index. The inflow of heated waters increased the percentage of Gammaridae, represented by species Dikerogammarus haemobaphes (Eichwald, 1841 and decreased the percentage of Chironomidae. The presence of the thermophilous bivalve Sinanodonta woodiana (Lea, 1934 was noted downstream of the canal.

Diet of four annual killifishes: an intra and interspecific comparison

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Gabriel Laufer

Full Text Available We examined the diet of 4 annual fishes, Austrolebias viarius, Austrolebias cheradophilus, Austrolebias luteoflammulatus and Cynopoecilus melanotaenia inhabiting temporal ponds of southeastern Uruguay, by analysis of stomach contents. Fishes were captured from fifty ephemeral ponds of Castillos Lagoon basin, in the region of the Humedales del Este. We identified 13099 individual prey items extracted from 669 stomachs of the four captured species. In the studied system, annual killifishes represents the most abundant and conspicuous top predators. Killifishes are generalist key predators at the ephemeral ponds of the studied system, consuming mostly aquatic items. Zooplancton represented the bulk of the diet in the four analyzed species, followed by eggs, algae and diatoms. Insects are the next group in prey number, as follows: Diptera larvae (especially Chironomidae and Cullicidae, Ephemeroptera (especially Betidae, and coleopteran larvae (especially Dytiscidae. Acari are also important prey in number. The four fish species differ in diet composition and in diet richness. A general pattern of differences in diet richness among killifish species and demographic groups could be related to variations in body sizes. As top predators annual killifishes are an important component of the temporal pond ecosystems. Understanding the natural history of this species and their communities is necessary in order to conserve them.

The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica.

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Kawarasaki, Yuta; Teets, Nicholas M; Denlinger, David L; Lee, Richard E

2013-10-15

During the austral summer, larvae of the terrestrial midge Belgica antarctica (Diptera: Chironomidae) experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Because slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae.

Effects of Ecohydraulic Bank Stabilization Structures on Bank Stability and Macroinvertebrate Community in Surabaya River

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Daru Setyo Rini

2018-01-01

Full Text Available There were 18 accelerated erosion sites identified along 7 km of Surabaya River Fishery Sanctuary Area. A model of ecohydraulic bank stabilization was applied to reduce bank erosion in Surabaya River at Gresik Regency Indonesia. The model is combination of reprofiled and revegetated bank with rock toe reinforcement and  addition of log groynes. Various native plant species were planted and naturally grown to establish multi-strata littoral vegetation structure. This study assessed effects of ecohydraulic bank stabilization on bank morphology, near bank velocity and littoral macroinvertebrate community during September 2014 to August 2016. The study found that rock toe enforcement, log groynes and reprofiled bank slope could stabilized the eroded bank, and littoral vegetation formation reduced near bank velocity at restored sites. There were 31 families of macroinvertebrate found in Surabaya River with high abundance of moderately pollution sensitive taxa Atyidae and pollution tolerant taxa Corixidae, Chironomidae and Tubificidae. The taxa richness, diversity index and abundance of sensitive and moderately sensitive macroinvertebrate group were increased after application of ecohydraulic bank stabilization at restored area. The results shown that ecohydraulic bank stabilization structure provides multi-benefits in improving bank stabilization against erosion and providing new micro-habitats for biotic community. Keywords:  ecohydraulic bank stabilization, macroinvertebrates, riparian restoration

Growth potential and habitat requirements of endangered age-0 pallid sturgeon (Scaphirhynchus albus) in the Missouri River, USA, determined using a individual-based model framework

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Deslauriers, David; Heironimus, Laura B.; Rapp, Tobias; Graeb, Brian D. S.; Klumb, Robert A.; Chipps, Steven R.

2018-01-01

An individual-based model framework was used to evaluate growth potential of the federally endangered pallid sturgeon (Scaphirhynchus albus) in the Missouri River. The model, developed for age-0 sturgeon, combines information on functional feeding response, bioenergetics and swimming ability to regulate consumption and growth within a virtual foraging arena. Empirical data on water temperature, water velocity and prey density were obtained from three sites in the Missouri River and used as inputs in the model to evaluate hypotheses concerning factors affecting pallid sturgeon growth. The model was also used to evaluate the impacts of environmental heterogeneity and water velocity on individual growth variability, foraging success and dispersal ability. Growth was simulated for a period of 100 days using 100 individuals (first feeding; 19 mm and 0.035 g) per scenario. Higher growth was shown to occur at sites where high densities of Ephemeroptera and Chironomidae larvae occurred throughout the growing season. Highly heterogeneous habitats (i.e., wide range of environmental conditions) and moderate water velocities (0.3 m/s) were also found to positively affect growth rates. The model developed here provides an important management and conservation tool for evaluating growth hypotheses and(or) identifying habitats in the Missouri River that are favourable to age-0 pallid sturgeon growth.

Morphological description and DNA barcoding of Hydrobaenus majus sp. nov. (Diptera: Chironomidae: Orthocladiinae) from the Russian Far East.

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Makarchenko, Eugenyi A; Makarchenko, Marina A; Semenchenko, Alexander A

2015-08-14

Illustrated descriptions of adult male, pupa and fourth instar larva, as well as DNA barcoding, of Hydrobaenus majus sp. nov. in comparison with the close related species H. sikhotealinensis Makarchenko et Makarchenko from the Russian Far East are provided. The species-specificity of H. majus sp. nov. COI sequences is analyzed and the sequences are presented as diagnostic characters--molecular markers of H. majus and H. sikhotealinensis.

A guide to the larvae of the Nearctic Diamesinae (Diptera; Chironomidae), the genera Boreoheptagyia, Protanypus, Diamesa, and Pseudokiefferiella

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Doughman, J.S.

1983-01-01

The subfamily Diamesinae consists of the monogeneric tribes Boreoheptagnini and Parotanypini and the diverse tribe Diamesini with seven genera. These midges are prevalent in clean, cool arctic-alpine waters, but less abundant in the lowlands. Keys and descriptions herein to the known species of these nine genera may prove valuable in the biomonitoring of these cool aquatic habitats. The larvae of Protanypus saetheri Wiederholm is described for the first time. Identification is based upon the absence of other species in the collection area. Examination of a series of larval D. incallida Walker collected in Wyoming and a review of pertinent literature shows that there is considerable variation in the procerus and the labral armature. Because these characters are often used in keys, this variability can lead to misidentification of less recognizable species of Diamesa. (USGS)

Toxicity of cadmium and lead on tropical midge larvae, Chironomus kiiensis Tokunaga and Chironomus javanus Kieffer (Diptera: Chironomidae)

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Ebau, Warrin; Rawi, Che Salmah Md; Din, Zubir; Al-Shami, Salman Abdo

2012-01-01

Objective To investigate the acute toxicity of cadmium and lead on larvae of two tropical Chironomid species, Chironomus kiiensis (C. kiiensis) Tokunaga and Chironomus javanus (C. javanus) Kieffer. Methods Different larval instars (first-fourth) were exposed using a static non-replacement testing procedures to various concentrations of cadmium and lead. Results In general, younger larvae (first and second instars) of both species were more sensitive to both metals than older larvae (third and forth instars). The toxic effects of the metals on C. kiiensis and C. javanus were influenced by the age of the larvae (first to fourth instars), types of metals (cadmium or lead) and duration of larval exposure (24, 48, 72 and 96 h) to the metals. Conclusions Cadmium was more toxic to the chironomids than lead and C. javanus was significantly more sensitive to both metals than C. kiiensis (P<0.05). PMID:23569984

Respiration of midges (Diptera; Chironomidae) in British Columbian lakes: oxy-regulation, temperature and their role as palaeo-indicators

DEFF Research Database (Denmark)

Brodersen, Klaus Peter; Pedersen, Ole; Walker, Ian R.

2008-01-01

1. The specific respiration rate of 13 chironomid taxa and Chaoborus were measured to test the hypothesis of the relation between a species' ability to regulate their oxygen uptake and their distributional patterns among nine study lakes in British Columbia, Canada. 2. Respiration patterns of ind...

Nanocladius (Plecopteracoluthus) shigaensis sp. nov. (Chironomidae: Orthocladiinae) whose larvae are phoretic on nymphs of stoneflies (Plecoptera) from Japan.

Science.gov (United States)

Inoue, Yasue; Komori, Chiharu; Kobayashi, Tadashi; Kondo, Natsuko; Ueno, Ryuhei; Takamura, Kenzi

2015-03-16

We identified a new species, Nanocladius (Plecopteracoluthus) shigaensis, from Shiga and Gifu Prefectures, Japan, whose larvae are phoretic on nymphs of Plecoptera. Although this new species is morphologically similar to Nanocladius (Plecopteracoluthus) asiaticus Hayashi (1998), which is phoretic on Megaloptera larvae, it differs from N. (P.) asiaticus: the color of the larval head capsule is light brown in N. (P.) shigaensis and dark brown in N. (P.) asiaticus and the larval capsule index of the former is significantly larger than that of the latter. Moreover, analyses based on DNA sequence of cytochrome c oxidase subunit I (COI) supported the hypothesis that N. (P.) shigaensis and N. (P.) asiaticus are two distinct species. This is the first record of a phoretic chironomid on a plecopteran nymph in the Palaearctic region.

New record of Parochlus carolinae (Chironomidae: Podonominae from the Ventania hill system with the description of the female

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Augusto SIRI

2014-01-01

Full Text Available Se presenta el primer reporte de Parochlus Enderlein del sistema serrano de Ventania, el cual constituye el primer registro de este género de la provincia de Buenos Aires. Se describe e ilustra la hembra de Parochlus caroli - nae Rodriguez et al. y se enmiendan las descripciones originales del macho y de la larva. Se remarcan caracteres del cuerno torácico de la pupa para distinguir P. carolinae de otras especies del género Parochlus.

Survival of Salmonella enterica in Freshwater and Sediments and Transmission by the Aquatic Midge Chironomus tentans (Chironomidae: Diptera)

Science.gov (United States)

Moore, Barry C.; Martinez, Edward; Gay, John M.; Rice, Daniel H.

2003-01-01

Survival of a nalidixic acid-resistant strain of Salmonella enterica serovar Typhimurium mr-DT-104 in water and sediments was tested using artificially contaminated aquaria. Water samples remained culture positive for salmonella for up to 54 days. Sediment samples were culture positive up to 119 days. In addition, potential mechanisms for spreading salmonella in the environments by chironomid larvae and adults were tested. We evaluated the acquisition of mr-DT-104 by chironomids from contaminated aquatic sediments and subsequent spread to uncontaminated sediments. Larval chironomids raised in contaminated sediments became culture positive, and the bacteria were carried over to adults after emergence. Contamination of clean sediments by chironomid larvae was not demonstrated. These findings clearly suggest that mr-DT-104 serovar organisms can survive in aquatic sediments for at least several months. Uptake of salmonellae by chironomid larvae and adults suggests that they are possible vectors of mr-DT-104 in both aquatic and terrestrial environments, although the role of larval defecation in movement of bacteria to new sediments was not demonstrated. PMID:12902242

Sympotthastia wuyiensis sp. n. from China, with description of the immature stages of S. takatensis (Tokunaga) (Diptera, Chironomidae).

Science.gov (United States)

Liu, Wenbin; Ferrington, Leonard C Jr; Wang, Xinhua

2016-06-20

Sympotthastia wuyiensis sp. n. is described and illustrated as male imago from China. The immature stages of S. takatensis (Tokunaga) are described. The generic diagnosis is emended. Key to the known adult males, larvae and pupae of the genus worldwide is presented.

Effects of seasonality and resource limitation on organic matter turnover by Chironomidae (Diptera) in southern Appalachian headwater streams

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Angela Romito; Susan Eggert; Jeffrey Diez; J. Wallace

2010-01-01

Despite their high abundance, secondary production, and known reliance on detrital material, the role of chironomids (Diptera) in fine particulate organic matter (FPOM) dynamics has not been well quantified. We conducted field trials using fluorescent pigment markers to estimate seasonal rates of consumption, annual secondary production, assimilation efficiency (AE),...

A revised subgeneric position for Polypedilum (Probolum) simantokeleum, with description of a new Uresipedilum species in Japan (Diptera: Chironomidae).

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Yamamoto, Nao; Yamamoto, Masaru

2015-08-11

Two Japanese Polypedilum species including a new species are redescribed and described based on the males. Polypedilum (Probolum) simantokeleum, Sasa, Suzuki et Sakai, 1998, is transferred to the subgenus Uresipedilum. Polypedilum (Uresipedilum) dissimilum sp. nov. is easily distinguished from other members of Uresipedilum by having a T-shaped tergal band. Definition of the subgenus Probolum is briefly discussed: we suggest Probolum should be defined as the species with the superior volsella bearing inner lobe pending adequate larval information.

Notes on the genus Conchapelopia Fittkau (Diptera: Chironomidae: Tanypodinae) from southern China, with description of a new species.

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Niitsuma, Hiromi; Tang, Hongqu

2017-02-22

Two interesting species, Conchapelopia togamaculosa Sasa & Okazawa and a new species, Conchapelopia brachiata sp. n., were collected from southern China. The male, pupa and larva of the new species are described, and new distributions of the former species are noted. Although the male of the new species is very distinct from that of the former in the hypopygial median volsella, the pupa and larva stunningly resemble those of the former.

A new species of Nilothauma Kieffer from China, with a key to known species of the genus (Diptera: Chironomidae).

Science.gov (United States)

Qi, Xin; Lin, Xiaolong; Wang, Xinhua; Shao, Qingjun

2014-10-03

A new species of the genus Nilothauma Kieffer, N. pandum sp. n., is described, and its morphological descriptions and illustrations are also given. A key to the males of Nilothauma is given. The adult male of N. pandum sp. n. can be distinguished from known species of the genus by the following combination of characters: anal point very broadly lanceolate with microtrichia in median ridge and apical margin, rounded at apex; superior volsella pad-like, expanded distally; median volsella curved, rounded at apex, with 2 long basal setae and 1 long median seta. 

New species of Pseudosmittia Edwards, 1932 and new records of Allocladius Kieffer, 1913 (Diptera: Chironomidae, Orthocladiinae) from South America.

Science.gov (United States)

Mauad, Melina; Siri, Augusto; Donato, Mariano

2013-01-01

Three new species of Pseudosmittia Edwards from the Neotropical region, P. satheri, P. larga and P. trapezoidea, are described and figured as males. Allocladiusfortispinatus (Edwards), A. globosus Andersen et al. and A. quadrus Andersen et al. are redescribed on the basis of new material and their geographical distribution updated. A phylogenetic analysis was performed in order to assess the phylogenetic relationships of the new species. As a result, the species P. sœtheri and P. larga are found to be sister species belonging to the angusta group. The species P. trapezoidea is the sister group of the clade ((P. propetropis (P. tropis--P. lamellata)) and belongs to the brevifurcata group sensu lato.

Two new and one newly recorded species of Polypedilum Kieffer 1912 with DNA barcodes from Oriental China (Chironomidae: Diptera).

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Yan, Chuncai; Song, Chao; Liu, Ting; Zhao, Guangjun; Hou, Ziyuan; Cao, Wei; Wang, Xinhua

2017-03-02

Polypedilum (Tripodura) enshiense Song & Wang sp. n. and P. (Tripodura) jianfengense Song & Wang sp. n. are described and illustrated as male imagines from China. P. (Uresipedilum) paraconvictum Yamamoto, Yamamoto & Hirowatari, 2016 is recorded from China for the first time. Cytochrome coxidase subunit I (COI) sequence of above species are uploaded to Barcode of Life Data Systems (BOLD).

Identification of Anhydrobiosis-related Genes from an Expressed Sequence Tag Database in the Cryptobiotic Midge Polypedilum vanderplanki (Diptera; Chironomidae)*

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Cornette, Richard; Kanamori, Yasushi; Watanabe, Masahiko; Nakahara, Yuichi; Gusev, Oleg; Mitsumasu, Kanako; Kadono-Okuda, Keiko; Shimomura, Michihiko; Mita, Kazuei; Kikawada, Takahiro; Okuda, Takashi

2010-01-01

Some organisms are able to survive the loss of almost all their body water content, entering a latent state known as anhydrobiosis. The sleeping chironomid (Polypedilum vanderplanki) lives in the semi-arid regions of Africa, and its larvae can survive desiccation in an anhydrobiotic form during the dry season. To unveil the molecular mechanisms of this resistance to desiccation, an anhydrobiosis-related Expressed Sequence Tag (EST) database was obtained from the sequences of three cDNA libraries constructed from P. vanderplanki larvae after 0, 12, and 36 h of desiccation. The database contained 15,056 ESTs distributed into 4,807 UniGene clusters. ESTs were classified according to gene ontology categories, and putative expression patterns were deduced for all clusters on the basis of the number of clones in each library; expression patterns were confirmed by real-time PCR for selected genes. Among up-regulated genes, antioxidants, late embryogenesis abundant (LEA) proteins, and heat shock proteins (Hsps) were identified as important groups for anhydrobiosis. Genes related to trehalose metabolism and various transporters were also strongly induced by desiccation. Those results suggest that the oxidative stress response plays a central role in successful anhydrobiosis. Similarly, protein denaturation and aggregation may be prevented by marked up-regulation of Hsps and the anhydrobiosis-specific LEA proteins. A third major feature is the predicted increase in trehalose synthesis and in the expression of various transporter proteins allowing the distribution of trehalose and other solutes to all tissues. PMID:20833722

GTPase Ran strongly accumulates at the kinetochores of somatic chromosomes in the spermatogonial mitoses of Acricotopus lucidus (Diptera, Chironomidae).

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Staiber, Wolfgang

2014-07-01

Unequal chromosome segregation and spindle formation occurs in the last gonial mitosis in the germ line of the chironomid Acricotopus lucidus. During this differential mitosis, all germ line-limited chromosomes (=Ks) migrate undivided to only one pole of the cell, while the somatic chromosomes (=Ss) first remain in the metaphase plane, and with the arrival of the Ks at the pole, they then separate equally. The evolutionarily conserved GTPase Ran plays a crucial role in many cellular processes. This includes the regulation of microtubule nucleation and stabilisation at kinetochores and of spindle assembly during mitosis, which is promoted by a RanGTP concentration gradient that forms around the mitotic chromosomes (Kalab et al. in Science 295:2452-2456, 2002, Nature 440:697-701, 2006). In the present study, a strong accumulation of Ran was detected by immunofluorescence at the kinetochores of the Ss in normal gonial and differential gonial mitoses of males of A. lucidus. In contrast, no Ran accumulation was observed at the kinetochores of the Ss in the metaphases of brain ganglia mitoses or of aberrant spermatocytes or in metaphases I and II of spermatocyte meiotic divisions. Likewise, there was no accumulation at the kinetochores of Drosophila melanogaster mitotic chromosomes from larval brains. The specific accumulation of Ran at the kinetochores of the Ss in differential gonial mitoses of A. lucidus strongly suggests that Ran is involved in a mechanism acting in this exceptional mitosis, which retains the Ss at the metaphase plane and prevents a premature separation and unequal segregation of the Ss during monopolar migration of the Ks.

The presence of species of Pseudochironomus Malloch 1915 (Diptera: Chironomidae) in watercourses of Chaco Serrano Ecoregion (Argentina, South America).

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Paggi, Analía C; Rodriguez Garay, Gretel N

2015-05-15

Male imagos of Pseudochironomus viridis (Kieffer) are redescribed, the immature stages are described and figured for the first time. During this study, larva and pupal exuviae associated to P. richardsoni (Malloch) were recorded for the first time for South America. The specimens were collected from a stream and a river in the Pampasic Hills System in the Chaco Serrano ecoregion of Argentina.

Karyotypical characteristics of two allopatric African populations of anhydrobiotic Polypedilum Kieffer, 1912 (Diptera, Chironomidae) originating from Nigeria and Malawi.

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Petrova, Ninel A; Cornette, Richard; Shimura, Sachiko; Gusev, Oleg A; Pemba, Dylo; Kikawada, Takahiro; Zhirov, Sergey V; Okuda, Takashi

2015-01-01

The African chironomid Polypedilumvanderplanki Hinton, 1951 is the only chironomid able to withstand almost complete desiccation in an ametabolic state known as anhydrobiosis. The karyotypes of two allopatric populations of this anhydrobiotic chironomid, one from Nigeria and another from Malawi, were described according to the polytene giant chromosomes. The karyotype from the Nigerian population was presented as the reference chromosome map for Polypedilumvanderplanki. Both populations, Nigerian and Malawian, showed the same number of chromosomes (2n=8), but important differences were found in the band sequences of polytene chromosomes, and in the number and the arrangement of active regions between the two populations. Such important differences raise the possibility that the Malawian population could constitute a distinct new species of anhydrobiotic chironomid.

The immature stages of two Caladomyia Säwedall, 1981 species, from São Paulo State, Brazil (Chironomidae, Chironominae, Tanytarsini

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Susana Trivinho-Strixino

2003-12-01

Full Text Available The pupae and larvae of Caladomyia ortoni Säwedall, 1981 and Caladomyia riotarumensis Reiff, 2000, from São Paulo State, are described and illustrated. Caladomyia ortoni Säwedall, 1981 = Nimbocera paulensis Trivinho-Strixino & Strixino, 1991, syn. nov.

Application of ecohydraulic bank protection model to improve river bank stability and biotic community in Surabaya River

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Daru Setyo Rini

2017-10-01

Full Text Available Ecohydraulic river bank protection design was developed as ECO-RIPRAP model and has been applied along 100 meter length to restore accelerated erosion sites in Surabaya River at Wringinanom and Klubuk. The model combined re-profiled and re-vegetated bank with rock toe reinforcement and addition of log groynes at 10 meter length interval. Various native plant species were planted on bank slopes, including water plants Ipomoea aquatica and Pistia stratiotes, grasses and shrubs Ipomoea carnea, Pluchea indica, Saccharum spontaneum, Arundo donax, and native tree species Ficus glomerata, Bambusa arundinacea, Dendrocalamus asper, Bambusa vulgaris, Ficus benjamina, Dillenia indica, Psidium guajava, Arthocarpus camansi, Arthocarpus elasticus, Hibiscus mutabilis, Nauclea sp., Inocarpus edulis, and Syzygium polyanthum. The river bank morphology after ECO-RIPRAP application showed alteration from erosion to sedimentation due to rock toe enforcement, log groynes protection, and increase of plant cover on littoral banks that decreased near bank velocity. The macro-invertebrate community shown increase of taxa richness, EPT richness, %EPT and %Atyidae, but decrease of %Chironomidae at restored sites. The fish community shown increase of taxa richness, increase of abundance by 54.2%, increase of Pangasius micronemus abundance by 25.6%, and increase of Hemibragus nemurus abundance by 6.3 % at restored reach. Rare fish species thrive back at restored area, namely Oxyeleotris marmorata, Mastacembelus unicolor and Hampala macrolepidota.

BIOLOGICAL WATER QUALITY ASSESSMENT OF THE WHITECLAWED CRAYFISH HABITAT BASED ON MACROINVERTEBRATE COMMUNITIES: USEFULNESS FOR ITS CONSERVATION

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GRANDJEAN F.

2003-04-01

Full Text Available A survey of the macroinvertebrates of three brooks harbouring the white-clawed crayfish was conducted in Haute-Vienne department (France. Its aim was to increase our understanding of these ecosystems to help the conservation of A. pallipes. These brooks run through pastoral areas with well-developed riparian vegetation, which offers an important shade. Water temperature, dissolved oxygen concentration, pH, and conductivity fell within the ranges found for this species. A total of 34, 31, 29 taxa and 1 502, 1 364, 2 707 individuals of macrobenthos were collected in Holme, Besque and Bellecombe streams, respectively. Results showed good to very good water quality with IBGN scores ranging from 15 (Bellecombe to 17 (Holme and Besque, reflecting a limited impact of the anthropogenic disturbances. Taxa diversity were high for Holme and Besque with Shannon index around 3.2, translating a great heterogeneity of habitat and an equilibrated faunal community. Bellecombe showed a limited diversity with Shannon index of 1.42, resulting from the presence of numberous Chironomidae. This brook suffers probably weak organic pollution which could be related to the low water flow observed during the sampling. The similarity test according to Jaccard index showed high percentage of common taxa among ETP (Ephemeroptera-Trichoptera-Plecoptera between all sites. The high similarity of benthic macroinvertebrate communities could be an useful criteria to identify brooks for restocking purpose.

Assessing the performance of macroinvertebrate metrics in the Challhuaco-Ñireco System (Northern Patagonia, Argentina

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Melina Mauad

2015-09-01

Full Text Available ABSTRACT Seven sites were examined in the Challhuaco-Ñireco system, located in the reserve of the Nahuel Huapi National Park, however part of the catchment is urbanized, being San Carlos de Bariloche (150,000 inhabitants placed in the lower part of the basin. Physico-chemical variables were measured and benthic macroinvertebrates were collected during three consecutive years at seven sites from the headwater to the river outlet. Sites near the source of the river were characterised by Plecoptera, Ephemeroptera, Trichoptera and Diptera, whereas sites close to the river mouth were dominated by Diptera, Oligochaeta and Mollusca. Regarding functional feeding groups, collector-gatherers were dominant at all sites and this pattern was consistent among years. Ordination Analysis (RDA revealed that species assemblages distribution responded to the climatic and topographic gradient (temperature and elevation, but also were associated with variables related to human impact (conductivity, nitrate and phosphate contents. Species assemblages at headwaters were mostly represented by sensitive insects, whereas tolerant taxa such as Tubificidae, Lumbriculidae, Chironomidae and crustacean Aegla sp. were dominant at urbanised sites. Regarding macroinvertebrate metrics employed, total richness, EPT taxa, Shannon diversity index and Biotic Monitoring Patagonian Stream index resulted fairly consistent and evidenced different levels of disturbances at the stream, meaning that this measures are suitable for evaluation of the status of Patagonian mountain streams.

Macroinvertebrados bentónicos del humedal de Palo Verde, Costa Rica

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F.A Trama

2009-11-01

Full Text Available El humedal de Palo Verde es uno de los más importantes de Centro America para aves acuáticas. Durante el período 2002 y 2005, se llevaron a cabo actividades de manejo para controlar la invasión de Typha domingensis. Con el fin de establecer una línea base para monitoreos futuros, en el 2003 se realizó una evaluación de macroinvertebrados acuáticos. Se efectuó un muestreo mensual durante un año, usando el método de sustratos artificiales. Se identificaron 116 táxones pertenecientes a 47 familias y a 18 órdenes. La mayor abundancia se encontró en la clase Conchostraca y la familia Chironomidae que juntas representaron casi la mitad de todos los individuos colectados. En contraste, el 97% de los táxones tuvieron, cada uno, menos del 1% del total de la abundancia. La diversidad de táxones, así como la abundancia de individuos y el número de especies, fueron mayores en la época seca que en la lluviosa. La curva acumulada de especies indicó que se hubiera registrado una mayor cantidad de táxones si los muestreos se hubieran extendido por más tiempo. Con este trabajo damos a conocer la primera lista de macroinvertebrados para el humedal de Palo Verde.

A Benthic Macroinvertebrate Multimetric Index for Assessment of the Ecological Integrity of Northeast Streams, Thailand

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Nantiya Rattanachan

2016-07-01

Full Text Available This study aims to develop a benthic macroinvertebrate multimetric index for assessing the ecological quality of streams in Northeastern Thailand. ANOSIM indicated that the benthic macroinvertebrate assemblage in both of each basin and each season were not significantly different (R = 0.09, p = 0.24 and R = 0.07, p = 0.35, respectively. The efficacy metrics of each basin consisting of the Mekong II, the Chi, and the Mun basins were integrated and calibrated. A total of 255 data sets of water physico-chemical and benthic macroinvertebrates during the dry period (cool and hot seasons were obtained. The stream classification could be divided into three groups: the reference group (48 stations, the stressed group (42 stations, and the intermediate group (165 stations. Twelve out of 56 metrics have been considered as a core metric for the development of a biological index for quality streams in the Northeast, including Total taxa, EPT taxa, Ephemeroptera taxa, Coleoptera taxa, % EPT, % Chironomidae, % Tolerant individuals, % Intolerant individuals, Beck's index, HBI, Predator taxa, and Clinger taxa. Moreover, this metric set covered the structure and function of organisms including the diversity of species, community structure, tolerance/intolerance measures, functional feeding group, and habit. From the efficacy validation of the biological index, the results of stream assessment corresponded to the classification sites with the physico-chemical characteristics.

Occurrence of polycyclic aromatic hydrocarbons below coal-tar-sealed parking lots and effects on stream benthic macroinvertebrate communities

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Scoggins, M.; McClintock, N.L.; Gosselink, L.; Bryer, P. [City Austin, Austin, TX (United States)

2007-12-15

Parking-lot pavement sealants recently have been recognized as a major source of polycyclic aromatic hydrocarbons (PAHs) in urban stream sediments in Austin, Texas. Laboratory and field studies have shown that PAHs in sediments can be toxic to aquatic organisms and can degrade aquatic communities. After identifying increases in concentrations of PAHs in sediments below seal-coated parking lots, we investigated whether the increases had significant effects on stream biota in 5 Austin streams. We sampled sediment chemistry and biological communities above and below the point at which stormwater runoff from the parking lots discharged into the streams, thus providing 5 upstream reference sites and 5 downstream treatment sites. Differences between upstream and downstream concentrations of total PAH ranged from 3.9 to 32 mg/kg. Analysis of the species occurrence data from pool and riffle habitats indicated a significant decrease in community health at the downstream sites, including decreases in richness, intolerant taxa, Diptera taxa, and density. In pool sediments, Chironomidae density was negatively correlated with PAH concentrations, whereas Oligochaeta density responded positively to PAH concentrations. In general, pool taxa responded more strongly than riffle taxa to PAHs, but riffle taxa responded more broadly than pool taxa. Increases in PAH sediment-toxicity units between upstream and downstream sites explained decreases in taxon richness and density in pools between upstream and downstream sites.

Colonização de macroinvertebrados bentônicos em detritos foliares em um riacho de primeira ordem na Floresta Atlântica do nordeste brasileiro

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Iris Gabrielly Arruda dos Santos

2015-03-01

Full Text Available O objetivo do estudo foi avaliar a colonização de macroinvertebrados bentônicos em detritos foliares de Inga ingoides (Leguminosae em experimentos de campo em um riacho de primeira ordem da Mata Atlântica do Estado de Pernambuco no nordeste do Brasil. Um total de 270 bolsas de folhiço, distribuídas em três trechos do riacho com características similares em relação à morfologia e parâmetros físicos e químicos da água foram submersas, entre fevereiro a julho de 2013 e retiradas após 7, 30, 60, 90 e 120 dias. Dois tratamentos foram utilizados: colonização e exclusão da macrofauna. O percentual de biomassa remanescente final (%R foi maior para bolsas de colonização do que para as de exclusão, evidenciando a efetiva participação dos macroinvertebrados no processo de decomposição. Os fragmentadores apresentaram menor participação no processo de decomposição foliar de I. ingoides, sendo Tripletides (Trichoptera: Leptoceridae, Polypedillum e Stenochironomus (Diptera, Chironomidae os táxons predominantes na macrofauna. Filtrador foi o grupo trófico funcional predominante (45,6%, seguido por predador (31,2%, coletor (11,8%, raspador (6,7% e fragmentador (4,8%.

Spatial uniformity in depth optima of midges: evidence from sedimentary archives of shallow Alpine and boreal lakes

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Tomi P. Luoto

2012-01-01

Full Text Available In this study, water depth optima, i.e. habitat preferences within a depth gradient, were estimated for mutual midge (Diptera: Nematocera; Ceratopogonidae, Chironomidae taxa in surface sediment intralake data sets from eastern Finland and Austrian Alps and in a regional data set across Finland. The aim was to investigate how the optima and tolerances differ in these data sets and to discuss whether the possible causal factor for deviance is related to local adaptation, taxa representativeness, or some other factor. A total of 20 mutual taxa were found from the data sets and the estimated optima and tolerances were highly similar, with the exception of three taxa, which had deviating optima in the Austrian lake. The reason for these differences was most likely that the optima were poorly estimated in the Austrian lake due to low abundances and number of occurrences of these taxa. No evidence for intraspecific niche separation or local habitat adaptation was found between the Austrian and Finnish sites, although, interspecific variation in habitats was evident. Therefore, water depth optima estimated from representative number of specimens may be applicable for various ecological, limnological, and paleolimnological purposes. However, when the optima are applied outside the data set’s coverage, the results should be interpreted with caution. In addition, the given optima are not applicable in sites deeper than the sites in the data sets.

Coexistence of fish species in a large lowland river: food niche partitioning between small-sized percids, cyprinids and sticklebacks in submersed macrophytes.

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Dukowska, Małgorzata; Grzybkowska, Maria

2014-01-01

In the spring and summer of each year, large patches of submersed aquatic macrophytes overgrow the bottom of the alluvial Warta River downstream of a large dam reservoir owing to water management practices. Environmental variables, macroinvertebrates (zoobenthos and epiphytic fauna, zooplankton) and fish abundance and biomass were assessed at this biologically productive habitat to learn intraseasonal dynamics of food types, and their occurrence in the gut contents of small-sized roach, dace, perch, ruffe and three-spined stickleback. Gut fullness coefficient, niche breadth and niche overlap indicated how the fishes coexist in the macrophytes. Chironomidae dominated in the diet of the percids. However, ruffe consumed mostly benthic chironomids, while perch epiphytic chironomids and zooplankton. The diet of dace resembled that in fast flowing water although this rheophilic species occurred at unusual density there. The generalist roach displayed the lowest gut fullness coefficient values and widest niche breadth; consequently, intraspecific rather than interspecific competition decided the fate of roach. Three-spined stickleback differed from the other fishes by consuming epiphytic simuliids and fish eggs. The diet overlap between fishes reaching higher gut fullness coefficient values was rather low when the food associated with the submersed aquatic macrophytes was most abundant; this is congruent with the niche overlap hypothesis that maximal tolerable niche overlap can be higher in less intensely competitive conditions.

Fluvial geomorphology and aquatic-to-terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

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Sullivan, S. Mažeika P.; Boaz, Lindsey E.; Hossler, Katie

2016-04-01

Although mercury (Hg) contamination is common in stream ecosystems, mechanisms governing bioavailability and bioaccumulation in fluvial systems remain poorly resolved as compared to lentic systems. In particular, streams in urbanized catchments are subject to fluvial geomorphic alterations that may contribute to Hg distribution, bioaccumulation, and export across the aquatic-to-terrestrial boundary. In 12 streams of urban Columbus, Ohio, we investigated the influence of fluvial geomorphic characteristics related to channel geometry, streamflow, and sediment size and distribution on (1) Hg concentrations in sediment and body burdens in benthic larval and adult emergent aquatic insects and (2) aquatic-to-terrestrial contaminant transfer to common riparian spiders of the families Pisauridae and Tetragnathidae via changes in aquatic insect Hg body burdens as well as in aquatic insect density and community composition. Hydrogeomorphic characteristics were weakly related to Hg body burdens in emergent insects (channel geometry) and tetragnathid spiders (streamflow), but not to Hg concentrations in sediment or benthic insects. Streamflow characteristics were also related to emergent insect density, while wider channels were associated with benthic insect community shifts toward smaller-bodied and more tolerant taxa (e.g., Chironomidae). Thus, our results provide initial evidence that fluvial geomorphology may influence aquatic-to-terrestrial contaminant Hg transfer through the collective effects on emergent insect body burdens as well as on aquatic insect community composition and abundance.

Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris in a lowland reservoir (Mušov, Czech Republic

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Adámek Z.

2010-08-01

Full Text Available The tubenose goby (Proterorhinus semilunaris is a gobiid species currently extending its area of distribution in Central Europe. The objective of the study was to evaluate the annual pattern of its feeding habits in the newly colonised habitats of the Mušov reservoir on the Dyje River (the Danube basin, Czech Republic with respect to natural food resources. In the reservoir, tubenose goby has established a numerous population, densely colonising stony rip-rap banks. Its diet was exclusively of animal origin with significant dominance of and preference for two food items – chironomid (Chironomidae larvae and waterlouse (Asellus aquaticus, which contributed 40.2 and 27.6%, respectively, to the total food bulk ingested. The index of preponderance for the two items was also very high, amounting to 73.8 and 26.5, respectively. In the annual pattern, a remarkable preference for chironomid larvae was recorded in the summer period whilst waterlouse were consumed predominantly in winter months. The proportion of other food items was rather marginal – only corixids, copepods, ceratopogonids and cladocerans were of certain minor importance with proportions of 5.4, 4.3, 4.1 and 3.9%, respectively. Certain signs of cannibalism were also recorded, with 0.9 and 0.2% of the diet consisting of their own progeny and eggs, respectively.

Age, growth and fall diet of channel catfish in Cheat Lake, West Virginia

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Hilling, Corbin D.; Welsh, Stuart A.; Smith, Dustin M.

2016-01-01

Acidification has historically impaired Cheat Lake's fish community, but recent mitigation efforts within the Cheat River watershed have improved water quality and species richness. Presently, channel catfish Ictalurus punctatus are abundant and attain desirable sizes for anglers. We evaluated the age, growth, and fall diet of the population. We collected a sample of 155 channel catfish from Cheat Lake from 5 August to 4 December 2014, a subset of which we aged (n = 148) using lapillus otoliths. We fit four growth models (von Bertalanffy, logistic, Gompertz, and power) to length-at-age data and compared models using an information theoretic approach. We collected fall diets from 55 fish sampled from 13 October to 4 December 2014. Total lengths of individuals in the sample ranged from 154 to 721 mm and ages ranged from 2 to 19 y. We AICc-selected the von Bertalanffy growth model as the best approximating model, and the power and Gompertz models also had considerable support. Diets were numerically dominated by Diptera larvae, specifically Chironomidae and Chaoboridae, while 39% of stomachs contained terrestrial food items. This study provides baseline data for management of Cheat Lake's channel catfish population. Further, this study fills a knowledge gap in the scientific literature on channel catfish, because few previously published studies have examined the population ecology of channel catfish in the Central Appalachian region.

Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers

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M. S. G. Moura e Silva

Full Text Available Abstract Biomonitoring is a cheap and effective tool for evaluation of water quality, and infer on the balance of aquatic ecosystems. The benthic macroinvertebrates are bioindicators sensitive to environmental changes, and can assist in detecting and preventing impacts such as organic enrichment and imbalance in the food chain. We compared the structure of benthic communities on artificial substrate samplers located in places near and far from net cages for production of Nile tilapia (Oreochromis niloticus. Samplers were manufactured with nylon net, using substrates such as crushed stone, gravel, loofah and cattail leaves. Samples were collected after 30 days of colonization, rinsed and then the specimens were identified and quantified. The following metrics were calculated: richness of Operational Taxonomic Units, Margalef richness, abundance of individuals, Shannon index and evenness index. The macrobenthic community structure was strongly modified according to the proximity of the net cages. Metrics showed significant differences (p < 0.05 between near and distant sites, for both periods (dry and rainy seasons. The position of the samplers significantly affected the structure of macroinvertebrate community, as near sites showed higher values for the community metrics, such as richness and diversity. Near sites presented a larger number of individuals, observed both in the dry and rainy seasons, with a predominance of Chironomidae (Diptera in the dry season and Tubificidae (Oligochaeta in the rainy season.

Experimental manipulation of leaf litter colonization by aquatic invertebrates in a third order tropical stream.

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Uieda, V S; Carvalho, E M

2015-05-01

Through a manipulative experiment, the colonization of leaf litter by invertebrates was investigated in two sections of a tropical stream (spatial scale) that differed in function of the canopy cover, one with the presence (closed area) and another without riparian vegetation (open area), during one month of the dry and one of the wet season (temporal scale). The work aimed to verify differences related to four variables: season, canopy cover, leaf type and leaf condition. Litter bags containing arboreal and herbaceous leaves (leaf type variable), non-conditioned and preconditioned (leaf condition variable) were placed at the bottom of the stream in each area (canopy cover variable) and season (dry and wet), and removed after 13-day colonization. The analysis of the remaining litter dry mass per leaf bag emphasizes differences related mainly to seasonality, canopy cover and leaf type, although leaf condition was also important when combined with those three factors. Comparing the abundance of invertebrates per treatment, there was a tendency of high predominance of Chironomidae during the dry season and greater taxa diversity and evenness during the wet season, when the water flow increase could alter the availability of microhabitats for local fauna. Even though canopy cover alone was not a significant source of variation in the abundance of invertebrates, the results showed a tendency of a combined effect of canopy cover with seasonality and leaf condition.

Change does not happen overnight: a case study on stream macroinvertebrates

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Guareschi S.

2016-01-01

Full Text Available The influence of day/night conditions on individual animal/plant species has been widely studied, but diel cycle studies of the entire stream macroinvertebrate community are extremely rare. This study explored potential dissimilarities between daytime and nighttime macroinvertebrate assemblages by extensive fieldwork conducted in the Lemme stream, a natural water course of NW Italy. Here numerous structural and functional metrics (richness, abundance, biomass, indicator taxa, composition, biomonitoring values and feeding groups were evaluated at the family level. Small-scale environmental variables were investigated to understand possible differences between macroinvertebrate assemblages in the daytime/nighttime. After collecting and identifying 21 459 organisms of 50 taxa, Chironomidae (Diptera was the most abundant under both day and night conditions. Our findings stressed that similar results and biological information on daytime/nighttime data were obtained. No marked differences could be related to various factors: heterotrophic condition of small-order streams, presence of aquatic predators under night and day conditions, absence of taxa with a specific phototaxis. Of all the environmental variables, velocity was always the most important in both situations, with some differences detected in the importance of the second variable (riverbed substrate diameter. This research, and future studies on different conditions and geographic areas, will contribute knowledge on stream macroinvertebrate diel activity, and provide useful information about efficient sampling strategies.

Bioassay of Lake Onego bottom sediments toxicity based on their chemical composition and deepwater macrozoobenthos state

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Kalinkina Nataliya Michailovna

2017-03-01

Full Text Available The bioassay of the toxicity of bottom sediments sampled in different areas of Lake Onega was carried out by crustaceans biotesting (Ceriodaphnia affinis Lillijeborg. It was shown that in the most areas of Lake Onega there are non-toxic bottom sediments. Toxic bottom sediments were found in Kondopogskaya Bay, intensively polluted with pulp-and-paper mill wastewaters. For the first time in the deep central part of Lake Onega the area was revealed where the toxic bottom sediments contain a high content of iron, manganese and other trace elements typical for the central areas of the lake. The mapping of the bottom of Lake Onega was accomplished, and three zones were identified based on the analysis of the data concerning the chemical composition of bottom sediments, bioassay toxicity data and the results of the deepwater macrozoobenthos assessment. For each zone the parameters of the main groups of benthos (Amphipoda, Oligochaeta, Chironomidae were defined. The first zone is located in the area of intensive anthropogenic influence (Kondopogskaya Bay, Petrozavodskaya Bay, Povenets Bay, Kizhi Skerries. The second zone is located mostly in the deep part of Petrozavodskaya Bay, where the most intensive development of amphipods is observed. The third area is identified for the first time: it is located in the central deep part of Lake Onega, where the communities of macrozoobenthos are limited by a natural toxic factor.

Trophic state changes can affect the importance of methane-derived carbon in aquatic food webs.

Science.gov (United States)

Schilder, Jos; van Hardenbroek, Maarten; Bodelier, Paul; Kirilova, Emiliya P; Leuenberger, Markus; Lotter, André F; Heiri, Oliver

2017-06-28

Methane-derived carbon, incorporated by methane-oxidizing bacteria, has been identified as a significant source of carbon in food webs of many lakes. By measuring the stable carbon isotopic composition (δ 13 C values) of particulate organic matter, Chironomidae and Daphnia spp. and their resting eggs (ephippia), we show that methane-derived carbon presently plays a relevant role in the food web of hypertrophic Lake De Waay, The Netherlands. Sediment geochemistry, diatom analyses and δ 13 C measurements of chironomid and Daphnia remains in the lake sediments indicate that oligotrophication and re-eutrophication of the lake during the twentieth century had a strong impact on in-lake oxygen availability. This, in turn, influenced the relevance of methane-derived carbon in the diet of aquatic invertebrates. Our results show that, contrary to expectations, methane-derived relative to photosynthetically produced organic carbon became more relevant for at least some invertebrates during periods with higher nutrient availability for algal growth, indicating a proportionally higher use of methane-derived carbon in the lake's food web during peak eutrophication phases. Contributions of methane-derived carbon to the diet of the investigated invertebrates are estimated to have ranged from 0-11% during the phase with the lowest nutrient availability to 13-20% during the peak eutrophication phase. © 2017 The Author(s).

Using d15N of Chironomidae to help assess lake condition and possible stressors in EPA?s National Lakes Assessment.

Science.gov (United States)

Background/Questions/Methods As interest in continental-scale ecology increases to address large-scale ecological problems, ecologists need indicators of complex processes that can be collected quickly at many sites across large areas. We are exploring the utility of stable isot...

Redescription of Chironomus salinarius (Diptera: Chironomidae), nuisance midges that emerged in brackish water of Jinhae-man (Bay), Kyongsangnam-do, Korea

Science.gov (United States)

Yum, Jin-Hwoa

2006-01-01

Huge numbers of non-biting midges emerged from brackish water which were made at the harbor construction field in Jinhae City, Kyongsangnam-do, Korea in late summer in 2005, and caused a serious nuisance to villagers. The midges were collected and identified as Chironomus salinarius (Kieffer, 1921). Although this species was recorded in Korea for the first time in 1998, the morphological descriptions were so brief and simple. A full redescription is made with detailed illustrations for ecological and control workers of this nuisance midge. PMID:16514284

Environmental controls on the distribution and diversity of lentic Chironomidae (Insecta: Diptera) across an altitudinal gradient in tropical South America

NARCIS (Netherlands)

Matthews-Bird, F.; Gosling, W.D.; Coe, A.L.; Bush, M.; Mayle, F.E.; Axford, Y.; Brooks, S.J.

To predict the response of aquatic ecosystems to future global climate change, data on the ecology and distribution of keystone groups in freshwater ecosystems are needed. In contrast to mid- and high-latitude zones, such data are scarce across tropical South America (Neotropics). We present the

A review of Rheocricotopus (Psilocricotopus chalybeatus species group from China, with the description of three new species (Diptera, Chironomidae

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Wenbin Liu

2014-03-01

Full Text Available The Rheocricotopus (Psilocricotopus chalybeatus species group from China is reviewed. Three new species, R. (P. brochus sp. n., R. (P. rotundus sp. n. and R. (P. serratus sp. n. are described as adult males. R. (P. imperfectus Makarchenko & Makarchenko, 2005, R. (P. robacki (Beck & Beck, 1964 and R. (P. valgus Chaudhuri & Sinharay, 1983 are recorded from China for the first time and annotated. The diagnosis for the species group is emended and a key to adult males of the species group in China is presented.

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

Energy Technology Data Exchange (ETDEWEB)

Lagauzere, S. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)], E-mail: lagauzere@gmail.com; Pischedda, L.; Cuny, P. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Gilbert, F. [EcoLab, Laboratoire d' Ecologie Fonctionnelle, UMR 5245 CNRS/INP/Universite Paul Sabatier, 29 Rue Jeanne Marvig, F-31055 Cedex 4, Toulouse (France); Stora, G. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Bonzom, J.-M. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)

2009-04-15

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments.

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

International Nuclear Information System (INIS)

Lagauzere, S.; Pischedda, L.; Cuny, P.; Gilbert, F.; Stora, G.; Bonzom, J.-M.

2009-01-01

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments

The taxonomic implication of frontal tubercles in Polypedilum subgenera diagnoses, with re-description of Polypedilum isigabeceum Sasa & Suzuki (Diptera, Chironomidae).

Science.gov (United States)

Yamamoto, Nao; Yamamoto, Masaru

2016-11-15

Polypedilum isigabeceum Sasa et Suzuki, 2000 was described as belonging to subgenus Polypedilum s. str. However, if we accept the conclusion of Sæther et al. (2010), the species might be placed into Kribionympha with P. unagiquartum Sasa, 1985 because of the presence of distinct frontal tubercles in the adult males. However, other taxonomic characters do not support their treatment. P. isigabeceum is re-described and reconfirmed to be assigned to the subgenus Polypedilum s. str. The taxonomic meaning of frontal tubercles is discussed for defining the subgeneric rankings within genus Polypedilum.

A novel computational approach of image analysis to quantify behavioural response to heat shock in Chironomus Ramosus larvae (Diptera: Chironomidae

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Bimalendu B. Nath

2015-07-01

Full Text Available All living cells respond to temperature stress through coordinated cellular, biochemical and molecular events known as “heat shock response” and its genetic basis has been found to be evolutionarily conserved. Despite marked advances in stress research, this ubiquitous heat shock response has never been analysed quantitatively at the whole organismal level using behavioural correlates. We have investigated behavioural response to heat shock in a tropical midge Chironomus ramosus Chaudhuri, Das and Sublette. The filter-feeding aquatic Chironomus larvae exhibit characteristic undulatory movement. This innate pattern of movement was taken as a behavioural parameter in the present study. We have developed a novel computer-aided image analysis tool “Chiro” for the quantification of behavioural responses to heat shock. Behavioural responses were quantified by recording the number of undulations performed by each larva per unit time at a given ambient temperature. Quantitative analysis of undulation frequency was carried out and this innate behavioural pattern was found to be modulated as a function of ambient temperature. Midge larvae are known to be bioindicators of aquatic environments. Therefore, the “Chiro” technique can be tested using other potential biomonitoring organisms obtained from natural aquatic habitats using undulatory motion as a behavioural parameter.

Development and evaluation of the Lake Multi-biotic Integrity Index for Dongting Lake, China

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Xing Wang

2015-06-01

Full Text Available A Lake Multi-biotic Integrity Index (LMII for the China’s second largest interior lake (Dongting Lake was developed to assess the water quality status using algal and macroinvertebrate metrics. Algae and benthic macroinvertebrate assemblages were sampled at 10 sections across 3 subregions of Dongting Lake. We used a stepwise process to evaluate properties of candidate metrics and selected ten for the LMII: Pampean diatom index, diatom quotient, trophic diatom index, relative abundance diatoms, Margalef index of algae, percent sensitive diatoms, % facultative individuals, % Chironomidae individuals, % predators individuals, and total number of macroinvertebrate taxa. We then tested the accuracy and feasibility of the LMII by comparing the correlation with physical-chemical parameters. Evaluation of the LMII showed that it discriminated well between reference and impaired sections and was strongly related to the major chemical and physical stressors (r = 0.766, P<0.001. The re-scored results from the 10 sections showed that the water quality of western Dongting Lake was good, while that of southern Dongting Lake was relatively good and whereas that of eastern Dongting Lake was poor. The discriminatory biocriteria of the LMII are suitable for the assessment of the water quality of Dongting Lake. Additionally, more metrics belonging to habitat, hydrology, physics and chemistry should be considered into the LMII, so as to establish comprehensive assessment system which can reflect the community structure of aquatic organisms, physical and chemical characteristics of water environment, human activities, and so on.

A Multimetric Benthic Macroinvertebrate Index for the Assessment of Stream Biotic Integrity in Korea

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Soon-Jin Hwang

2012-10-01

Full Text Available At a time when anthropogenic activities are increasingly disturbing the overall ecological integrity of freshwater ecosystems, monitoring of biological communities is central to assessing the health and function of streams. This study aimed to use a large nation-wide database to develop a multimetric index (the Korean Benthic macroinvertebrate Index of Biological Integrity—KB-IBI applicable to the biological assessment of Korean streams. Reference and impaired conditions were determined based on watershed, chemical and physical criteria. Eight of an initial 34 candidate metrics were selected using a stepwise procedure that evaluated metric variability, redundancy, sensitivity and responsiveness to environmental gradients. The selected metrics were number of taxa, percent Ephemeroptera-Plecoptera-Trichoptera (EPT individuals, percent of a dominant taxon, percent taxa abundance without Chironomidae, Shannon’s diversity index, percent gatherer individuals, ratio of filterers and scrapers, and the Korean saprobic index. Our multimetric index successfully distinguished reference from impaired conditions. A scoring system was established for each core metric using its quartile range and response to anthropogenic disturbances. The multimetric index was classified by aggregating the individual metric ..scores and the value range was quadrisected to provide a narrative criterion (Poor, Fair, Good and Excellent to describe the biological integrity of the streams in the study. A validation procedure showed that the index is an effective method for evaluating stream conditions, and thus is appropriate for use in future studies measuring the long-term status of streams, and the effectiveness of restoration methods.

A Multimetric Benthic Macroinvertebrate Index for the Assessment of Stream Biotic Integrity in Korea

Science.gov (United States)

Jun, Yung-Chul; Won, Doo-Hee; Lee, Soo-Hyung; Kong, Dong-Soo; Hwang, Soon-Jin

2012-01-01

At a time when anthropogenic activities are increasingly disturbing the overall ecological integrity of freshwater ecosystems, monitoring of biological communities is central to assessing the health and function of streams. This study aimed to use a large nation-wide database to develop a multimetric index (the Korean Benthic macroinvertebrate Index of Biological Integrity—KB-IBI) applicable to the biological assessment of Korean streams. Reference and impaired conditions were determined based on watershed, chemical and physical criteria. Eight of an initial 34 candidate metrics were selected using a stepwise procedure that evaluated metric variability, redundancy, sensitivity and responsiveness to environmental gradients. The selected metrics were number of taxa, percent Ephemeroptera-Plecoptera-Trichoptera (EPT) individuals, percent of a dominant taxon, percent taxa abundance without Chironomidae, Shannon’s diversity index, percent gatherer individuals, ratio of filterers and scrapers, and the Korean saprobic index. Our multimetric index successfully distinguished reference from impaired conditions. A scoring system was established for each core metric using its quartile range and response to anthropogenic disturbances. The multimetric index was classified by aggregating the individual metric ..scores and the value range was quadrisected to provide a narrative criterion (Poor, Fair, Good and Excellent) to describe the biological integrity of the streams in the study. A validation procedure showed that the index is an effective method for evaluating stream conditions, and thus is appropriate for use in future studies measuring the long-term status of streams, and the effectiveness of restoration methods. PMID:23202765

Fish assemblages in stream stretches occupied by cattail (Typhaceae, Angiospermae stands in Southeast Brazil

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Fabíola Carla da Rocha

Full Text Available Macrophytes are a major component of lentic and lotic aquatic ecosystems. As consequences of environmental degradation, species of cattail (genus Typha may become dominant along streams. The purpose of this study was to investigate the structure and feeding of fish assemblages in stream stretches under influence of Typha sp., also addressing the influences of temporal variation on composition, abundance, biomass, diversity, species richness, and feeding of fish. Six streams (labelled S1-S6 in the upper rio Turvo basin, southeast Brazil, with dense stands of Typha sp. in the instream and riparian habitat, were studied in six campaigns during three central months in both of the dry and wet periods, by using a standardized collection effort. Thirty-seven fish species were registered, totaling 4,228 individuals and 3.9 kg of biomass. Abundance, biomass, diversity, and species richness was higher in the wet period, but only the temporal variation in the species richness revealed to be statistically significant. Cluster analyses with composition and abundance showed little temporal similarity, but indicated two groups of streams (S1-S2-S5 and S3-S4-S6, that were corroborated along the axis 1 of the ordination analysis. Resident species was represented by six species, most of them considered tolerant and generalists. Chironomidae aquatic larvae and detritus were the most important items in the fish diet. These results suggest that the fish populations are opportunistic in exploring stream stretches occupied by cattail.

Successional trends of the benthic macroinvertebrate community in a new southeastern cooling reservoir

International Nuclear Information System (INIS)

Griffin, M.A.; Herring, M.K.

1990-01-01

Lakes created by river impoundments provide new lentic habitats for benthic macroinvertebrates. As new lakes age, benthic macroinvertebrate succession proceeds as first colonizers are replaced and stable populations eventually become established. L Lake, a 400 ha reservoir, was constructed in 1985 on the Department of Energy's Savannah River Site in South Carolina to receive heated effluent from a nuclear production reactor. Benthic macroinvertebrates were collected in L Lake with a ponar grab sampler at 2 and 4 meters at 10 locations in 5 lake regions. Monthly collections were made from 1986 through 1989. Annual average densities of benthic macroinvertebrates increased substantially during the study (ranging from 3955.5--4471.6 organisms/m 2 in 1986 to 8948.1--11,694.1 organisms/m 2 in 1988). Annual mean biomass also increased (ranging from 0.749--0.907g AFDM/m 2 in 1986 to 2074--11,322 g AFDM/m 2 in 1988). Mean annual taxa richness ranged from 9.3--12.2 per ponar in 1986 to 11.8--15.3 per ponar in 1988. Some early colonizers (Chironomidae: Chironomini) dominated throughout the study (ranging from 60.3--79.1% of all organisms). Other chironomids (Tanytarsini and Tanypodinae) declined while slower colonizers (oligochaetes and nematodes) generally increased from 1986 through 1988. The increases in macroinvertebrate density, biomass and changes in community composition observed are typical of early reservoir succession. 14 refs., 12 figs., 1 tab

Effect of land use on the composition, diversity and abundance of insects drifting in neotropical streams

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B. C. G. Gimenez

Full Text Available Abstract Streams may exhibit differences in community structure of invertebrate drift, which may be a reflex of variation in environmental factors, able to change in conditions of anthropogenic interventions. The aim of this study was to analyze the composition, diversity and abundance of insects drifting in two neotropical streams under different land use and to identify the environmental factors involved in determining such patterns. 54 taxa of aquatic insects were identified in urban and rural streams. The results indicated significant differences in species composition due to the replacement of specialist species by generalist species in the urban stream. Higher diversity of taxa was recorded in the rural stream, with high levels of dissolved oxygen and high water flow, which favored the occurrence of sensitive groups to environmental disturbances, such as Ephemeroptera, Plecoptera, Trichoptera and Coleoptera taxa, that living mainly in clean and well oxygenated waters. On the other hand, a higher density of insects drifting, especially Chironomidae, was observed in the urban stream, where high values of pH, electrical conductivity and nitrogen were observed. These larvae are able to explore a wide range of environmental conditions, owing to their great capacity for physiological adaptation. Despite observing the expected patterns, there were no significant differences between streams for the diversity and abundance of species. Thus, the species composition can be considered as the best predictor of impacts on the drifting insect community.

Colonization by benthic macroinvertebrates in two artificial substrate types of a Riparian Forest

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Lívia Borges dos Santos

Full Text Available Abstract: Aim To analyze the efficiency of organic and inorganic substrates in samples of benthic macroinvertebrates of riparian forests from the Cerrado. Specific objectives (i characterize the ecological succession and taxonomic richness of benthic macroinvertebrates in stream affluent of a riparian forest; (ii analyze the influence of seasonality on the colonization of macroinvertebrates; and (iii determine the effect of the types of artificial substrates on the richness, composition and abundance of the benthic community. Methods Sampling was carried out in the rainy and dry seasons, and we installed in the watercourse two types of substrates: organic (leaf packs and inorganic (bricks, organized in pairs. Six samples per season were done to verify colonization, succession, richness and abundance of benthic community. The substrates were carefully sorted and the organisms were identified to the lowest possible taxonomic level. Results The ecological succession was clearly observed, with the initial occurrence of Chironomidae and Baetidae (considered early colonizers, and a late occurrence of organisms such as Helotrephidae and Trichoptera (considered late colonizers. No significant difference was found in the richness and abundance among the studied seasons (rainy and dry, but the organic substrate was significantly higher than the inorganic substrate for these parameters. Conclusion Organic artificial substrates are more efficient in characterizing the community of benthic macroinvertebrates in the study area, because they are more similar to the conditions of the substrate found naturally in the environment.

Contaminants as habitat disturbers: PAH-driven drift by Andean paramo stream insects.

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Araújo, Cristiano V M; Moreira-Santos, Matilde; Sousa, José P; Ochoa-Herrera, Valeria; Encalada, Andrea C; Ribeiro, Rui

2014-10-01

Contaminants can behave as toxicants, when toxic effects are observed in organisms, as well as habitat disturbers and fragmentors, by triggering avoidance responses and generating less- or uninhabited zones. Drift by stream insects has long been considered a mechanism to avoid contamination by moving to most favorable habitats. Given that exploration and transportation of crude oil represent a threat for surrounding ecosystems, the key goal of the present study was to assess the ability of autochthonous groups of aquatic insects from the Ecuadorian paramo streams to avoid by drift different concentrations of polycyclic aromatic hydrocarbons (PAH) contained in the soluble fraction of locally transported crude oil. In the laboratory, different groups of insects were exposed to PAH for 12h. Three different assays, which varied in taxa and origin of the organisms, concentrations of PAH (0.6-38.8µgL(-1)), and environment settings (different levels of refuge and flow) were performed. For Anomalocosmoecus palugillensis (Limnephilidae), drift was a major cause of population decline in low concentration treatments but at higher concentrations mortality dominated. PAH was highly lethal, even at lower concentrations, for Chironomidae, Grypopterygidae (Claudioperla sp.) and Hydrobiosidae (Atopsyche sp.), and, therefore, no conclusion about drift can be drawn for these insects. Contamination by PAH showed to be a threat for benthic aquatic insects from Ecuadorian paramo streams as it can cause a population decline due to avoidance by drift and mortality. Copyright © 2014 Elsevier Inc. All rights reserved.

Estudo da dieta natural da ictiofauna de um reservatório centenário, São Paulo, Brasil

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Amanda R. Ribeiro

2014-12-01

Full Text Available Este estudo teve como objetivo caracterizar e comparar a alimentação de 13 espécies de peixes em três zonas (zona de influência fluvial, zona de transição e zona lacustre do reservatório de Itupararanga. Foram analisados 436 estômagos, sendo encontrados 17 recursos alimentares, todos de origem autóctone. As dietas predominantes das espécies foram: peixe, inseto, material vegetal e detritos na zona de influência fluvial, peixe, sedimento e material vegetal na zona de transição e inseto, escama e peixe na zona lacustre. Através do Índice Alimentar, as espécies foram categorizadas nas guildas: piscívora, insetívora, detritívora e carcinófaga. O Cluster indicou separação da guilda insetívora em espécies generalistas (insetos diversos e especialista (Chironomidae o que aumenta para cinco guildas. Na zona fluvial foram verificadas quatro guildas; na zona de transição três guildas e na zona lacustre duas guildas. Observou-se ainda uma dominância de espécies piscívoras que pode estar relacionada à idade do reservatório. Este estudo ampliou o conhecimento dos hábitos alimentares dos peixes em reservatórios antigos e suas diferenças, comparando as zonas existentes.

Discovering hidden biodiversity: the use of complementary monitoring of fish diet based on DNA barcoding in freshwater ecosystems.

Science.gov (United States)

Jo, Hyunbin; Ventura, Marc; Vidal, Nicolas; Gim, Jeong-Soo; Buchaca, Teresa; Barmuta, Leon A; Jeppesen, Erik; Joo, Gea-Jae

2016-01-01

Ecological monitoring contributes to the understanding of complex ecosystem functions. The diets of fish reflect the surrounding environment and habitats and may, therefore, act as useful integrating indicators of environmental status. It is, however, often difficult to visually identify items in gut contents to species level due to digestion of soft-bodied prey beyond visual recognition, but new tools rendering this possible are now becoming available. We used a molecular approach to determine the species identities of consumed diet items of an introduced generalist feeder, brown trout (Salmo trutta), in 10 Tasmanian lakes and compared the results with those obtained from visual quantification of stomach contents. We obtained 44 unique taxa (OTUs) belonging to five phyla, including seven classes, using the barcode of life approach from cytochrome oxidase I (COI). Compared with visual quantification, DNA analysis showed greater accuracy, yielding a 1.4-fold higher number of OTUs. Rarefaction curve analysis showed saturation of visually inspected taxa, while the curves from the DNA barcode did not saturate. The OTUs with the highest proportions of haplotypes were the families of terrestrial insects Formicidae, Chrysomelidae, and Torbidae and the freshwater Chironomidae. Haplotype occurrence per lake was negatively correlated with lake depth and transparency. Nearly all haplotypes were only found in one fish gut from a single lake. Our results indicate that DNA barcoding of fish diets is a useful and complementary method for discovering hidden biodiversity.

What you need is what you eat? Prey selection by the bat Myotis daubentonii.

Science.gov (United States)

Vesterinen, Eero J; Ruokolainen, Lasse; Wahlberg, Niklas; Peña, Carlos; Roslin, Tomas; Laine, Veronika N; Vasko, Ville; Sääksjärvi, Ilari E; Norrdahl, Kai; Lilley, Thomas M

2016-04-01

Optimal foraging theory predicts that predators are selective when faced with abundant prey, but become less picky when prey gets sparse. Insectivorous bats in temperate regions are faced with the challenge of building up fat reserves vital for hibernation during a period of decreasing arthropod abundances. According to optimal foraging theory, prehibernating bats should adopt a less selective feeding behavior--yet empirical studies have revealed many apparently generalized species to be composed of specialist individuals. Targeting the diet of the bat Myotis daubentonii, we used a combination of molecular techniques to test for seasonal changes in prey selectivity and individual-level variation in prey preferences. DNA metabarcoding was used to characterize both the prey contents of bat droppings and the insect community available as prey. To test for dietary differences among M. daubentonii individuals, we used ten microsatellite loci to assign droppings to individual bats. The comparison between consumed and available prey revealed a preference for certain prey items regardless of availability. Nonbiting midges (Chironomidae) remained the most highly consumed prey at all times, despite a significant increase in the availability of black flies (Simuliidae) towards the end of the season. The bats sampled showed no evidence of individual specialization in dietary preferences. Overall, our approach offers little support for optimal foraging theory. Thus, it shows how novel combinations of genetic markers can be used to test general theory, targeting patterns at both the level of prey communities and individual predators. © 2016 John Wiley & Sons Ltd.

[Food habits and winter diet of Charadrius melodus (Charadriiformes: Charadriidae) in Boca Ciega, Tamaulipas, Mexico].

Science.gov (United States)

Banda-Villanueva, Iris; Contreras-Lozano, Jorge; Garcia-Salas, Juan; González-Páez, Hugo

2013-06-01

The Piping Plover (Charadrius melodus) is a migratory endangered species that arrives, along with a great number of other winter migratory birds, to Boca Ciega every year. In spite of the importance of this ecosystem, these species, are threatened by the current habitat change caused by the dredging activities in the area. With the aim to generate new information about the importance of this area during winter, we studied C melodus activities during the winter season in Laguna Madre, from December 2009 to March 2010. Our objectives were: 1) determine the importance of the area during winter, 2) describe C. melodus ethology, feeding substrate preferences and food items, 3) to analyze and describe the sympatric diversity associated with C melodus. A total of ninety nine individuals were observed during the monitoring. The Cochran and Kendall test showed a high significance of the species with the substrate and signs tests using a binomial distribution that indicated a high preference for algal type of substrate. The highest activity recorded for this species during this winter season was feeding. The principal food items found in sediments were larvae of Diptera: Chironomidae and Ephydridae. The sympatric species of C. melodus were two families of Charadriiforms: Scolopacidae (nine species) and Charadriidae (two species). We concluded that this is an important area for feeding, protection and rest sites for this species, and its protection and management is recommended.

A key to larvae of species belonging to the genus Diamesa from Alps and Apennines (Italy

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Bruno Rossaro

2015-07-01

Full Text Available A key to species belonging to the genus Diamesa Meigen, 1835 (Diptera, Chironomidae from the Alps and Apennines (Italy is presented using characters observable in the fourth-instar larva. The larvae are separated on the basis of qualitative and quantitative characters. At present fifteen species from the Italian Alps are described in all three life stages, but only twelve species groups can be separated as larvae. The separation is based on the length and thickness of anal setae, antennal ratio, head capsule color and few other characters of the labrum and mentum. The shape of mental and mandibular teeth is still a valid taxonomic character, but unfortunately these characters can be rarely used because teeth are often excessively worn in samples collected in the field. Quantitative characters show variability within each species, differing according to the duration of larval development and must be used with caution. The species groups which can be separated in the larval stage are: the dampfi group, which includes D. dampfi and D. permacra, the latitarsis group including D. modesta and D. latitarsis, the zernyi group including D. zernyi and D. vaillanti. The species within each of these groups at present cannot be separated. D. starmachi, D. steinboecki, D. goetghebueri, D. bertrami, D. aberrata, D. incallida, D. cinerella, D. tonsa and D. insignipes can be separated from all the other known species in larval stage.

[Effects of large-area planting water hyacinth on macro-benthos community structure and biomass].

Science.gov (United States)

Liu, Guo-Feng; Liu, Hai-Qin; Zhang, Zhi-Yong; Zhang, Ying-Ying; Yan, Shao-Hua; Zhong, Ji-Cheng; Fan, Cheng-Xin

2010-12-01

The effects on macro-benthos and benthos environment of planting 200 hm2 water hyacinth (E. crassipens) in Zhushan Bay, Lake Taihu, were studied during 8-10 months consecutive surveys. Results indicated that average densities of mollusca (the main species were Bellamya aeruginosa) in far-planting, near-planting and planting area were 276.67, 371.11 and 440.00 ind/m2, respectively, and biomass were 373.15, 486.57 and 672.54 g/m2, respectively, showed that average density and biomass of planting area's were higher than those of others. However, the average density and biomass of Oligochaeta (the main species was Limodrilus hoffmeisteri) and Chironomidae in planting area were lower than that of outside planting area. The density and biomass of three dominant species of benthic animal increased quickly during 8-9 months, decreased quickly in October inside and outside water hyacinth planting area. The reason of this phenomenon could be possible that lots of cyanobacteria cells died and consumed dissolve oxygen in proceed decomposing. Algae cells released lots of phosphorus and nitrogen simultaneously, so macro-benthos died in this environment. The indexes of Shannon-Weaver and Simpson indicated that water environment was in moderate polluted state. On the basis of the survey results, the large-area and high-density planting water hyacinth haven't demonstrated a great impact on macrobenthos and benthos environment in short planting time (about 6 months planting time).

River ecosystem response to prescribed vegetation burning on Blanket Peatland.

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Brown, Lee E; Johnston, Kerrylyn; Palmer, Sheila M; Aspray, Katie L; Holden, Joseph

2013-01-01

Catchment-scale land-use change is recognised as a major threat to aquatic biodiversity and ecosystem functioning globally. In the UK uplands rotational vegetation burning is practised widely to boost production of recreational game birds, and while some recent studies have suggested burning can alter river water quality there has been minimal attention paid to effects on aquatic biota. We studied ten rivers across the north of England between March 2010 and October 2011, five of which drained burned catchments and five from unburned catchments. There were significant effects of burning, season and their interaction on river macroinvertebrate communities, with rivers draining burned catchments having significantly lower taxonomic richness and Simpson's diversity. ANOSIM revealed a significant effect of burning on macroinvertebrate community composition, with typically reduced Ephemeroptera abundance and diversity and greater abundance of Chironomidae and Nemouridae. Grazer and collector-gatherer feeding groups were also significantly less abundant in rivers draining burned catchments. These biotic changes were associated with lower pH and higher Si, Mn, Fe and Al in burned systems. Vegetation burning on peatland therefore has effects beyond the terrestrial part of the system where the management intervention is being practiced. Similar responses of river macroinvertebrate communities have been observed in peatlands disturbed by forestry activity across northern Europe. Finally we found river ecosystem changes similar to those observed in studies of wild and prescribed forest fires across North America and South Africa, illustrating some potentially generic effects of fire on aquatic ecosystems.

First record of Odontomesa Pagast from China, with description of the immature stages of O. ferringtoni Sæther (Diptera, Chironomidae, Prodiamesinae).

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Liu, Wenbin; Ferrington, Leonard C Jr; Wang, Xinhua

2016-06-28

The genus Odontomesa Pagast is newly recorded from China. Based on associated material collected from China and U.S.A, the immature stages of Odontomesa fulva (Kieffer) and Odontomesa ferringtoni Sæther are redescribed. Odontomesa sp. A Sæther is confirmed as conspecific with O. ferringtoni. The generic diagnosis of immature stages is emended. Keys to the known larvae and pupae of the genus are presented.

Taxonomic review on the subgenus Tripodura Townes (Diptera: Chironomidae: Polypedilum) from China with eleven new species and a supplementary world checklist.

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Zhang, Ruilei; Song, Chao; Qi, Xin; Wang, Xinhua

2016-07-05

The subgenus Tripodura Townes of Polypedilum Kieffer from China including 26 species is reviewed. Eleven new species, named P. (T.) absensilobum Zhang & Wang sp. n., P. (T.) apiculusetosum Zhang & Wang sp. n., P. (T.) arcuatum Zhang & Wang sp. n., P. (T.) bilamella Zhang & Wang sp. n., P. (T.) conghuaense Zhang & Wang sp. n., P. (T.) dengae Zhang & Wang sp. n., P. (T.) mengmanense Zhang & Wang sp. n., P. (T.) napahaiense Zhang & Wang sp. n., P. (T.) parallelum Zhang & Wang sp. n., P. (T.) pollicium Zhang & Wang sp. n. and P. (T.) trapezium Zhang & Wang sp. n. are described and illustrated based on male imagines. Three species, P. (T.) quadriguttatum Kieffer, P. (T.) unifascia (Tokunaga) and P. (T.) udominutum Niitsuma are firstly recorded in China. A key to known male imagines of Chinese species and an updated world checklist of subgenus Tripodura are presented.

Functional and structural rearrangements of salivary gland polytene chromosomes of Chironomus riparius Mg. (Diptera,Chironomidae) in response to freshly neutralized aluminium

Energy Technology Data Exchange (ETDEWEB)

Michailova, P.; Ilkova, J.; White, K.N

2003-05-01

Aluminium impacts on aquatic biota can be detected using polytene chromosomes as bio-markers - Although recent work has shown that environmentally relevant concentrations of freshly neutralized aluminium (AI) are bioavailable and toxic to freshwater invertebrates, the genotoxicity of Al has not been examined. Here we show that freshly neutralized Al affects structure and function of the salivary gland polytene chromosomes of the ubiquitous chironomid larva Chironomus riparius over three generations. Exposure to 500 {mu}g l{sup -1} added Al for 24-25 days resulted in a significantly higher frequency of numerous somatic aberrations, while no structural aberrations were found in F1 controls and few in the second and third generation. Aberrations also included deletions of sections of chromosome G of C. riparius larvae as well as deletions of one or more Balbiani rings. Changes in functional activity included decreased activity of the Balbiani rings (BR), and an increase in the number of decondensed centromeres. The activity of the nucleolar organizer (NOR) significantly decreased in F1 chironomids exposed to Al, while in the F2 and F3 generations the NOR showed normal (high) activity. First generation chironomids were generally more susceptible to Al although no clear evidence of tolerance was apparent over three generations. The possible use of alterations in chironomid polytene chromosomes as biomarkers of trace metal pollution is discussed.

Functional and structural rearrangements of salivary gland polytene chromosomes of Chironomus riparius Mg. (Diptera,Chironomidae) in response to freshly neutralized aluminium

International Nuclear Information System (INIS)

Michailova, P.; Ilkova, J.; White, K.N.

2003-01-01

Aluminium impacts on aquatic biota can be detected using polytene chromosomes as bio-markers - Although recent work has shown that environmentally relevant concentrations of freshly neutralized aluminium (AI) are bioavailable and toxic to freshwater invertebrates, the genotoxicity of Al has not been examined. Here we show that freshly neutralized Al affects structure and function of the salivary gland polytene chromosomes of the ubiquitous chironomid larva Chironomus riparius over three generations. Exposure to 500 μg l -1 added Al for 24-25 days resulted in a significantly higher frequency of numerous somatic aberrations, while no structural aberrations were found in F1 controls and few in the second and third generation. Aberrations also included deletions of sections of chromosome G of C. riparius larvae as well as deletions of one or more Balbiani rings. Changes in functional activity included decreased activity of the Balbiani rings (BR), and an increase in the number of decondensed centromeres. The activity of the nucleolar organizer (NOR) significantly decreased in F1 chironomids exposed to Al, while in the F2 and F3 generations the NOR showed normal (high) activity. First generation chironomids were generally more susceptible to Al although no clear evidence of tolerance was apparent over three generations. The possible use of alterations in chironomid polytene chromosomes as biomarkers of trace metal pollution is discussed

Responses of Chironomidae (Diptera; Insecta to the exclusion of shrimps and Ephemeroptera in a coastal forest stream, Rio de Janeiro, Brazil

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ML. Souza

Full Text Available In a benthic community on a continuous flat granite substrate in a third-order coastal forest stream, the dominant chironomid (Cricotopus increased in number when shrimps (Macrobrachium olfersi and Potimirim glabra and baetid ephemeropterans were excluded by electricity. The response appeared to be mediated by an increase in periphyton and sediments, rather than a reduction of direct predation or interference. Chironomids, periphyton and sediments decreased significantly compared to the control when shrimps only were excluded. Baetid ephemeropteran appeared to be the most important determinants of periphyton and sediment mass; the density of chironomids appeared to follow the quantity of periphyton and sediments.

USING delta15N OF CHIRONOMIDAE TO HELP ASSESS CONDITION AND STRESSORS IN LAKES, RIVERS AND STREAMS OF THE UNITED STATES.

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To assess large-scale ecological conditions efficiently, indicators that can be collected quickly at many sites need to be developed. We explore the utility of delta 15N from basal food chain organisms to provide information on N loading and processing in lakes, rivers and stream...

Taxonomic study on the subgenus Uresipedilum (Diptera: Chironomidae: Polypedilum, with description of a new species from the Yaewyama Islands, Okinawa, Japan

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Nao Yamamoto

2015-07-01

Full Text Available As a result of a multi-year survey, we recognized four species including a new species of the subgenus Uresipedilum from the Yaeyama Islands, the Ryukyus, Japan. Polypedilum (Uresipedilum paraconvictum sp. nov. is described. P. (U. classiglobum Zhang et Wang (2004 P. (U. bingoparadoxum Kawai et al. (1998 and P. (U. iriofegeum Sasa et Suzuki (2000 are re-described. The first species is newly recorded from Japan, and the second species is new to the Ryukyus. The diagnostic characters of the subgenus are discussed.

Health assessment using aqua-quality indicators of alpine streams (Khunjerab National Park), Gilgit, Pakistan.

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Ali, Salar; Gao, Junfeng; Begum, Farida; Rasool, Atta; Ismail, Muhammad; Cai, Yongjiu; Ali, Shaukat; Ali, Shujaat

2017-02-01

This preliminary research was conducted to evaluate the alpine stream health by using water quality as an indicator in Khunjerab National park of the Karakoram ranges located in Pak-China boarder Pakistan having altitude of 3660 m. This study investigated the stream health in the context of the presence or absence of sensitive species, their diversity, and their taxa richness. The water and macroinvertebrate samples were collected from 17 different locations from upstream and downstream of the river by using random sampling method. Macroinvertebrate samples were obtained using kick net (500-μm mesh size) and hand-picking method (NYSDEC). A total of 710 counts including 41 families of macroinvertebrates were recorded comprising of 7 orders including: Ephemeroptera (46%) being the most dominant group, Plecoptera (33%), Trichoptera (5%), Chironomidae (Diptera) (14%), Heteroptera (1%), and Coleoptera (1%). Ephemeroptera, Trichoptera, and Plecoptera (EPT) were found in abundance at the main source, Qarchanai, Dhee, and Tourqeen Nullah, as compared to the other locations of the stream. The most dominant macroinvertebrate was Ephemeroptera whose relative abundance is Pi = 0.49 by using the Shannon index. However, different statistical tools, including principal component analysis (PCA), cluster analysis (CA), ANOVA, and linear regression model, show a strong correlation between water quality and macroinvertebrates. The overall results of the biological indicators showed better ecological health at downstream compared to upstream. This study will provide basic information and understanding about the macroinvertebrates for future researchers, and the data will be helpful for upcoming research programs on alpine streams for the discovery and occurrences of macroinvertebrates and associated fauna.

Aquatic macroinvertebrates associated with Eichhornia azurea (Swartz Kunth and relationships with abiotic factors in marginal lentic ecosystems (São Paulo, Brazil

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CV. Silva

Full Text Available Marginal lakes are characterised by their having high biological diversity due to the presence of aquatic macrophytes in their coastal zones, providing habitats for refuge and food for animal community members. Among the fauna components associated with macrophytes, aquatic macroinvertebrates are important because they are an energy source for predators and fish. In six lakes and two different seasons (March and August 2009, the ecological attributes of aquatic macroinvertebrate community associated with Eichhornia azurea were compared and the controlling environmental factors were identified. Since the attributes of macroinvertebrate community are strictly associated with abiotic variables of each distinct habitat, our hypothesis was that each site associated with the same floating aquatic macrophyte (E. azurea should have a typical composition and density of organisms. We identified 50 taxa of macroinvertebrates, with greater taxa richness for aquatic insects (37 taxa divided into eight orders; the order Diptera being the most abundant in the two study periods. On the other hand, higher values of total taxa richness were recorded in August. Dissolved oxygen and pH presented the greatest number of significant positive correlations with the different taxa. The animals most frequently collected in the six lakes in March and August 2009 were Hirudinea, Oligochaeta, Hydrachnidae, Conchostraca, Ostracoda, Noteridae, Ceratopogonidae, Chironomidae, Culicidae, Caenidae, Pleidae, Aeshnidae, Libellulidae, Coenagrionidae and Nematoda. Only densities of Trichoptera, Ostracoda and Conchostraca presented the highest significant differences between lakes in both study periods and considering the composition of macroinvertebrates no significant differences were registered for macroinvertebrate composition.

The influence of urbanisation on macroinvertebrate biodiversity in constructed stormwater wetlands.

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Mackintosh, Teresa J; Davis, Jenny A; Thompson, Ross M

2015-12-01

The construction of wetlands in urban environments is primarily carried out to assist in the removal of contaminants from wastewaters; however, these wetlands have the added benefit of providing habitat for aquatic invertebrates, fish and waterbirds. Stormwater quantity and quality is directly related to impervious area (roads, sealed areas, roofs) in the catchment. As a consequence, it would be expected that impervious area would be related to contaminant load and biodiversity in receiving waters such as urban wetlands. This study aimed to establish whether the degree of urbanisation and its associated changes to stormwater runoff affected macroinvertebrate richness and abundance within constructed wetlands. Urban wetlands in Melbourne's west and south east were sampled along a gradient of urbanisation. There was a significant negative relationship between total imperviousness (TI) and the abundance of aquatic invertebrates detected for sites in the west, but not in the south east. However macroinvertebrate communities were relatively homogenous both within and between all study wetlands. Chironomidae (non-biting midges) was the most abundant family recorded at the majority of sites. Chironomids are able to tolerate a wide array of environmental conditions, including eutrophic and anoxic conditions. Their prevalence suggests that water quality is impaired in these systems, regardless of degree of urbanisation, although the causal mechanism is unclear. These results show some dependency between receiving wetland condition and the degree of urbanisation of the catchment, but suggest that other factors may be as important in determining the value of urban wetlands as habitat for wildlife. Copyright © 2015 Elsevier B.V. All rights reserved.

Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

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Augusto Oliveira

2010-12-01

Full Text Available The objective of this study was to evaluate benthic macroinvertebrate communities as bioindicators of water quality in five streams located in the "Reserva Particular do Patrimônio Natural" (RPPN Mata Samuel de Paula and its surroundings, in the municipality of Nova Lima near the city of Belo Horizonte, Minas Gerais State, southeastern Brazil. This region has been strongly modified by human activities including mining and urbanization. Samples were collected in the field every three months between August 2004 and November 2005, totaling six samplings in the rainy and dry seasons. This assessment identified one area ecologically altered while the other sampling sites were found to be minimally disturbed systems, with well-preserved ecological conditions. However, according to the Biological Monitoring Work Party (BMWP and the Average Score Per Taxon (ASPT indices, all sampling sites had excellent water quality. A total of 14,952 organisms was collected, belonging to 155 taxa (148 Insecta, two Annelida, one Bivalvia, one Decapoda, one Planariidae, one Hydracarina, and one Entognatha. The most abundant benthic groups were Chironomidae (47.9%, Simuliidae (12.3%, Bivalvia (7.5%, Decapoda (6.1%, Oligochaeta (5.2%, Polycentropodidae (3.7%, Hydropsychidae (2.5%, Calamoceratidae (1.8%, Ceratopogonidae (1.7%, and Libellulidae (1.2%. The assessment of the benthic functional feeding groups showed that 34% of the macroinvertebrates were collector-gatherers, 29% predators, 24% collector-filterers, 8% shredders, and 5% scrapers. The RPPN Mata Samuel de Paula comprises diversified freshwater habitats that are of great importance for the conservation of many benthic taxa that are intolerant to organic pollution.

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California

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Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

2012-01-01

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98–58.0 μg Se/g; midge larvae, 12.7–50.6 μg Se/g; mosquitofish, 13.2–20.2 μg Se/g; and mollies, 12.8–30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

Aquatic ecosystems of the lower Pecos drainage, October-December, 1980

International Nuclear Information System (INIS)

Anon.

1981-01-01

Emphasis of work completed in 1980 was placed on analysis of macrobenthos and preparation of the dominant component, the Chironomidae (Diptera) for further study. One series of chironomid larvae was examined by scanning electron microscopy. The limnological survey techniques used during this study are the same as those described in earlier reports of work at the Los Medanos site by Sublette and Sublette. The Pecos River below Carlsbad is a severely perturbed stream. Human activity has resulted in the regulation of stream flow and nutrient enrichment from sewage effluents and return flow from fields adjacent to the river. Stream flow regulation is most noticeable below 10 Mile Dam near Loving where virtually all flow is diverted into irrigation ditches. Flow regulation minimizes the effects of spates (periods of high flow) resulting in reduced attachment sites for macrobenthos. A protracted period of no spates preceded the January 1978 sampling period and, as would be expected, numbers of taxa were reduced. After a period of heavy local flooding, a colonizer effect was observed in the composition of the January 1979 samples. By January of 1980, the fauna had returned essentially to the 1978 condition. A heavy saline inflow at Malaga Bend results in impoverished macrobenthos in terms of numbers of species and individuals. This is believed to result from both elevated salinity and heavy metals concentrations; a synergistic effect may exist. Slight variations in fish composition occur between up-stream, lower salinity stations and down-stream, higher salinity stations. Up-stream stations show greater diversity in fish populations

Seasonal variation in Chironomid emergence from coastal pools

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Alexander T. Egan

2015-07-01

Full Text Available Understanding the phenology of emergences can be useful in determining seasonal chironomid life cycle patterns, which are often influenced by ice cover and temperature in cold climates. Lake Superior is the largest lake in North America and with a mean surface temperature of 3.9 °C influences regional climate. Coastal pools at Isle Royale, a wilderness archipelago in the northern part of the lake, occur in dense patches on low-gradient volcanic bedrock between the lakeshore and forest, creating variable microhabitats for Chironomidae. Four sites were sampled monthly from April to October, 2010. Surface-floating pupal exuviae were collected from a series of pools in two zones: a lower zone near the lake influenced by wave splash, and an upper zone near the forest and influenced by upland runoff. We used Jaccard’s and Whittaker’s diversity indexes to test community similarity across months. Temperature loggers in pools collected hourly readings for most of the study. Assemblage emergences were stable in upper pools, with significant similarity across late spring and summer months. Assemblages were seasonally variable in lower pools, with significant dissimilarity across spring, summer, and fall months. Few species in either zone were unique to spring or fall months. However, many summer species in the splash zone had a narrow emergence period occurring during calm weather following distinct increases in mean water temperature. Regardless of input of cold lake water to the lower zone, pools from both zones generally had corresponding temperature trends.

Calcified aquatic insect larval constructions in the Pleistocene tufa of Jebel El Mida, Gafsa, southern Tunisia: Recognition and paleoenvironmental significance

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Ben Ahmed, Walid; Henchiri, Mohsen; Mastouri, Amna; Slim S'himi, Najet

2018-04-01

Calcified aquatic larval cases were recognized and identified in the Pleistocene tufa masses of Jebel El Mida, Gafsa, southern Tunisia. These larval constructions belong to three main insect families: caddisflies (Trichoptera, Hydropsychidae), midges (Diptera, Chironomidae) and aquatic moths (Lepidoptera, Pyralidae) that inhabited tubes in the tufa and spun nets. Each insect community has its distinctive characteristics of larval constructions that allow their recognition. The larval constructions recognized comprise fixed and portable (for caddisflies) dwelling cases and silken retreats and feeding capture nets. These last-mentioned are almost completely eroded and only remnants are preserved. The spatial distribution of these larval cases within the tufa is not random but, rather imposed by some specific paleohydraulic conditions. It's the reason why aquatic insect larval constructions are considered as prominent tool for the reconstruction of tufa and travertine depositional environments. Chironomid fixed dwelling cases (diameters range from 0.6 mm for clustered tubes to 3 mm) indicate the deposition of tufa under lotic (flowing) or lentic (standing) water conditions. The later hydraulic condition is shared with hydropsychids with fixed retreats (0.2-4 mm in diameter). Portable case-building caddisflies (case length ranging from 5 to 20 mm, and diameter from 3 to 5 mm at the cephalic end) prefer lentic conditions and are almost completely missing in high-energy flowing water locations that are preferred by pyralids (tubes are between 5 and 10 mm long and 3 mm in diameter). These insect families benefit from inhabiting the tufa by the availability of construction materials of their cases and the necessary space for their development.

Benthic fauna of extremely acidic lakes (pH 2-3)

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, G G

2001-07-01

The structure of the benthic invertebrate communities were investigated in terms of composition, abundance, and biomass from extremely acidic lakes with pH values from 2 to 3 in areas where coal was intensively mined in the Lusatian region in the eastern region of Germany. Benthic invertebrates colonisation on leaves and the breakdown rate processing of the three deciduous leaf: Betula pendula (birch), Fraxinus excelsior (ash), and Juglans regia (walnut) were investigated. Also, the main key-species of these acidic environments were investigated, in terms of description of pupal exuviae of Chironomus crassimanus and the feeding habit of this acid-resistant species through analysis of their gut content. The benthic food web in extremely acidic mining Lusatian lakes is very short in terms of species richness, trophic relationship, guilds and functional feeding groups. Collector-filters and scraper-grazers were absent in extremely acidic mining lakes (AML 107, AML 111 and AML 117). Shredders as Limnophyes minimus (Diptera, Chironomidae, Orthocladiinae) and Hydrozetes lacustris (Acari, Hydrozetidae) occurred in low abundance in AML 107 and AML 111, and it may be in response to slow leaf breakdown process in these ecosystems, except in AML 117 where the H. lacustris contributed most to ecosystems functioning via the processing of litter. Aquatic insects as Sialis lutaria (Megaloptera, Sialidae), Orectochilus villosus (Coleoptera, Gyrinidae), Coenagrion mercuriale (Odonata, Coenagrionidae), and Phryganeidae (Trichoptera) are the top-predators of these ecosystems. They did not depend on the level of pH in the lakes, but on the availability of food resources. (orig.)

Copper, cadmium, and zinc concentrations in juvenile Chinook salmon and selected fish-forage organisms (aquatic insects) in the upper Sacramento River, California

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Saiki, Michael K.; Martin, Barbara A.; Thompson, Larry D.; Walsh, Daniel

2001-01-01

This study assessed the downstream extent andseverity of copper (Cu), cadmium (Cd), and zinc (Zn)contamination from acid mine drainage on juvenile chinook salmon(Oncorhynchus tshawytscha) and aquatic insects over aroughly 270-km reach of the Sacramento River below KeswickReservoir. During April–May 1998, salmon were collected fromfour sites in the river and from a fish hatchery that receiveswater from Battle Creek. Salmon from river sites were examinedfor gut contents to document their consumption of variousinvertebrate taxa, whereas salmon from river sites and thehatchery were used for metal determinations. Midge(Chironomidae) and caddisfly (Trichoptera) larvae and mayfly(Ephemeroptera) nymphs were collected for metal determinationsduring April–June from river sites and from Battle and Buttecreeks. The fish hatchery and Battle and Butte creeks served asreference sites because they had no history of receiving minedrainage. Salmon consumed mostly midge larvae and pupae (44.0%,damp-dry biomass), caddisfly larvae (18.9%), Cladocera (5.8%),and mayfly nymphs (5.7%). These results demonstrated thatinsects selected for metal determinations were important as fishforage. Dry-weight concentrations of Cu, Cd, and Zn weregenerally far higher in salmon and insects from the river thanfrom reference sites. Within the river, high metalconcentrations persisted as far downstream as South Meridian (thelowermost sampling site). Maximum concentrations of Cd (30.7 μg g-1) and Zn (1230 μg g-1),but not Cu (87.4 μg g-1), in insects exceeded amounts that other investigators reported as toxic when fed for prolonged periods to juvenile salmonids.

Relation of chironomids with Aeromonas species

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Sivan eLaviad

2016-05-01

Full Text Available Chironomids (Diptera: Chironomidae, also known as non-biting midges, are one of the most abundant groups of insects in aquatic habitats. They undergo a complete metamorphosis of four life stages of which three are aquatic (egg, larva, pupa, and the adult emerges into the air. Chironomids serve as a natural reservoir of Aeromonas and Vibrio cholerae species. Here we review existing knowledge about the mutual relations between Aeromonas species and chironomids. Using 454-pyrosequencing of the 16S rRNA gene, we found that the prevalence of Aeromonas species in the insects’ egg masses and larvae was 1.6% and 3.3% of the insects’ endogenous microbiota, respectively. Aeromonas abundance per egg mass remained stable during a six-month period of bacterial monitoring. Different Aeromonas species were isolated and some demonstrated the ability to degrade the insect’s egg masses and to prevent eggs hatching. Chitinase was identified as the enzyme responsible for the egg mass degradation. Different Aeromonas species isolated from chironomids demonstrated the potential to protect their host from toxic metals. Aeromonas is a causative agent of fish infections. Fish are frequently recorded as feeding on chironomids. Thus, fish might be infected with Aeromonas species via chironomid consumption. Aeromonas strains are also responsible for causing gastroenteritis and wound infections in humans. Different virulence genes were identified in Aeromonas species isolated from chironomids. Chironomids may infest drinking water reservoirs, hence be the source of pathogenic Aeromonas strains in drinking water. Chironomids and Aeromonas species have a complicated mutual relationship.

Selenium in aquatic biota inhabiting agricultural drains in the Salton Sea Basin, California.

Science.gov (United States)

Saiki, Michael K; Martin, Barbara A; May, Thomas W

2012-09-01

Resource managers are concerned that water conservation practices in irrigated farmlands along the southern border of the Salton Sea, Imperial County, California, could increase selenium concentrations in agricultural drainwater and harm the desert pupfish (Cyprinodon macularius), a federally protected endangered species. As part of a broader attempt to address this concern, we conducted a 3-year investigation to collect baseline information on selenium concentrations in seven agricultural drains inhabited by pupfish. We collected water, sediment, selected aquatic food-chain taxa (particulate organic detritus, filamentous algae, net plankton, and midge [Chironomidae] larvae), and two poeciliid fishes (western mosquitofish Gambusia affinis and sailfin molly Poecilia latipinna) for selenium determinations. The two fish species served as ecological surrogates for pupfish, which we were not permitted to sacrifice. Dissolved selenium ranged from 0.70 to 32.8 μg/L, with selenate as the major constituent. Total selenium concentrations in other environmental matrices varied widely among drains, with one drain (Trifolium 18) exhibiting especially high concentrations in detritus, 5.98-58.0 μg Se/g; midge larvae, 12.7-50.6 μg Se/g; mosquitofish, 13.2-20.2 μg Se/g; and mollies, 12.8-30.4 μg Se/g (all tissue concentrations are based on dry weights). Although toxic thresholds for selenium in fishes from the Salton Sea are still poorly understood, available evidence suggests that ambient concentrations of this element may not be sufficiently elevated to adversely affect reproductive success and survival in selenium-tolerant poeciliids and pupfish.

Micro x-ray absorption spectroscopic analysis of arsenic localization and biotransformation in Chironomus riparius Meigen (Diptera: Chironomidae) and Culex tarsalis Coquillett (Culicidae)

International Nuclear Information System (INIS)

Mogren, Christina L.; Webb, Samuel M.; Walton, William E.; Trumble, John T.

2013-01-01

The distribution and speciation of arsenic (As) were analyzed in individuals of various life stages of a midge, Chironomus riparius, and the mosquito Culex tarsalis exposed to 1000 μg/l arsenate. X-ray absorption spectroscopy (XAS) revealed that C. riparius larvae accumulate As in their midgut, with inorganic arsenate [As(V)] being the predominant form, followed by arsenite [As(III)] and an As-thiol. Reduced concentrations of As in pupal and adult stages of C. riparius indicate excretion of As between the larval and pupal stages. In adults, As was limited to the thorax, and the predominant form was an As-thiol. In Cx. tarsalis, As was not found in high enough concentrations to determine As speciation, but the element was distributed throughout the larva. In adults, As was concentrated in the thorax and eyes of adults. These results have implications for understanding the biotransformation of As and its movement from aquatic to terrestrial environments. -- Highlights: •C. riparius larvae reduced arsenate to arsenite in the midgut. •C. riparius larvae accumulated As in the midgut, with 27% as a transformed As-thiol. •C. riparius adults retained As in the thorax, with 53% as As-thiol. •Larvae of Cx. tarsalis did not have a specific site of As accumulation. •Low concentrations of As in adults suggest reduced terrestrial transfer potential. -- Arsenic accumulation and biotransformation in aquatic insects is variable, but the location and speciation of As provides insight into the detoxification mechanisms of aquatic Diptera

Characterization of six small HSP genes from Chironomus riparius (Diptera, Chironomidae): Differential expression under conditions of normal growth and heat-induced stress.

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Martín-Folgar, Raquel; de la Fuente, Mercedes; Morcillo, Gloria; Martínez-Guitarte, José-Luis

2015-10-01

Small heat shock proteins (sHSPs) comprise the most numerous, structurally diverse, and functionally uncharacterized family of heat shock proteins. Several Hsp genes (Hsp 90, 70, 40, and 27) from the insect Chironomus riparius are widely used in aquatic toxicology as biomarkers for environmental toxins. Here, we conducted a comparative study and characterized secondary structure of the six newly identified sHsp genes Hsp17, Hsp21, Hsp22, Hsp23, Hsp24, and Hsp34. A characteristic α-crystallin domain is predicted in all the new proteins. Phylogenetic analysis suggests a strong relation to other sHSPs from insects and interesting evidence regarding evolutionary origin and duplication events. Comparative analysis of transcription profiles for Hsp27, Hsp70, and the six newly identified genes revealed that Hsp17, Hsp21, and Hsp22 are constitutively expressed under normal conditions, while under two different heat shock conditions these genes are either not activated or are even repressed (Hsp22). In contrast, Hsp23, Hsp24, and Hsp34 are significantly activated along with Hsp27 and Hsp70 during heat stress. These results strongly suggest functional differentiation within the small HSP subfamily and provide new data to help understand the coping mechanisms induced by stressful environmental stimuli. Copyright © 2015 Elsevier Inc. All rights reserved.

Common antigenic determinants of haemoglobin as basis of immunological cross-reactivity between chironomid species (Diptera, Chironomidae): studies with human and animal sera.

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Baur, X; Dewair, M; Haegele, K; Prelicz, H; Scholl, A; Tichy, H

1983-01-01

Chironomids, of which approximately 10,000 species exist, are reported to cause severe immediate type allergic diseases in man. In the present study, immunological cross-reactivity between 14 chironomid species from different continents was proven by RAST inhibition, double immunodiffusion and a new allergoprint technique, based upon PAGE separation of insect crude extracts. Using isolated chironomid haemoglobins and sera of sensitized persons, as well as rabbit antibodies against larval crude extract or against the haemoglobin fraction of Chironomus thummi, it could be proven that cross-reactivity derives at least predominantly from haemoglobin components with common antigenic determinants in the different species. Images Fig. 2 Fig. 7 Fig. 8 Fig. 9 PMID:6197219

Multi-scale approach to the environmental factors effects on spatio-temporal variability of Chironomus salinarius (Diptera: Chironomidae) in a French coastal lagoon

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Cartier, V.; Claret, C.; Garnier, R.; Fayolle, S.; Franquet, E.

2010-03-01

The complexity of the relationships between environmental factors and organisms can be revealed by sampling designs which consider the contribution to variability of different temporal and spatial scales, compared to total variability. From a management perspective, a multi-scale approach can lead to time-saving. Identifying environmental patterns that help maintain patchy distribution is fundamental in studying coastal lagoons, transition zones between continental and marine waters characterised by great environmental variability on spatial and temporal scales. They often present organic enrichment inducing decreased species richness and increased densities of opportunist species like C hironomus salinarius, a common species that tends to swarm and thus constitutes a nuisance for human populations. This species is dominant in the Bolmon lagoon, a French Mediterranean coastal lagoon under eutrophication. Our objective was to quantify variability due to both spatial and temporal scales and identify the contribution of different environmental factors to this variability. The population of C. salinarius was sampled from June 2007 to June 2008 every two months at 12 sites located in two areas of the Bolmon lagoon, at two different depths, with three sites per area-depth combination. Environmental factors (temperature, dissolved oxygen both in sediment and under water surface, sediment organic matter content and grain size) and microbial activities (i.e. hydrolase activities) were also considered as explanatory factors of chironomid densities and distribution. ANOVA analysis reveals significant spatial differences regarding the distribution of chironomid larvae for the area and the depth scales and their interaction. The spatial effect is also revealed for dissolved oxygen (water), salinity and fine particles (area scale), and for water column depth. All factors but water column depth show a temporal effect. Spearman's correlations highlight the seasonal effect (temperature, dissolved oxygen in sediment and water) as well as the effect of microbial activities on chironomid larvae. Our results show that a multi-scale approach identifies patchy distribution, even when there is relative environmental homogeneity.

New or little-known species of Chaetocladius s. str. Kieffer, 1911 (Diptera: Chironomidae: Orthocladiinae) from the Amur River basin (Russian Far East).

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Makarchenko, Eugenyi A; Makarchenko, Marina A; Semenchenko, Alexander A

2017-03-27

Chironomids of the subgenus Chaetocladius s. str. from the Amur River basin are revised using both morphological characters and molecular data. Three new species, C. egorych sp. nov., C. lopatinskiy sp. nov. and C. yavorskayae sp. nov., are described and figured. The pupa of C. fedotkin is described for the first time. Adult males of C. ligni and C. piger, little-known in the Far East, are redescribed and annotated, and key to males of the Chaetocladius s. str. from the Amur River basin is provided. A reference 658 bp barcode sequence from a fragment of the mitochondrial gene cytochrome oxidase I (COI) was used as a tool for species delimitation. Comparisons with corresponding regions of COI between 5 species in the subgenus produced K2P genetic distances of 8.3-12.6%, values well associated with interspecific variation. Molecular data were also used for the reconstruction of the phylogenetic relationships within the subgenus Chaetocladius s. str.

Response of benthic macroinvertebrate communities to highway construction in an Appalachian watershed

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Hedrick, Lara B.; Welsh, S.A.; Anderson, James T.; Lin, L.-S.; Chen, Y.; Wei, X.

2010-01-01

Highway construction in mountainous areas can result in sedimentation of streams, negatively impacting stream habitat, water quality, and biotic communities. We assessed the impacts of construction of a segment of Corridor H, a four-lane highway, in the Lost River watershed, West Virginia, by monitoring benthic macroinvertebrate communities and water quality, before, during, and after highway construction and prior to highway use at upstream and downstream sites from 1997 through 2007. Data analysis of temporal impacts of highway construction followed a Before-After-Control-Impact (BACI) study design. Highway construction impacts included an increase in stream sedimentation during the construction phase. This was indicated by an increase in turbidity and total suspended solids. Benthic macroinvertebrate metrics indicated a community more tolerant during and after construction than in the period before construction. The percent of Chironomidae and the Hilsenhoff Biotic Index (HBI) increased, while percent of Ephemeroptera, Plecoptera, and Trichoptera (EPT) decreased. Our 10-year study addressed short-term impacts of highway construction and found that impacts were relatively minimal. A recovery of the number of EPT taxa collected after construction indicated that the benthic macroinvertebrate community may be recovering from impacts of highway construction. However, this study only addressed a period of 3 years before, 3 years during, and 4 years post construction. Inferences cannot be made concerning the long-term impacts of the highway, highway traffic, runoff, and other factors associated with highway use. Continual monitoring of the watershed is necessary to determine if the highway has a continual impact on stream habitat, water quality, and biotic integrity. ?? 2010 Springer Science+Business Media B.V.

Group-specific multiplex PCR detection systems for the identification of flying insect prey.

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Daniela Sint

Full Text Available The applicability of species-specific primers to study feeding interactions is restricted to those ecosystems where the targeted prey species occur. Therefore, group-specific primer pairs, targeting higher taxonomic levels, are often desired to investigate interactions in a range of habitats that do not share the same species but the same groups of prey. Such primers are also valuable to study the diet of generalist predators when next generation sequencing approaches cannot be applied beneficially. Moreover, due to the large range of prey consumed by generalists, it is impossible to investigate the breadth of their diet with species-specific primers, even if multiplexing them. However, only few group-specific primers are available to date and important groups of prey such as flying insects have rarely been targeted. Our aim was to fill this gap and develop group-specific primers suitable to detect and identify the DNA of common taxa of flying insects. The primers were combined in two multiplex PCR systems, which allow a time- and cost-effective screening of samples for DNA of the dipteran subsection Calyptratae (including Anthomyiidae, Calliphoridae, Muscidae, other common dipteran families (Phoridae, Syrphidae, Bibionidae, Chironomidae, Sciaridae, Tipulidae, three orders of flying insects (Hymenoptera, Lepidoptera, Plecoptera and coniferous aphids within the genus Cinara. The two PCR assays were highly specific and sensitive and their suitability to detect prey was confirmed by testing field-collected dietary samples from arthropods and vertebrates. The PCR assays presented here allow targeting prey at higher taxonomic levels such as family or order and therefore improve our ability to assess (trophic interactions with flying insects in terrestrial and aquatic habitats.

Composição da fauna cavernícola brasileira, com uma análise preliminar da distribuição dos taxons

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Eleonora Trajano

1990-01-01

Full Text Available New data on Brazilian cave fauna are added to previous surveys and the relative abundance and distribution of the cavernicolous taxa is discussed. Terrestrial representatives of several arthropod families and genera are common in both tropical and subtropical Brazilian caves: Endecous and Eidmanacris crickets, Reduviidae heteropterans, Carabidae, Catopinae and Ptilodactylidae beetles, dipterans such as the Chironomidae, Keroplatidae, Phoridae and Drosophilidae, Hydropsychidae trichopterans, Pseudonnanolenidae and Chelodesnidae millipedes, Plato, Ctenus, Loxosceles and Blechroscelis spiders, Pachylinae opilionids, Chernetidae pseudoscorpions and acarians such as the Macrochelidae and Uropodidae. Other taxa are mainly or exclusively tropical Blattelidae, Blattidae and BlaberidaE cockroaches, Histeridae beetles, Noctuoidea moths, social insects as termites and ants, Styloniscidae isopods, Migalomorpha spiders, Amblypigi On the other hand, Psauridae spiders, Goniosoma and Tricommatinae opilionids, Elmidae beetles, and Philosciidae isopods seems to be mainly subtropical. Brazilian aquatic cave fauna seems to be less diversified than the terrestrial one. Siluriform fishes such as pimelodids, trichomycterids and loricariids predominate throughout the country, besides decapod (Macrobrachium shrimps, Potamidae crabs, Aegla anomurans, the latter exclusive of subtropical caves and amphipod (Spelaeogammarus, in tropical caves, and Hyalella crustaceans. Insect larvae (e.g. Elmidae coleopterans, Nematocera dipterans, trichopterans and adults (e.g. Veliidae and Naucoridae heteropterans, Dytiscidae coleopterans, oligochaetes and gastropods such as the Hydrobiidae, are also relatively common. Blechroscelis spiders, Goniosoma opilionids, Zelurus heteropterans, Eidmanacris crickets, Keroplatidae dipterans and Macrobrachium shrimps, among others, live next to the entrance zone in the majority of the caves. But, these animals become troglofiles under certain

Food Web Responses to Artificial Mixing in a Small Boreal Lake

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Lauri Arvola

2017-07-01

Full Text Available In order to simulate food web responses of small boreal lakes to changes in thermal stratification due to global warming, a 4 year whole-lake manipulation experiment was performed. Within that time, period lake mixing was intensified artificially during two successive summers. Complementary data from a nearby lake of similar size and basic water chemistry were used as a reference. Phytoplankton biomass and chlorophyll a did not respond to the greater mixing depth but an increase was observed in the proportional abundance of diatoms, and the proportional abundance of cryptophytes also increased immediately after the onset of mixing. Obligate anoxic green sulphur bacteria vanished at the onset of mixing but gradually recovered after re-establishment of hypolimnetic anoxic conditions. No major effect on crustacean zooplankton was found, but their diversity increased in the metalimnion. During the mixing, the density of rotifers declined but protozoan density increased in the hypolimnion. Littoral benthic invertebrate density increased during the mixing due to Ephemeroptera, Asellus aquaticus and Chironomidae, whereas the density of Chaoborus larvae declined during mixing and lower densities were still recorded one year after the treatment. No structural changes in fish community were found although gillnet catches increased after the onset of the study. The early growth of perch (Perca fluviatilis increased compared to the years before the mixing and in comparison to the reference lake, suggesting improved food availability in the experimental lake. Although several food web responses to the greater mixing depth were found, their persistence and ecological significance were strongly dependent on the extent of the disturbance. To better understand the impacts of wind stress on small lakes, long term whole-lake experiments are needed.

Aquatic insects as the main food resource of fish the community in a Neotropical reservoir

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Ana Paula Vidotto-Magnoni

Full Text Available We evaluated the feeding of fish species of the Nova Avanhandava Reservoir, low Tietê River, São Paulo State, Brazil. Fishes were collected in two stretches of the reservoir: Santa Bárbara (14 samples and Bonito (two samples between September 2002 and March 2004, using gill and seining nets. The results of stomach contents analysis were expressed with the frequency of occurrence and gravimetric method, combined in the Alimentary Index (AI. The 20 species studied consumed 52 food items, grouped in 10 food categories: aquatic insects, terrestrial insects, crustaceans, fish, macroinvertebrates, microcrustaceans, algae, vegetal matter, detritus/sediment and scales. The aquatic insects (mainly Chironomidae, Odonata and Ephemeroptera were the most common food resources, consumed by 18 species. The diet composition of the community (species grouped indicated that the dominant food category in the diet of fishes was aquatic insects (AI = 77.6%, followed by crustaceans (AI = 7.1%. Four trophic guilds were identified according a cluster analysis (Pearson distance: insectivorous (10 species, omnivorous (4 species, detritivorous (3 species and piscivorous/carcinophagous (3 species. Despite the highest number of species, the insectivorous guild was responsible for more than 80% in captures in number and biomass (CPUEn and CPUEb. The low values of niche breadth presented by all species, along with the low values of diet overlap between species pairs indicate a high degree of food resources partitioning among species. The aquatic insects, despite being the main food resource of insectivorous fishes, also complemented the diet of other species, which demonstrate the importance of this food resource for the fish community, sustaining a high diversity, abundance and biomass of fishes.

Timing the tides: genetic control of diurnal and lunar emergence times is correlated in the marine midge Clunio marinus.

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Kaiser, Tobias S; Neumann, Dietrich; Heckel, David G

2011-05-20

The intertidal zone of seacoasts, being affected by the superimposed tidal, diurnal and lunar cycles, is temporally the most complex environment on earth. Many marine organisms exhibit lunar rhythms in reproductive behaviour and some show experimental evidence of endogenous control by a circalunar clock, the molecular and genetic basis of which is unexplored. We examined the genetic control of lunar and diurnal rhythmicity in the marine midge Clunio marinus (Chironomidae, Diptera), a species for which the correct timing of adult emergence is critical in natural populations. We crossed two strains of Clunio marinus that differ in the timing of the diurnal and lunar rhythms of emergence. The phenotype distribution of the segregating backcross progeny indicates polygenic control of the lunar emergence rhythm. Diurnal timing of emergence is also under genetic control, and is influenced by two unlinked genes with major effects. Furthermore, the lunar and diurnal timing of emergence is correlated in the backcross generation. We show that both the lunar emergence time and its correlation to the diurnal emergence time are adaptive for the species in its natural environment. The correlation implies that the unlinked genes affecting lunar timing and the two unlinked genes affecting diurnal timing could be the same, providing an unexpectedly close interaction of the two clocks. Alternatively, the genes could be genetically linked in a two-by-two fashion, suggesting that evolution has shaped the genetic architecture to stabilize adaptive combinations of lunar and diurnal emergence times by tightening linkage. Our results, the first on genetic control of lunar rhythms, offer a new perspective to explore their molecular clockwork.

Insect emergence in relation to floods in wet meadows and swamps in the River Dalälven floodplain.

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Vinnersten, T Z Persson; Östman, Ö; Schäfer, M L; Lundström, J O

2014-08-01

Annual variation in flood frequency and hydroperiod during the vegetation season has ecological impacts on the floodplain biota. Although many insect groups may have a lower emergence during a flood event, it is poorly known how annual emergence of insects in temporary wetlands is related to the variation in hydrology. Between May and September, we studied the weekly emergence of 18 insect taxa over six consecutive years, 2002-2007, in six temporary flooded wetlands (four wet meadows and two forest swamps) in the River Dalälven floodplains, Central Sweden. We used emergence traps to collect emerging insects from terrestrial and aquatic parts of wet meadows and swamp forests. In all wetlands, the insect fauna was numerically dominated by the orders Diptera, Hymenoptera, Coleoptera and Homoptera. On a weekly basis, 9 out of the 18 insect taxa had lower emergence in weeks with flood than in weeks with no flood, whereas no taxon had a higher emergence in weeks with flood. Over the seasons, we related insect emergence to seasonal flood frequency and length of hydroperiod. The emergence of most studied taxa decreased with increasing hydroperiod, which suggests that emergence after floods do not compensate for the reduced emergence during floods. Only Culicidae and the aquatic Chironomidae sub-families Tanypodinae and Chironominae showed an increase in emergence with increasing hydroperiod, whereas Staphylinidae peaked at intermediate hydroperiod. We conclude that a hydroperiod covering up to 40% of the vegetation season has a significant negative effect on the emergence of most taxa and that only a few taxa occurring in the temporary wetlands are actually favoured by a flood regime with recurrent and unpredictable floods.

Indirect effects of bioinsecticides on the nontarget fauna: The Camargue experiment calls for future research

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Poulin, Brigitte

2012-10-01

Following its high selectivity and low toxicity to nontarget organisms, Bacillus thuringiensis var. israelensis (Bti) has become the most commonly used microbial agent to control mosquitoes worldwide. Considered non-toxic to mammals, birds, fish, plants and most aquatic organisms, Bti direct effects on the nontarget fauna are largely limited to non-biting midges (Chironomidae). Studies addressing the indirect effects of Bti through food web perturbations are scanty and showed no significant results. Mosquito-control in southern France was implemented in 1965 using various insecticides over 400 km of coast. In spite of a high mosquito nuisance, the Camargue wetlands were excluded from this control programme to preserve biodiversity. The expanding use of Bti has prompted the implementation of an experimental mosquito control in 2006 involving 2500 of the 25,000 ha of larval biotopes of the Camargue, accompanied by impact studies on the nontarget fauna. Using birds from natural and human-inhabited areas as model species, we assessed trophic perturbations caused by three years of Bti applications. The preliminary results of this 5-yr programme revealed significant effects of Bti spraying on abundance of reed-dwelling invertebrates serving as food to passerines, as well as on the diet and breeding success of house martins nesting in rural estates and small towns. Very few studies (if any) have provided such compelling evidence of an insecticide affecting vertebrate populations, putting into question the environmental-friendly character of Bti, at least in some areas. The significance of these results are discussed within a wider context and completed with an analysis of the current Bti bibliography to highlight and orient priorities for future research on this topic.

Macroinvertebrados dulceacuícolas de la Isla del Coco, Costa Rica: especies y comparación con otras islas del Pacífico Tropical Oriental

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Pablo E. Gutiérrez-Fonseca

2013-06-01

Full Text Available La Isla del Coco es una isla oceánica localizada en el Pacífico Tropical Oriental a unos 492km de Cabo Blanco. La isla cuenta con un área terrestre de 24km² y un área marina protegida de 9 640km². Fue declarada Parque Nacional en 1978 y Patrimonio de la Humanidad por la UNESCO en 1997. Se realizó una gira de recolecta del 22 de mayo al 12 junio 2008. Se recolectaron macroinvertebrados acuáticos en 20 tramos de tres ríos (Genio, Chatham y Sucio y dos quebradas (Minuto y quebrada sin nombre atrás de estación de guarda parques. En 13 sitios se toma- ron parámetros fisicoquímicos. En total se recolectaron 455 individuos de 20 táxones de 15 familias de insectos acuáticos y otros macroinvertebrados. La familia Staphylinidae presentó la mayor abundancia seguida por Chironomidae, los dípteros fueron el orden con mayor riqueza taxonómica. Una relación entre distancia y número de familias se observó apoyando en parte la Teoría de Biogeografía de Islas. La relación mejoró al corregir área con elevación, indicando que islas montañosas tenían alta riqueza, posiblemente debido a la mayor intercepción de nubes que alimentan los ambientes dulceacuícolas que favorecen el establecimiento de la fauna acuática. Las variables ambientales fueron similares en todos los sitios.

Influence of environmental factors on benthic macroinvertebrate communities of urban streams in Vereda habitats, Central Brazil Influência de variáveis ambientais na comunidade de macroinvertebrados bentônicos de córregos urbanos de Veredas, Brasil Central

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Renata de Moura Guimaraes Souto

2011-09-01

Full Text Available AIM: Veredas and the aquatic and semi-aquatic communities play a key role in watershed protection in the Cerrado Biome. Information about the effects of physical and chemical variables and habitat integrity on benthic communities has been increased in recent years; however, there is no study evaluating the influence of urbanization on macroinvertebrates of Vereda streams. Thus, improving the knowledge of the relationship between abiotic properties and benthic fauna is very important for understanding the functioning of ecological processes and health of aquatic ecosystems. This study investigated the influence of physical and chemical variables on benthic macroinvertebrate communities along a gradient of anthropogenic disturbance in four Vereda streams in Uberlândia (MG, one in a preserved area and three in the urban area; METHODS: samplings were collected during the dry and rainy seasons; RESULTS: principal component analysis separated the stream in the preserved area from those in the urban area by having lower values of BOD, COD, sediment size, conductivity, detergents, pH, deposited solids and total dissolved solids. Pollution sensitive groups (e.g., Ephemeroptera and Trichoptera were associated to the stream in the preserved area, and more tolerant groups (e.g., Chironomidae and Oligochaeta had greater abundance in the streams of the urban area. Canonical Correspondence Analysis indicated that dissolved oxygen, conductivity, BOD, oil and grease, and turbidity explained 56% of the variance in the distribution and abundance of macroinvertebrates; CONCLUSIONS: Benthic communities of Vereda streams in urban areas in the Cerrado Biome seem to be highly affected by human activities that increase water organic pollution and sedimentation.OBJETIVO: Veredas e comunidades aquáticas e semi-aquáticas desempenham importante papel na proteção das bacias hidrográficas no Bioma Cerrado. Informações sobre efeitos de variáveis físico-químicas e da

ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

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Moreau, X.; Saez, G.; Thiery, A. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Clot-Faybesse, O.; Guiraudie-Capraz, G. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Bienboire-Frosini, C. [' Neurobiologie Integrative et Adaptative' -UMR 6149, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France); Pherosynthese, Le Rieu Neuf, 84490 St Saturnin d' Apt (France); Martin, C. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, UAPV, 33 rue Louis Pasteur, 84000 Avignon (France); De Jong, L. [Equipe ' Biomarqueurs and Bioindicateurs Environnementaux' , UMR-CNRS 6116 IMEP, Universite de Provence, 3 Place Victor Hugo, 13331 Marseille cedex 3 (France)], E-mail: laetitia.moreau@univ-provence.fr

2008-06-15

A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11 days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats. - Semi-quantification of midge larval MXR transporters by ELISA is a simple and sensitive method to detect chemically polluted situations in running freshwaters.

ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

International Nuclear Information System (INIS)

Moreau, X.; Saez, G.; Thiery, A.; Clot-Faybesse, O.; Guiraudie-Capraz, G.; Bienboire-Frosini, C.; Martin, C.; De Jong, L.

2008-01-01

A new simple and sensitive method to distinguish chemically polluted from unpolluted situations in freshwater ecosystems is reported. For this purpose, Chironomus gr thumni larvae were collected from a polluted urban river downstream a sewage treatment plant. For the first time, ELISA assay was used to semi-quantify the multixenobiotic resistance transporters (MXR) in these small pertinent bioindicators. The use of samples immediately fixed in the field gives a delay to isolate larvae and allows multi-sampling along a longitudinal transect in a river at a given time. Results exhibit an induction of MXR proteins in larvae from the polluted river and a deinduction in larvae maintained 11 days in unpolluted water. They show new evidences to use midge larvae in biomonitoring environmental programs. They answer to first biomarker calibration steps for the ongoing development of MXR transporters as a detection tool of xenobiotic impacts on bioindicator invertebrates in their freshwater habitats. - Semi-quantification of midge larval MXR transporters by ELISA is a simple and sensitive method to detect chemically polluted situations in running freshwaters

Diagnoses for Nubensia, n. gen. (Diptera, Chironomidae, Chironomini), with the first full descriptions of the adult female and larva of N. nubens (Edwards, 1929).

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Spies, Martin; Dettinger-Klemm, Andreas

2015-07-30

A new genus, Nubensia Spies, is proposed for N. nubens (Edwards, 1929), n. comb., based on morphological evaluation of both adult sexes, the pupa and larva. The material studied includes name-bearing syntype specimens and the first reared associations linking three life stages for individual members of this species. The larva represents a unique morphotype previously described incompletely only from studies of subfossil chironomid remains. The problems with placement of the species in any previously established genus are discussed in detail, and various related issues in taxonomy and nomenclature are commented on. The verified distribution of N. nubens ranges from the British Isles and central Europe to the western Mediterranean, including northern Africa, with possible extensions to Turkey and central Asia. Larvae have been found on mostly coarse, variously covered substrates near the shores of lakes and banks of slowly flowing running waters, under both oligotrophic and eutrophic conditions.

Paleoecología: el uso de los quironómidos fósiles (Diptera: Chironomidae) en reconstrucciones paleoambientales durante el Cuaternario en la Patagonia

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Julieta MASSAFERRO

2009-01-01

Entre los indicadores biológicos lacustres más utilizados en las reconstrucciones ambientales, se encuentran el polen, los ostrácodos y las diatomeas, y entre los insectos, los coleópteros y los quironómidos. Este grupo ha cobrado gran importancia en los últimos tiempos, debido a los resultados prometedores que se han obtenido en reconstrucciones climáticas realizadas en América del Norte y Europa. En América del Sur, el uso de los quironómidos fósiles en estudios cuaternarios es relativament...

Paleoecología: el uso de los quironómidos fósiles (Diptera: Chironomidae en reconstrucciones paleoambientales durante el Cuaternario en la Patagonia

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Julieta MASSAFERRO

2009-01-01

Full Text Available Entre los indicadores biológicos lacustres más utilizados en las reconstrucciones ambientales, se encuentran el polen, los ostrácodos y las diatomeas, y entre los insectos, los coleópteros y los quironómidos. Este grupo ha cobrado gran importancia en los últimos tiempos, debido a los resultados prometedores que se han obtenido en reconstrucciones climáticas realizadas en América del Norte y Europa. En América del Sur, el uso de los quironómidos fósiles en estudios cuaternarios es relativamente limitado, principalmente por su escaso conocimiento taxonómico regional. La mayor parte de estos estudios fueron realizados en lagos glaciares patagónicos de Argentina y Chile. Las larvas de quironómidos constituyen una valiosa herramienta paleolimnológica, por ser un grupo de organismos altamente sensible a cambios ambientales, tanto naturales como artificiales. Además, es un grupo de insectos ampliamente distribuido y con una abundancia y diversidad relativamente altas. Sus cápsulas cefálicas se preservan en los sedimentos lacustres y poseen caracteres importantes que permiten identificar géneros y muchas veces especies. El estudio de los ensambles de quironómidos en sedimentos lacustres puede ser utilizado con distintos objetivos, por ejemplo, para estudios de eutrofización, ya que responden rápidamente a cambios en la concentración de nutrientes, materia orgánica y otros elementos, como metales pesados. No obstante, uno de los potenciales más importantes de este grupo de insectos es su sensibilidad a los cambios de temperatura, por este motivo, la aplicación más importante de su estudio en sedimentos se centra en las reconstrucciones climáticas. Esta contribución es una síntesis de los resultados de los trabajos publicados en la Patagonia argentina y chilena, sobre la base del uso de los quironómidos fósiles en reconstrucciones paleoambientales.

Diversity of non-biting midge larvae assemblages in the Jacuí River basin, Brazil.

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Floss, Elzira Cecília Serafini; Kotzian, Carla Bender; Spies, Márcia Regina; Secretti, Elisangela

2012-01-01

The richness and composition of a mountain-river chironomid larvae assemblage in the Jacuí River basin, Brazil were studied, and compared with other riverine non-biting midge larvae assemblages previously studied in the country. Additionally, the influence of some regional-scale environmental characteristics on the spatial distribution of these assemblages was tested. The specimens were collected at 12 sites in the middle course of the Jacuí River basin (in the state of Rio Grande do Sul) between April 2000 and May 2002. Around 100 taxa were recorded. The dominant taxa belonged to the genera Rheotanytarsus, Cricotopus, Polypedilum, and Pseudochironomus. Twenty-two rare taxa were found, representing 22% of the total of taxa inventoried. Fourteen genera (Aedokritus, Axarus, Endotribelos, Kiefferulus, Manoa, Oukuriella, Phaenopsectra, Stenochironomus, Xenochironomus, Xestochironomus, Cardiocladius, Metriocnemus, Paracladius, and Rheocricotopus) represent new occurrences in Rio Grande do Sul. The similarity analysis of the chironomid larvae assemblages inventoried in 32 regions of Brazil indicated five groups with similarity higher than 50%. The groups, when the effects of spatial autocorrelation were removed, displayed a weak positive correlation between the assemblage composition and the aquatic system or hydraulic conditions and the hydrographic basin, and a weak negative correlation in relation to the biome. The altitude showed no correlation with the composition of the assemblage. The relatively high richness of the region surveyed in relation to other Brazilian regions corroborates some tendencies already noted in other parts of the world, such as: i) lotic systems may constitute an exception to the rule that diversity is greater in tropical regions, ii) regions of transitional relief may contain the greatest richness of Chironomidae, and iii) in rivers, the group might have its spatial distribution influenced to a greater extent by local environmental

Interplay of anthropogenic and natural disturbance impacts on the hyporheic ecology

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Mori, N.; Brancelj, A.; Simčič, T.; Lukančič, S.

2009-04-01

The hyporheic invertebrate community from the pre-alpine river (W Slovenia) was studied in order to analyze the impacts of high discharge and in-stream gravel extraction. Two distinct river reaches were sampled from June 2004 to May 2005. At impacted site, where gravel extraction was carried out, the response of hyporheic community to the anthropogenic disturbance was studied. Physical and chemical parameters, together with the amounts organic matter and activity of the biofilm were measured. Invertebrates were sampled by Bou-Rouch pumping method. Discharge of the Bača River varied from 108 m3s-1 in October 2004 to 1.6 m3s-1 in March 2005. Streambed sediments at both sites were composed of heterogeneous mixture of boulders, cobbles, pebbles, gravel, sand and silt. Oxygen saturation was close to 100 %, indicating good sediment permeability. A total of 75 invertebrate taxa were identified, 40 of which belonged to the occasional hyporheos, 26 to the permanent hyporheos and 9 were stygobites. At both sites, fauna was dominated numerically by juveniles of Cyclopoida and early stages of Leuctra larvae (Plecoptera). Chironomidae (Diptera) contributed significantly to the total invertebrate density at reference site and Baetoidea (Ephemeroptera) to the total density at impacted site. At both sites a decrease in density occurred immediately after disturbance. The recovery was relatively fast (two and a half months). The CCA analysis revealed the importance of fine sediment amounts for hyporheic invertebrate distribution. The results indicated that discharge play an important role in shaping hyporheic invertebrate community in the Bača River and that the removal of sediments due to gravel extraction led to the impoverishment of the structural characteristics of the hyporheic community.

Prescribed-fire effects on an aquatic community of a southwest montane grassland system

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Caldwell, Colleen A.; Jacobi, Gerald Z.; Anderson, Michael C.; Parmenter, Robert R.; McGann, Jeanine; Gould, William R.; DuBey, Robert; Jacobi, M. Donna

2013-01-01

The use of prescription fire has long been recognized as a reliable management tool to suppress vegetative succession processes and to reduce fuel loading to prevent catastrophic wildfires, but very little attention has been paid to the effects on aquatic systems. A late-fall prescribed burn was implemented to characterize effects on an aquatic community within a montane grassland system in north-central New Mexico. The fire treatment was consistent with protocols of a managed burn except that the fire was allowed to burn through the riparian area to the treatment stream to replicate natural fire behavior. In addition to summer and fall preburn assessment of the treatment and reference stream, we characterized immediate postfire effects (within a week for macroinvertebrates and within 6 months for fish) and seasonal effects over a 2-year period. Responses within the treatment stream were compared with an unburned reference stream adjacent to the prescription burn. During the burn, the diel range in air temperature increased by 5°C while diel range in water temperature did not change. Carbon–nitrogen ratios did not differ between treatment and reference streams, indicating the contribution of ash from the surrounding grassland was negligible. Although total taxa and species richness of aquatic macroinvertebrates were not altered, qualitative indices revealed departure from preburn condition due to loss of sensitive taxa (mayflies [order Ephemeroptera] and stoneflies [order Plecoptera]) and an increase in tolerant taxa (midges [order Chironomidae]) following the burn. Within 1 year of the burn, these attributes returned to preburn conditions. The density and recruitment of adult Brown Trout Salmo trutta did not differ between pre- and postburn collections, nor did fish condition differ. Fire is rarely truly replicated within a given study. Although our study represents one replication, the results will inform managers about the importance in timing (seasonality

Evidence for Isostatic Emergence and Holocene Environmental Change Recorded in Chironomid Assemblages and Sediment Composition of Coastal Lake T1 in SW Greenland

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Berman, K.; Axford, Y.; Lasher, G. E.

2017-12-01

Multi-proxy analysis of a coastal lake in southwest Greenland near Nuuk provides evidence for regional environmental changes, including the timing of isostatic rebound and the temperature history of the area. T1 (informal name) is a small lake 50 km south of Nuuk, at 17.5 m elevation and currently isolated from glacial meltwater drainage. The lake's sediment record begins approximately 9500 cal years BP, when the site was submerged beneath sea level due to glacial isostatic depression following the Last Glacial Maximum. The record captures the transition of the environment from a submerged, glacially-influenced marine site to a non-glacially fed (and initially meromictic) freshwater lake 8600 cal years BP. Magnetic susceptibility, a proxy for sediment minerogenic content, decreased rapidly from 9500 to 8600 years BP, before abruptly stabilizing and remaining relatively low and steady for the rest of the record. The transition to a lacustrine environment was characterized by a rapid and relatively simultaneous increase in primary productivity (inferred from biogenic silica concentrations) and shift towards terrestrial versus marine sources of organic matter (inferred from carbon:nitrogen ratios and nitrogen isotopes) between 8700 and 8400 years BP. Together, these proxies and the presence of marine shells below the transition provide robust evidence for the transition from a marine environment to a freshwater lake in response to regional postglacial isostatic rebound. Within the Holocene, measures of bulk sediment composition (e.g., biogenic silica, loss-on-ignition and magnetic susceptibility) are relatively stable. Chironomid (Insecta: Diptera: Chironomidae) assemblages, which in some environments are quantitative proxies for summer temperature changes, show species-level shifts within the Holocene that will be interpreted in this presentation alongside indicators of landscape change including carbon:nitrogen ratios, bulk sediment spectral reflectance and bulk

Development of an early warning system for strong environmental pollution by measuring the activation of defined universally existing stress genes. Final report; Das Auftreten spezifischer Stressproteine bei Umweltbelastung in Chironomiden: Entwicklung eines neuen Fruehwarnsystems fuer starke Umweltbelastung durch Messung der Aktivierung definierter, universell vorkommender Stressgene bei ausgewaehlten Indikatororganismen. Abschlussbericht

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Kloetzel, P.M.; Mueller, W.

1991-12-31

In the present pilot study we established an ELISA based detection system which allows sensitive monitoring of stress induction as a result of heavy metal pollution. The system is based on the immunological detection of the stress induced hsp70 in larvae of Chironomidae. Using this system it is possible to detect environmental pollution by heavy metals far beyond lethal toxicity values. Since only very few animals are needed the system can also be used in field tests. For poluted isopodes as Oniscus asellus for example a single animal turned out be sufficient to monitor stress induction by Pb{sup +}. The established system ought to serve as basis for a more extended study in which different animals are collected from various polluted environments and tested with respect to already induced hsp synthesis. (orig.) [Deutsch] In der vorliegenden Pilotstudie konnte ein sensitives Nachweissystem fuer die Induktion des ubiquitaeren Stresssystem durch Schwermetalle auf der Basis der immunologischen Detektion von HSP70 etabliert werden. Dieses, auf ELISA Basis arbeitende Testverfahren ermoeglicht es Schwermetallbelastungen weit unterhalb der Toxizitaetsgrenze ueber die Induktion der HSP70 Synthese in Chironomidenlarven nachzuweisen. Die Tatsache, dass nur wenige Tiere fuer eine statistische Aussage benoetigt werden laesst eine Anwendungsmoeglichkeit auch auf Freilandtiere erwarten. So reicht fuer bleibelastete Freiland-Asseln ein einziges Tier zum immunologischen Belastungsnachweis aus. Damit sind die Grundlagen fuer die zweite Phase, die Freilandphase, in welcher sowohl Freilandtiere als auch Gewaesser- und Sedimentproben von verschiedenen Standorten in die Untersuchungen miteinbezogen werden sollen; geschaffen. Es koennen jetzt Tiere aus belasteten Gewaessern bezueglich bereits erfolgter Stressproteinproduktion aber auch auf eine Neuinduzierbarkeit nach zusaetzlicher Laborbelastung untersucht werden. Ebenso koennen Labortiere auf ihre Reaktion gegenueber belasteten

The first hop: Use of Beaufort Sea deltas by hatch-year semipalmated sandpipers

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Churchwell, Roy T.; Kendall, Steve J.; Brown, Stephen C.; Blanchard, Arny L.; Hollmen, Tuula E.; Powell, Abby

2018-01-01

River deltas along Alaska’s Beaufort Sea coast are used by hatch-year semipalmated sandpipers (Calidris pusilla) after leaving their terrestrial natal sites, but the drivers of their use of these stopover sites on the first “hop” of fall migration are unknown. We quantified sandpiper temporal distribution and abundance as related to food resources at three river deltas during the beginning of their fall migration (post-breeding period) to compare the habitat quality among these deltas. We conducted population counts, sampled invertebrates, and captured birds to collect blood samples from individuals for triglyceride and stable isotope analyses to determine fattening rates and diet. Patterns of sandpiper and invertebrate abundance were complex and varied among deltas and within seasons. River deltas were used by sandpipers from late July to late August, and peak sandpiper counts ranged from 1000 to 4000 individuals, of which 98% were hatch-year semipalmated sandpipers. Isotopic signatures from blood plasma samples indicated that birds switched from a diet of upland tundra to delta invertebrate taxa as the migration season progressed, suggesting a dependence on delta invertebrates. Despite differences in diet among deltas, we found no differences in fattening rates of juvenile sandpipers as indicated by triglyceride levels. The number of sandpipers was positively associated with abundance of Amphipoda and Oligochaeta at the Jago and Okpilak-Hulahula deltas; an isotopic mixing model indicated that sandpipers consumed Amphipoda and Oligochaeta at Jago, mostly Chironomidae at Okpilak-Hulahula and Spionidae at Canning. Regardless of the difference in sandpiper diets at the Beaufort Sea deltas, their similar fattening rates throughout the season indicate that all of these stopover sites provide a critical food resource for hatch-year sandpipers beginning their first migration.

Oviposition of aquatic insects in a tropical high altitude stream.

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Rios-Touma, Blanca; Encalada, A C; Prat, N

2012-12-01

The persistence of aquatic insect populations in streams depends on the recruitment of larval populations from egg masses deposited by adults, especially after disturbance. However, recruitment of aquatic populations by oviposition is a process that remains unstudied in streams and rivers. The objectives of our study were to document flying and oviposition patterns of aquatic insects in a high altitude tropical stream during both dry and wet seasons. In particular we studied 1) richness and abundance of adult forms of aquatic insects flying and ovipositing; 2) number of eggs (oviposition pattern), egg mass identity, and morphology; and 3) substrate preferences by ovipositing females. We found 2,383 aquatic insects corresponding to 28 families, with dipterans representing 89% of total individuals collected. Adult insects had lower richness (28 taxa) than larval diversity (up to 52 taxa) and distinct community composition. Richness and relative abundance of most taxa (adults) were not significantly different between seasons, behaviors, diel period, or all three. During both sampling periods we found females with eggs in a total of 15 different families (13 in the dry season and 14 in the wet season). There were no significant differences in the proportion of females with eggs between seasons, diel periods, or different behaviors (flying versus ovipositing traps) of the different female taxa. Few types of egg masses were found in rocks at the stream during both seasons, and most egg masses found corresponded to families Baetidae and Chironomidae. Finally, we provide the first description of eggs masses (size, shape, color, and number of eggs per female) of gravid females (10 taxa) and those found in the stream substrate (six taxa) of Andean macroinvertebrates. This is the first study reporting oviposition, adult diversity, and oviposition patterns of aquatic insects in the Andean region.

Reed beds may facilitate transfer of tributyltin from aquatic to terrestrial ecosystems through insect vectors in the Archipelago Sea, SW Finland.

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Lilley, Thomas M; Meierjohann, Axel; Ruokolainen, Lasse; Peltonen, Jani; Vesterinen, Eero; Kronberg, Leif; Nikinmaa, Mikko

2012-08-01

Due to their adsorptive behavior, organotin compounds (OTCs), such as tributyltin (TBT), are accumulated in aquatic sediments. They resist biodegradation and, despite a ban in 2008, are a potential source for future exposure. Sediment OTCs have mostly been measured from sites of known high concentrations such as ports, shipping lanes, and marine dredging waste sites. The possible flow of OTCs from marine to terrestrial ecosystems, however, has not been studied. In the present study, the authors assessed whether sediments in common reed beds (Phragmites australis) accumulate TBT and whether chironomid (Diptera: Chironomidae) communities developing in reed-bed sediments act as vectors in the transfer of TBT from aquatic to terrestrial ecosystems in the Airisto channel, Archipelago Sea. The authors also investigated whether distance from the only known source and depth and TBT concentration of the adjacent shipping lane affect reed-bed concentrations. Thirty-six sites along the Airisto channel were sampled at 2-km intervals with triplicate samples from reed beds and the adjacent shipping lane for sediment and seven reed-bed sites for chironomids, and these were analyzed with an solid phase extraction liquid chromatography tamdem mass spectrometry method. The closer to the source the sample site was, the higher the measured TBT concentrations were; and the deeper the shipping lane, the lower the concentration of TBT in reed-bed sediments. The chironomid TBT concentrations correlated with reed-bed sediment TBT concentrations and showed evidence of accumulation. Therefore, TBT may be transferred, through the food web, from aquatic to terrestrial ecosystems relatively close to a source through ecosystem boundaries, such as common reed beds, which are areas of high insect biomass production in the Archipelago Sea. Copyright © 2012 SETAC.

Hypoxia and anoxia effects on alcohol dehydrogenase activity and hemoglobin content in Chironomus riparius Meigen, 1804

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Valentina Grazioli

2016-02-01

Full Text Available The metabolic effects of low oxygen content on alcohol-dehydrogenase (ADH activity and hemoglobin (Hb concentration were investigated in IV-instar larvae of Chironomus riparius (Diptera: Chironomidae from an Italian stream. Two series of short-term (48 h experiments were carried out: exposure to (1 progressive hypoxia (95 to 5% of oxygen saturation and (2 anoxia (at <5% of oxygen saturation. In (1, Hb amount increased with increasing oxygen depletion up to a critical value of oxygenation (about 70% of oxygen saturation. Below this percentage, the Hb amount declined to values comparable with those present in the control. The respiration rate (R remained almost constant at oxygen saturation >50% and decreased significantly only after 48 h of treatment (= <5% of oxygen saturation reaching values <100 mmolO2 gAFDW-1 h-1. ADH activity showed two phases of growth, within the first 14 h and over 18 h of exposure. Overall, we inferred that i Hb might function as short-term oxygen storage, enabling animals to delay the on-set of anaerobiosis; and ii alcoholic fermentation co-occurs for a short time with aerobic respiration, becoming the prevalent metabolic pathway below 5% of oxygen saturation (<1 mg L-1. These considerations were supported also by results from anoxia exposure (2. In such condition, larvae were visibly stressed, becoming immobile after few minutes of incubation, and ADH reached higher values than in the hypoxia treatment (2.03±0.15 UADH mg prot-1. Overall, this study showed a shift from aerobic to anaerobic activity in C. riparius larvae exposed to poorly oxygenated water with an associated alteration of ADH activity and the Hb amount. Such metabolites might be valid candidate biomarkers for the environmental monitoring of running waters.

Mining pollution and the diet of the purple-striped Gudgeon Mogurnda Mogurnda Richardson (Eleotridae) in the Finniss River, Northern Territory, Australia

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Jeffree, R.A.; Williams, N.J.

1980-01-01

During the dry season of 1974, collections of the purple-striped Gudgeon Mogurnda Mogurnda were taken from the Finniss River of the Northern Territory; during the wet season, this river receives acidic and metallic pollutants from the formerly mined area of Rum Jungle. The fish consumed a great variety of foods, with high abundances of dytiscidae, chironomidae, ceratopogonidae, trichoptera, odonata, copepoda, decapoda, and pisces. For no food was there a significant regression against habitat descriptors in both of the zones; this emphasizes that pollution effects are more complex than simply depressing or raising the abundances of the dietary species. Five foods were more abundant in the diets of the polluted zone, and three in those of the unpolluted zone. The dietary abundances of two foods, both crustacean, increased in the polluted zone, compared to the unpolluted zone, through the dry season. Two categories of foods: (1) those obtaining oxygen directly from the atmosphere or via a film or bubble of air; and (2) the converse set (aquatic respirers), were contrasted for their usefulness in distinguishing between the zones, by both hierarchical agglomerative and discriminant function analyses. One collection from the polluted zone was reclassified as unpolluted on the basis of its grouping behaviour. The relevance for pollution studies of dietary analysis of euryphagous fish, rather than sampling aquatic fauna directly, is discussed in terms of food substitution, switching, strategies for abundance and recovery by the fauna, and possible effects of the pollutants on the fish as an intervening collector. Downstream patterns of abundance of the invertebrate fauna in this study are broadly similar to those of other studies in which such chemically diverse metals as Pb, Zn, and Cu are the pollutants, but there are differences for some faunal components.

[Selective feeding in fish: Effect of feeding and defensive motivations evoked by natural odors].

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Kasumyan, A O; Marusov, E A

2015-01-01

The effect of feeding and defensive motivations evoked by natural olfactory signals (the food odor, the alarm pheromone) on choice and consumption of food items different in color and taste, and the manifestation of foraging behavior were examined in fish (koi Cyprinus carpio, roach Rutilus rutilus). The agar-agar pellets of red and green color having one of the amino acids (glycine, L-proline, L-alanine; all in concentration of 0.1 M) were simultaneously offered to single fishes in pure water, and in water extract of Chironomidae larvae or in water extract of fish skin. It was found out that odors used have different effects on fish foraging activity and on pellet selection for both pellet choice and consumption. On background of food odor, fish grasped pellets more often than in pure water. The equal choice of red and green pellets in pure water shifted to the preference of red ones in the presence of food odor. Despite the increase in the absolute number of pellets grasped, the relative consumption reduced and was replaced by selective consumption of pellets with glycine regardless of their color. Increasing demand for the food quality, due to the increased feeding motivation in response to food odor, is an important adaptation enhancing selection and consumption of food with more appropriate sensory qualities for fish. Defensive motivation caused by alarm pheromone suppressed predisposition. of fish to feed. Fish grasped pellets several times less often than in pure water and refused most of them. Any changes in the color or taste preferences were absent. Feeding behavior of fish of both species was characterized by repeated intraoral pellet testing, but in koi handling was less typical than in roach. In both species, handling activity was higher in those cases when the pellet was finally rejected. This activity was enhanced also on the background of food odor.

Results of Macroinvertebrate Sampling Conducted at 33 SRS Stream Locations, July--August 1993

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Specht, W.L.

1994-12-01

In order to assess the health of the macroinvertebrate communities of SRS streams, the macroinvertebrate communities at 30 stream locations on SRS were sampled during the summer of 1993, using Hester-Dendy multiplate samplers. In addition, three off-site locations in the Upper Three Runs drainage were sampled in order to assess the potential for impact from off-site activities. In interpreting the data, it is important to recognize that these data were from a single set of collections. Macroinvertebrate communities often undergo considerable temporal variation, and are also greatly influenced by such factors as water depth, water velocity, and available habitat. These stations were selected with the intent of developing an on-going sampling program at a smaller number of stations, with the selection of the stations to be based largely upon the results of this preliminary sampling program. When stations within a given stream showed similar results, fewer stations would be sampled in the future. Similarly, if a stream appeared to be perturbed, additional stations or chemical analyses might be added so that the source of the perturbation could be identified. In general, unperturbed streams will contain more taxa than perturbed streams, and the distribution of taxa among orders or families will differ. Some groups of macroinvertebrates, such as Ephemeroptera (mayflies), Plecoptera (stoneflies) and Trichoptera (caddisflies), which are collectively called EPT taxa, are considered to be relatively sensitive to most kinds of stream perturbation; therefore a reduced number of EPT taxa generally indicates that the stream has been subject to chemical or physical stressors. In coastal plain streams, EPT taxa are generally less dominant than in streams with rocky substrates, while Chironomidae (midges) are more abundant. (Abstract Truncated)

The Evolution of SINEs and LINEs in the genus Chironomus (Diptera).

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Papusheva, Ekaterina; Gruhl, Mary C; Berezikov, Eugene; Groudieva, Tatiana; Scherbik, Svetlana V; Martin, Jon; Blinov, Alexander; Bergtrom, Gerald

2004-03-01

Genomic DNA amplification from 51 species of the family Chironomidae shows that most contain relatives of NLRCth1 LINE and CTRT1 SINE retrotransposons first found in Chironomus thummi. More than 300 cloned PCR products were sequenced. The amplified region of the reverse transcriptase gene in the LINEs is intact and highly conserved, suggesting active elements. The SINEs are less conserved, consistent with minimal/no selection after transposition. A mitochondrial gene phylogeny resolves the Chironomus genus into six lineages (Guryev et al. 2001). LINE and SINE phylogenies resolve five of these lineages, indicating their monophyletic origin and vertical inheritance. However, both the LINE and the SINE tree topologies differ from the species phylogeny, resolving the elements into "clusters I-IV" and "cluster V" families. The data suggest a descent of all LINE and SINE subfamilies from two major families. Based on the species phylogeny, a few LINEs and a larger number of SINEs are cladisitically misplaced. Most misbranch with LINEs or SINEs from species with the same families of elements. From sequence comparisons, cladistically misplaced LINEs and several misplaced SINEs arose by convergent base substitutions. More diverged SINEs result from early transposition and some are derived from multiple source SINEs in the same species. SINEs from two species (C. dorsalis, C. pallidivittatus), expected to belong to the clusters I-IV family, branch instead with cluster V family SINEs; apparently both families predate separation of cluster V from clusters I-IV species. Correlation of the distribution of active SINEs and LINEs, as well as similar 3' sequence motifs in CTRT1 and NLRCth1, suggests coevolving retrotransposon pairs in which CTRT1 transposition depends on enzymes active during NLRCth1 LINE mobility.

Taphonomy of the fossil insects of the middle Eocene Kishenehn Formation

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Dale E. Greenwalt

2015-12-01

Full Text Available The lacustrine oil shales of the Coal Creek Member of the Kishenehn Formation in northwestern Montana comprise a relatively unstudied middle Eocene fossil insect locality. Herein, we detail the stratigraphic position of the fossiliferous unit, describe the insect fauna of the Coal Creek locality and document its bias towards very small but remarkably pre-served insects. In addition, the depositional environment is examined and the mineral constituents of the laminations that comprise the varves of the Kishenehn oil shale are defined. Fifteen orders of insects have been recorded with the majority of all insects identified as aquatic with the families Chironomidae (Diptera and Corixidae (Hemiptera dominant. The presence of small aquatic insects, many of which are immature, the intact nature of >90% of the fossil insects and the presence of Daphnia ephippia, all indicate that the depositional environment was the shallow margin of a large freshwater lake. The fossil insects occur within fossilized microbial mat layers that comprise the bedding planes of the oil shale. Unlike the fossiliferous shales of the Florissant and Okanagan Highlands, the mats are not a product of diatomaceous algae nor are diatom frustules a component of the sediments or the varve structure. Instead, the varves are composed of very fine eolian siliciclastic silt grains overlaid with non-diatomaceous, possibly cyanobacteria-derived microbial mats which contain distinct traces of polyaromatic hydrocarbons. A distinct third layer composed of essentially pure calcite is present in the shale of some exposures and is presumably derived from the seasonal warming-induced precipitation of carbonate from the lake’s waters. The Coal Creek locality presents a unique opportunity to study both very small middle Eocene insects not often preserved as compression fossils in most Konservat-Lagerstätte and the processes that led to their preservation.

Effects of repeated insecticide pulses on macroinvertebrate drift in indoor stream mesocosms.

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Berghahn, Rüdiger; Mohr, Silvia; Hübner, Verena; Schmiediche, Ronny; Schmiedling, Ina; Svetich-Will, Erkki; Schmidt, Ralf

2012-10-15

Pesticide contaminations via run-off or spray drift have been reported to result in the mass drift of macroinvertebrates as well as causing structural and functional changes of the corresponding stream sections. However, pesticide pulses in the field are associated with sudden increases in flow velocity, water turbidity, and changes in water temperature, which can also induce drift. Only through replicated community testing under highly controlled conditions can these effects be disentangled. In a stream mesocosm study, 12-h pulses of 12 μg/L imidacloprid were set three times at weekly intervals and are considered a "pulse series". Two pulse series of this neonicotinoid insecticide were run in both spring and summer with 4 treatment and 4 control stream mesocosms used in each pulse series. Prior to the start of the mesocosm experiment, both pulse concentration and duration had been screened for drift responses in larval Baetidae, Chironomidae and adult Gammarus roeseli in laboratory experiments. In the subsequent mesocosm study, each pulse caused a pronounced increase in the drift of insect larvae and gammarids. The drift response was taxon-specific, which was related to preferred habitat and exposure to other stressors like current velocity, in addition to imidacloprid sensitivity. Activity measurements employing a Multispecies Freshwater Biomonitor(®) revealed that in Baetis sp. the diurnal activity pattern became more pronounced even 12h after the pulse though with slightly decreased mean physical activity. Adult G. roeseli showed a drastic pulse by pulse decrease in physical activity which after the 3rd pulse lasted longer than 24h. In conclusion, drift is a sensitive, ecologically relevant endpoint and should be regarded when a specific risk assessment for lotic surface waters is done, e.g. in the context of a spatially explicit risk assessment. Copyright © 2012 Elsevier B.V. All rights reserved.

Production dynamics and life cycle of dominant chironomids (diptera, chironomidae) in a subtropical stream in China: adaptation to variable flow conditions in summer and autumn

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Yan, Yunjun; Li, Xiaoyu

2007-07-01

The production dynamics and trophic basis of 7 dominant species of chironomids were investigated in the area of a second-order river of the Hanjiang River basin, in central China from June 2003 to June 2004. The results showed that Tvetenia discoloripes was by far the most abundant chironomid, dominating the overall standing stock of the taxa. In terms of lif ecycle, Chaetocladius sp., Eukiefferiella potthasti and T. discoloripes developed 1 generation a year, whereas Microtendipes sp. and Pagastia sp. developed two, while Pentaneura sp. and Polypedilum sp. developed three. T. discoloripes was the most productive chironomid with 120.305 8 g/m2. a, Pentaneura sp. and E. potthasti had relatively high production values of >17 g/m2.a, and the rest were 0.5), especially for filter-collectors Microtendipes sp., Chaetocladius sp., Chaetocladius sp., T. discoloripes and Pagastia sp. All species except Pentaneura sp. consumed a large portion of amorphous detritus, constituting more than 90% of their diets, and contributing nearly 90% to their secondary production. All the 7 chironomids represent obvious adaptation to local highly variable climate in summer and autumn in life cycle pattern, production dynamics, and food type.

Using delta15N of Chironomidae as an index of nitrogen sources and processing within watersheds as part of EPA’s National Aquatic Resource Surveys

Science.gov (United States)

Nitrogen (N) removal in watersheds is an important regulating ecosystem service that can help reduce N pollution in the nation’s waterways. However, processes that remove N such as denitrification are generally determined at point locations. Measures that integrate N proc...

Contribution to the knowledge of Stenochironomus Kieffer (Diptera, Chironomidae) from Brazil: seven new species and description of females and immatures of some previously known species.

Science.gov (United States)

Dantas, Galileu P S; Hamada, Neusa; Mendes, Humberto F

2016-05-30

Twenty two species of Stenochironomus Kieffer are known from Brazil, 19 of which occur in the Amazon region. In order to increase knowledge of the taxonomy of this genus in the Amazon region, collections were carried out in streams located in Presidente Figueiredo, Manaus and Itacoatiara municipalities, Amazonas State. Leaves and wood mined by Stenochironomus larvae were collected and transported to the laboratory where they were kept until adult emergence. Seven new species were found, one of which is described in the immature stages and as adults of both sexes (S. amazonicus sp. n.), one as immatures and adult male (S. liviae sp. n.), four as male and pupa (S. bare sp. n., S. figueiredoensis sp. n., S. gracilis sp. nov. and S. manauara sp. n.) and one only as male (S. suzanae sp. n.). Additionally, the female, pupa and larva of S. impendens Borkent, pupa and larva of S. jubatus Borkent, female and pupa of S. zonarius Borkent and female of S. palliaculeatus Borkent were described.

Nucleolar organizer (NO) size as a measure of instantaneous growth in Chironomus riparius larvae (Diptera: Chironomidae) : a tool for monitoring individual and population responses to stress

Energy Technology Data Exchange (ETDEWEB)

Martin, J.P.; Ciborowski, J.J.; Wytrykush, C. [Windsor Univ., Windsor, ON (Canada)

2009-07-01

This presentation reported on 2 laboratory experiments that were conducted using Chironomus riparius larvae to relate nucleolar growth (NO) size to chironomid growth. In one experiment, 5 treatments varied in diet quality only, which was manipulated by providing midge larvae with 1.0 mg of food per individual per day, but varying the ratio of Tetramin to non-nutritious methyl-cellulose. A second experiment followed a 2 x 2 factorial design. The factors were growth period and diet quality. Diet quality and growth period were found to influence the individual biomass considerably. NO size was related to the quality of the diet provided at the end of the experiment, regardless of larval biomass. Therefore, NO size appears to be related to growth rate at time of collection rather than larval size. The authors proposed using NO size of larvae in natural populations as a measure of growth on which to base estimates of secondary production and as a new way to monitor individual and population responses to environmental stress. Preliminary field measurements of larval production and NO size from oil sands-affected and reference wetlands were found to be consistent with laboratory results.

The BPA-substitute bisphenol S alters the transcription of genes related to endocrine, stress response and biotransformation pathways in the aquatic midge Chironomus riparius (Diptera, Chironomidae).

Science.gov (United States)

Herrero, Óscar; Aquilino, Mónica; Sánchez-Argüello, Paloma; Planelló, Rosario

2018-01-01

Bisphenol S (BPS) is an industrial alternative to the endocrine disruptor bisphenol A (BPA), and can be found in many products labeled "BPA-free". Its use has grown in recent years, and presently it is considered a ubiquitous emerging pollutant. To date there is a lack of information on the effects of BPS on invertebrates, although they represent more than 95% of known species in the animal kingdom and are crucial for the structure and proper function of ecosystems. In this study, real-time RT-PCR was used to determine the early detrimental effects of BPS on the transcriptional rate of genes in the model species Chironomus riparius, specifically those related to the ecdysone pathway (EcR, ERR, E74, Vtg, cyp18a1) crucial for insect development and metamorphosis, stress and biotransformation mechanisms (hsp70, hsp40, cyp4g, GPx, GSTd3) that regulate adaptive responses and determine survival, and ribosome biogenesis (its2, rpL4, rpL13) which is essential for protein synthesis and homeostasis. While 24-hour exposure to 0.5, 5, 50, and 500 μg/L BPS had no effect on larval survival, almost all the studied genes were upregulated following a non-monotonic dose-response curve. Genes with the greatest increases in transcriptional activity (fold change relative to control) were EcR (3.8), ERR (2), E74 (2.4), cyp18a1 (2.5), hsp70 (1.7), hsp40 (2.5), cyp4g (6.4), GPx (1.8), and GST (2.1), while others including Vtg, GAPDH, and selected ribosomal genes remained stable. We also measured the transcriptional activity of these genes 24 hours after BPS withdrawal and a general downregulation compared to controls was observed, though not significant in most cases. Our findings showed that BPS exposure altered the transcriptional profile of these genes, which may have consequences for the hormone system and several metabolic pathways. Although further research is needed to elucidate its mode of action, these results raise new concerns about the safety of BPA alternatives.

The BPA-substitute bisphenol S alters the transcription of genes related to endocrine, stress response and biotransformation pathways in the aquatic midge Chironomus riparius (Diptera, Chironomidae.

Directory of Open Access Journals (Sweden)

Óscar Herrero

Full Text Available Bisphenol S (BPS is an industrial alternative to the endocrine disruptor bisphenol A (BPA, and can be found in many products labeled "BPA-free". Its use has grown in recent years, and presently it is considered a ubiquitous emerging pollutant. To date there is a lack of information on the effects of BPS on invertebrates, although they represent more than 95% of known species in the animal kingdom and are crucial for the structure and proper function of ecosystems. In this study, real-time RT-PCR was used to determine the early detrimental effects of BPS on the transcriptional rate of genes in the model species Chironomus riparius, specifically those related to the ecdysone pathway (EcR, ERR, E74, Vtg, cyp18a1 crucial for insect development and metamorphosis, stress and biotransformation mechanisms (hsp70, hsp40, cyp4g, GPx, GSTd3 that regulate adaptive responses and determine survival, and ribosome biogenesis (its2, rpL4, rpL13 which is essential for protein synthesis and homeostasis. While 24-hour exposure to 0.5, 5, 50, and 500 μg/L BPS had no effect on larval survival, almost all the studied genes were upregulated following a non-monotonic dose-response curve. Genes with the greatest increases in transcriptional activity (fold change relative to control were EcR (3.8, ERR (2, E74 (2.4, cyp18a1 (2.5, hsp70 (1.7, hsp40 (2.5, cyp4g (6.4, GPx (1.8, and GST (2.1, while others including Vtg, GAPDH, and selected ribosomal genes remained stable. We also measured the transcriptional activity of these genes 24 hours after BPS withdrawal and a general downregulation compared to controls was observed, though not significant in most cases. Our findings showed that BPS exposure altered the transcriptional profile of these genes, which may have consequences for the hormone system and several metabolic pathways. Although further research is needed to elucidate its mode of action, these results raise new concerns about the safety of BPA alternatives.

Nucleolar organizer (NO) size as a measure of instantaneous growth in Chironomus riparius larvae (Diptera: Chironomidae) : a tool for monitoring individual and population responses to stress

International Nuclear Information System (INIS)

Martin, J.P.; Ciborowski, J.J.; Wytrykush, C.

2009-01-01

This presentation reported on 2 laboratory experiments that were conducted using Chironomus riparius larvae to relate nucleolar growth (NO) size to chironomid growth. In one experiment, 5 treatments varied in diet quality only, which was manipulated by providing midge larvae with 1.0 mg of food per individual per day, but varying the ratio of Tetramin to non-nutritious methyl-cellulose. A second experiment followed a 2 x 2 factorial design. The factors were growth period and diet quality. Diet quality and growth period were found to influence the individual biomass considerably. NO size was related to the quality of the diet provided at the end of the experiment, regardless of larval biomass. Therefore, NO size appears to be related to growth rate at time of collection rather than larval size. The authors proposed using NO size of larvae in natural populations as a measure of growth on which to base estimates of secondary production and as a new way to monitor individual and population responses to environmental stress. Preliminary field measurements of larval production and NO size from oil sands-affected and reference wetlands were found to be consistent with laboratory results.

Ecología trófica y aspectos reproductivos de Trichomycterus areolatus (Pisces,Trichomycteridaeen ambientes lóticos artificiales

Directory of Open Access Journals (Sweden)

Evelyn Habit

2005-06-01

Full Text Available Doce de las dieciséis especies de peces presentes en la cuenca del río Itata ingresan al menos en una época del año a los canales de riego, constituyendo un hábitat frecuentemente utilizado por la ictiofauna nativa. Sin embargo sólo el siluriforme Trichomycterus areolatus se encuentra en altas abundancias todo el año, siendo la especie dominante de estos ambientes fluviales artificiales. Entre los factores que pueden dar cuenta de su éxito relativo dentro de los canales están sus hábitos bentónicos y adaptación a ambientes ritrales, una oferta de recursos tróficos concordante con sus hábitos alimentarios y una menor abundancia de depredadores. En este estudio se analiza comparativamente la ecología trófica de esta especie en 174 individuos que habitan en el río Itata (Octava Región de Chile y 231 de canales de riego que nacen de este sistema fluvial. Además se analizan las relaciones de talla-peso y frecuencia estacional de estados reproductivos, con el fin de inferir acerca del estado de las poblaciones y su condición de residentes en canales de riego. La dieta de las poblaciones de canales incluye una mayor riqueza de táxones y una mayor cantidad de presas consumidas respecto a las del curso natural. El análisis de selectividad muestra que T. areolatus prefiere, tanto en el río como en los canales de riego,presas tales como Chironomidae, Baetidae, Elmidae, Plecoptera y Hyallela. Además, en los canales de riego prefiere presas de mayor biomasa como los lumbricúlidos. Si bien las poblaciones locales de canales presentan, al igual que los ejemplares de río, un crecimiento de tipo isométrico, éstos alcanzan mayores tallas y pesos corporales que los individuos de los cauces naturales. De acuerdo al análisis de estados reproductivos de 345 ejemplares en diferentes períodos del año, las poblaciones de ambientes de canal se reproducen sincrónicamente con las del río, aunque con un leve retardo en la actividad

Water quality assessment of fifth-order tributaries of the reservoir at the Marechal Mascarenhas de Morais Hydroelectric Power Station in the Rio Grande watershed (State of Minas Gerais, Brazil Avaliação da qualidade da água dos afluentes de quinta ordem do reservatório da Usina Hidrelétrica de Marechal Mascarenhas de Morais na bacia hidrográfica do médio rio Grande (Minas Gerais, Brasil

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Douglas de Pádua Andrade

2012-09-01

Full Text Available Aim: This study assessed the water quality from the springs and river mouths of the fifth-order tributaries which compose the reservoir of Marechal Mascarenhas de Morais HPS in the middle Rio Grande watershed, Minas Gerais, Brazil. Methods: It has been studied 14 tributaries distributed in the reservoir, two points for tributary - spring and river mouth. Eighteen limnological variables added to the Rapid Assessment Protocol and Trophic Level Index were evaluated. The benthic macroinvertebrates had been collected by the use of a granulometric sieve and a Petersen-type sampler. Results: The cluster analysis of limnological data revealed the existence of two tributary groups. Group I consisted of eutrophic tributaries degraded by human activities, while group II exhibited good water quality and well-preserved environments. Group I was divided into two subgroups, Ia tributaries were characterized by being altered by human activities, while the Ib subgroup was composed of highly impacted tributaries. By ordering the PCA, it can be observed spatial segregation of groups, where the most polluted tributaries were separated from those which are better preserved. A total of 8,987 individuals belonging to 36 families of macroinvertebrates were identified. The family Chironomidae was the most abundant. There was no significant difference in total abundance and the richness of macroinvertebrates taxa inhabiting springs, by those who inhabiting the river mouths. Conclusions: It was noticed that most of the tributaries which supply and composes the reservoir are already degraded and have low quality water. It is observed that the human presence drastically affected water quality and faunal composition of tributaries. Thus, it is necessary a complementary study of the tributaries in working with issues related to reservoirs, as these components have direct influence on the water quality and composition of these lentic environments.Objetivos: O trabalho avaliou

Morphological redescription and DNA barcoding of Linevitshia prima Makarchenko, 1987 (Diptera: Chironomidae: Diamesinae) from Amur River basin (Russian Far East), with notes on systematics of the genus.

Science.gov (United States)

Makarchenko, Eugenyi A; Semenchenko, Alexander A

2014-10-10

Additions and corrections to the diagnosis of the genus Linevitshia for male adult, pupa and larva are given, and systematic position of the genus is discussed. Illustrated redescription of adult male and first description of 4th instar larva of L. prima Makarchenko from Amur River basin are provided. Comparison of data based on a new material with those of L. yezoensis Endo showed that the latter name is a junior synonym of L. prima. The species-specificity of L. prima COI sequences is analyzed and the sequences are presented as diagnostic characters-molecular markers of L. prima.

Ecological and ecotoxicological responses in the assessment of the ecological status of freshwater systems: A case-study of the temporary stream Brejo of Cagarrão (South of Portugal).

Science.gov (United States)

Palma, P; Matos, C; Alvarenga, P; Köck-Schulmeyer, M; Simões, I; Barceló, D; López de Alda, M J

2018-09-01

The objective of the study was to assess the integrated use of macroinvertebrate indexes and ecotoxicological parameters in the evaluation of the ecological status of a temporary stream with a strong agricultural influence. Water quality was analysed at two sampling sites along the stream, considering: chemical supporting parameters; hazardous substances (pesticides); benthic macroinvertebrate communities, through quality (Iberian Biological Monitoring Working Party and Iberian Average Score Per Taxon) and multi-metric indices (Southern Portuguese Index of Invertebrates and Ecological Quality Ratio); and ecotoxicological responses using lethal and sub-lethal bioassays. The water chemical characterization showed high levels of organic matter and nutrients, mainly in the dry period ((biochemical oxygen demand (BOD 5 ): 18.5-25.5mgL -1 , chemical oxygen demand (COD): 60.8-193.7mgL -1 ; total phosphorus (TP): 0.17-0.33mgL -1 )), which may compromise the support of biological life. In accordance with the physicochemical results, the stream had an ecological status less than good. Of the 25 pesticides analysed, only five, namely terbuthylazine, 2-methyl-chlorophenoxyacetic acid, bentazone, mecoprop and metolachlor were quantified. In general, the concentrations of pesticides detected were low, except at the source of the stream in January 2012 (sum of pesticides 2.29μgL -1 ), mainly due to the concentration of bentazone (1.77μgL -1 ), both values surpassing the European Commission threshold values. The analysis of benthic macroinvertebrates showed low levels of abundance and family diversity, with communities dominated by resistant groups to organic pollution and pesticides, such as the Chironomidae family. In general, the reproduction ecotoxicological results showed a very marked decrease in the number of juveniles per female. The Spearman correlation identified pesticides, namely MCPA (R=-0.89; p<0.05), as the main responsible for the observed effect. The results

Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

International Nuclear Information System (INIS)

Planello, R.; Martinez-Guitarte, J.L.; Morcillo, G.

2007-01-01

Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

Long-term fate and bioavailability of sediment associated 2,3,7,8-tetrachlorodibenzofuran in littoral enclosures

Energy Technology Data Exchange (ETDEWEB)

Currie, R.S.; Fairchild, W.L.; Holoka, M.H.; Muir, D.C.G.

2000-06-01

the fate and bioavailability of 2,3,7,8-tetrachlorodibenzofuran (TCDF; 4,6-tritium labeled) was examined over a 3-year period in littoral enclosures in a small oligotrophic lake in the Experimental Lakes Area. Tetrachlorodibenzofuran was added as a single dose or as five small multiple additions over a 5-d period in a sediment slurry. Tetrachlorodibenzofuran was rapidly redistributed, mainly to bottom sediments reflecting removal on settling particles. Between 0 and 120 d. 80 to 90% of TCDF in the water column was associated with particles (>1 {micro}m). The highest concentration of TCDF in suspended particles was consistently observed in the smallest size fraction (0.22--1 {micro}m) at 326 to 464 d post treatment. Mode of addition had no effect on TCDF concentrations in water or surficial sediments or pore waters throughout the experiment. Mean TCDF concentrations in surficial sediment were 1.830 {+-} 1.180 pg/g whereas they averaged 1.260 {+-} 596 pg/g OC from 318 to 851 d post treatment. Increasing concentrations of TCDE in lower sediment layers at 952 d suggests that TCDF was either diffusing into the sediment or undergoing burial. Fugacity (f) calculations indicated that the TCDF in enclosures shifted from disequilibrium favoring the water column to a disequilibrium with respect to bottom sediments from day 21 onward. Initially, TCDF was more bioavailable to filtering and deposit feeders (mussels, Chironomidae, Hexagenia sp., and zooplankton) in enclosures receiving multiple additions; however, differences were rarely statistically significant. Concentrations of TCDF in all organisms were initially high, and they decreased in later sampling periods. Biota--sediment-accumulation factors (BSAFs) in mussels and crayfish were >1 in the early sampling periods, which reflected greater bioavailability of the added particle-borne TCDF. By 851 d, BSAFs had declined to 0.02 to 0.04, reflecting removal of TCDF from the water column and from surficial sediments.

Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

International Nuclear Information System (INIS)

Planello, R.; Martinez-Guitarte, J.L.; Morcillo, G.

2010-01-01

Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl 2 , 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

Survival strategies of freshwater insects in cold environments

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Valeria LENCIONI

2004-09-01

literature regarding adaptation strategies in aquatic insects is presented, highlighting the scarcity of information on freshwater insects from Alpine regions. Most references are on Diptera Chironomidae from North America and North Europe. Some recent findings on aquatic insects from Italian Alpine streams are also presented.

Shifts in the diets of slimy sculpin (Cottus cognatus) and lake whitefish (Coregonus clupeaformis) in Lake Ontario following the collapse of the burrowing amphipod Diporeia

Science.gov (United States)

Owens, Randall W.; Dittman, Dawn E.

2003-01-01

In Lake Ontario, the diets of slimy sculpin Cottus cognatus and lake whitefish Coregonus clupeaformis shifted from a diet dominated by the burrowing amphipod, Diporeia, and to a lesser extent, Mysis, to a more diverse diet, after Diporeia collapsed, to one dominated by Mysis and prey that were formerly less important or uncommon such as Chironomidae, Oligochaeta, and Ostracoda. Additionally, lake whitefish still preyed on native mollusks like Sphaeriidae and Gastropoda, but also preyed on exotic mollusks, Dreissena spp., which are swallowed intact and subsequently crushed in its muscular stomach. Whether Diporeia was abundant (1992) or scarce (1999), selection indices for Diporeia by slimy sculpins was positive, suggesting that Diporeia was a preferred prey. Unlike lake whitefish, slimy sculpins avoided Dreissena; therefore, energy diverted to Dreissena production was a real loss for slimy sculpins. The shifts in the diet of these benthic fishes corresponded with drastic changes in the benthic community between 1992 and 1999. The collapse of Diporeia, formerly the most abundant macroinvertebrate in the benthic community, along with sharp declines in the abundance of Oligochaeta and Sphaeriidae, coincided with the establishment and rapid expansion of Dreissena bugensis, the quagga mussel, and to a lesser degree Dreissena polymorpha, the zebra mussel. It appears that the Diporeia population first collapsed at depths >70 m in southeastern Lake Ontario by autumn 1992, at shallower depths in the eastern Lake Ontario by 1995, and along the entire south shore line at depths 100 m by 1999. In response to the disappearance of Diporeia, populations of two native benthivores, slimy sculpin and lake whitefish, collapsed in eastern Lake Ontario, perhaps due in part to starvation, because Diporeia was their principal prey. Presently, alternative food resources do not appear sufficient to sustain these two benthivores at their former levels of abundance. We do not expect slimy

Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

Energy Technology Data Exchange (ETDEWEB)

Planello, R. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Martinez-Guitarte, J.L. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Morcillo, G. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain)]. E-mail: gmorcillo@ccia.uned.es

2007-02-01

Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius

Energy Technology Data Exchange (ETDEWEB)

Planello, R.; Martinez-Guitarte, J.L. [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain); Morcillo, G., E-mail: gmorcillo@ccia.uned.es [Grupo de Biologia y Toxicologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, UNED, Senda del Rey 9, 28040 Madrid (Spain)

2010-03-01

Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10 mM CdCl{sub 2}, 12 h and 24 h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon

Science.gov (United States)

Cross, Wyatt F.; Baxter, Colden V.; Donner, Kevin C.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O.; Wellard Kelly, Holly A.; Rogers, R. Scott

2011-01-01

Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris. Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa (P. antipodarum, G. lacustris, and Tubificida). In contrast to invertebrates, production of rainbow trout (Oncorhynchus mykiss) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post-flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer—resource interactions were not

Alimentación de dos especies de anfibios (Anura: Hylidae en la estación de bajas temperaturas y su relación con la acumulación de energía en Santa Fe, Argentina Feeding of two amphibian species (Anura: Hylidae during the low temperatures season and its relationship with energy storage in Santa Fe, Argentina

Directory of Open Access Journals (Sweden)

Carolina Elizabet Antoniazzi

2013-06-01

was to analyze and compare the feeding and development of fat bodies during the low temperature season for H. pulchellus and Dendropsophus nanus. We analyzed entire gastrointestinal tract contents of both species (H. pulchellus=110 specimens; D. nanus=114 specimens and applied an index (IRI% that combines prey abundance, volume and frequency to describe frogs diets; we used fat bodies weights as indicators of stored energy reserves. We compared diet between species with a niche overlap index (Ojk: 0-1 and used null models to ascribe statistical significance to evaluate overlap; and we analyzed variation in empty guts proportions through months and between species. Also, using ANCOVAs we explored differences in fat bodies, number and volume of prey consumed along months, between species and sexes. The most important preys in H. pulchellus diet during the cold season were Araneae (IRI%=34.96, Chironomidae (IRI%=33.08, Tipulidae (IRI%=11.44 and Gryllidae (IRI%=7.31; while for D. nanus, Chironomidae (IRI%=48.14, Tipulidae (IRI%=18.41, Psychodidae (IRI%=7.44 and Araneae (IRI%=7.34. Diet overlap between species was elevated (Ojk=0.78 and higher than expected by chance (mean simulated indices: Ojk=0.04; p[observed≥expected]<0.01; p[observed≤expected]=1. In H. pulchellus there was a monthly variation in number of prey per gut, while in D. nanus there was a difference in fat bodies development between sexes. Fat bodies development, number of prey per gut and preys volume also varied between species. Despite diet similarity between H. pulchellus and D. nanus, each species showed a different strategy to accumulate energy and support their activity during the cold season. The low rate of gastrointestinal emptiness in H. pulchellus (<10% in any analyzed month together with the poor development of their fat bodies, allows us to point out that, to sustain the breeding elevated energy demands, this species continues with a high feeding rate even at the low temperatures of cold

Avaliação rápida da integridade ecológica em riachos urbanos na bacia do rio Corumbá no Centro-Oeste do Brasil

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Giovanna Gomes Cordeiro

2016-06-01

Full Text Available A urbanização tem ocasionado o lançamento de volumes significativos de efluentes domésticos parcialmente tratados nos corpos hídricos brasileiros causando diversos prejuízos ecológicos para estes ecossistemas. Para avaliar a integridade ecológica de riachos na região de Cerrado do Brasil Central foram selecionados quatro pontos de coleta, considerando o nível de influência antrópica ao qual estão submetidos. Foram analisados parâmetros físicos e químicos da água, o uso da paisagem e a comunidade de macroinvetebrados bentônicos. As coletas foram realizadas em julho de 2015 e foram mensuradas "in situ" as variáveis condutividade elétrica, temperatura da água, pH, oxigênio dissolvido, turbidez, largura e comprimento do riacho e velocidade da correnteza. Em seguida, foram coletadas amostras para o seston, perifíton, macroinvertebrados bentônicos e sedimento depositado. O ponto "Referência" apresentou menor abundância de larvas de Chironomus (Chironomidae: Diptera e maior riqueza taxonômica, além de maior abundância dos grupos taxonômicos Ephemeroptera, Plecoptera e Trichoptera, mostrando ser o sistema mais íntegro dentre os analisados. A sub-bacia delimitada a partir desse ponto mostrou uma maior porcentagem de áreas com vegetação nativa (51%. Os pontos com presença de efluentes domésticos ("ETE" e "Jusante" por sua vez, apresentaram valores mais elevados de condutividade elétrica, turbidez, maior abundância de larvas de Chironomus e menor riqueza de táxons, mostrando elevado impacto em função das atividades antrópicas. A avaliação rápida realizada com a composição da comunidade bentônica e as variáveis físicas e químicas da água foi suficiente na identificação das alterações na integridade ecológica causadas pela influência antrópica na bacia hidrográfica do rio Corumbá.

Macroinvertebrates as tadpole food: importance and body size relationships Macroinvertebrados como alimento de girinos: importância e relações com tamanho de corpo

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Silvia L. Dutra

2005-12-01

Full Text Available Macroinvertebrates as food were recorded for three anurans tadpoles: Hyla saxicola (Bokermann, 1964 (Hylidae, Scinax machadoi (Bokermann & Sazima, 1973 (Hylidae, and Bufo rubescens (Lutz, 1925 (Bufonidae. These species are commonly found in the mountain streams at Serra do Cipó National Park, Minas Gerais State, Brazil. Tadpoles were collected in pools of second-order reach in Mascates stream and third and fourth order reaches of Indaiá stream from March-October, 2003. Biometrical data were recorded before dissecting each individual and a feeding importance index was estimated. Eight taxa of chironomids and three taxa of mayfly exuviae were found in the guts, but no significantly differences were found between tadpole species (ANOVA, p > 0.05. The results support the drift transport hypothesis that predicts that tadpoles commonly ingest suspended matter in lotic ecosystems, are generalist feeders, and macroinvertebrates are probably incidental ingested.A presença de macroinvertebrados como item na dieta de girinos foi estudada para as espécies Hyla saxicola (Bokermann, 1964 (Hylidae, Scinax machadoi (Bokermann & Sazima, 1973 (Hylidae e Bufo rubescens (Lutz, 1925 (Bufonidae. Estas espécies são comumente encontradas nos córregos de altitude no Parque Nacional da Serra do Cipó, Estado de Minas Gerais, Brasil. Os girinos foram coletados em poções em um trecho de segunda ordem no córrego Mascates, e em trechos de terceira e quarta ordens no córrego Indaiá, entre março e outubro de 2003. Medidas biométricas foram mensuradas antes da dessecação de cada indivíduo e foi estimado um índice de importância de alimentação para os macroinvertebrados encontrados. Oito taxa de Chironomidae e três taxa de exúvias de Ephemeroptera foram encontrados, mas não houve diferenças significativas entre os macroinvertebrados encontrados nas espécies de girinos (ANOVA, p > 0,05. Os resultados obtidos corroboram a hipótese de transporte por

Under siege: Isolated tributaries are threatened by regionally impaired metacommunities

International Nuclear Information System (INIS)

Merriam, Eric R.; Petty, J. Todd

2016-01-01

Pristine streams are often targeted as conservation priorities because of their ability to preserve regional biodiversity. However, isolation within heavily degraded regions likely alters important metapopulation and metacommunity processes (e.g., rescue and mass effects), affecting the ability of in-tact communities to boost regional conditions. To test this hypothesis, we sampled invertebrate communities and physicochemical conditions from 168 streams within the mountaintop removal-valley fill mining region of West Virginia. We used redundancy analysis to first test for significant effects of local (observed physicochemical conditions) and neighborhood (streams within a 5 km buffer) degradation on assemblage structure across all taxa and stress tolerance (low, moderate, high) and dispersal (low, high) categories. We then used generalized linear and hurdle models to characterize changes in community metrics and individual taxa, respectively. Local condition consistently explained the majority of variation (partial R"2 up to 5 × those of neighborhood condition) in community structure and was the only factor affecting sensitive taxa. Neighborhood condition explained significant variation in moderately tolerant taxa with low dispersal capacity and highly tolerant taxa, regardless of dispersal. Decreased occurrence (Baetis) and abundance (Maccaffertium) of key taxa and corresponding metrics (%E, %EPT) suggest decreased dispersal and associated mass and rescue effects within degraded neighborhoods. Decreased neighborhood conditions also resulted in the proliferation of tolerant taxa (Chironomidae, Chimarra, Hemerodromia). Our results suggest communities within even the most pristine streams are at risk when isolated within heavily impacted regions. Consequently, protection of regional species' pools in heavily impacted regions will require more than simply conserving un-impacted streams. - Graphical abstract: In heavily degraded regions, even the most pristine

Under siege: Isolated tributaries are threatened by regionally impaired metacommunities

Energy Technology Data Exchange (ETDEWEB)

Merriam, Eric R., E-mail: emerriam@mix.wvu.edu; Petty, J. Todd

2016-08-01

Pristine streams are often targeted as conservation priorities because of their ability to preserve regional biodiversity. However, isolation within heavily degraded regions likely alters important metapopulation and metacommunity processes (e.g., rescue and mass effects), affecting the ability of in-tact communities to boost regional conditions. To test this hypothesis, we sampled invertebrate communities and physicochemical conditions from 168 streams within the mountaintop removal-valley fill mining region of West Virginia. We used redundancy analysis to first test for significant effects of local (observed physicochemical conditions) and neighborhood (streams within a 5 km buffer) degradation on assemblage structure across all taxa and stress tolerance (low, moderate, high) and dispersal (low, high) categories. We then used generalized linear and hurdle models to characterize changes in community metrics and individual taxa, respectively. Local condition consistently explained the majority of variation (partial R{sup 2} up to 5 × those of neighborhood condition) in community structure and was the only factor affecting sensitive taxa. Neighborhood condition explained significant variation in moderately tolerant taxa with low dispersal capacity and highly tolerant taxa, regardless of dispersal. Decreased occurrence (Baetis) and abundance (Maccaffertium) of key taxa and corresponding metrics (%E, %EPT) suggest decreased dispersal and associated mass and rescue effects within degraded neighborhoods. Decreased neighborhood conditions also resulted in the proliferation of tolerant taxa (Chironomidae, Chimarra, Hemerodromia). Our results suggest communities within even the most pristine streams are at risk when isolated within heavily impacted regions. Consequently, protection of regional species' pools in heavily impacted regions will require more than simply conserving un-impacted streams. - Graphical abstract: In heavily degraded regions, even the most

Land use effects on leaf litter breakdown in low-order streams draining a rapidly developing tropical watershed in Puerto Rico

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Pedro J Torres

2014-04-01

Full Text Available El uso de la tierra influye significativamente sobre los procesos en ecosistemas de riachuelo, como la descomposición de la hojarasca. En el presente estudio, se evaluaron las tasas de descomposición de la hojarasca en arroyos tropicales menores de zonas boscosa, agrícola y urbana en Puerto Rico. Para medir las tasas de descomposición se colocaron bolsas de malla gruesa en nueve riachuelos, tres para cada uno de los tipos de uso de tierra. Se midieron los cambios en la masa de hojarasca con el tiempo, las tasas de descomposición, la composición de macroinvertebrados y los aspectos fisico-químicos del riachuelo. Los riachuelos mostraron diferencias en la fisico-química del agua: los riachuelos urbanos presentaron los valores más altos en casi todas las variables. Las características físicas del riachuelo fueron evaluadas utilizando un protocolo visual, el cual indica que los riachuelos urbanos y asociados a la agricultura están más degradados que los asociados a bosques. La tasa de descomposición de la hojarasca fue rápida en todos los riachuelos (k=0.006-0.024. La descomposición estuvo relacionada con las condiciones físicas del riachuelo, siendo más rápido en aquellos asociados al bosque. Los invertebrados que colonizaron las hojas fueron principalmente efemerópteros (Leptophlebiidae, Baetidae, and Caenidae, dípteros (Chironomidae, tricópteros (Polycentropodidae y escarabajos (Elmidae and Gyrinidae. Contrario a lo encontrado en otros estudios, no hallamos decápodos. Hubo poca evidencia de que los insectos afecten la descomposición. Los resultados sugieren que el uso de la tierra es un factor importante que afecta el proceso de descomposición de la hojarasca en los riachuelos. Contrario a los estudios en zonas templadas, hallamos evidencia de una relación positiva de los nutrientes de tierra agrícola con las tasas de descomposición. Los cambios en las características físicas de los riachuelos parecen ser los

Avaliação da comunidade de macroinvertebrados aquáticos como ferramenta para o monitoramento de um reservatório na bacia do rio Pitangui, Paraná, Brasil

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Ivana F Barbola

2011-06-01

Full Text Available Os macroinvertebrados bentônicos e nectônicos representam elementos importantes na estrutura e funcionamento dos ecossistemas aquáticos e sua distribuição é influenciada pela natureza química do substrato, composição da vegetação e profundidade da lâmina d'água. O conhecimento desta fauna contribui para a avaliação da qualidade da água e a elaboração de ações visando à conservação da biodiversidade. No presente estudo foram avaliadas diferentes medidas bióticas da comunidade de invertebrados da represa de Alagados, importante manancial da cidade de Ponta Grossa, no Paraná. Em cinco diferentes pontos de amostragem, foram coletados 18.473 exemplares de macroinvertebrados aquáticos ou semi-aquáticos, pertencentes a 46 táxons dos filos Annelida (Hirudinea e Oligochaeta, Mollusca (Gastropoda, Platyhelminthes (Turbellaria, Nematoda e Arthropoda (Arachnida, Crustacea e Insecta. Esta comunidade foi constituída predominantemente por organismos predadores (45,7% dos táxons amostrados, seguidos de coletores e/ou filtradores (23,9%; raspadores (15,2%, fragmentadores (13% e detritívoros (2,2%. De modo geral, os índices de diversidade (H' e equitabilidade (J foram significativamente baixos para os cinco locais investigados, com H' variando de 0,3301 a 1,0396. Quanto à tolerância dos organismos à poluição orgânica, alguns táxons mais sensíveis foram muito raros (Plecoptera ou em baixa frequência (Trichoptera e Ephemeroptera. Entre os grupos mais resistentes a ambientes poluídos estão os Chironomidae e os Hirudinea, ambos bastante comuns nas amostras de Alagados. Este estudo reforça a importância da análise de bioindicadores na avaliação da qualidade de água para consumo humano e também para a conservação de ecossistemas, considerando que um programa de monitoramento ambiental deve integrar medidas físicas, químicas e biológicas.

Reconstructing the ecological impacts of eight decades of mining, metallurgical, and municipal activities on a small boreal lake in northern Canada.

Science.gov (United States)

Doig, Lorne E; Schiffer, Stephanie T; Liber, Karsten

2015-07-01

As a result of long-term metal mining and metallurgical activities, the sediment of Ross Lake (Flin Flon, MB, Canada) is highly contaminated with metals and other elements. Although the effluents likely were discharged into Ross Lake as early as the late 1920s, lake biophysical data were not collected until 1973, more than 4 decades after the onset of mining and municipal activities. The early influence of these activities on the ecology of Ross Lake is unknown, as are the effects of improvements to metallurgical effluent quality and discontinuation of municipal wastewater discharge into the lake's north basin. To address this knowledge gap, analyses typical of paleolimnological investigations were applied to cores of sediment collected in 2009 from the south basin of Ross Lake. Stratigraphic analyses of physicochemical sediment characteristics (e.g., the concentrations of metals and other elements, organic C, total N, and δ(13)C and δ(15)N values) and subfossil remains (diatoms, Chironomidae, Chaoborus, and Cladocera) were used to infer historical biological and chemical changes in Ross Lake. With the onset of mining activities, concentrations of various elements (e.g., As, Cr, Cu, Zn, and Se) increased dramatically in the sediment profile, eventually declining with improved tailings management. Nevertheless, concentrations of metals in recent sediments remain elevated compared with pre-industrial sediments. Constrained cluster analyses demonstrated distinct pre-industrial and postindustrial communities for both the diatoms and chironomids. The biodiversity of the postindustrial diatom assemblages were much reduced compared with the pre-industrial assemblages. The postindustrial chironomid assemblage was dominated by Chironomus and to a lesser extent by Procladius, suggesting that Ross Lake became a degraded environment. Abundances of Cladocera and Chaoborus were severely reduced in the postindustrial era, likely because of metals toxicity. Overall, improvements

Limnological study of Lake Shastina, Siskiyou County, California

Science.gov (United States)

Dong, Alex E.; Beatty, Kenneth W.; Averett, Robert C.

1974-01-01

about 5 million cells per litre.Zooplankton numbers were greatest in March, July, and September, with lesser concentrations in June. Three major zooplankton groups, Cladocera, Copepoda, and Rotifera, were present. The major groups of benthic organisms were Oligochaeta, Chironomidae, and Chaoborus, with numbers ranging from 3350, 890, and 8450 per square metre, respectively.A discussion on algal control is included.

Pollutant loads and water quality in streams of heavily populated and industrialised towns

Science.gov (United States)

Ntengwe, F. W.

The availability of portable water is often taken for granted and water allowed to get polluted. Industries, settlements, farms, markets, leaking sewer lines, poor hygiene practices are all potential sources of pollution. Each pollutant has its own effect on water and the environment. A study was conducted in Kitwe Stream in order to establish whether engineering and other human activities affect water quality. Samples were collected at ten points, the first point being at the source while the tenth point was at the confluence with the Kafue River. The samples were analysed for physical, chemical and biological parameters. The results revealed high levels of concentration and loads of total suspended solids (TSS). The points with high TSS values were P4 (118 mg/l) and P6 (140 mg/l) representing daily loads of 7.74 and 8.71 tonnes, respectively. The highest values of coliform were found at points P9 (2099), P10 (2558) followed by P4 (1149), P5 (1256) and P6 (1370). High values of nitrites were found at points P4 (34 mg/l), P5 (32 mg/l), P6 (21 mg/l) and P10 (12.4 mg/l). Chlorides were also found to be high at points P4, P5 and P6 with values of 70 mg/l, 80 mg/l and 87 mg/l, respectively. These parameters exceeded the maximum contaminant level (MCL) of 100 mg/l for TSS, 1 mg/l for nitrites, 500/100 ml for coliform in Zambia. The conductivity and coliform were also found to be high (>500 μS/cm, >500). The benthic study revealed a normal diversity of invertebrates but chironomidae was found to be on average 60% of total species counted. The fish activity was high upstream and low downstream at the mouth of the stream where it joins the Kafue River. There was no fish activity at the middle points. The planktons (phytoplankton and zooplankton) count revealed a high count (15-30 per ml) in places where there was high fish activity and a low count (1-5 per ml) where there was no activity. The stream water quality was therefore affected by the human activities.

Biogeographical and ecological comments on “A new Neotropical species of the genus Parochlus Enderlein, 1912 (Chironomidae: Podonominae and new distribution in Argentina” by Rodríguez et al. 2009

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Mariano DONATO

2010-01-01

Full Text Available Rodríguez et al . (2009 describieron una nueva especie del género Parochlus Enderlein de la subfamilia Podonominae. Se discuten varios aspectos concernientes a aspectos ecológicos y biogeográficos de la antedicha contribución. El nuevo rango de temperaturas propuesto por los autores para dicha especie está apoyada en evidencias débiles y debería ser interpretada como tentativa. La aseveración que este nuevo registro se localizó en la provincia biogeográfica del Monte es errónea. La localidad tipo de la nueva especie pertenece a la provincia biogeográfica Chaqueña.

Oribatid mite (Acari: Oribatida) and Chironomid (Diptera: Chironomidae) communities from a high-Andean cushion peatland in Peru (14°S) and their use for palaeoenvironmental reconstruction during the Nasca cultural period

OpenAIRE

Hense, Jonathan Boray

2016-01-01

The edaphic Oribatid mites and Chironomid larvae of five different successional stages of a high-Andean cushion peatland in southern Peru (14°S) were investigated. In total, 17 Oribatid mite taxa, belonging to eight families could be identified. Taxonomic remarks for the species found and an analysis of community structures are provided. The investigation shows significantly higher Oribatid mite densities in the early and medium successional stages in comparison to the successional climax eco...

Experimental acidification of two biogeochemically-distinct neotropical streams: Buffering mechanisms and macroinvertebrate drift

International Nuclear Information System (INIS)

Ardón, Marcelo; Duff, John H.; Ramírez, Alonso; Small, Gaston E.; Jackman, Alan P.; Triska, Frank J.; Pringle, Catherine M.

2013-01-01

Research into the buffering mechanisms and ecological consequences of acidification in tropical streams is lacking. We have documented seasonal and episodic acidification events in streams draining La Selva Biological Station, Costa Rica. Across this forested landscape, the severity in seasonal and episodic acidification events varies due to interbasin groundwater flow (IGF). Streams that receive IGF have higher concentrations of solutes and more stable pH (∼ 6) than streams that do not receive IGF (pH ∼ 5). To examine the buffering capacity and vulnerability of macroinvertebrates to short-term acidification events, we added hydrochloric acid to acidify a low-solute, poorly buffered (without IGF) and a high-solute, well buffered stream (with IGF). We hypothesized that: 1) protonation of bicarbonate (HCO 3 − ) would neutralize most of the acid added in the high-solute stream, while base cation release from the sediments would be the most important buffering mechanism in the low-solute stream; 2) pH declines would mobilize inorganic aluminum (Ali) from sediments in both streams; and 3) pH declines would increase macroinvertebrate drift in both streams. We found that the high-solute stream neutralized 745 μeq/L (96% of the acid added), while the solute poor stream only neutralized 27.4 μeq/L (40%). Protonation of HCO 3 − was an important buffering mechanism in both streams. Base cation, Fe 2+ , and Ali release from sediments and protonation of organic acids also provided buffering in the low-solute stream. We measured low concentrations of Ali release in both streams (2-9 μeq/L) in response to acidification, but the low-solute stream released double the amount Ali per 100 μeq of acid added than the high solute stream. Macroinvertebrate drift increased in both streams in response to acidification and was dominated by Ephemeroptera and Chironomidae. Our results elucidate the different buffering mechanisms in tropical streams and suggest that low

Comparison of laboratory single species and field population-level effects of the pyrethroid insecticide lambda-cyhalothrin on freshwater invertebrates.

Science.gov (United States)

Schroer, A F W; Belgers, J D M; Brock, T C M; Matser, A M; Maund, S J; Van den Brink, P J

2004-04-01

The toxicity of the pyrethroid insecticide lambda-cyhalothrin to freshwater invertebrates has been investigated using data from short-term laboratory toxicity tests and in situ bioassays and population-level effects in field microcosms. In laboratory tests, patterns of toxicity were consistent with previous data on pyrethroids. The midge Chaoborus obscuripes was most sensitive (48- and 96-h EC50 = 2.8 ng/L). Other insect larvae (Hemiptera, Ephemeroptera) and macrocrustacea (Amphipoda, Isopoda) were also relatively sensitive, with 48- and 96-h EC50 values between 10 and 100 ng/L. Generally, microcrustacea (Cladocera, Copepoda) and larvae of certain insect groups (Odonata and Chironomidae) were less sensitive, with 48-h EC50 values higher than 100 ng/L. Mollusca and Plathelminthes were insensitive and were unaffected at concentrations at and above the water solubility (5 microg/L). Generally, the EC50 values based on initial population responses in field enclosures were similar to values derived from laboratory tests with the same taxa. Also, the corresponding fifth and tenth percentile hazard concentrations (HC5 and HC10) were similar (laboratory HC5 = 2.7 ng/L and field HC5 = 4.1 ng/L; laboratory and field HC10 = 5.1 ng/L), at least when based on the same sensitive taxonomic groups (insects and crustaceans) and when a similar concentration range was taken into account. In the three field enclosure experiments and at a treatment level of 10 ng/L, consistent effects were observed for only one population (Chaoborus obscuripes), with recovery taking place within 3 to 6 weeks. The laboratory HC5 (2.7 ng/L) and HC10 (5.1 ng/L) based on acute EC50 values of all aquatic arthropod taxa were both lower than this 10 ng/L, a concentration that might represent the "regulatory acceptable concentration." The HC5 and HC10 values in this study in The Netherlands (based on static laboratory tests with freshwater arthropods) were very similar to those derived from a previous study in

Histone H1 heterogeneity in the midge, Chironomus thummi. Structural comparison of the H1 variants in an organism where their intrachromosomal localization is possible.

Science.gov (United States)

Hoyer-Fender, S; Grossbach, U

1988-09-01

discriminates the group of C. thummi H1 histones clearly from Drosophila and calf thymus H1. Limited trypsin digestion yielded a protected peptide of uniform size in six of the seven variants which was considerably smaller than the protected central domain of calf thymus H1. 6. Two other species of Chironomidae, C. pallidivittatus and Glyptotendipes barbipes were found to contain five and three H1 subfractions, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Using biofilms and grazing chironomids (Diptera: Chironomidae) to determine primary production, nitrogen stable isotopic baseline and enrichment within wetlands differing in anthropogenic stressors and located in the Athabasca oil sands region of Alberta

Energy Technology Data Exchange (ETDEWEB)

Frederick, K.; Ciborowski, J.J. [Windsor Univ., Windsor, ON (Canada); Wytrykush, C.M. [Syncrude Canada Ltd., Edmonton, AB (Canada)

2009-07-01

This presentation reported on a study that investigated the effects of oil sands process materials (OSPM) and construction disturbances on primary production and nitrogen stable isotope enrichment in reclaimed and reference wetlands at oil sands mines in the Athabasca basin. Productivity and food web analyses were instrumental in evaluating the succession and viability of reclaimed wetlands. Primary production was estimated through chlorophyll a (Chl a) concentrations and biomass. Carbon (C) and nitrogen (N) stable isotope ratios were used to identify energy sources, storage and the magnitude and direction of energy transfer within food webs. The objectives were to determine primary productivity, the N baseline, and N enrichment from biofilms and grazing invertebrates colonizing artificial substrates immersed in the water column of two OSPM-affected, two constructed reference and two natural reference wetlands. The lower biomass and Chl a concentrations in OSPM-affected and constructed wetlands suggests that both anthropogenic disturbance and OSPM have an adverse effect on primary productivity and overall wetland function.

Tools for the development of a benthic quality index for Italian lakes

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Angelo SOLIMINI

2006-02-01

Full Text Available In this paper, we propose a methodology to develop a benthic quality index useful for Italian lakes. The existing data about benthic macroinvertebrates of the Italian lakes were collected over a period of 50 years, but only a few lakes such as the Maggiore and the Mergozzo have been intensely studied. Some large lakes such as Lake Como are still almost uninvestigated. In total, 570 benthic macroinvertebrate taxa were identified; of which 373 belong to Chironomidae and 85 to Oligochaeta. With the aim of relating environmental variables with macrobenthos assemblages, we carried out a canonical correlation analysis (CANON using a database that included 1060 sampling points. Both environmental (13 variables describing morphometry and hydrochemistry and biological data (57 taxa were available, but only taxa present in at least 10 samples were selected for data analysis. Three canonical variates were ecologically significant. The first one was correlated with conductivity, pH and alkalinity and accounted for 20% of the total variation. The second one was positively correlated with total phosphorus and N-NH4, and inversely with dissolved oxygen, and accounted for 18% of the total variation. The third one showed a direct correlation with maximum lake depth and volume and an inverse correlation with water temperature, and accounted for 17% of the total variation. A Trophic Status Index (TSI, based on the table 11 of the Italian Law 152/99 (without including chlorophyll, was calculated by ranking percent oxygen saturation, transparency and total phosphorus. TSI was used to test a Benthic Quality Index for Italian Lakes (BQIL which is proposed in the present paper. The algorithm considered three steps. First, the means of three variables were calculated: percent oxygen saturation, transparency and total phosphorus weighted by the taxa abundances. These values are interpreted as optimum for each taxon and used to assign an indicator weight (BQIW. Second

Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

Science.gov (United States)

Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

2012-04-01

Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

Hydroclimatic shifts recorded in peat archive from Rąbień mire (Central Poland) - better understanding of past climate changes using multidisciplinary approach

Science.gov (United States)

Słowiński, Michał; Marcisz, Katarzyna; Płóciennik, Mateusz; Obremska, Milena; Pawłowski, Dominik; Okupny, Daniel; Słowińska, Sandra; Borówka, Ryszard; Kittel, Piotr; Forysiak, Jacek; Michczyńska, Danuta J.; Lamentowicz, Mariusz

2016-04-01

Hydrological changes are main drivers of the processes occurring in the peatland ecosystem, e.g. organic matter accumulation and decomposition. Hydroclimatic changes in mires are caused by various non-climatic factors, such as hydroseral succession or land use changes. Central Europe, namely Poland, is characterized by a transitional climate with influence o both continental and Atlantic air masses, which makes a this region a very sensitive to climate change. Here we explore a potential of multidisciplinary approach in reconstruction of past climate change and particularly hydroclimatic conditions which control in Sphagnum peatland ecosystem. We reconstructed 3300 years (between 3,500 BC and 200 BC) history of development of Rąbień mire using several biotic proxies (pollen, plant macrofossils, testate amoebae, Cladocera, Chironomidae) and geochemistry. Study site - Rąbień mire (area 42 ha) is located in central Poland and it is protected nature reserve. The origin of the mire depression is connected with the development of the thermokarst basin isolated by dunes. Rąbień mire is limnogenic, i.e. formed by the process of terrestrialisation of a water body and thickness of biogenic deposits is 6.2 m (440 cm of lacustrine sediment and 180 cm of peat). Our results demonstrate the high potential of Rąbień peat record for reconstructing the palaeohydrological dynamics. The studied time interval is characterized by two pronounced dry periods: ~2,500 to ~1,700 cal. BC and ~800 to ~600 cal. BC, and two periods of significant increases in water table: ~1,100 to ~800 cal. BC and ~600 to ~250 cal. BC. The timing of the wet shift at 600 cal. BC corresponds to wet periods in different sites from Central and Eastern Europe. Our investigation reveals a complex pattern of proxies, what might be linked to the past atmospheric circulation patterns. Extreme hydroclimatic conditions most possibly had a direct impact on the functioning of peatland ecosystems. What has been

Experimental acidification of two biogeochemically-distinct neotropical streams: Buffering mechanisms and macroinvertebrate drift

Energy Technology Data Exchange (ETDEWEB)

Ardón, Marcelo, E-mail: ardonsayaom@ecu.edu [Department of Biology and North Carolina Center for Biodiversity, East Carolina University, Greenville, NC 27858 (United States); Duff, John H. [U.S. Geological Survey, Menlo Park, CA 94025 (United States); Ramírez, Alonso [Department of Environmental Sciences, University of Puerto Rico, San Juan, PR 00931 (Puerto Rico); Small, Gaston E. [Department of Ecology, Evolution, and Behavior, University of Minnesota, St. Paul, MN 55108 (United States); Jackman, Alan P. [University of California, Davis, CA 95616 (United States); Triska, Frank J. [U.S. Geological Survey, Menlo Park, CA 94025 (United States); Pringle, Catherine M. [Odum School of Ecology, University of Georgia, Athens, GA 30602 (United States)

2013-01-15

Research into the buffering mechanisms and ecological consequences of acidification in tropical streams is lacking. We have documented seasonal and episodic acidification events in streams draining La Selva Biological Station, Costa Rica. Across this forested landscape, the severity in seasonal and episodic acidification events varies due to interbasin groundwater flow (IGF). Streams that receive IGF have higher concentrations of solutes and more stable pH (∼ 6) than streams that do not receive IGF (pH ∼ 5). To examine the buffering capacity and vulnerability of macroinvertebrates to short-term acidification events, we added hydrochloric acid to acidify a low-solute, poorly buffered (without IGF) and a high-solute, well buffered stream (with IGF). We hypothesized that: 1) protonation of bicarbonate (HCO{sub 3}{sup −}) would neutralize most of the acid added in the high-solute stream, while base cation release from the sediments would be the most important buffering mechanism in the low-solute stream; 2) pH declines would mobilize inorganic aluminum (Ali) from sediments in both streams; and 3) pH declines would increase macroinvertebrate drift in both streams. We found that the high-solute stream neutralized 745 μeq/L (96% of the acid added), while the solute poor stream only neutralized 27.4 μeq/L (40%). Protonation of HCO{sub 3}{sup −} was an important buffering mechanism in both streams. Base cation, Fe{sup 2+}, and Ali release from sediments and protonation of organic acids also provided buffering in the low-solute stream. We measured low concentrations of Ali release in both streams (2-9 μeq/L) in response to acidification, but the low-solute stream released double the amount Ali per 100 μeq of acid added than the high solute stream. Macroinvertebrate drift increased in both streams in response to acidification and was dominated by Ephemeroptera and Chironomidae. Our results elucidate the different buffering mechanisms in tropical streams and

Новые данные по фауне комаров-звонцов (Diptera, Chironomidae) Туниса

OpenAIRE

Булааба, С.; Крашенинников, А.

2014-01-01

В р. Медведице выявлено семь видов макрофитов (Sagittaria sagittifolia L., Sparganium erectum L., Typha angustifolia L., Butomus umbellatus L., Bolboschoenus maritimus (L.) Palla, Eleocharis palustris (L.) R. Br., Glyceria arundinaceae Kunth), живые ткани которых заселяются личинками хирономидминеров. Наиболее заселяемым макрофитом (2298,65 экз/кг) является стрелолист обыкновенный. Из семи изученных видов хирономид максимальная численность в растительных тканях характерна для личинок Endochir...

Hábitos alimenticios y dieta invernal de Charadrius melodus (Charadriiformes: Charadriidae en Boca Ciega, Tamaulipas, México Food habits and winter diet of Charadrius melodus (Charadriiformes: Charadriidae in Boca Ciega, Tamaulipas, Mexico

Directory of Open Access Journals (Sweden)

Iris Banda-Villanueva

2013-06-01

2009 to March 2010. Our objectives were: 1 determine the importance of the area during winter, 2 describe C. melodus ethology, feeding substrate preferences and food items, 3 to analyze and describe the sympatric diversity associated with C. melodus. A total of ninety nine individuals were observed during the monitoring. The Cochran and Kendall test showed a high significance of the species with the substrate and signs tests using a binomial distribution that indicated a high preference for algal type of substrate. The highest activity recorded for this species during this winter season was feeding. The principal food items found in sediments were larvae of Diptera: Chironomidae and Ephydridae. The sympatric species of C. melodus were two families of Charadriiforms: Scolopacidae (nine species and Charadriidae (two species. We concluded that this is an important area for feeding, protection and rest sites for this species, and its protection and management is recommended.