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Sample records for chironomidae

  1. Dansmuggen in natuurontwikkelingsgebieden (Chironomidae)

    OpenAIRE

    Moller Pillot, H.K.M.

    1999-01-01

    Chironomidae in newly created nature reserves In a newly created nature reserve near Eindhoven many interesting species of Chironomidae were found. Several new species to the Dutch fauna were identified and one species (of the genus Neozavrelia) proved to be new to science. The fauna of these young habitats is poorly known, but proves to be very interesting.

  2. Hibernal Emergence of Chironomidae in Ukraine

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    Viktor Baranov; Leonard C. Ferrington Jr.

    2013-01-01

    Twenty-seven species of Chironomidae were detected emerging in the Crimea during the period from December 2010 to March 2013. Twenty-three are Orthocladiinae and 4 are Chironominae (one Chironomini and three Tanytarsini species). Nine species are recorded for the first time in Crimea. At the genus-level the hibernal emergence in Crimea shows resemblance to the patterns reported for streams in Kansas.

  3. Hibernal Emergence of Chironomidae in Ukraine

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    Viktor Baranov

    2013-12-01

    Full Text Available Twenty-seven species of Chironomidae were detected emerging in the Crimea during the period from December 2010 to March 2013. Twenty-three are Orthocladiinae and 4 are Chironominae (one Chironomini and three Tanytarsini species. Nine species are recorded for the first time in Crimea. At the genus-level the hibernal emergence in Crimea shows resemblance to the patterns reported for streams in Kansas.

  4. Chironomidae (Diptera, Chironomidae) as biological indicators of water bodies ecological condition

    International Nuclear Information System (INIS)

    The paper presents data confirming that Chironomidae are good to be used as an indicative criterion when classifying lakes. It was found that their quantity and presence of certain species could serve as an index in assessment of water body ecological condition. Results of cytotaxonomic analysis helped to reveal the nature of Chironomini species diversity in STS water bodies. (author)

  5. Changes in terrestrial chironomid (Diptera: Chironomidae) community after soil drainage

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan

    Aachen : Shaker Verlag, 2000, s. 285-289. [International Symposium on Chironomidae /13./. Aachen (DE), 17.04.2000-19.04.2000] Institutional research plan: CEZ:AV0Z6066911 Subject RIV: EH - Ecology, Behaviour

  6. Invloed van inundatie van graslanden op terrestrische dansmuggen (Diptera: Chironomidae)

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    Moller Pilot, H.

    2005-01-01

    Influence of flooding on terrestrial chironomids in grassland (Diptera: Chironomidae) Although flooding is an important factor for the invertebrate fauna of grassland, not much is published on this topic. As in other groups the different species of terrestrial Chironomidae display different reactions during flooding. Some larvae will move to drier parts, others remain on the spot. All species can survive for some time submerged in water, but the uptake of water can be a problem, especially in...

  7. Mass occurrence and sporadic distribution of Corynocera ambigua Zetterstedt (Diptera, Chironomidae) in Danish lakes. Neo- and palaeolimnological records

    DEFF Research Database (Denmark)

    Brodersen, Klaus Peter; Lindegaard, C.

    1999-01-01

    Corynocera ambigua, Chironomidae, zoobenthos, charophytes, palaeolimnology, late-glacial, Denmark......Corynocera ambigua, Chironomidae, zoobenthos, charophytes, palaeolimnology, late-glacial, Denmark...

  8. Chironomidae From a Sewage Treatment Station of Southern Brazil

    Science.gov (United States)

    Signoretti, R. P.; Sonoda, K. C.; Ferraz, E.

    2005-05-01

    As the great number of insects living and reproducing at a municipal sewage treatment station located in Piracicaba City and the fear about how dangerous it could be for human healthy, a study was conduct to identify the taxa presented there and to analyze their community structure using stable isotopes. The Chironomidae identification was performed on specific level. The sewage treatment station is a man-made wetland system, situated 30m nearby the Piracicaba River. It treats the sewage from an urban area with 3000 inhabitants. The sewage discharge varies from 133 to 186L/s/ha. The samples were taken on the ending of the rainy season with a D-frame net. The material was washed (210mm mesh size), sorted and preserved in 70% alcohol. Chironomidae had a low participation in the community, with 14.9% of the specimens. Goeldichironomus serratus (47.8% from total Chironomidae), G. holoprasinus (43.5%) and Chironomus decorus (8.7%) were identified. Those species are worldwide recognized as pollution-resistant, used as indicators of environmental water quality. The wetland studied showed low dissolved oxygen (1.5mg/L) on the sampling period and the presence of those Chironomidae species should be expected. The low diversity and high dominance are common features for those impacted environments.

  9. CHIRONOMIDAE TYPES AT THE MUSEUM OF COMPARATIVE ZOOLOGY, BOSTON

    OpenAIRE

    Fabio Laurindo da Silva

    2011-01-01

    The Chironomidae (Insecta: Diptera) type collection deposited at the Museum of Comparative Zoology (MCZ) are listed and reviewed. It is represented by 23 primary types, as well as paratypes and paralectotypes for an additional 29 species, mostly resulting from research endeavors of H. Loew and H. K Townes. Notes updating the taxonomic status of several species are provided.

  10. Chironomid midges (Diptera, chironomidae) show extremely small genome sizes.

    Science.gov (United States)

    Cornette, Richard; Gusev, Oleg; Nakahara, Yuichi; Shimura, Sachiko; Kikawada, Takahiro; Okuda, Takashi

    2015-06-01

    Chironomid midges (Diptera; Chironomidae) are found in various environments from the high Arctic to the Antarctic, including temperate and tropical regions. In many freshwater habitats, members of this family are among the most abundant invertebrates. In the present study, the genome sizes of 25 chironomid species were determined by flow cytometry and the resulting C-values ranged from 0.07 to 0.20 pg DNA (i.e. from about 68 to 195 Mbp). These genome sizes were uniformly very small and included, to our knowledge, the smallest genome sizes recorded to date among insects. Small proportion of transposable elements and short intron sizes were suggested to contribute to the reduction of genome sizes in chironomids. We discuss about the possible developmental and physiological advantages of having a small genome size and about putative implications for the ecological success of the family Chironomidae. PMID:26003979

  11. Species of Oukuriella Epler (Diptera, Chironomidae) inside freshwater sponges in Brazil

    OpenAIRE

    Fabio de Oliveira Roque; Susana Trivinho-Strixino; Sheyla Regina Marques Couceiro; Neusa Hamada; Cecília Volkmer-Ribeiro; Maria Conceição Messias

    2004-01-01

    Larvae of Oukuriella Epler, 1986 (Diptera, Chironomidae) inside freshwater sponges are reported for the first time in Brazil.Espécies de Oukuriella Epler (Diptera, Chironomidae) no interior de esponjas de água doce no Brasil. Larvas de Oukuriella Epler, 1986 no interior de esponjas de água doce são registradas pela primeira vez no Brasil.

  12. Chironomidae (Diptera: Insecta) da ilha de Santa Maria

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    Ramos, João; Raposeiro, Pedro M.; Cunha, Andreia; Silva, Alexandra A.; Costa, Ana C.; Gonçalves, Vitor

    2010-01-01

    O presente trabalho surge no âmbito da Expedição Científica do Departamento de Biologia da Universidade dos Açores à ilha de Santa Maria, durante a qual foram amostrados diversos ambientes aquáticos para o estudo da sua biodiversidade. O trabalho realizado possibilitou a actualização da lista de espécies de Chironomidae para a ilha de Santa Maria, tendo sido encontrados quatro novos registos para esta ilha.

  13. Biodiversity of Chironomidae at the North Temperate Lakes LTER Site

    Science.gov (United States)

    Berg, M. B.; Olson, S.; Hayford, B.; Gresens, S. E.; Kennedy, J.; Bouchard, R. W.; Ferrington, L. C.

    2005-05-01

    The National Science Foundation has established a network of Long Term Ecological Research (LTER) sites to enhance research at large spatial scales, extended temporal scales, and to facilitate intersite comparisons of system structure and processes. Present knowledge of Chironomidae community structure at LTER sites is insufficient to accomplish these goals. Our project objectives are to determine species composition of Chironomidae in a wide variety of aquatic habitats at LTERs, describe all undescribed species/life stage associations, determine the temporal seasonality of emergence and develop a data base of species by habitat and emergence times. Our methods include light trapping and sweep netting for adults, dip-netting and hand-picking wood/aquatic vegetation for larvae, collecting surface-floating pupal exuviae, and rearing to associate life stages. Our initial focus on the North Temperate Lakes LTER in Wisconsin and has documented 80 genera (representing > 125 species, including 18 undescribed species and/or unknown life stages) from 11 lakes, 5 streams and 2 bogs. Taxa include species with larvae that are: epiphytic, endophytic, xylophagic, phoretic on mollusks or other aquatic insects, specialized to feed on freshwater sponges, predators of black fly pupae, and those occurring in hyporheic zones, marginal semi-aquatic habitats or terrestrial soils.

  14. Genomic changes in speciation of the family Chironomidae, Diptera

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    PARASKEVA MICHAILOVA

    2015-04-01

    Full Text Available The mode of speciation adopted by a species or group of related species of animals (insects is clearly determined to a certain extent by the architecture of their genetic system. Chromosome rearrangements, the localization and appearance of the heterochromatin as well as the reproductive relations in sympatric, allopathric speciation and intrograssion process of different species of Chironomidae family are considered. A high chromosome polymorphism and changes in the constitutive heterochromatin are shown as predominant mechanism in the phyletic evolution of some species. Based on an analysis of inversions in different chromosome arms, a chromosome evolution in the "plumosus" group (genus Chironomus is traced. It was found that the floating inversions in an initial standard karyotype became fixed in a derived karyotype and underlined that the heterochromatin is a dynamic element in the speciation of family Chironomidae. In addition, hybridization tests revealed that pre - and postmating isolating mechanisms were operating in process of formation in different sibling species. It is concluded that the species with overlapping ranges are characterized by more complex chromosome changes, while in species with allopatric speciation there are less chromosome rearrangements. In this case, the distance between the populations is a very important factor as well.

  15. Ecological patterns of Chironomidae assemblages in Dynaric karst springs

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    Płóciennik M.

    2016-01-01

    Full Text Available Springs are one of important freshwater habitats in the Dynaric Mountains. Nevertheless, there were no intensive studies on dipteran communities in the region. Here we present an ecological analysis of Chironomidae communities recorded from a set of 27 springs along the Cvrcka River mainstream (the Republic of Srpska, Bosnia and Herzegovina. Environmental classification of Cvrcka springs divide them into three groups reflecting the level of human impact. Chironomidae communities divide investigated springs into three groups more dependent on bottom substrate quality. CCA indicates that the hard bottom and altitude are primary (significant factors determining midge assemblages. Secondary factors influencing communities are oxygen concentration and conductivity. There are clear differences in diversity and abundance in these three types of spring communities. Type II aggregates natural sites for Cvrcka valley. Samples characterized by high abundance of Chironomus seems to be an outliers in Cvrcka canyon. Eucrenon and hypocrenon communities are distinct, but no differences in the diversity level or the environmental assemblage relation were recorded for both mesohabitats. This study proves that solely environmental classification of spring habitats reflects well human impact, but invertebrate communities may not clearly follow general classification, reacting to a set of natural and altered conditions.

  16. Species of Oukuriella Epler (Diptera, Chironomidae inside freshwater sponges in Brazil

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    Fabio de Oliveira Roque

    2004-06-01

    Full Text Available Larvae of Oukuriella Epler, 1986 (Diptera, Chironomidae inside freshwater sponges are reported for the first time in Brazil.Espécies de Oukuriella Epler (Diptera, Chironomidae no interior de esponjas de água doce no Brasil. Larvas de Oukuriella Epler, 1986 no interior de esponjas de água doce são registradas pela primeira vez no Brasil.

  17. The importance of scanning electron microscopy (sem) in taxonomy and morphology of Chironomidae (Diptera)

    OpenAIRE

    Andrzej Kownacki; Eva Szarek-Gviazda; Olga Woźnicka

    2015-01-01

    The paper reports on the value of scanning electron microscopy (SEM) in the taxonomy and morphology of Chironomidae. This method has been relatively rarely used in Chironomidae studies. Our studies suggest that the SEM method provides a lot of new information. For example, the plastron plate of the thoracic horn of Macropelopia nebulosa (Meigen) under light microscopy is visible as points, while under SEM we have found that it consists of a reticular structure with holes. By using SEM a more ...

  18. Seasonal variation of vitamin and sterol content of chironomidae larvae.

    Science.gov (United States)

    Kara, Tuba

    2013-11-15

    In the present study, seasonal variation of vitamin and sterol content of Chironomidae larvae were determined by using HPLC. As the result of vitamin analysis, we found alpha-tocopherol, retinol, K1, K2, D2 and D3. When the seasonal variation of vitamin groups were compared, a significant increase was observed in vitamin K1, K2, D2 and alpha-tocopherol in all seasons. A significant increase was observed in vitamin D3 in spring. And also vitamin A level high in autumn and winter, alpha-tocopherol level was significantly high among vitamins. When vitamin groups were compared statistically, differences were detected between seasons (p < 0.001). Analyzing the content of sterol, we found ergosterol, cholesterol, stigmasterol and beta-sitosterol in all seasons. Cholesterol level was found to be significantly high in sterols. When sterol contents were compared statistically, differences were detected between seasons (p < 0.001). In conclusion, the reasons for these differences are larval development feature and the variety of food in different seasons. PMID:24511704

  19. 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.

  20. 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; Maria da Conceição Messias

    1989-01-01

    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.

  1. 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.

  2. Gastromermis kolleonis n. sp. (Nematoda: Mermithidae), a Parasite of Midges (Chironomus sp. Chironomidae) from Argentina

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    de Doucet, Maria M. A.; Poinar, George O.

    1984-01-01

    Gastromermis kolleonis n. sp. (Nematoda: Mermithidae) is described from the Arroyo Saldan River in Córdoba, Argentina. This species parasitizes midges of the genus Chironomus (Chironomidae: Diptera). It is distinguished from other members of the genus by the presence of six longitudinal chords, vulval flaps, degree of ventral displacement of the mouth, and size and shape of the spicule and amphids.

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

    Science.gov (United States)

    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 and pupae of these…

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

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    Elena Lukashevich; Andrey Przhiboro

    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.

  5. Pupae of Mesozoic Oryctochlus Kalugina, 1985 (Chironomidae: Podonominae), with description of two new species

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    Elena Lukashevich

    2012-01-01

    The Mesozoic Chironomidae are briefly reviewed. Two new species, Oryctochlus brundini n.sp. and O. kaluginae n.sp. from the Late Jurassic of Mongolia, are described based on pupae. The species of Oryctochlus known from pupae are photographed and keyed, their chaetotaxy is discussed.doi: 10.5324/fn.v31i0.1400.Published online: 17 October 2012.

  6. The importance of scanning electron microscopy (sem in taxonomy and morphology of Chironomidae (Diptera

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    Andrzej Kownacki

    2015-07-01

    Full Text Available The paper reports on the value of scanning electron microscopy (SEM in the taxonomy and morphology of Chironomidae. This method has been relatively rarely used in Chironomidae studies. Our studies suggest that the SEM method provides a lot of new information. For example, the plastron plate of the thoracic horn of Macropelopia nebulosa (Meigen under light microscopy is visible as points, while under SEM we have found that it consists of a reticular structure with holes. By using SEM a more precise picture of the body structure of Chironomidae can be revealed. It allows researchers to explain inconsistencies in the existing descriptions of species. Another advantage of the SEM method is obtaining spatial images of the body and organs of Chironomidae. However, the SEM method also has some limitations. The main problem is dirt or debris (e.g. algae, mud, secretions, mucus, bacteria, etc., which often settles on the external surface of structures, especially those which are uneven or covered with hair. The dirt should be removed after collection of chironomid material because if left in place it can become chemically fixed to various surfaces. It unnecessarily remains at the surface and final microscopic images may contain artifacts that obscure chironomid structures being investigated. In this way many details of the surface are thus unreadable. The results reported here indicate that SEM examination helps us to identify new morphological features and details that will facilitate the identification of species of Chironomidae and may help to clarify the function of various parts of the body. Fast development of electron microscope technique allows us to learn more about structure of different organisms.

  7. Studies in South-Occidental Amazon: contribution to the knowledge of Brazilian Chironomidae (Insecta: Diptera) - doi: 10.4025/actascibiolsci.v34i2.9195

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    Daniel Silva de Sousa; Maria Rosélia Marques Lopes; Gisele Cristina Rosin; Alice Michyio Takeda; Lisandro Juno Soares Vieira

    2012-01-01

    Chironomidae (Diptera) are a diverse and large group of small flies, whose larvae inhabit nearly every possible niche in most freshwater aquatic ecosystems. The Acre river is an important affluent of the Purus river. Our objective was to contribute to the knowledge of Chironomidae in this region by making the first survey of Chironomidae composition in the Acre river (Amazon Basin), and relate its distribution to physical and chemical variables. Samples were collected at three sites using a m...

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

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    Rieradevall, M.; M.L. Chaves; Prat, N.

    2007-01-01

    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 pres...

  9. 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

  10. 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

  11. 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

    2016-01-01

    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. PMID:27256514

  12. A preliminary survey of the non-biting midges (Diptera: Chironomidae of the Dominican Republic

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    Fabio Laurindo da Silva

    2015-12-01

    Full Text Available Chironomidae (Diptera are among the most diverse and widespread aquatic insects, with roughly 5,500 described species. However, prior to the present work, no species of Chironomidae had been documented from the island of Hispaniola. Collections of non-biting midges, with emphasis on the lotic fauna, were made in the Dominican Republic during July of 2015. In total, 578 specimens belonging to 27 genera and at least 44 species within the subfamilies Chironominae (20 taxa, Orthocladiinae (16 taxa and Tanypodinae (8 taxa were found. The subfamilies Chironominae and Orthocladiinae predominated. Polypedilum was the most widespread and diverse genus of Chironominae. Metriocnemus were collected in bromeliad tanks. The chironomid fauna in Dominican Republic includes multiple genera with worldwide distributions, including Holarctic and Neotropical components.

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

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27256514

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

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    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. dissidens (Walker) and E. pagana (Meigen). A key is presented to identify these species. Corrections are given to update a previously given key (Moller Pillot, 1984).

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

    Science.gov (United States)

    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. PMID:26909630

  16. [Genetic Differentiation of Populations of Baikal Endemic Sergentia baicalensis Tshern. (Diptera, Chironomidae)].

    Science.gov (United States)

    Kravtsova, L S; Bukin, Yu S; Peretolchina, T E; Shcherbakov, D Yu

    2015-07-01

    The population structure of endemic species Sergentia baicalensis (Diptera, Chironomidae) from Lake Baikal was studied using the first subunit of the cytochrome C oxidase mitochondrial gene (Col). Two populations inhabiting different basins of this lake, the southern-central and northern, were detected. It was confirmed that the divergence time of this species was dated to Late Miocene (9.53 ± 3.9 Mya), during the period when geographically separated basins existed in the Baikal rift zone. PMID:26410937

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

    OpenAIRE

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

    2011-01-01

    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 l...

  18. Evaluating potential sources of variation in Chironomidae catch rates on sticky traps

    Science.gov (United States)

    Smith, Joshua T.; Muehlbauer, Jeffrey D.; Kennedy, Theodore

    2016-01-01

    Sticky traps are a convenient tool for assessing adult aquatic insect population dynamics, but there are many practical questions about how trap sampling artefacts may affect observed results. Utilising study sites on the Colorado River and two smaller streams in northern Arizona, USA, we evaluated whether catch rates and sex ratios of Chironomidae, a ubiquitous aquatic insect, were affected by spraying traps with insecticide, placing traps at different heights above ground, and placing traps at different locations within a terrestrial habitat patch. We also evaluated temporal variation in Chironomidae counts monthly over a 9-month growing season. We found no significant variation in catch rates or sex ratios between traps treated versus untreated with insecticide, nor between traps placed at the upstream or downstream end of a terrestrial habitat patch. Traps placed near ground level did have significantly higher catch rates than traps placed at 1.5 m, although sex ratios were similar across heights. Chironomidae abundance and sex ratios also varied from month-to-month and seemed to be related to climatic conditions. Our results inform future sticky trap studies by demonstrating that trap height, but not insecticide treatment or precise trap placement within a habitat patch, is an important source of variation influencing catch rates.

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

    Science.gov (United States)

    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. PMID:26243331

  20. Diel drift of Chironomidae larvae in a pristine Idaho mountain stream

    Science.gov (United States)

    Tilley, L.J.

    1989-01-01

    Simultaneous hourly net collections in a meadow and canyon reach of a mountain stream determined diel and spatial abundances of drifting Chironomidae larvae. Sixty-one taxa were identified to the lowest practical level, 52 in the meadow and 41 in the canyon. Orthocladiinae was the most abundant subfamily with 32 taxa and a 24 h mean density of 294 individuals 100 m-3 (meadow) and 26 taxa and a mean of 648 individuals 100 m-3 (canyon). Chironominae was the second most abundant subfamily. Nonchironomid invertebrates at both sites and total Chironomidae larvae (meadow) were predominantly night-drifting. Parakiefferiella and Psectrocladius were day-drifting (meadow) whereas 8 other chironomid taxa (meadow) and 2 taxa (canyon) were night-drifting. All others were aperiodic or too rare to test periodicity, Stempellinella cf brevis Edwards exhibited catastrophic drift in the canyon only. The different drift patterns between sites is attributed to greater loss of streambed habitat in the canyon compared to the meadow as streamflow decreased. Consequent crowding of chironomid larvae in the canyon caused catastrophic drift or interfered with drift periodicty. This study adds to knowledge of Chironomidae drift and shows influences on drift of hydrologic and geomorphic conditions. ?? 1989 Kluwer Academic Publishers.

  1. Composición y abundancia de Chironomidae (Diptera) en un río serrano de zona semiárida (San Luis, Argentina) Composition and abundance of Chironomidae (Diptera) in a semiarid stream (San Luis, Argentina)

    OpenAIRE

    ANA I MEDINA; Analía C. Paggi

    2004-01-01

    En numerosas investigaciones acerca de las comunidades bentónicas de ambientes lóticos ha quedado excluído el estudio de la diversidad y abundancia de la familia Chironomidae (Diptera), debido a las dificultades que presenta la taxonomía de los estados inmaduros. En este trabajo se estudió la composición y abundancia larval de la familia Chironomidae en el tramo no-regulado del río Grande. Se identificaron 24 géneros correspondientes a tres subfamilias; Chironominae, Tanypodinae y Orthocladii...

  2. Lista faunística de los Quironómidos (Diptera, Chironomidae) de Madrid (España)

    OpenAIRE

    Soriano, O.; Cobo, F.

    2006-01-01

    A check list of the Chironomids (Diptera, Chironomidae) recorded from Madrid is provided for the first time. New unpublished records are included, of which six are new for the Iberian Peninsula. 218 species were found, coming from both lotic and lenitic environments.

    En el presente trabajo se aporta por primera vez una lista faunística de los quironómidos (Diptera, Chironomidae) citados en Madrid. También se añaden citas inéditas, siendo seis de ellas nuevas citas para la p...

  3. Studies in South-Occidental Amazon: contribution to the knowledge of Brazilian Chironomidae (Insecta: Diptera - doi: 10.4025/actascibiolsci.v34i2.9195

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    Daniel Silva de Sousa

    2012-03-01

    Full Text Available Chironomidae (Diptera are a diverse and large group of small flies, whose larvae inhabit nearly every possible niche in most freshwater aquatic ecosystems. The Acre river is an important affluent of the Purus river. Our objective was to contribute to the knowledge of Chironomidae in this region by making the first survey of Chironomidae composition in the Acre river (Amazon Basin, and relate its distribution to physical and chemical variables. Samples were collected at three sites using a modified Petersen grab. A grain size analysis showed heterogeneity between sampling sites. Eighteen morphospecies of Chironomidae larvae were recorded. In site 2, there was higher density of Chironomidae. Higher richness was observed in site 1, and the composition of this site was similar to site 3. The present study showed that the Chironomidae community was influenced by urban area. Chironomidae can be considered an important component of the fauna of this river and a potential instrument in future studies of ecology in the region. 

  4. 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 ostatní: 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

  5. Feeding habits of Chironomidae larvae (Insecta: Diptera in Vargem Limpa stream, Bauru, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Gabriel Lucas Bochini

    2008-06-01

    Full Text Available The present study analyzed the feeding habits and structure of the Chironomidae fauna in Vargem Limpa stream, in December 2004. The main food item ingested by most of the analyzed genera (Beardius, Caladomyia, Chironomus, Clinotanypus, Corynoneura, Cricotopus, Cryptochironomus, Dicrotendipes, Endotribelos, Harnischia, Fissimentum, Lopescladius, Polypedilum, Tanypus and Tanytarsus was identified as detritus, except for the Cladopelma whose main food item was algae. Ablabesmyia was the only genus that exhibited items of animal origin in the diet. The diets of 17 genera were investigated, and the majority of the individuals were classified as collectors.

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

    OpenAIRE

    Maria-Monica Tudorancea; C. Tudorancea

    2001-01-01

    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 Chironomu...

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

    OpenAIRE

    Andrey Przhiboro; Lauri Paasivirta

    2012-01-01

    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 t...

  8. 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

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

    Science.gov (United States)

    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. PMID:26934147

  10. 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.

  11. A Preliminary Study on the Identification of the Littoral Oligochaete (Annelida) and Chironomidae (Diptera) Fauna of Lake Kovada, a National Park in Turkey

    OpenAIRE

    Arslan, Naime; Yalçın ŞAHİN

    2006-01-01

    Samples were collected from 7 different stations between January 2002 and December 2002 with a view to identifying the littoral benthic fauna (Oligochaeta and Chironomidae) of Lake Kovada, located in Southern Anatolia. As a result of this study, 35 species were determined, comprising 15 species from Oligochaeta (8 Naidid and 7 Tubificid), and 20 species from Chironomidae (4 Tanypodin, 2 Orthocladiin, 12 Chironomini and 2 Tanytarsin). Species richness varied between 11 and 19. The littoral Oli...

  12. Colonização de Chironomidae (Diptera: Insecta) em diferentes tipos de substratos artificiais - DOI: 10.4025/actascibiolsci.v27i2.1325 Chironomidae (Diptera: Insecta) colonization in different types of artificial substrates - DOI: 10.4025/actascibiolsci.v27i2.1325

    OpenAIRE

    Alice Michiyo Takeda; Adriana Felix dos Anjos

    2005-01-01

    Substratos artificiais são utilizados para estudos sobre colonização da fauna aquática. O objetivo deste estudo foi verificar a composição, densidade e riqueza de larvas de Chironomidae em diferentes tipos de substratos artificiais ao longo de 96 dias de exposição no rio Paraná. Doze morfoespécies de larvas de Chironomidae foram identificadas. Cricotopus sp.1 foi predominante nos quatro tipos de substratos (11933 ind./m-2) e a maior densidade média da maioria dos táxons de Chironomidae foi ve...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    Nadja Gomes Machado; Danielle Christine Stenner Nassarden; Francyele dos Santos; Isabelle Christina Gonçalves Boaventura; Gregory Perrier; Fernanda Silveira Carvalho de Souza; Eucarlos de Lima Martins; Marcelo Sacardi Biudes

    2015-01-01

    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 ...

  16. Predation by Erythemis nymphs (Odonata) on Chironomidae (Diptera) and Elmidae (Coleoptera) in different conditions of habitat complexity

    OpenAIRE

    João Ânderson Fulan; Marcelo Rodrigues dos Anjos

    2015-01-01

    Abstract Aim: The goal of this study was to analyze the effects of predation by nymphs of Erythemis Hagen, 1861 on Elmidae and Chironomidae and to check if the presence and the architecture of aquatic macrophytes may mediate this interaction. Methods: All prey as well as nymphs were captured near macrophytes in a small lagoon alongside a highway near Humaitá, Amazonas, Brazil. Twelve buckets were used in three different treatments: with Pistia stratiotes Linnaeus, 1753, with Salvinia auricula...

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

    OpenAIRE

    Débora Rebechi; Mário Antônio Navarro-Silva

    2012-01-01

    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 anal...

  18. First record of larvae of Chironomidae (Insecta, Diptera) as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae), an ectosymbiont on larvae of Corydalidae (Megaloptera) Primeiro registro de larvas de Chironomidae como presas de Temnocephala sp. (Platyhelminthes, Temnocephalidae), um ectosimbionte de larvas de Corydalidae (Maegaloptera)

    OpenAIRE

    Susana Trivinho-Strixino; Fabio Laurindo da Silva; Francisco Valente-Neto

    2012-01-01

    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 megalop...

  19. 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.

  20. Predation by Erythemis nymphs (Odonata on Chironomidae (Diptera and Elmidae (Coleoptera in different conditions of habitat complexity

    Directory of Open Access Journals (Sweden)

    João Ânderson Fulan

    2015-12-01

    Full Text Available Abstract Aim: The goal of this study was to analyze the effects of predation by nymphs of Erythemis Hagen, 1861 on Elmidae and Chironomidae and to check if the presence and the architecture of aquatic macrophytes may mediate this interaction. Methods: All prey as well as nymphs were captured near macrophytes in a small lagoon alongside a highway near Humaitá, Amazonas, Brazil. Twelve buckets were used in three different treatments: with Pistia stratiotes Linnaeus, 1753, with Salvinia auriculata Aublet and without macrophytes. Results: We found a mortality rate of 100% of Chironomidae and Elmidae larvae in the treatment without macrophytes. There was a greater survival of Elmidae compared to Chironomidae in the treatments with P. stratiotes and S. auriculata; however, there was a greater survival of both preys on treatment with P. stratiotes. Conclusions: We conclude that the presence of macrophytes decreased the efficiency of predation of Erythemis nymphs under experimental conditions. The architecture of macrophytes affected predation as macrophytes with longer roots and with greater habitat complexity promoted a greater survival of prey.

  1. Estado del conocimiento taxonómico de la fauna de Chironomidae (Diptera: Nematocera de la Patagonia Current state of the taxonomic knowledge of the Chironomidae fauna (Diptera: Nematocera from Patagonia

    Directory of Open Access Journals (Sweden)

    Mariano Donato

    2009-06-01

    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.The Chironomidae (Diptera: Nematocera family is one of the most widely distributed group of insects and often the most abundant in freshwater environments. Representatives of this family can exploit a wide range of environmental gradients. The information here presented is based on the compilation of distributional data obtained from bibliography, the study of the type material deposited in the Natural History Museum (UK and the collection material from Museo de La Plata (Argentina. Nine subfamilies are recorded from Patagonia, being the monotypic subfamily Chilenomyiinae endemic for the area. From the 111 known

  2. 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.

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  6. Community Structure of Chironomidae (Midges) in Two Brazilian Rivers in Relation to Contrasting Land Uses

    Science.gov (United States)

    Sonoda, K. C.; Matthaei, C.; Vettorazzi, C. A.; Trivinho-Strixino, S.

    2005-05-01

    We investigated whether the conversion of riparian land use from indigenous forest to pasture is associated with changes in midge community composition in two South Brasilian rivers. Our study was conducted in the main rivers (Sao Jose dos Dourados 6th order; Aguapei 7th order) of two catchments in Sao Paulo State. Both catchments are dominated by agricultural ecosystems but retain substantial patches of native riparian forest in certain areas. Replicated artificial substrates (baskets filled with clay rocks) were exposed in forested and pasture reaches in both rivers. Both land uses had to be present for at least 500m along both river banks, and the riparian forest had to be at least 50m wide. In each river, six baskets per reach type were sampled after a colonization period of 44 days, and all Chironomidae in these samples were sorted and identified to genus level (a total of 3399 individuals belonging to 28 different taxa). As expected, land use affected midge communities. Total midge density was significantly higher in pasture reaches than in forested reaches. By contrast, midge taxon richness was higher at the forested reaches. These results show the importance of native riparian forests for preserving aquatic biodiversity in Brasilian rivers.

  7. 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.

  8. 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.

  9. 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

    OpenAIRE

    Marcos Callisto; Michael D.C. Goulart; Pablo Moreno; Martins, Rogério P.

    2006-01-01

    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 ...

  10. 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.

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

    Science.gov (United States)

    Pramual, Pairot; Simwisat, Kusumart; Martin, Jon

    2016-01-01

    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. PMID:27395909

  12. The Chironomidae collection at the Zoological Institute (St Petersburg: history, current state and role for further research

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    Andrey Przhiboro

    2012-10-01

    Full Text Available This paper briefly reviews the collection of Chironomidae (Diptera housed at the Zoological Institute of Russian Academy of Sciences in St Petersburg (ZIN. Although it is the oldest and one of the largest Chironomidae collections in Russia, most of the collection has been unknown to specialists for decades. The collection consists of three main parts: dry specimens (about 20000 pinned adults, material in ethanol (over 25000 vials with larvae, pupae and adults and permanent slides (over 12000 slides with larvae, pupae and adults. Based on a study of the collection itself, published sources and archival data, major periods for the formation of the collection are here described. Collectors and expeditions, whose contributions were most important, are listed, as well as the regions where the material was collected. The role of chironomid researchers, who made important contributions to the creation, enrichment or study of the collection, is also described. The contributions by Aleksei Chernovskii and Vera Pankratova are considered in more detail. According to a preliminary estimate, the collection contains type specimens of no less than 150 species described by 24 authors, and thousands of specimens determined by experts. The Chironomidae collection of ZIN is particularly important because it hopefully will enable us to correctly interpret many species names proposed in 1930-1980’s, mostly based on brief descriptions of larvae and currently often considered nomina dubia. In addition, the collection includes the unprocessed material from vast territory of the former Soviet Union, including many distant regions, which are still difficult to access. doi: 10.5324/fn.v31i0.1402.Published online: 17 October 2012.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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. PMID:26628222

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26274889

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

    Science.gov (United States)

    Chordas, Stephen W., III; 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.

  18. Preliminary Study of Phylogenetic Relationship of Rice Field Chironomidae (Diptera Inferred From DNA Sequences of Mitochondrial Cytochrome Oxidase Subunit I

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    Salman A. Al-Shami

    2009-01-01

    Full Text Available Problem statement: Chironomidae have been recorded in rice fields throughout the world including in many countries such as India, Australia and the USA. Although some studies provide the key to genera level and note the difficulty of identifying the larvae to species level. Chironomid researches have been hindered because of difficulties in specimen preparation, identification, morphology and literature. Systematics, phylogenetics and taxonomic studies of insects developed quickly with emergence of molecular techniques. These techniques provide an effective tool toward more accurate identification of ambiguous chironomid species. Approach: Samples of chironomids larvae were collected from rice plots at Bukit Merah Agricultural Experimental Station (BMAES, Penang, Malaysia. A 710 bp fragment of mitochondrial gene Cytochrome Oxidase subunit I (COI was amplified and sequenced. Results: Five species of Chironomidae; three species of subfamily Chironominae, Chironomus kiiensis, Polypedilum trigonus, Tanytarsus formosanus, two species of subfamily Tanypodinae, Clinotanypus sp and Tanypus punctipennis were morphologically identified. The phylogenetic relationship among these species was been investigated. High sequence divergence was observed between two individuals of the presumed C. kiiensis and it is suggested that more than one species may be present. However the intraspecific sequence divergence was lower between the other species of Tanypodinae subfamily. Interestingly, Tanytarsus formosanus showed close phylogenetic relationship to Tanypodinae species and this presumably reflect co-evolutionary traits of different subfamilies. Conclusion: The sequence of the mtDNA cytochrome oxidase subunit I gene has proven useful to investigate the phylogenetic relationship among the ambiguous species of chironomids.

  19. First record of larvae of Chironomidae (Insecta, Diptera as prey of Temnocephala sp. (Platyhelminthes, Temnocephalidae, an ectosymbiont on larvae of Corydalidae (Megaloptera Primeiro registro de larvas de Chironomidae como presas de Temnocephala sp. (Platyhelminthes, Temnocephalidae, um ectosimbionte de larvas de Corydalidae (Maegaloptera

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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.Primeiro registro de larvas de Chironomidae como presas de Temnocephala sp. (Platyhelminthes, Temnocephalidae, um ectosimbionte de larvas de Corydalidae (Maegaloptera. Este estudo constitui o primeiro registro de Temnocephala Blanchard (Platyhelminthes, Temnocephalidae, um ectosimbionte em larvas de Megaloptera, como um possível predador de larvas de Chironomidae. Vinte e oito larvas de Corydalidae (Corydalus e Protochauliodes foram examinadas sobre estereomicroscópio na busca por Temnocephala e larvas de Chironomidae, das quais cinco larvas de Megaloptera continham 24 Temnocephala sp. associadas. Além disso, oito Temnocephala possuíam em seu conteúdo estomacal larvas de Chironomidae, uma interação desconhecida anteriormente. A análise do conteúdo estomacal revelou Corynoneura como o quironomídeo mais abundante, e também algumas larvas de Larsia, Rheotanytarsus e Tanytarsus. Este estudo inclui Corydalus e Protochauliodes como hospedeiros de Temnocephala, os quais podem ser importantes

  20. Effects of a native and a non-native macrophyte species of Hydrocharitaceae on Chironomidae and Oligochaeta assemblages structure doi: 10.4025/actascibiolsci.v35i3.10855

    OpenAIRE

    Gisele Cristina Rosin; Alice Michiyo Takeda; Janielly Carvalho Camargo; Mariana Carolina Teixeira; Sue Ellen Prata Fernandes; Rômulo Diego de Lima Behrend

    2013-01-01

    This study investigated the structure of the Oligochaeta and Chironomidae assemblages associated with monospecific stands of two submerged macrophyte species: Egeria najas and Hydrilla verticillata. Samplings were carried out in Leopoldo Backwater and Paraná river, in August 2008. To assess the structure of Oligochaeta and Chironomidae assemblage in each macrophyte we calculated: species density, richness, diversity, and evenness. A detrended correspondence analysis (DCA) was used to summariz...

  1. 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

    OpenAIRE

    Alice Michiyo Takeda; Patrícia Almeida Sacramento; Tércio Abel Pezenti; Fernanda de Almeida Gurski; Priscila Colombelli Alessio; Gisele Daiane Pinha

    2013-01-01

    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 lake...

  2. Мониторинговые исследования Волги и ее притоков у Саратова и индикационное значение личинок хирономид рода Procladius (Diptera, Chironomidae)

    OpenAIRE

    АНИКИНА М.А.; СЕРГЕЕВА И.В.

    2008-01-01

    In the composite of the bioindication complex of Chironomidae of the Saratov Region basins the eurytopic larva of genus Procladius (Diptera, Chironomi-dae, Tanypodinae) dominate being the markers of toxic water.

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

    International Nuclear Information System (INIS)

    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

  4. Variação temporal de larvas de Chironomidae (Diptera no Alto Rio Paraguai (Cáceres, Mato Grosso, Brasil Temporal variation of Chironomidae larvae (Diptera in the Upper Paraguay River (Cáceres, Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Fernando H. Aburaya

    2007-01-01

    Full Text Available A composição das assembléias de Chironomidae e os possíveis fatores ambientais que influenciam a distribuição temporal deste grupo no alto rio Paraguai, em Cáceres, foram abordados no presente estudo durante o período de novembro de 2004 a outubro de 2005. Para considerar a diversidade de habitats na região, selecionamos nove pontos amostrais, onde coletamos 2988 indivíduos, distribuídos em 34 espécies pertencentes a oito tribos de três subfamílias. Os gêneros Labrundinia sp.1, Polypedilum (Asheum e Polypedilum (Tripodura estiveram presentes em quase todos os meses amostrados. A maior riqueza e abundância foram registradas no período de seca, revelando Polypedilum como o gênero mais expressivo. Ficou evidente o efeito das vaiáveis ambientais sobre os atributos da diversidade do alto rio Paraguai.The aim of this study is to determine the influence of environmental variables on the time distribution of assemblages of Chironomidae in the Upper Paraguay River. The samples were collected from November 2004 to October of 2005. To consider the diversity of habitats in the region, nine different sampling points were sampled and 2988 individuals were collected, distributed in 34 species, eight tribes and three subfamilies. The genus Labrundinia sp.1, Polypedilum (Asheum and Polypedilum (Tripodura occurred almost every month during the study. Richness and abundance were higher during the dry period of the year, and the genus Polypedilum was the most abundant. There was evident the effect of the environmental variables on the attributes of diversity in the Upper Paraguay River.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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

    environmentally relevant ecosystem function by reducing nitrate to dinitrogen gas. Thereby, they remove inorganic nitrogen that originates from organic matter mineralisation and anthropogenic pollution. Nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide, is emitted from lakes only as a......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 an...... minor fraction of the nitrate reduced. However, when lake sediments are densely colonised by macrofauna, the rates of nitrous oxide emission increase significantly. We hypothesise that the guts of bacterivorous macrofauna represent short-term habitats in which high denitrification activity and...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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. PMID:25613586

  10. Phoretic association between larvae of Rheotanytarsus (Diptera: Chironomidae) and genera of Odonata in a first-order stream in an area of Atlantic Forest in southeastern Brazil

    OpenAIRE

    Beatriz F. J. Vescovi Rosa; Renato T. Martins; Vívian C. de Oliveira; Roberto da G. Alves

    2009-01-01

    In this note, the occurrence of phoresy between larvae of Rheotanitarsus sp. (Diptera: Chironomidae) and larvae of Heteragrion sp. (Odonata: Megapodagrionidae) and of unidentified genera of Calopterygidae (Odonata) collected in a first-order stream in an area of Atlantic Forest in southeastern Brazil is reported. During the dry season of 2007 and the rainy season of 2008, with the aid of a Surber sampler, 15 samples of each of the following mesohabitats were collected: litter from riffle area...

  11. Rapid Recovery of Chironomidae (Diptera) in Little Mill Creek (Kansas, U.S.A.) After the Decommissioning of a Waste Water Treatment Plant

    Science.gov (United States)

    Bouchard, R. W.; Ferrington, L. C.

    2005-05-01

    In June 1995 the Lenexa Waste Water Treatment Plant was decommissioned, providing an opportunity to study recovery of Chironomidae community structure in Little Mill Creek. Using pupal exuviae, weekly changes in the species richness and composition of Chironomidae emerging upstream and downstream of the effluent outfall was evaluated from two weeks before decommissioning to eight weeks post-decommissioning. Chironomidae emergence was clearly different between upstream and downstream sites both before and shortly after effluent input ceased. Before decommissioning, sites immediately downstream of the effluent had low species richness and were dominated by Chironomus riparius (Meigen) and other tolerant taxa, with some recovery at sites farther downstream. Two weeks after decommissioning, only sites immediately downstream of the former effluent were clearly impacted, but effects were reduced compared to pre-recovery collections. At five weeks post-decommissioning, species richness was only slightly lower at the sites immediately downstream of the former effluent and the composition of common species (i.e., >5% of relative abundance) was similar between upstream and downstream sites. Rapid recovery of chironomid emergence below the sewage effluent likely resulted from both colonization of drifting larvae from upstream sources and adult dispersal and oviposition, indicating rapid responses in emergence as water quality conditions improved.

  12. Fossil Chironomidae (Insecta: Diptera) as quantitative indicators of past salinity in African lakes

    Science.gov (United States)

    Eggermont, Hilde; Heiri, Oliver; Verschuren, Dirk

    2006-08-01

    We surveyed sub-fossil chironomid assemblages in surface sediments of 73 low- to mid-elevation lakes in tropical East Africa (Uganda, Kenya, Tanzania, Ethiopia) to develop inference models for quantitative paleosalinity reconstruction. Using a calibration data set of 67 lakes with surface-water conductivity between 34 and 68,800 μS/cm, trial models based on partial least squares (PLS), weighted-averaging (WA), weighted-averaging partial least squares (WA-PLS), maximum likelihood (ML), and the weighted modern analogue technique (WMAT) produced jack-knifed coefficients of determination ( r2) between 0.83 and 0.87, and root-mean-squared errors of prediction (RMSEP) between 0.27 and 0.31 log 10 conductivity units, values indicating that fossil assemblages of African Chironomidae can be valuable indicators of past salinity change. The new inference models improve on previous models, which were calibrated with presence-absence data from live collections, by the much greater information content of the calibration data set, and greater probability of finding good modern analogues for fossil assemblages. However, inferences still suffered to a greater (WA, WMAT) or lesser (WA-PLS, PLS and ML) extent from weak correlation between chironomid species distribution and salinity in a broad range of fresh waters, and apparent threshold response of African chironomid communities to salinity change near 3000 μS/cm. To improve model sensitivity in freshwater lakes we expanded the calibration data set with 11 dilute (6-61 μS/cm) high-elevation lakes on Mt. Kenya (Kenya) and the Ruwenzori Mts. (Uganda). This did not appreciably improve models' error statistics, in part because it introduced a secondary environmental gradient to the faunal data, probably temperature. To evaluate whether a chironomid-based salinity inference model calibrated in East African lakes could be meaningfully used for environmental reconstruction elsewhere on the continent, we expanded the calibration data

  13. Chironomidae (Diptera) community structure in two subsystems with different states of conservation in a floodplain of southern Brazil Estrutura da comunidade de Chironomidae (Diptera) em dois subsistemas em diferentes estados de conservação de uma planície de inundação do sul do Brasil

    OpenAIRE

    Gisele Cristina Rosin; Danielle Paula de Oliveira Mangarotti; Alice Michiyo Takeda

    2010-01-01

    AIM: Our study aimed to compare the composition, distribution, diversity, abundance and dominance of Chironomidae in two subsystems of the Upper Paraná River floodplain, with different levels of conservation. We expected to find the highest values of diversity and lowest dominance of taxa in the most conserved areas (Ivinhema subsystem). We also expected to detect differences in the composition and distribution of communities between the subsystems, because of the level of conservation of eac...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    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.

  17. 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

  18. 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

    Directory of Open Access Journals (Sweden)

    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

  19. 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

  20. 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

    Directory of Open Access Journals (Sweden)

    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

  1. Larvas de Chironomidae arvas (Diptera da planície de inundação do alto rio Paraná: distribuição e composição em diferentes ambientes e períodos hidrológicos - DOI: 10.4025/actascibiolsci.v29i1.127 Chironomidae larvae (Diptera from the upper Paraná river floodplain: distribution and composition in different environments and hydrological periods

    Directory of Open Access Journals (Sweden)

    Alice Michiyo Takeda

    2007-11-01

    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 1478 larvas 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. A variação 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

  2. 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

    OpenAIRE

    Adriana Felix dos Anjos; Alice Michiyo Takeda

    2009-01-01

    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 ...

  3. Diversity and distribution of chironomids (Diptera, Chironomidae in pristine Alpine and pre-Alpine springs (Northern Italy

    Directory of Open Access Journals (Sweden)

    Bruno ROSSARO

    2011-09-01

    Full Text Available The diversity and distribution of chironomids (Diptera, Chironomidae were studied in relation to environmental factors in 81 springs under pristine conditions in the Italian Prealps and Alps (Trentino and Veneto, NE-Italy, 46°N, 10-11°E. Each spring was surveyed once, between May and November, in 2005 or in 2007-2008, within 50 m of the spring's source (eucrenal. A total of 173 macroinvertebrate samples were collected, in which 26,871 chironomids (including larvae, pupae, pupal exuviae and adults were counted. Five subfamilies (Tanypodinae, Diamesinae, Prodiamesinae, Orthocladiinae and Chironominae, 54 genera and 104 species/groups of species were identified. As expected, Orthocladiinae accounted for a large part of specimens (82%, followed by Diamesinae (10%, Chironominae Tanytarsini (6% and Tanypodinae (2%. Together the Chironominae Chironomini and Prodiamesinae contributed less than 0.05% of the fauna. Larvae represented 97.5% of specimens, mostly juveniles (62.6%. Maximum richness and diversity occurred at intermediate altitudes (ca 900-2100 m a.s.l.. Most taxa were found in a small proportion of sites, and frequencies declined gradually for more widely distributed species. A high number (67% of rare (= present in less than 10% of sites taxa were found. Three to 27 taxa were identified per spring. The rheocrene/rheo-helocrene springs were richest in taxa (generally >15 taxa, the mineral spring was poorest, with only three taxa. Most taxa were crenophilous, including lentic, rheobiontic and bryophilous taxa. A Principal Component Analysis (PCA was performed including 98 taxa. Axes were interpreted calculating the correlation coefficients between site scores and 24 environmental factors. The species with the highest scores were Pseudokiefferiella parva, Corynoneura sp. A, Metriocnemus eurynotus gr., Paratrichocladius skirwithensis and Tvetenia calvescens. Five clusters of sites were identified with K-means analysis on the basis of the first

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  5. 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)

    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. δ13C 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)

  6. Phytophilous Chironomidae (Diptera and other macroinvertebrates in the ox-bow Infernão Lake (Jataí Ecological Station, Luiz Antônio, SP, Brazil

    Directory of Open Access Journals (Sweden)

    TRIVINHO-STRIXINO S.

    2000-01-01

    Full Text Available Infernão Lake, located within the Jataí Ecological Station in Luiz Antônio Municipal district (São Paulo State, Brazil, is one of the most typical ox-bow lake of the Mogi-Guaçu River, and it presents, as the main feature, its great quantity of aquatic macrophytes, whose intensive development, in the last years practically covered the whole mirror of water. With the purpose to point out the composition and to establish the relative participation of the phytophilic zoocoenosis that inhabits the different macrophytes of that lake, a collection program of the main vegetation stands was established. The collections, were carried out randomly, during dry season (1994, in stands of Salvinia auriculata, Utricularia sp., Cabomba piauhyensis, Eichhornia azurea and Scirpus cubensis being used specific methodology for each vegetable type. The analysis of the different macrophytes showed the presence of 4,130 macroinvertebrates of 28 families, in which Chironomidae (Diptera and Naididae (Oligochaeta were the most representative, contributing on the average with 51% and 25% of the total fauna. Asheum, Beardius, Chironomus, Goeldichironomus, Parachironomus and Polypedilum were the most abundant Chironomidae genera. Species of the genus Dero (Dero and D. (Aulophorus represented the most typical Naididae of the phytofauna. With clear faunistic gradient from the shore to the center of the lake, the taxocoenosis indicated low similarity (PSc 60% among the associated communities on different vegetables, when grouped into feeding guilds, with expressive participation, in most of the macrophytes, of the collector-gatherers category, except on S. auriculata, whose predators (> 50% and collector-filterers (> 20% dominance turned that zoocoenosis distinct from the others.

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. 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.

    Science.gov (United States)

    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. PMID:25728359

  9. 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.

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26249988

  10. 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. PMID:26885875

  11. Phoretic association between larvae of Rheotanytarsus (Diptera: Chironomidae and genera of Odonata in a first-order stream in an area of Atlantic Forest in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Beatriz F. J. Vescovi Rosa

    2009-12-01

    Full Text Available In this note, the occurrence of phoresy between larvae of Rheotanitarsus sp. (Diptera: Chironomidae and larvae of Heteragrion sp. (Odonata: Megapodagrionidae and of unidentified genera of Calopterygidae (Odonata collected in a first-order stream in an area of Atlantic Forest in southeastern Brazil is reported. During the dry season of 2007 and the rainy season of 2008, with the aid of a Surber sampler, 15 samples of each of the following mesohabitats were collected: litter from riffle areas, litter from pool areas and sediment in pool areas. Eighty-five Odonata larvae were obtained, 10 (11.76% with cases of phoresy by Rheotanytarsus sp.. These chironomids were associated with only one specimen of Megapodagrionidae, whereas the other larvae were recorded in association with Calopterygidae. Most of the Odonata with cases of phoresy by Rheotanytarsus sp. were recorded in the dry season. In the present study, the absence of the phoretic association with other potential hosts for Rheotanytarsus sp. found in the samples indicates a possible preference of these larvae for Odonata, which accounted for only 2.42% of the collected macroinvertebrates in litter and sediment.

  12. Avaliação da importância da unidade de conservação na preservação da diversidade de Chironomidae (Insecta: Diptera) no córrego Vargem Limpa, Bauru, Estado de São Paulo = Assessment of importance of the conservation unit in the preservation of Chironomidae (Insecta: Diptera) diversity in the Vargem Limpa stream, Bauru, São Paulo State

    OpenAIRE

    Fabio Laurindo da Silva; Diana Calcidoni Moreira; Sonia Silveira Ruiz; Gabriel Lucas Bochini

    2007-01-01

    Este estudo avaliou a qualidade das águas do córrego Vargem Limpa e testou a hipótese de que trechos protegidos, do sistema aquático, localizados no interior de uma unidade de conservação, favorecem a preservação da diversidade de Chironomidae (Insecta: Diptera). Foram realizadas amostragens em quatro pontos e algumas variáveis físicas equímicas da água foram aferidas. Os resultados, obtidos com o estudo, indicaram o predomínio de gêneros associados a substratos arenosos e que os trechos prot...

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

    Science.gov (United States)

    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

  14. 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.

  15. 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

    Directory of Open Access Journals (Sweden)

    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

  16. 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

  17. Larvas de Chironomidae arvas (Diptera) da planície de inundação do alto rio Paraná: distribuição e composição em diferentes ambientes e períodos hidrológicos - DOI: 10.4025/actascibiolsci.v29i1.127 Chironomidae larvae (Diptera) from the upper Paraná river floodplain: distribution and composition in different environments and hydrological periods

    OpenAIRE

    Alice Michiyo Takeda; Gisele Cristina Rosin

    2007-01-01

    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 anális...

  18. 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

    OpenAIRE

    Gisele Cristina Rosin; Alice Michiyo Takeda

    2007-01-01

    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 anális...

  19. 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

    OpenAIRE

    Alice Michiyo Takeda; Adriana Felix dos Anjos

    2009-01-01

    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...

  20. Avaliação da importância da unidade de conservação na preservação da diversidade de Chironomidae (Insecta: Diptera) no córrego Vargem Limpa, Bauru, Estado de São Paulo, Brasil - DOI: 10.4025/actascibiolsci.v29i4.883 Assessment of importance of the conservation unit in the preservation of Chironomidae (Insecta: Diptera) diversity in the Vargem Limpa stream, Bauru, São Paulo State - DOI: 10.4025/actascibiolsci.v29i4.883

    OpenAIRE

    Sonia Silveira Ruiz; Diana Calcidoni Moreira; Fabio Laurindo da Silva; Gabriel Lucas Bocchini

    2008-01-01

    Este estudo avaliou a qualidade das águas do córrego Vargem Limpa e testou a hipótese de que trechos protegidos, do sistema aquático, localizados no interior de uma unidade de conservação, favorecem a preservação da diversidade de Chironomidae (Insecta: Diptera). Foram realizadas amostragens em quatro pontos e algumas variáveis físicas e químicas da água foram aferidas. Os resultados, obtidos com o estudo, indicaram o predomínio de gêneros associados a substratos arenosos e que os trechos pro...

  1. Сравнительный морфологический анализ двух видов Camptochironomus Kieffer, 1918 (Diptera, Chironomidae) - c. tentans (Fabricius, 1805) и c. pallidivittatus Edwards, 1929 Нижнего Поволжья

    OpenAIRE

    ПОЛУКОНОВА Н.В.

    2014-01-01

    Представлен морфологический анализ двух видов Camptochironomus Kieffer, 1918 (Chironomidae, Diptera) C. tentans (Fabricius, 1805) и C. pallidivittatus Edwards, 1929 Нижнего Поволжья.

  2. ОСОБЕННОСТИ БИОТОПИЧЕСКОГО РАСПРЕДЕЛЕНИЯ ХИРОНОМИД РОДА PROCLADIUS SKUSE, 1889 (DIPTERA, CHIRONOMIDAE) В ВОЛГЕ И ЕЁ ПРИТОКАХ В ГРАНИЦАХ САРАТОВСКОЙ ОБЛАСТИ

    OpenAIRE

    АНИКИНА М.А.

    2011-01-01

    From 20 species of chironomidae of genus Procladius, extended in waters and water-currents of Russia, in territory of the Saratov area meet only two species P. (H.) choreus (Meigen) and P. (H.) ferrugineus (Kieffer) which live in the most various waters.

  3. Late Quaternary Environmental Changes Inferred from the stable Oxygen Isotope Composition of Aquatic Insects (Chironomidae: Diptera) and Stable Hydrogen Isotope Composition of bulk sediments from Idavain Lake, Southwest Alaska

    Science.gov (United States)

    Wang, Y.; Finney, B.; Wooller, M. J.

    2007-12-01

    Several techniques are available to examine the isotopic composition of historic lake waters, providing data that can subsequently be used to examine environmental changes. Recently-developed techniques are the stable oxygen isotope analysis of subfossil chironomid (Diptera: Chironomidae) head capsules (mostly chitin) preserved in lake sediments and stable hydrogen isotope analyses directly on bulk sediments. An advantage of using δ18O of chironomids is that the chitinous chironomid headcapsules preserve well in lake sediments, retaining the stable oxygen isotope signature of the lake in which they lived. An advantage of δD analyses of bulk sediments is that a sediment core can be analyzed relatively easily and when the %C (total organic carbon) and %H profiles correlate the data can be used to infer past δD changes of the organics in the sediments. We present results from these analyses of a lake sediment core from Idavain Lake (58°46'N, 155°57'W, 223m above sea level) in southwest Alaska in concert with other paleolimnological proxies, including δ15N, δ13C, LOI, magnetic susceptibility, organic content and opal concentrations for a better understanding of paleolimnological changes since deglaciation for the region. Our preliminilary result shows that downcore shifts of δ18O analyzed from chironomid head capsules coincide well with LOI and pollen changes. The δD of sediments and TOM showed large magnitude changes and reflected the relative lake level changes during the record. This study aim to test the correlation between stable isotope analyese on chiornomid head capsules, lake water, and bulk sediments. In the addition, our study will add to the relatively small database of paleoenvironmental reconstructions from terrestrial sites in Southwest Alaska.

  4. ФАУНА, КАРИОТИПЫ И ЭКОЛОГИЯ КОМАРОВ-ЗВОНЦОВ РОДА CHIRONOMUS MEIGEN, 1803 (DIPTERA, CHIRONOMIDAE) ТИСО-САМШИТОВОЙ РОЩИ (СЕВЕРО-ЗАПАДНЫЙ КАВКАЗ)

    OpenAIRE

    Кармоков, Мухамед; Полуконова, Наталья

    2014-01-01

    Data on fauna, features of ecology and karyotypes of non-biting midges from genus Chironomus Meigen, 1803 (Diptera, Chironomidae) at temporary reservoirs of upper courses of Sukanskiy gorge (Central Caucasus, northern macroslope) are submitted. Three species of chironomus are found: Chironomus : Ch. piger Strenzke, 1959, Ch. dorsalis Meigen, 1818 и Ch. riparius Meigen, 1804. All species are widespread and typical inhabitants of temporary reservoirs. Chromosomal reorganizations it is not revea...

  5. 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

  6. ЭКОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА CRICOTOPUS SALINOPHILUS (DIPTERA, CHIRONOMIDAE) ИЗ СОЛЕНЫХ РЕК БАССЕЙНА ОЗ. ЭЛЬТОН

    OpenAIRE

    Зинченко, Т.; Головатюк, Л.; Абросимова, Э.

    2010-01-01

    Приведены результаты экспериментальных исследований биологии нового для науки вида комаров-звонцов Cricotopus salinophilus Zinchenko, Makarchenko et Makarchenko рода Cricotopus van der Wulp (Diptera, Chironomidae). Выявлена положительная корреляционная связь численности и биомассы этого вида с показателями минерализации рек. Дается экологическая характеристика хирономид из высокоминерализованных рек аридной зоны Приэльтонья....

  7. Denopelopia amicitia, a new Tanypodinae from Brazil (Diptera, Chironomidae)

    Science.gov (United States)

    Dantas, Galileu P.S.; Hamada, Neusa; Mendes, Humberto F.

    2016-01-01

    Abstract A new species of Denopelopia from Brazil is described based on adult male and pupa. The male of the new species can be distinguished from all other species of the genus by the genitalia and fore-tibial spur morphology. The pupa is very similar to those of Denopelopia atria, but it can be distinguished by the absence of distinct constrictions in the respiratory atrium of the thoracic horn. Generic diagnosis to male and pupa of Denopelopia is emended and keys to male and pupae of known species are provided. PMID:26877674

  8. Denopelopia amicitia, a new Tanypodinae from Brazil (Diptera, Chironomidae).

    Science.gov (United States)

    Dantas, Galileu P S; Hamada, Neusa; Mendes, Humberto F

    2016-01-01

    A new species of Denopelopia from Brazil is described based on adult male and pupa. The male of the new species can be distinguished from all other species of the genus by the genitalia and fore-tibial spur morphology. The pupa is very similar to those of Denopelopia atria, but it can be distinguished by the absence of distinct constrictions in the respiratory atrium of the thoracic horn. Generic diagnosis to male and pupa of Denopelopia is emended and keys to male and pupae of known species are provided. PMID:26877674

  9. Review of Dicrotendipes Kieffer from China (Diptera, Chironomidae)

    OpenAIRE

    Xin Qi; Xiao-Long Lin; Xinhua Wang

    2012-01-01

    Abstract The genus Dicrotendipes Kieffer from China, including 8 species, is reviewed. Two new species, Dicrotendipes nudus sp. n. and Dicrotendipes saetanumerosus sp. n. are described and the male imagines are illustrated; the record of Dicrotendipes fusconotatus (Kieffer) is the first for China. A key to the males of Dicrotendipes in China is given.

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

    International Nuclear Information System (INIS)

    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)

  11. New Neotropical Nilothauma Kieffer, 1921 From Brazil (Diptera, Chironomidae)

    Science.gov (United States)

    Mendes, H. F.; Andersen, T.

    2005-05-01

    The larvae of Nilothauma Kieffer, 1921 are found in the littoral and sublittoral sediments of both standing and flowing waters. The adults are easily recognized as they have one or several median, setose projections on tergite IX. The genus was recently revised, and 25 species in four species groups are recognized from the Holarctic, Oriental, Australian and Afrotropical regions. Two species from Peru described in Nilothauma, are now considered to belong in Paratendipes Kieffer, 1911, as they both lack any projection on tergite IX. No species of Nilothauma from the Neotropical region have been named so far, although both larvae and pupa exuviae have been recorded repeatedly from Brazil. In the present paper we describe and figure four new species of Nilothauma from Brazil. Three of the species are described on male imagines only, while the fourth species also have associated pupal exuviae. The genus groups with the genera Neelamia Soponis, 1986 and Paranilothauma Soponis, 1986, both of which are restricted to the Neotropical region.

  12. 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.

  13. ENVIRONMENTAL REQUIREMENTS AND POLLUTION TOLERANCE OF COMMON FRESHWATER CHIRONOMIDAE

    Science.gov (United States)

    Data on the environmental requirements and pollution tolerance of 230 taxa of freshwater chironomids were compiled from 33 references. This compilation was prepared to assist biologists in evaluating data from macroinvertebrate samples collected for the assessment of water qualit...

  14. CHIRONOMIDAE TOXICITY TESTS--BIOLOGICAL BACKGROUND AND PROCEDURES

    Science.gov (United States)

    Toxicity tests must be based on an understanding of the test animal's life cycle. The first section of this report describes the biological information needed to develop toxicity test procedures. The second section describes three categories of toxicity test systems - short-expos...

  15. 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. PMID:25901113

  16. Parachironomus Lenz from China and Japan (Diptera, Chironomidae

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    Chuncai Yan

    2015-04-01

    Full Text Available Members of the genus Parachironomus Lenz known from China and Japan are revised, and a key to their male adults is given. Parachironomus poyangensis sp. n. is described in this life stage. Parachironomus frequens (Johannsen and P. monochromus (van der Wulp are recorded from China for the first time, thus are redescribed from Chinese specimens. Parachironomus kamaabeus Sasa & Tanaka and P. toneabeus Sasa & Tanaka are new junior synonyms of P. frequens. Three Chinese or Japanese species formerly placed in Parachironomus are transferred to other genera, resulting in the new combinations Cryptochironomus inafegeus (Sasa, Kitami & Suzuki, Demicryptochironomus (Irmakia lobus (Yan, Sæther, Jin & Wang, and Microchironomus lacteipennis (Kieffer. Chironomus sauteri Kieffer, Parachironomus kisobilobalis Sasa & Kondo and P. kuramaexpandus Sasa are removed from Parachironomus; the last of these three denotes a valid species of uncertain generic placement, the first two are nomina dubia.

  17. Genotoxic effect of Phenanthrene on Chironomus sancticaroli (Diptera: Chironomidae

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    Gisele dos Santos Morais

    2014-08-01

    Full Text Available Phenanthrene, a Polycyclic Aromatic Hydrocarbon, remains adsorbed to sedimentary particles in aquatic environments. It affects mainly benthic organisms, and is considered potentially genotoxic. In ecotoxicology, species of Chironomus Meigen, 1803 are widely known as bioindicators of the effects of chemicals on aquatic organisms. This study investigates the effects of phenanthrene on the size of the head capsule of Chironomus sancticaroli Strixino & Strixino, 1981 larvae after chronic (eight days exposure, and DNA damage after acute (96 hours and chronic exposure (eight days, under laboratory conditions. DNA damage, evaluated using the alkaline comet assay, detected effects for both exposure periods, indicating that phenanthrene is toxic for C. sancticaroli. For the acute exposure, we analyzed five concentrations of phenanthrene, between 0.16 mg.l-1 and 1.60 mg.l-1, detecting significant differences (Kruskall-Wallis test with p < 0.05 in the degree of DNA damage in all groups. These effects were not dose-dependent. For the chronic exposure, two concentrations (0.16 mg.l-1, 0.83 mg.l-1 were analyzed, and DNA damage was observed in both. Again, the effects were not dose-dependent. This indicates that phenanthrene is genotoxic to larvae of C. sancticaroli even at low concentrations. The size of the head capsule was evaluated after chronic exposure to concentrations of 0.16 mg.l-1 and 0.83 mg.l-1. Significant differences (ANOVA test with p < 0.05 were detected in the two concentrations, and a reduction in the size of the larval head capsule was observed. This suggests that phenanthrene causes delay in larval development. These results indicate that phenanthrene affects the development of and causes DNA damage in C. sancticaroli larvae. Therefore, we suggest that C. sancticaroli can be used as a biological indicator for environmental contamination with phenanthrene.

  18. Emergence of chironomidae in a newly impounded cooling reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Lauritsen, D. (Normandeau Associates, Inc., Aiken, SC (USA). Southeastern Regional Office)

    1990-01-01

    L Lake, a once-through cooling reservoir on the Savannah River Plant in South Carolina, was created in late 1985. Biological sampling, initiated in January 1986, included monthly emergence trap sampling in littoral regions. Chironomids were the most abundant insects emerging from L Lake in the first three years of sampling (1986--1988). Glyptotendipes lobiferus dominated emergence in all three years, although its relative abundance declined substantially after the first year (mean emergence was 6.38/m{sup 2}/day in 1986, and declined to 1.79 /m{sup 2}/day in 1988). The relative importance of other littoral chironomid species changed over the three years--facultative chironomids were most abundant in the first year, while in 1987 and 1988, community composition began to shift towards species that are considered to be less characteristic of enriched habitats. This benthic community succession'' is probably in part due to the shift in the food base from decomposing organic material (after impoundment) to autochthonous production (with increasing reservoir age). 11 refs., 6 figs., 3 tabs.

  19. New phytotelmic habitat of Metriocnemus eryngiotelmatus (Diptera: Chironomidae) Un nuevo hábitat de fitotelmata para Metriocnemus eryngiotelmatus (Diptera: Chironomidae)

    OpenAIRE

    Augusto Siri; Mariano Donato; Analía C. Paggi

    2008-01-01

    This is the first report of the non-biting midge Metriocnemus eryngiotelmatus Donato & Paggi 2005 associated to the impounded water of Dipsacus fullonum L. plants.Esta es la primera cita de Metriocnemus eryngiotelmatus Donato & Paggi 2005, asociado al agua almacenada en las axilas de Dipsacus fullonum L.

  20. Two new species of Goeldichironomus Fittkau from southeast Brazil (Diptera, Chironomidae) Duas novas espécies de Goeldichironomus Fittkau do sudeste do Brasil (Diptera, Chironomidae)

    OpenAIRE

    Susana Trivinho-Strixino; Giovanni Strixino

    2005-01-01

    The adult and immature stages of two new species of Goeldichironomus are described and figured. Larvae of G. luridus sp. nov., reared in the laboratory from egg masses, are abundant on organically enriched sediments of a chicken slaughter-house effluent treatment lagoon. Larvae of G. petiolicola sp. nov., live inside petioles of aquatic macrophytes such as Eichhornia azurea and Pontederia lanceolata.Os adultos e os estágios imaturos de duas novas espécies de Goeldichironomus são descritos e i...

  1. Two new species of Goeldichironomus Fittkau from southeast Brazil (Diptera, Chironomidae Duas novas espécies de Goeldichironomus Fittkau do sudeste do Brasil (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Susana Trivinho-Strixino

    2005-12-01

    Full Text Available The adult and immature stages of two new species of Goeldichironomus are described and figured. Larvae of G. luridus sp. nov., reared in the laboratory from egg masses, are abundant on organically enriched sediments of a chicken slaughter-house effluent treatment lagoon. Larvae of G. petiolicola sp. nov., live inside petioles of aquatic macrophytes such as Eichhornia azurea and Pontederia lanceolata.Os adultos e os estágios imaturos de duas novas espécies de Goeldichironomus são descritos e ilustrados. As larvas de G. luridus sp. nov., criadas em laboratório para obtenção dos adultos, habitam os sedimentos organicamente enriquecidos de uma lagoa de estabilização de um matadouro de aves. As larvas de G. petiolicola sp. nov., vivem no interior dos pecíolos de macrófitas aquáticas como Eichhornia azurea e Pontederia lanceolata.

  2. 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

    2016-01-01

    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. PMID:27395973

  3. Survivorship and longevity of Diamesa mendotae Muttkowski (Diptera: Chironomidae under snow

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    A.M. Anderson

    2013-04-01

    Full Text Available Diamesa mendotae Muttkowski commonly grow and emerge from groundwater dominated streams in winter. Previous estimates of longevity for adults of D. mendotae collected from the snow surface averaged 18.6 days post-collection, with 76.9% of individuals dying between Day 10 and Day 30 post-collection and 4.4% surviving over 40 days. Maximum longevities for males and females were 48 and 54 days, respectively. In this paper, we report survivorship and longevity of fieldcollected adults of D. mendotae kept at ambient snow temperature conditions. Adults (n=140 were collected in February from snow along groundwater-dominated sections of the Kinnickinnic River (Wisconsin, USA. All individuals were placed in vials, buried in snow, and retrieved in batches of 10 males and 10 females at 4-day intervals for 28 days. Once retrieved, adults were maintained at 6°C in controlled environmental chambers to determine survivorship and longevity. All individuals survived snow burial treatment, indicating they are capable of surviving sub-freezing field conditions for at least 28 days. Estimates of adult maximum longevity were as high as 66 days, higher than previous estimates for this genus. Our results suggest adults of D. mendotae can persist under snow cover, with high survivorship and longevity, potentially increasing their probability of successful reproduction in regions where lethal winter air temperatures occur.

  4. Mouthparts deformities in chironomid larvae (Chironomidae, Diptera) in Labe river basin in years 1993-1999

    International Nuclear Information System (INIS)

    We have studied the occurrences of mouth part deformities in chironomid larvae, which are regarded as a sublethal effect resulting from larval exposure to toxicants. These endpoint have been used in several cases as bio-indicator for sediment pollution. Material for the study was collected from eight localities of the rivers Labe and Vltava (six and two localities, respectively) in 1993, 1996 and 1999. We selected two common chironomid genera, Chironomus and Glyptotendipes, for the analysis of morphological abnormalities. We investigated two types of abnormalities: 1) apparent mechanical damage, and 2) abnormal deformities such as mentum gaps, split or missing teeth on the mentum, etc. We found a different occurrence of deformities between the two genera. We detected higher frequencies of deformities in populations of Chironomus larvae (0-57 %) than in populations of Glyptotendipes larvae (0-19 %). We suggest that the genus Chironomus is a more sensitive indicator of toxic stress. The highest frequency of mouth part deformities in chironomid larvae was detected in the middle part of the river Labe which is contaminated by various agricultural and industrial chemicals. (authors)

  5. Two new species and one new record of Parakiefferiella Thienemann, 1936 from China (Diptera, Chironomidae)

    Science.gov (United States)

    Liu, Wenbin; Sun, Bingjiao; Yan, Chuncai; Song, Chao; Wang, Xinhua

    2015-01-01

    Abstract Two new species of the genus Parakiefferiella Thienemann, 1936 (Parakiefferiella fasciata Liu & Wang, sp. n. and Parakiefferiella liupanensis Liu & Wang, sp. n.) are described as adult males from China. Parakiefferiella tamatriangulata Sasa is recorded from China for the first time. A key to the known adult males of Parakiefferiella from China is presented. The generic diagnosis of male Parakiefferiella given by Cranston et al. (1989) is emended. PMID:26798300

  6. Life cycle and production of chironomidae (diptera) in Biandantang, a typical macrophytic lake (Hubei, China)

    Science.gov (United States)

    Yun-Jun, Yan

    2000-09-01

    The life cycle and annual production of four dominant species of Chironomids ( Chironomus plumosus, Chironomus sp., Clinotanypus sp., Tokunagayusurika akamusi) were studied with samples taken monthly in Biandantang Lake at eight stations from April, 1996 to March, 1997. Instarfrequency data showed C. plumosus was univoltine, while the other three were bivoltine. Production in wet weight (g/(m2·a)) calculated by the size-frequency method for each species were: C. plumosus, 2.663; Chironomus sp., 1.161; Clinotanypus sp., 0.270; T. akamusi, 1.476. Based on the mean standing stock, their P/B ratios were 3.2, 4.0, 6.2, and 4.4, respectively.

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

    International Nuclear Information System (INIS)

    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)

  8. Thienemannia spiesi sp. nov., a crenophilous species from the Schapbach Quelle, Bavaria, Germany (Diptera: Chironomidae: Orthocladiinae

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    Joel Moubayed-Breil

    2016-06-01

    Full Text Available A description of the male and female imago and pupal exuviae of Thienemannia spiesi sp. nov. is provided based on material collected in the Schapbach Quelle (spring, Bavaria, Germany. This description increases the total number of species known worldwide in the genus to eleven. The new species, T. spiesi, can be distinguished from other related species (except T. libanica Laville and Moubayed 1985 by the following combination of characters: chaetotaxy of the wing membrane, inferior volsella nose-shaped and not sinuous, gonostylus bearing a crista dorsalis, spines present on tergite VII of the pupal exuviae. Comments on its ecology and taxonomic position are provided.

  9. INSECTICIDE EFFECTS ON NORMAL DEVELOPMENT AND HATCH OF EMBRYOS OF 'PARATANYTARSUS PARTHENOGENETICUS' (DIPTERA: CHIRONOMIDAE)

    Science.gov (United States)

    Simple, low cost methods are needed to determine the effect of pesticides on non-target aquatic organisms. In this report, embryos of Paratanytarsus parthenogeneticus were exposed from deposition to hatch to five pesticides. Four of the five pesticides affected development or hat...

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

    International Nuclear Information System (INIS)

    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)

  11. 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.

  12. Profundal chironomids (Chironomidae, Diptera) of mountain lakes in different stages of acidification (High Tatras, Slovakia)

    International Nuclear Information System (INIS)

    We have studied chironomid larvae in the profundal zone of mountain lakes of the High Tatras (Slovakia). Material was collected in 1987-1991 from 17 lakes representing different stages of acidification and various altitude levels (forest, subalpine, alpine lakes). We have found no relationship between acidification and total abundance and diversity of chironomids; these parameters were negatively correlated with maximum lake depth. Species composition, however, differed: Tanytarsus. gregarius gr, Zalutschia tatrica and Chironomus sp. occurred only in strongly acidified lakes; T. lugens gr. and Micropsectra spp. were present in non-acidified and acidified lakes. A comparison with the results of HRABE (1939, 1942) showed no significant changes in composition of chironomids: this suggests that some lakes were already affected by acidification at the beginning of 20th century. (authors)

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

    Science.gov (United States)

    Paul, Nilotpol; Mazumdar, Abhijit

    2015-01-01

    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. PMID:25947870

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

    Science.gov (United States)

    Zakrzewska, Marta; Giłka, Wojciech

    2015-01-01

    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. PMID:26624727

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

    International Nuclear Information System (INIS)

    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

  16. 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. PMID:26061223

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

    International Nuclear Information System (INIS)

    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/m2 (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 109 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)

  18. A new genus of Podonominae (Diptera: Chironomidae) in Late Eocene Rovno amber from Ukraine

    OpenAIRE

    Baranov, Viktor; Andersen, Trond; Perkovsky, Evgeny

    2014-01-01

    The genus Palaeoboreochlus Baranov et Andersen, n. gen. is erected based on P. inornatus Baranov et Andersen, n. sp. described from a male found in Late Eocene Rovno amber. The new genus groups with Boreochlus Edwards in the tribe "Boreochlini".

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

    Science.gov (United States)

    Pinho, Luiz Carlos; Andersen, Trond

    2015-01-01

    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. PMID:25947768

  20. 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)

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26701570

  2. Notes on Nilothauma Kieffer from Oriental China, with descriptions of three new species (Diptera, Chironomidae).

    Science.gov (United States)

    Qi, Xin; Tang, Hongqu; Wang, Xinhua

    2016-01-01

    Three new species of Nilothauma Kieffer are described and figured from Oriental China: Nilothauma angustum sp. n. based on the male only, Nilothauma aristatum sp. n. based on the male, pupa and larva, and Nilothauma bilobatum sp. n. based on the male and pupa. In addition, new distribution records are given for Nilothauma japonicum Niitsuma, Nilothauma nojirimaculatum Sasa, Nilothauma hibaratertium Sasa, and Nilothauma acre Adam & Sæther. A key to known males of Nilothauma Kieffer in China is provided. PMID:27110183

  3. TOXICITY OF VERTICAL SEDIMENTS IN THE TRENTON CHANNEL, DETROIT RIVER, MICHIGAN, TO CHIRONOMUS TENTANS (INSECTA: CHIRONOMIDAE)

    Science.gov (United States)

    The objective of this study was to determine the effects of sediment from various sediment core depths on survival and weight gain of larvae of the dipteran midge, Chironomus tentans, during 10-d laboratory exposures. ediment cores were collected from 12 sites in the Trenton Chan...

  4. 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.

  5. SURVIVAL AND GROWTH OF 'TANYTARSUS DISSIMILIS' (CHIRONOMIDAE) EXPOSED TO COPPER, CADMIUM, ZINC, AND LEAD

    Science.gov (United States)

    Tanytarsus dissimilis (Johannsen) was exposed to four heavy metals. Static exposure began during embryogenesis and continued through hatching and larval development to the 2nd or 3rd instar. The LC50 concentrations for cadmium, copper, and zinc were 3.8, 16.3, and 36.8 micrograms...

  6. Inventario de los Quironómidos (Diptera: Chironomidae) de Portugal

    OpenAIRE

    Cobo, Fernando; Soriano, Óscar; González González, Marcos A.

    2002-01-01

    Los autores quieres expresar su agradecimiento al Dr. Peter H. Langton por su inestimable ayuda en la recopilación de las citas de la fauna macaronésica, al Dr. Martin Spies por sus acertados comentarios sobre el estatus taxonómico de alguna de las especies aquí inventariadas, y al Dr. José Luis Pérez-Cirera por su atenta revisión del manuscrito.

  7. Three new species of Polypedilum Kieffer (Diptera: Chironomidae) from Neotropical region.

    Science.gov (United States)

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

    2015-01-01

    Three new species of Polypedilum from Brazil, belonging to subgenera Tripodura and Pentapedilum are described and illustrated. P. (Pe.) puri sp. n. and P. (Tr.) guato sp. n. are described based on male adults and P. (Tr.) kadiweu sp. n. on male adult, pupa and larva. PMID:25947755

  8. Two new species of Olecryptotendipes Zorina, 2007 from China (Diptera, Chironomidae)

    OpenAIRE

    Yan,Chuncai; Xinhua Wang; Wenjun Bu

    2012-01-01

    Abstract Two new species, Olecryptotendipes exilis sp. n. and Olecryptotendipes melasmus sp. n. are described and illustrated as males and Chinese males of Olecryptotendipes lenzi are re-examined. A key to all known males of Olecryptotendipes is provided.

  9. Two new species of Bryophaenocladius Thienemann, 1934 (Diptera, Chironomidae) from China

    OpenAIRE

    Xiaolong Lin; Xin Qi; Xinhua Wang

    2012-01-01

    Abstract Two new species of Bryophaenocladius Thienemann, 1934, Bryophaenocladius mucronatus sp. n. and Bryophaenocladius parictericus sp. n. are described and illustrated as males. A key to male imagines of the genus from China is presented.

  10. Typology of remote Tatra lakes (Slovakia) based on chironomid assemblages (Diptera: Chironomidae)

    International Nuclear Information System (INIS)

    A chironomid pupal exuviae technique was used to classify 22 selected remote mountain lakes in the Tatra Mts. Pupal exuviae were sampled in 2000-2002. Chironomid assemblages were ordinated by CCA. The relationship between chironomids and environmental parameters was significantly determined by three (amongst 14) environmental variables: altitude, pH and chlorophyll a content. According to correlation of environmental variables with canonical axes, three types of lake were distinguished and characteristic chironomid assemblages were described. Acidified lakes were found to have specific taxonomic composition without respect to differences in altitude. (authors)

  11. Cloning and expression of an atrazine inducible cytochrome P450 from Chironomus tentans (Diptera: Chironomidae)

    Science.gov (United States)

    Previous studies performed in our lab have measured the effect of atrazine exposure on cytochrome P450-dependent monooxygenase activity and have found increased activity in midge larvae (Chironomus tentans) as a result of atrazine exposure (1-10 ppm). Here we report the cloning and expression of a ...

  12. 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.

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

    International Nuclear Information System (INIS)

    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)

  14. Fossil midges (Diptera: Chironomidae) as palaeoclimatic indicators for the Eurasian region

    Science.gov (United States)

    Brooks, Stephen J.

    2006-08-01

    Chironomids (non-biting midges) have been used in palaeoenvironmental studies in Eurasia since the 1920s. Initially changes in chironomid assemblages were largely interpreted as a response to changes in trophic status or water depth. It was only with the advent of chironomid-temperature inference models in the early 1990s that their potential as palaeoclimatic indicators was fully exploited. This paper provides a brief review of the pioneering studies but focuses on the most recent advances. Better taxonomic resolution of fossil midges, expansion of modern training sets, use of air temperature data derived from meteorological stations rather than surface-water temperature data, and Bayesian statistical approaches have lead to improvements in the performance of chironomid-temperature transfer functions. Applications of these transfer functions to derive chironomid-inferred temperature estimates from Lateglacial (ca 15,000-11,200 cal. yr BP) and Holocene (11,200 cal. yr BP to Present) sequences from throughout Eurasia are reviewed in this paper. Chironomid-inferred Lateglacial reconstructions closely reflect oxygen isotope records from Greenland ice cores. Holocene reconstructions are less consistent. Some closely follow instrumental records or corroborate other proxy data, while other reconstructions are less successful. As a result of soil development during the Holocene, changes in pH, nutrients, DO and DOC had a greater influence than temperature on the composition of some midge assemblages. One way to mitigate this is through consensus temperature reconstructions from several sites in the same region. The challenge for future workers is for further improvement in taxonomic resolution of sub-fossil chironomid larvae, to improve further the performance of chironomid-temperature inference models, to develop training sets for southern Europe and Russia and to improve our understanding of the ecological responses of chironomids.

  15. 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.

  16. ACUTE AND CHRONIC EFFECTS OF ALUM TO MIDGE LARVA (DIPTERA: CHIRONOMIDAE)

    Science.gov (United States)

    The use of aluminum sulfate (alum) to precipitate phosphorus in highly eutrophic lakes is increasing. As use increases, the need to study the effects of alum on the biota increases. Possible adverse effects of alum on lake organisms may be due to chemical toxicity from dissolved ...

  17. Subfossil chironomid fauna (Diptera: Chironomidae) of Ladove Pleso Lake (High Tatra Mts., Slovakia)

    International Nuclear Information System (INIS)

    Subfossil chironomid remains (head capsules) taken from a 20.0 cm long sediment core from Ladove Pleso Lake (High Tatra Mts.) were studied. 19 291 head capsules were found and 9 chironomid taxa were identified. Analysis of the chironomid remains has revealed very stable taxonomic composition of the profundal community. The sub-fossil record was dominated by Micropsectra radialis (81.3 %), followed by Pseudodiamesa spp. (15.8 %). Other, very sparsely abundant taxa identified were Heterotrissocladius marcidus, Tanypodinae species indet., Bryophaenocladius, Chaetocladius/Parametriocnemus, Eukiefferiella, Or thocladius and Tokunagaia cf. f. l. rectangularis. The larvae of the Tokunagaia cf. f. l. rectangularis are rheophilous and cold stenothermic. Most species of Bryophaenocladius are terrestrial. Discover y of both taxa in the sediment core is coincidental. Heterotrissocladius marcidus is a common member of the profundal chironomid fauna of all investigated Tatra lakes. M. radialis is indicative of non-acidified conditions, and, together with Pseudodiamesa spp., also indicates ultraoligotrophic lake conditions throughout all of the investigated history of Ladove Pleso Lake. (authors)

  18. 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. PMID:27119557

  19. A new species of Smittia Holmgren, 1869 (Diptera: Chironomidae from Georgia, USA

    Directory of Open Access Journals (Sweden)

    Broughton A. Caldwell

    2015-07-01

    Full Text Available Smittia denotata sp. nov. is described from adult males collected during winter months from two Georgia locations. The immature stages and female are unknown. The species is readily recognizable by the distinctive long, basally microtrichose, tapered anal point with rounded apex, virga consisting of two separate spine clusters, and gonostylus with crista dorsalis and curved outer thorn-like projection.

  20. 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

  1. LIFE CYCLE AND PRODUCTION OF CHIRONOMIDAE(DIPTERA) IN BIANDANTANG, A TYPICAL MACROPHYTIC LAKE (HUBEI, CHINA)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The life cycle and annual production of four dominant species of Chironomids (Chironomus plumosus, Chironomus sp., Clinotanypus sp., Tokunagayusurika akamusi) were studied with samples taken monthly in Biandantang Lake at eight stations from April, 1996 to March, 1997. Instar-frequency data showed C. plumosus was univoltine, while the other three were bivoltine. Production in wet weight (g/(m2.a)) calculated by the size-frequency method for each species were: C. plumosus, 2.663; Chironomus sp.,1.161 ;Clinotanypus sp., 0.270; T. akamusi, 1.476. Based on the mean standing stock, their P/B ratios were 3.2, 4.0, 6.2 and 4.4, respectively.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Apedilum griseistriatum comb. nov., placement of Chironomus (Polypedilum griseistriatum (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Mariano Donato

    2015-03-01

    Full Text Available The study of the type material of Chironomus (Polypedilum griseistriatum Edwards, 1931 described from Patagonia lead us to formally transfer the species to Apedilum Townes, 1945 as a new combination, and a reared specimen allows us to describe its pupa. Based on several larvae belonging to Apedilum collected in the proximity of the localities in which the adults and pupae were found, we tentatively describe the larval stage. Subfossil larval head capsules of the same species were found in Laguna Stibnite at 46°S in Chile dated to about 2,500 years ago and in Puerto Blest, Lago Nahuel Huapi at 41°S in Argentina dated about 2,000 years ago. We discuss the habitat of the species based on both modern and subfossil material. Identification keys to male adult, pupae and fourth instar larvae are also provided.

  4. Polytene chromosomes of Chironomidae (Diptera as a bioassay of trace-metal-induced genome instability

    Directory of Open Access Journals (Sweden)

    Paraskeva Vladimirova Michailova

    2012-10-01

    Full Text Available Chironomids are a ubiquitous group of aquatic insects that are very sensitive to environmental stress. Due to the presence of polytene (‘giant’ salivary gland chromosomes, it is possible to define the genome response of several Chironomid species to various stress agents. The aim of this study was to assess the genotoxic changes in populations of widely distributed chironomid species from aquatic basins in Bulgaria, Italy, Russia, U.K. and Poland, which were exposed to high concentrations of trace metals. We analyzed the structural and functional alterations of polytene chromosomes of the salivary glands of larvae belonging to three different cytocomplexes of the genus Chironomus (“thummi”, “lacunarius”, “pseudothummi”, and genera Glyptotendipes and Kiefferulus. Somatic structural chromosome rearrangements (para- and pericentric heterozygous inversions, deletions, deficiencies and amplifications were used to estimate a Somatic index (S for each population. The highest S indexes were detected in Chironomus riparius populations from locations with high concentrations of trace metals in the sediment. Each species showed specific genome responses to stress agents which we discussed in the light of the specific DNA structures and cytogenetic characteristics of the species. In larvae from polluted sediments two key structures of the salivary gland chromosomes (Balbiani Rings and Nucleolar Organizer sharply reduced their activity to levels below those observed under non-polluted conditions. It is concluded that polytene chromosomes can be used as tools for evaluating the genotoxicity of the aquatic environment. Structural and functional chromosome alterations provide cost-effective early-warning signals of genotoxic concentrations of environmental pollutants.doi: 10.5324/fn.v31i0.1355.Published online: 17 October 2012.

  5. Rheotanytarsus dactylophoreus, a new mountain species from streams in the Eastern Pyrenees and Corsica (Diptera: Chironomidae)

    OpenAIRE

    Joel Moubayed-Breil; Peter H. Langton; Patrick Ashe

    2012-01-01

    The description of Rheotanytarsus dactylophoreus sp. nov. is based on adult males, pharate males and pupal exuviae collected in low and middle mountain streams located in the Eastern Pyrenees and Corsica is presented. The most distinctive character in the adult male is the unusually long, finger-like, digitus and in the pupal exuviae is the thoracic horn which is spinulate laterally (extending from swollen base into tapered apical half). The distribution of R. dactylophoreus sp. nov. indicate...

  6. Rheotanytarsus dactylophoreus, a new mountain species from streams in the Eastern Pyrenees and Corsica (Diptera: Chironomidae

    Directory of Open Access Journals (Sweden)

    Joel Moubayed-Breil

    2012-10-01

    Full Text Available The description of Rheotanytarsus dactylophoreus sp. nov. is based on adult males, pharate males and pupal exuviae collected in low and middle mountain streams located in the Eastern Pyrenees and Corsica is presented. The most distinctive character in the adult male is the unusually long, finger-like, digitus and in the pupal exuviae is the thoracic horn which is spinulate laterally (extending from swollen base into tapered apical half. The distribution of R. dactylophoreus sp. nov. indicates that this pyreneocorsican species is a Tyrrhenian faunal element which spread westwards to mountain streams of the Eastern Pyrenees perhaps during the repeated waves of migration from the Paleocene (Montian till the late Miocene.doi: 10.5324/fn.v31i0.1375.Published online: 17 October 2012.

  7. Eight New and Four Newly Recorded Species of Chironomidae (Insecta: Diptera from Korea

    Directory of Open Access Journals (Sweden)

    Han Il Ree

    2012-10-01

    Full Text Available Adult chironomids were collected by various methods, such as light traps, sweeping on grasses, aspiration of light-attracted adults, and sweeping of swarming males with insect nets at various localities. All collected specimens were slide-mounted and identified. I report eight species new to science: Chironomus jangchungensis n. sp., Demicryptochironomus paracamptolabis n. sp., Demicryptochironomus wontongensis n. sp., Microtendipes paratamagouti n. sp., Polypedilum macrohemisphere n. sp., Eukiefferiella busanensis n. sp., Psectrocladius paratogaminimus n. sp., and Pseudosmittia seosania n. sp. I also report four species for the first time in Korea: Chironomus fujiprimus Sasa, Pentapedilum convexum Johannsen, Tanytarsus smolandicus Brundin, and Tanytarsus oyamai Sasa. All species are fully described with illustrations. This is the first report of the genera Eukiefferiella and Pseudosmittia in Korea.

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

    International Nuclear Information System (INIS)

    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 35S-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)

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Complete mitochondrial genome of the Antarctic midge Parochlus steinenii (Diptera: Chironomidae).

    Science.gov (United States)

    Kim, Sanghee; Kim, Hanna; Shin, Seung Chul

    2016-09-01

    Parochlus steinenii is a winged midge found in the Antarctic Peninsula and its offshore islands. We determined the complete mitochondrial genome sequence of P. steinenii, which is comprised of 16 803 nucleotides and contains 13 protein-coding genes (PCGs), 22 tRNA genes, and the large (rrnL) and small (rrnS) rRNA genes. Its total A + T content is 72.5%. The PCG arrangement of P. steinenii is identical to that of the ancestral Diptera ground pattern. This is the first report on the mitogenome sequence of an Antarctic midge, and provides insights into the evolution of dipterans in Antarctica. PMID:26642812

  11. Chromosome analysis of chironomids (Diptera: Chironomidae – obligatory miners of freshwater sponges (Porifera

    Directory of Open Access Journals (Sweden)

    N Durnova

    2009-08-01

    Full Text Available Karyotypic characteristics of the chironomids Demeijerea rufipes (Linnaeus, 1761 and Xenochironomus sp., obligatory miners of freshwater sponges, are considered. The karyotype of Xenochironomus sp. is described for the first time. It is assumed that the ordered spatial organization of chromosomes of these species, expressed in terms of the presence of chromocentres of different degrees of stability and an almost complete absence of polymorphism for chromosome rearrangements, represents an adaptation to inhabiting host tissues, i.e. to habitat relative constancy.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Determination of larval instars in Chironomus sancticaroli (Diptera: Chironomidae) using novel head capsule structures

    OpenAIRE

    Vinicius S. Richardi; Débora Rebechi; José M. R. Aranha; Mário A. Navarro-Silva

    2013-01-01

    Determining the age composition of a population is important when conducting ecological, taxonomic and environmental assessments. Morphometric measurements of the head capsule, especially the length and width, are widely used in the identification of insect instars, but alternative ways for determining the age of insects can expand the options for the analysis of field and laboratory populations. This study evaluated the morphometry of the antennae, mandibles, mentum and ventromental plates t...

  14. Determination of larval instars in Chironomus sancticaroli (Diptera: Chironomidae using novel head capsule structures

    Directory of Open Access Journals (Sweden)

    Vinicius S. Richardi

    2013-04-01

    Full Text Available Determining the age composition of a population is important when conducting ecological, taxonomic and environmental assessments. Morphometric measurements of the head capsule, especially the length and width, are widely used in the identification of insect instars, but alternative ways for determining the age of insects can expand the options for the analysis of field and laboratory populations. This study evaluated the morphometry of the antennae, mandibles, mentum and ventromental plates to discriminate among the four larval instars of Chironomus sancticaroli Strixino & Strixino, 1981. The larvae were reared in the laboratory under constant temperature (25°C and photoperiod of 12/12 hours for 19 days, with a supply of food. Fifteen larvae were removed randomly every day, cleared in KOH, and slide-mounted, and had the antennae, mandibles, mentum and ventromental plates measured. The dimensions of the four structures studied allowed us to statistically distinguish each of the four larval instars. The data fit an exponential equation according to the Brooks-Dyar rule, which allows an estimate of the larval instar of specimens collected in the field, even when development takes place under different conditions. The duration of each instar was also obtained from our data, and showed an overlap of instars during development.

  15. 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 of...... the water bodies of Quito and Bogota differed significantly. There was no correlation between sample similarities and distances among the sites either. The low number of taxa recorded can be attributed to the combination of naturally limited species pool and the heavy pollution in natural water bodies...

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

    International Nuclear Information System (INIS)

    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)

  17. New species and records of Parametriocnemus Goetghebuer from China (Diptera, Chironomidae).

    Science.gov (United States)

    Li, Xing; Lin, Xiao-Long; Wang, Xin-Hua

    2013-01-01

    The Chinese species of Parametriocnemus Goetghebuer are reviewed. Two species, Parametriocnemus fortis sp. n. and Parametriocnemus vittatus sp. n. are described and illustrated as males, and Parametriocnemus ornaticornis (Kieffer), Parametriocnemus scotti (Freeman) and Parametriocnemus brundini Sinharay & Chaudhuri are recorded from China for the first time. A key to the males of the seven Chinese Parametriocnemus speciesis given. PMID:23950683

  18. New species and records of Parametriocnemus Goetghebuer from China (Diptera, Chironomidae)

    OpenAIRE

    Xing Li; Xiaolong Lin; Xinhua Wang

    2013-01-01

    Abstract The Chinese species of Parametriocnemus Goetghebuer are reviewed. Two species, Parametriocnemus fortis sp. n. and Parametriocnemus vittatus sp. n. are described and illustrated as males, and Parametriocnemus ornaticornis (Kieffer), Parametriocnemus scotti (Freeman) and Parametriocnemus brundini Sinharay & Chaudhuri are recorded from China for the first time. A key to the males of the seven Chinese Parametriocnemus speciesis given.

  19. New species and records of Parametriocnemus Goetghebuer from China (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Xing Li

    2013-07-01

    Full Text Available The Chinese species of Parametriocnemus Goetghebuer are reviewed. Two species, P. fortis sp. n. and P. vittatus sp. n. are described and illustrated as males, and P. ornaticornis (Kieffer, P. scotti (Freeman and P. brundini Sinharay & Chaudhuri are recorded from China for the first time. A key to the males of the seven Chinese Parametriocnemus species is given.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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

  2. 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.

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

    OpenAIRE

    Sebastião José de Oliveira; Maria da Conceição Messias; Adenildo da Silva-Vasconcelos

    1992-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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. PMID:26072670

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

    Institute of Scientific and Technical Information of China (English)

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

    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).

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

    Science.gov (United States)

    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)

  9. 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.

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

    Science.gov (United States)

    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.

  11. Germ line transformation and in vivo labeling of nuclei in Diptera: report on Megaselia abdita (Phoridae) and Chironomus riparius (Chironomidae).

    Science.gov (United States)

    Caroti, Francesca; Urbansky, Silvia; Wosch, Maike; Lemke, Steffen

    2015-06-01

    To understand how and when developmental traits of the fruit fly Drosophila melanogaster originated during the course of insect evolution, similar traits are functionally studied in variably related satellite species. The experimental toolkit available for relevant fly models typically comprises gene expression and loss as well as gain-of-function analyses. Here, we extend the set of available molecular tools to piggyBac-based germ line transformation in two satellite fly models, Megaselia abdita and Chironomus riparius. As proof-of-concept application, we used a Gateway variant of the piggyBac transposon vector pBac{3xP3-eGFPafm} to generate a transgenic line that expresses His2Av-mCherry as fluorescent nuclear reporter ubiquitously in the gastrulating embryo of M. abdita. Our results open two phylogenetically important nodes of the insect order Diptera for advanced developmental evolutionary genetics. PMID:26044750

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

    Science.gov (United States)

    Makarchenko, Eugenyi A; Makarchenko, Marina A

    2015-01-01

    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. PMID:26249914

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

    Science.gov (United States)

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

    2015-01-01

    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. PMID:26623616

  14. 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)

    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

  15. 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.; Jensen, Michael Tranekjær

    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...

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

    Science.gov (United States)

    Giłka, Wojciech; Dobosz, Roland

    2015-01-01

    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. PMID:26249942

  17. Environmental controls on the distribution and diversity of lentic Chironomidae (Insecta: Diptera) across an altitudinal gradient in tropical South America.

    Science.gov (United States)

    Matthews-Bird, Frazer; Gosling, William D; Coe, Angela L; Bush, Mark; Mayle, Francis E; Axford, Yarrow; Brooks, Stephen J

    2016-01-01

    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 distribution and diversity of chironomid species using surface sediments of 59 lakes from the Andes to the Amazon (0.1-17°S and 64-78°W) within the Neotropics. We assess the spatial variation in community assemblages and identify the key variables influencing the distributional patterns. The relationships between environmental variables (pH, conductivity, depth, and sediment organic content), climatic data, and chironomid assemblages were assessed using multivariate statistics (detrended correspondence analysis and canonical correspondence analysis). Climatic parameters (temperature and precipitation) were most significant in describing the variance in chironomid assemblages. Temperature and precipitation are both predicted to change under future climate change scenarios in the tropical Andes. Our findings suggest taxa of Orthocladiinae, which show a preference to cold high-elevation oligotrophic lakes, will likely see range contraction under future anthropogenic-induced climate change. Taxa abundant in areas of high precipitation, such as Micropsectra and Phaenopsectra, will likely become restricted to the inner tropical Andes, as the outer tropical Andes become drier. The sensitivity of chironomids to climate parameters makes them important bio-indicators of regional climate change in the Neotropics. Furthermore, the distribution of chironomid taxa presented here is a vital first step toward providing urgently needed autecological data for interpreting fossil chironomid records of past ecological and climate change from the tropical Andes. PMID:26811777

  18. The presence of species of Pseudochironomus Malloch 1915 (Diptera: Chironomidae) in watercourses of Chaco Serrano Ecoregion (Argentina, South America).

    Science.gov (United States)

    Paggi, Analía C; Rodriguez Garay, Gretel N

    2015-01-01

    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. PMID:26249080

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

    Science.gov (United States)

    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

  20. A novel computational approach of image analysis to quantify behavioural response to heat shock in Chironomus Ramosus larvae (Diptera: Chironomidae

    Directory of Open Access Journals (Sweden)

    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.

  1. A revised subgeneric position for Polypedilum (Probolum) simantokeleum, with description of a new Uresipedilum species in Japan (Diptera: Chironomidae).

    Science.gov (United States)

    Yamamoto, Nao; Yamamoto, Masaru

    2015-01-01

    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. PMID:26623588

  2. 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

    2015-01-01

    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. PMID:26623746

  3. Changes in carbon sources fueling benthic secondary production over depth and time: coupling Chironomidae stable carbon isotopes to larval abundance.

    Science.gov (United States)

    Frossard, Victor; Verneaux, Valérie; Millet, Laurent; Magny, Michel; Perga, Marie-Elodie

    2015-06-01

    Stable C isotope ratio (δ(13)C) values of chironomid remains (head capsules; HC) were used to infer changes in benthic C sources over the last 150 years for two French sub-Alpine lakes. The HCs were retrieved from a series of sediment cores from different depths. The HC δ(13)C values started to decrease with the onset of eutrophication. The HC δ(13)C temporal patterns varied among depths, which revealed spatial differences in the contribution of methanotrophic bacteria to the benthic secondary production. The estimates of the methane (CH4)-derived C contribution to chironomid biomass ranged from a few percent prior to the 1930s to up to 30 % in recent times. The chironomid fluxes increased concomitantly with changes in HC δ(13)C values before a drastic decrease due to the development of hypoxic conditions. The hypoxia reinforced the implication for CH4-derived C transfer to chironomid production. In Lake Annecy, the HC δ(13)C values were negatively correlated to total organic C (TOC) content in the sediment (Corg), whereas no relationship was found in Lake Bourget. In Lake Bourget, chironomid abundances reached their maximum with TOC contents between 1 and 1.5 % Corg, which could constitute a threshold for change in chironomid abundance and consequently for the integration of CH4-derived C into the lake food webs. Our results indicated that the CH4-derived C contribution to the benthic food webs occurred at different depths in these two large, deep lakes (deep waters and sublittoral zone), and that the trophic transfer of this C was promoted in sublittoral zones where O2 gradients were dynamic. PMID:25630956

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

    OpenAIRE

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

    2015-01-01

    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

  5. Diet and functional feeding groups of Chironomidae (Diptera in the Middle Paraná River floodplain (Argentina

    Directory of Open Access Journals (Sweden)

    M. Celeste Galizzi

    2012-06-01

    Full Text Available The gut contents of nine genera of benthic Chironominae and Tanypodinae from the Middle Paraná River floodplain habitats (a lake and a secondary channel were analyzed to determine their feeding patterns and functional feeding groups. Amorphous detritus, animal and vegetal tissues, and mineral materials (predominantly sand were observed in the larval guts. Amorphous detritus were the main food item found for Polypedilum (Tripodura sp., Chironomus gr. decorus sp., Endotribelos sp., Phaenopsectra sp., Cladopelma sp., and Pelomus sp. (Chironominae, while animal tissues (mainly oligochaetes were the most important food item found for Ablabesmyia (Karelia sp., Coelotanypus sp., and Procladius sp. (Tanypodinae. Dietary overlap was calculated for all pairs of genera. Within predators, the highest overlap was obtained between Coelotanypus sp. and Ablabesmyia (Karelia sp., while within detritivores the highest niche overlap was obtained between Endotribelos sp. and Phaenopsectra sp.

  6. New species of Paratanytarsus Thienemann & Bause 1913 (Diptera: Chironomidae from the Mediterranean Region (Corsica, southern France and Lebanon

    Directory of Open Access Journals (Sweden)

    Joel Moubayed-Breil

    2012-10-01

    Full Text Available Three new species of Paratanytarsus are described, from Corsica, southern France and Lebanon, based on the adult males and associated pupal exuviae. These descriptions increase the number of western Palaearctic species in the genus to 23. The pupal exuviae of the new species resemble those of P. bituberculatus (Edwards. Main diagnostic characters as well as additional illustrations of P. bituberculatus are also presented. Characters are given for distinguishing the adult males and the pupal exuviae from other related species. A key to the adult males and pupal exuviae of the described species is provided.doi: 10.5324/fn.v31i0.1372.Published online: 17 October 2012.

  7. New species of Paratanytarsus Thienemann & Bause 1913 (Diptera: Chironomidae) from the Mediterranean Region (Corsica, southern France and Lebanon)

    OpenAIRE

    Joel Moubayed-Breil; Patrick Ashe; Peter H. Langton

    2012-01-01

    Three new species of Paratanytarsus are described, from Corsica, southern France and Lebanon, based on the adult males and associated pupal exuviae. These descriptions increase the number of western Palaearctic species in the genus to 23. The pupal exuviae of the new species resemble those of P. bituberculatus (Edwards). Main diagnostic characters as well as additional illustrations of P. bituberculatus are also presented. Characters are given for distinguishing the adult males and the pupal ...

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

    Science.gov (United States)

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

    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.

  9. Characterization of Chironomidae (Diptera) surface-floating pupal exuviae sample sort time from coastal tropical aquatic systems.

    Science.gov (United States)

    Kranzfelder, Petra; Ferrington, Leonard C

    2015-03-01

    Many studies either ignore chironomids or only identify specimens to subfamily or tribe due to the associated difficulty and high cost with processing and identifying larvae. An efficient form of sampling chironomids involves collections of surface-floating pupal exuviae (SFPE). SFPE sample sorting has been shown to be more time efficient than traditional dip-net methods in temperate urban and peri-urban streams. However, no published studies have tested the time efficiency of SFPE sample sorting from coastal tropical aquatic systems. We calculated sort times for SFPE samples collected from a coastal tropical stream and an estuary and used multiple linear regression analysis to quantify the relationship between sample sort time and number of specimens, average body length of specimens, and dry weight of sample residue. The average amount of time required to sort very small samples was 69.3 min, while moderate samples averaged 85.6 min and large samples averaged 153.5 min. However, on average, small samples were nine times more time consuming per specimen than large samples. Additionally, dry weight of small-sized residue and the number of specimens contributed significantly to sort time. Therefore, we recommend collecting larger samples, which can be achieved by sampling for 20 min over 200-m reaches for stream sites and 500- to 1,000-m reaches for riverine and estuarine sites. Also, we suggest collecting during periods of low wave action and disturbance by boat wake to reduce the amount of sample residue. This research will enhance project planning and budgeting of future studies using the SFPE method to monitor coastal tropical aquatic systems. PMID:25647801

  10. Morpho-histological characterization of immature of the bioindicator midge Chironomus sancticaroli Strixino and Strixino (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    Vinicius Sobrinho Richardi

    2015-09-01

    Full Text Available ABSTRACTChironomidae immature are used as bioindicators of sediment quality in aquatic ecosystems and ecotoxicological assays. Histological descriptions for this family are outdated and limited and there are no studies with Neotropical species. The aim of this study was to describe the tissue architecture of several organs of the larva of Chironomus sancticaroli. For the description of the histological pattern, the larvae were fixed in Duboscq solution for insects at 56 °C, followed by routine histologic processing, infiltration in paraffin, and the sections were stained with Hematoxylin–Eosin. After examining the slides, the tube digestive, salivary gland, excretory, nervous, endocrine, circulatory, and integumentary systems and fat body were histologically characterized. The histology allows evaluation of cell morphology, and for being not expensive and easily accessible can be routinely used in biomonitoring. In addition, is a useful tool in ecotoxicological assays and allow to evaluate biomarkers at tissue and cell levels.

  11. Morpho-histological characterization of immature of the bioindicator midge Chironomus sancticaroli Strixino and Strixino (Diptera, Chironomidae)

    OpenAIRE

    Vinicius Sobrinho Richardi; Maiara Vicentini; Débora Rebechi; Luis Fernando Fávaro; Mário Antônio Navarro-Silva

    2015-01-01

    ABSTRACTChironomidae immature are used as bioindicators of sediment quality in aquatic ecosystems and ecotoxicological assays. Histological descriptions for this family are outdated and limited and there are no studies with Neotropical species. The aim of this study was to describe the tissue architecture of several organs of the larva of Chironomus sancticaroli. For the description of the histological pattern, the larvae were fixed in Duboscq solution for insects at 56 °C, followed by routin...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  14. TOXICITY OF TWO HERBICIDES 2,4 -D DIMETHYLAMINE AND BENSULFURON METHYL TO RICE FIELD CHIRONOMUS KIIENSIS (TOKUNAGA) ( DIPTERA: CHIRONOMIDAE)

    Institute of Scientific and Technical Information of China (English)

    Al-Shami S A; Che Salmah M R; Siti Azizah M N; Abu Hassan A; Azmi M

    2006-01-01

    Fourth instar larvae of Chironomus kiiensis(Tokunaga) were exposed to various concentrations of two commonly used herbicides: 2,4 - D Dimethylamine and Bensulfuron methyl in the rice fields. The bioassay experiment was carried out in a rearing unit in the laboratory at a room temperature ( (27 ± 2) ℃ ). A thin layer of sand sediments and tissue papers were provided as substrate in each unit. Each concentration of all herbicides was prepared in 250 mL distilled water. The experiment was performed in triplicate and 20 chironomid larvae were placed in each rearing unit. The larvae were fed with fish food (Sanyuichiban(R)) at 2 d intervals and all units were aerated by air pumps. The experiment was monitored every 24 h for mortality of C. kiiensis. The 2,4 - D Dimethylamine bioassay was carried out for 24 h while Bensulfuron methyl was run for 72 h. Dead larvae, pupae and living or dead adults were counted and removed daily.The LC50 of 2,4 - D Dimethylamine was 2 638 mg ai L-1, more than 2 000 times higher than the recommended dose of 0.753 mg ai L-1 used for controlling weeds in the rice field. Bensulfuron methyl was more toxic than the 2,4 - D Dimethylamine. The LC50 of the Bensulfuron methyl was recorded at 1.29 mg ai L-1, and approximately was more 20 times than that of the recommended dose of 0. 057 mg ai L-1. Bensulfuron methyl was found to be slow acting. The mortality of the larvae was only observed after 72 h. However, this herbicide interfered with the emergence of C. kiiensis to adults at and above the recommended dose used in the rice fields. Based on their LC50 values, this study showed that applying these herbicides in the rice fields at doses recommended by the manufacturers was safe for C. kiiensis and presumably to other living organisms in the water.

  15. Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

    OpenAIRE

    Lagauzère, Sandra; Pischedda, Laura; Cuny, Philippe; Gilbert, Franck; Stora, Georges; Bonzom, Jean-Marc

    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 s...

  16. Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination.

    Science.gov (United States)

    Lagauzère, S; Pischedda, L; Cuny, P; Gilbert, F; Stora, G; Bonzom, J-M

    2009-04-01

    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 72h, 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. PMID:19121883

  17. The Tanytarsini (Diptera: Chironomidae) in the collection of the Museum of Amber Inclusions, University of Gdańsk.

    Science.gov (United States)

    Zakrzewska, Marta; Giłka, Wojciech

    2015-01-01

    Non-biting midges of the tribe Tanytarsini collected in the Museum of Amber Inclusions, University of Gdańsk, Poland, are reviewed. Among over 1500 chironomid specimens examined (inclusions in Baltic amber), 44 Tanytarsini individuals were found, of which 27 well preserved specimens were determined to 7 species, including 3 species described as new. Stempellinella electra sp. nov. (male) displays morphological hypopygial characters unique for the genus, and the antenna composed of 13 flagellomeres. A new checklist of fossil and extant species of this genus is also given, including Stempellinella sofiae (Fusari et Lamas, 2014) comb. nov. Tanytarsus glaesarius sp. nov. (male) is the only Eocene species of the genus with a reduced number of antennal flagellomeres. Tanytarsus protogregarius sp. nov. (male) is the oldest known representative of the gregarius species group. Notes on phylogenetic relations of the new species with their extant congeners are also provided. PMID:25947696

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

    OpenAIRE

    Milca PETROVICI; Maria - Mirela BOGDĂNESCU; Mălina PÎRVU

    2012-01-01

    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 the...

  19. Some observations of buccal deformities in chironomid larvae (diptera: chironomidae) from the ciénaga grande de santa marta, colombia

    OpenAIRE

    RISS WOLFGANG; KAHLHEBER ANTJE; WERDING BERND

    2013-01-01

    The mouthpart deformities of chironomid larvae are considered as indicators ofenvironmental stress caused by water pollution such as heavy metals, pesticides, butas well by organic contamination. In the present study larvae from the side channelsof the Ciénaga Grande de Santa Marta were investigated. The chironomid communityof the channels are dominated by species of the genera Goeldichironomus andChironomus. All together 21 taxa were determined. The average proportion of mouthpartdeformities...

  20. Chromosome analysis of Endochironomus albipennis Meigen, 1830 and morphologically similar Endochironomus sp. (Diptera, Chironomidae) from water bodies of the Volga region, Russia

    Science.gov (United States)

    Durnova, Natalya; Sigareva, Ludmila; Sinichkina, Olga

    2015-01-01

    Abstract Based upon the detailed chromosome map of polytene chromosomes of the eurybiont species Endochironomus albipennis Meigen, 1830, the localization of the centromere regions using a C-banding technique is defined. Chromosomal polymorphism in populations from two water bodies in the Volga region has been studied, 17 sequences are described. Polytene chromosomes of Endochironomus sp. (2n=6), having larvae morphologically similar to those of Endochironomus albipennis Meigen, 1830 (2n=6) are described for the first time. PMID:26752268

  1. Loss of centromeric histone H2AT120 phosphorylation accompanies somatic chromosomes inactivation in the aberrant spermatocytes of Acricotopus lucidus (Diptera, Chironomidae).

    Science.gov (United States)

    Staiber, Wolfgang

    2016-01-01

    In the germ line of the chironomid Acricotopus lucidus, two cells with quite different chromosome constitutions result from the last unequal gonial mitosis. In the male, the future primary spermatocyte receives all the germ line-limited chromosomes (=Ks) together with somatic chromosomes (=Ss), and later on undergoes meiotic divisions, while the connected aberrant spermatocyte gets only Ss and remains undivided with chromosomes inactivated in a metaphase-like condensed state. This raises the question whether the centromeres of the permanently condensed Ss of the aberrant spermatocyte remain active during meiosis of the connected regular spermatocyte. Active centromeres exhibit an epigenetic phosphorylation mark at threonine 120 of histone H2A. To visualise the centromeric H2A phosphorylation of the Ss in the aberrant spermatocyte, meiotic stages were immunostained with different anti-phospho histone H2AT120 antibodies. Clear H2AT120ph signals appear at the centromeres of the Ss during prophase, persist on the metaphase-like condensed Ss during meiosis I of the connected primary spermatocyte and disappear during transition to meiosis II. The centromeres of the Ss and Ks of the regular spermatocytes display H2AT120ph signals from prophase I to anaphase II. The loss of the H2AT120 phosphorylation detected on the centromeres of the Ss of the aberrant spermatocyte indicating their deactivation supports the idea of a programmed inactivation of the Ss to block the entry of the germ line-derived aberrant spermatocyte, lacking Ks, into meiosis, and thus to prevent the generation of sperms possessing only Ss. This mechanism would ensure the presence of the Ks in the germ line. PMID:25820679

  2. 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)

    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

  3. 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.

  4. Multi-scale approach to the environmental factors effects on spatio-temporal variability of Chironomus salinarius (Diptera: Chironomidae) in a French coastal lagoon

    Science.gov (United States)

    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.

  5. USING delta15N OF CHIRONOMIDAE TO HELP ASSESS CONDITION AND STRESSORS IN LAKES, RIVERS AND STREAMS OF THE UNITED STATES.

    Science.gov (United States)

    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...

  6. 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

    Science.gov (United States)

    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.

  7. Diagnoses for Nubensia, n. gen. (Diptera, Chironomidae, Chironomini), with the first full descriptions of the adult female and larva of N. nubens (Edwards, 1929).

    Science.gov (United States)

    Spies, Martin; Dettinger-Klemm, Andreas

    2015-01-01

    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. PMID:26250262

  8. ELISA detection of multixenobiotic resistance transporter induction in indigenous freshwater Chironomidae larvae (Diptera): A biomarker calibration step for in situ monitoring of xenobiotic exposure

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. 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)

    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

  10. A review of Norwegian Gymnometriocnemus (Diptera, Chironomidae) including the description of two new species and a new name for Gymnometriocnemus volitans (Goetghebuer) sensu Brundin

    Science.gov (United States)

    Stur, Elisabeth; Ekrem, Torbjørn

    2015-01-01

    Abstract Examination of the syntypes of Metriocnemus volitans Goetghebuer, 1940 revealed that these specimens belong to the genus Chaetocladius and are not con-specific with Gymnometriocnemus volitans (Goetghebuer, 1940) sensu Brundin (1956) and Sæther (1983). A literature search showed that Gymnometriocnemus kamimegavirgus Sasa & Hirabayashi, 1993 fits well with the species figured and diagnosed by Brundin (1956) as well as with specimens of this species from Norway. We present arguments for Chaetocladius volitans (Goetghebuer) comb. n. and for the use of Gymnometriocnemus kamimegavirgus for Gymnometriocnemus volitans sensu Brundin. In addition, we provide DNA barcode data that indicate the presence of at least seven Gymnometriocnemus species in Norway of which six are collected as male adults. Two of these, Gymnometriocnemus (Gymnometriocnemus) pallidus sp. n. and Gymnometriocnemus (Raphidocladius) autumnalis sp. n. are regarded as new to science and diagnosed based on adult male morphology and DNA barcodes. The species Gymnometriocnemus (Gymnometriocnemus) marionensis Sæther, 1969 is re-established and a key to all Holarctic species is provided. PMID:26167125

  11. Characterization of six small HSP genes from Chironomus riparius (Diptera, Chironomidae): Differential expression under conditions of normal growth and heat-induced stress.

    Science.gov (United States)

    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. PMID:26129721

  12. A review of Rheocricotopus (Psilocricotopus chalybeatus species group from China, with the description of three new species (Diptera, Chironomidae

    Directory of Open Access Journals (Sweden)

    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.

  13. 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...

  14. 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.

  15. 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...

  16. 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)

    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

  17. Revealing the Biodiversity in Chironomidae (Diptera): Results From an Emergence Trap Study of a Ravine Spring-run in Northern Florida

    Science.gov (United States)

    Caldwell, B. A.; Rasmussen, A. K.; Pescador, M. L.

    2005-05-01

    Research for this project was conducted as part of a larger scale investigation of the aquatic insect fauna of a Florida spring-run ravine system that focused especially on stonefly and caddisfly taxa. The present research focused largely on documenting chironomid midge species diversity, emergence phenology, and overall composition by utilizing repeated emergence trap sampling at a single site within a first order, forested ravine stream in the Florida panhandle area. The approximate two year survey revealed a rich and distinctive chironomid fauna, with a variety of feeding types and microhabitat specific taxa. Many of the study species were considered to be common and widespread; however, several species and two genera were new records for the state. Several undescribed species were also noted. Emergence occurred in all months but with greatest densities generally recorded from December through March of the second year. The single location examined to date on this ravine stream ranks near the upper range of chironomid species richness reported on a world-wide basis for first order lotic systems. Other aspects of composition and apparent community patterns, was well as the importance and significance of first order stream biodiversity, are examined and discussed.

  18. Taxonomic study on the subgenus Uresipedilum (Diptera: Chironomidae: Polypedilum, with description of a new species from the Yaewyama Islands, Okinawa, Japan

    Directory of Open Access Journals (Sweden)

    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.

  19. 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)

    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.

  20. Cytogenetic index and functional genome alterations in Chironomus piger Strenzke (Diptera, Chironomidae) in the assessment of sediment pollution: a case study of Bulgarian and UK rivers.

    Science.gov (United States)

    Michailova, P; Ilkova, J; Dean, A P; White, K N

    2015-01-01

    The genotoxicity of trace metals in the sediments from a number of polluted sites on UK and Bulgarian rivers to Chironomus piger was assessed by an examination of genome instability as demonstrated by structural and functional changes to the salivary glands chromosomes. Based on the metal assays, the sediments were characterized to range from 'extremely' to 'strongly contaminated'. The cytogenetic index calculated on the basis of somatic structural chromosome alterations in the polytene chromosomes indicates a high level of pollution (0.07-0.06 in Bulgarian and 0.10-0.13 in UK stations). Exposure of C. piger to contaminated sediments resulted in a high level of chromosome damage as indicated by a somatic index of between 1.96 and 4.0. The transcription mechanism of the Balbiani rings and nucleolar organizer was damaged as their activity was either partially or completely suppressed. We have demonstrated that the C. piger genome is a sensitive sublethal indicator of sediment contamination, and is a highly suitable candidate for ecotoxicological monitoring of running waters. PMID:25450937

  1. Functional and structural rearrangements of salivary gland polytene chromosomes of Chironomus riparius Mg. (Diptera,Chironomidae) in response to freshly neutralized aluminium.

    Science.gov (United States)

    Michailova, P; Ilkova, J; White, K N

    2003-01-01

    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 microg 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. PMID:12628199

  2. Evaluation of mentum deformities of Chironomus spp. (Chironomidae: Diptera) larvae using modified toxic score index (MTSI) to assess the environmental stress in Juru River Basin, Penang, Malaysia.

    Science.gov (United States)

    Al-Shami, Salman Abdo; Salmah, Mad Rawi Che; Hassan, Ahmad Abu; Azizah, Mohd Nor Siti

    2011-06-01

    Morphological mentum deformities which represent sublethal effect of exposure to different types of pollutants were evaluated in Chironomus spp. larvae inhabiting three polluted rivers of Juru River Basin in northwestern peninsular Malaysia. Using mentum deformity incidences, the modified toxic score index (MTSI) was developed based on Lenat's toxic score index (TSI). The suggested MTSI was compared with TSI in terms of its effectiveness to identify different pollutants including heavy metals. The MTSI showed stronger relationship to total deformity incidence expressed as percentage. Additionally, the multivariate RDA model showed higher capability of MTSI to explain the variations in heavy metal contents of the river sediments. The MTSI was recommended in bioassessment of water and sediment quality using the mentum deformities of Chironomus spp. larvae from aquatic ecosystems receiving anthropogenic, agricultural, or industrial discharges. PMID:20697808

  3. A New Species Group in the Genus Tanytarsus van der Wulp(Diptera:Chironomidae)Based on a Fossil Record from Baltic Amber

    Institute of Scientific and Technical Information of China (English)

    Wojciech GI(L)KA

    2010-01-01

    A new fossil chironomid,Tanytarsus serafini,found in Baltic amber is described and illustrated based on adult males.The new species and similar extant species of the genus Tanytarsus van der Wulp are compared.Due to several distinct characters of wing,legs and hypopygium,a new species group for Tanytarsus serafini is proposed,and its diagnostic features are evaluated.

  4. 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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    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 life cycle, 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 <10 g/m2.a. All the production temporal variation tended to follow biomass patterns. T. discoloripes, Chaetocladius sp. and Pagastia sp. concentrated most of their production in winter, whereas E. potthasti, Pentaneura sp. and Polypedilum sp. had relatively higher production throughout the year. Only Microtendipes sp. had a production that peaked in summer.The overlap in temporal distribution of production among the chironomid species was generally high (>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.

  5. Ecological and Genetic Relationship of Chironomus circumdatus (Diptera, Chironomidae From Mitochondrial Cytochrome Oxidase Subunit I in Chiang Mai Province, Northern Thailand

    Directory of Open Access Journals (Sweden)

    W. Roongruangwongse

    2012-04-01

    Full Text Available This study provides means for more accurate identification of Chironomus circumdatus species for environmental and ecological management by Population of C. circumdatus (86 individuals and water samples were collected from three different sites of Chiang Mai Province, Thailand. Specimens of Einfeldia sp. were used as an initial out group. The genetic relationship of C. circumdatus specimens from these sources was determined by using DNA sequence analysis of partial mtDNA gene’s Cytochrome Oxidase Subunit I (COI. Analysis of genetic distance on the basis of sequence difference for COI mitochondrial gene showed very little genetic difference and the data from phylogenetic analysis revealed a very large genetic difference among all populations of this species for the COI gene sequences. In addition, NJ tree was related to with physicochemical parameters of the water samples.

  6. First record and ecological features of Goeldichironomus petiolicola (Diptera: Chironomidae mining Eichhornia crassipes in the Middle Paraná River floodplain, Argentina Primer registro y aspectos ecológicos de Goeldichironomus petiolicola (Diptera: Chironomidae minador de Eichhornia crassipes en la llanura aluvial del río Paraná Medio, Argentina

    Directory of Open Access Journals (Sweden)

    Luciana Montalto

    2012-06-01

    Full Text Available The first records from Argentina of larvae of Goeldichironomus petiolicola Trivinho-Strixino & Strixino mining in Eichhornia crassipes (Martius Solms petioles in wetlands of the Paraná River floodplain were analyzed. G petiolicola larvae and pupae were collected seasonally during 2005 from stands of E. crassipes and bottom sediment samples in floodplain habitats. Larvae inside E. crassipes petioles were reared with the purpose of obtaining their complete life cycle. G. petiolicola was the most abundant chironomid species living inside E. crassipes petioles; the III and IV instar larvae and pupae were found during all the seasons while the I and II instar larvae were not found. The highest average densities of G. petiolicola larvae inside the E. crassipes petioles were recorded in Autumn-Winter (588.5 ind.kg-1 dw - 778.7 ind.kg-1 dw. This suggests that they have better conditions for survival, allowing the individuals to develop more slowly until the next flooded period with higher temperatures. The r (Dyar value obtained was 1.66. We conclude that G. petiolicola mines into E. crassipes petioles mainly when the plants begin their senescence process and does not cause important damage to them.Se presenta el primer registro para Argentina de Goeldichironomus petiolicola Trivinho-Strixino & Strixino, especie cuyos estadios inmaduros minan dentro de los pecíolos de Eichhornia crassipes (Martius Solms, en humedales del río Paraná Medio. Las larvas y pupas de G petiolicola fueron recolectadas estacionalmente durante 2005, de los stands de E. crassipes y en muestras de sedimento en diferentes ambientes de la llanura. Ejemplares de la especie fueron criados en laboratorio a fin de completar su ciclo de vida. G petiolicola fue el quironómido más abundante que habita en el interior de los pecíolos de E. crassipes, se registraron los estadios de larva III y IV y pupa durante todas las estaciones. No fueron registrados los estadios larvales I y II. Las mayores densidades medias de G petiolicola fueron obtenidas en otoño-invierno (588,5 ind.kg¹ dw - 778,7 ind.kg¹ dw, esto sugiere que presentan mejores condiciones para la supervivencia, lo que permite a los individuos obtener un desarrollo más lento hasta el próximo período de inundación, con mayores temperaturas. El valor calculado de r (Dyar fue 1,66. G petiolicola mina dentro de los pecíolos de E. crassipes, principalmente, durante el inicio del proceso de senescencia del vegetal, por lo que no provoca daños importantes.

  7. First record and ecological features of Goeldichironomus petiolicola (Diptera: Chironomidae) mining Eichhornia crassipes in the Middle Paraná River floodplain, Argentina Primer registro y aspectos ecológicos de Goeldichironomus petiolicola (Diptera: Chironomidae) minador de Eichhornia crassipes en la llanura aluvial del río Paraná Medio, Argentina

    OpenAIRE

    Luciana Montalto; Soledad Capello; Analía C. Paggi

    2012-01-01

    The first records from Argentina of larvae of Goeldichironomus petiolicola Trivinho-Strixino & Strixino mining in Eichhornia crassipes (Martius) Solms petioles in wetlands of the Paraná River floodplain were analyzed. G petiolicola larvae and pupae were collected seasonally during 2005 from stands of E. crassipes and bottom sediment samples in floodplain habitats. Larvae inside E. crassipes petioles were reared with the purpose of obtaining their complete life cycle. G. petiolicola was the mo...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    Gerson A. Müller; Fernando T. Name; Frederico C.L. Pacheco; Carlos B. Marcondes

    2010-01-01

    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. ...

  10. Pakomáři rodu .i.Chironomus./i. MEIGEN (Diptera, Chironomidae) v Novohradských horách (jižní Čechy)

    Czech Academy of Sciences Publication Activity Database

    Matěna, Josef; Matěnová, V.

    České Budějovice : Jihočeská univerzita a Entomologický ústav AV ČR, 2002 - (Papáček, M.), s. 241-244 ISBN 80-7040-524-4. [Biodiverzita a přírodní podmínky Novohradských hor.. Nové Hrady (CZ), 10.01.2002-11.01.2002] R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6017912 Keywords : chironomus * macrozoobenthos * ecology Subject RIV: EH - Ecology, Behaviour

  11. 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.

  12. Tegundafjölbreytni og útbreiðsla rykmýssamfélaga (Chironomidae) í fjöruvist stöðuvatna á Íslandi

    OpenAIRE

    Erlín Emma Jóhannsdóttir 1975

    2016-01-01

    Rykmý er ríkjandi botndýrahópur í fjöruvist stöðuvatna á Íslandi og er mikilvægur hlekkur í vistkerfum vatna. Þrátt fyrir það hafa fáar rannsóknir farið fram á rykmýi í fjöruvist vatna hér á landi. Markmið þessarar rannsóknar var að lýsa samfélögum og útbreiðslu rykmýs í fjöruvist stöðuvatna á Íslandi og kanna hvaða umhverfisþættir móta helst samfélög rykmýs. Rykmýslirfum var safnað af steinum í fjöruvist 34 vatna og þær greindar til tegunda og fæðuöflunarhópa. Þrjátíu og átta tegundir rykmýs...

  13. Spatio-temporal effects of selected physico-chemical variables of water, algae and sediment chemistry on the larval community of nuisance Chironomidae (Diptera) in a natural and a man-made lake in central Florida

    Czech Academy of Sciences Publication Activity Database

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

    2002-01-01

    Roč. 470, - (2002), s. 181-193. ISSN 0018-8158 Institutional research plan: CEZ:AV0Z6066911 Keywords : community structure * chironomid midges * variation partitioning Subject RIV: EH - Ecology, Behaviour Impact factor: 0.694, year: 2002

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

    OpenAIRE

    Gizelle Amora; Neusa Hamada; Lívia Maria Fusari; Vanderly Andrade-Souza

    2015-01-01

    Abstract 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 Tok...

  15. Evaluation of long term effects of thermal effluents on stream biota

    International Nuclear Information System (INIS)

    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

  16. Chironomid larvae inhabiting bromeliad phytotelmata in a fragment of the Atlantic Rainforest in Rio de Janeiro State.

    Science.gov (United States)

    Sodré, V M; Rocha, O; Messias, M C

    2010-08-01

    A study of chironomids (Diptera, Chironomidae) occurring in phytotelmata of Bromeliaceae was carried out in a fragment of the Atlantic Rain Forest in an area of the city of Magé, Pau Grande, one of the metropolitan areas of Rio de Janeiro City, during a period of 13 months between September 2006 and September 2007. Eight samplings were performed at intervals of 1 (1/2) months and the content of the phytotelmata of the bromeliad species Neoregelia concentrica (Vellozo) L.B. Smith, 1934 and Aechmea nudicaulis (Linnaeus) Grisebach, 1864, were examined. A taxonomical inventory and evaluation of the numerical abundance of Chironomidae larvae were performed in 50 specimens of the bromeliads, being 13 individuals of N. concentrica and 37 of A. nudicaulis. Three taxa of Chironomidae belonging to three distinct subfamilies were recorded: Polypedilum sp., Orthocladiinae genus A and Monopelopia sp. A total of 293 individuals of Chironomidae, were recorded, being 9 Polypedilum sp., 233 Orthocladiinae genus A, and 51 Monopelopia sp., the latter representing the first record of Monopelopia in phytotelmata in Rio de Janeiro State. Considering all samples, a mean density of 3.32 +/- 2.62 chironomid larvae per phytotelmata was recorded. There was a positive relationship between the chironomid abundance and both precipitation and the volume of water in the phytotelmata. Apparently there is no preference by the chironomids regarding the colonistion of the bromeliad species. PMID:20730345

  17. Influence of selected sediment physical parameters on spatial distribution of larval .i.Glyptotendipes paripes./i. (Diptera: Chronomidae) in three central Florida lakes

    Czech Academy of Sciences Publication Activity Database

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

    2007-01-01

    Roč. 90, č. 4 (2007), s. 593-604. ISSN 0015-4040 Institutional research plan: CEZ:AV0Z60660521 Keywords : Chironomidae * sediments * larval distribution Subject RIV: EH - Ecology, Behaviour Impact factor: 0.687, year: 2007

  18. 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; Flindt, Mogens; Kristensen, Erik

    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...

  19. NEW RECORDS AND RANGE EXTENSIONS FOR SEVERAL CHIRONOMID GENERA IN LAKE SUPERIOR

    Science.gov (United States)

    Recent USEPA investigations of Lake Superior benthos in Minnesota, Wisconsin, and Michigan waters have resulted in the discovery of six uncommon genera of Chironomidae. Five new records of genera for Lake Superior and five significant Nearctic range extensions are reported. New r...

  20. Cryoprotective dehydration and the resistance to inoculative freezing in the Antarctic midge, Belgica antarctica

    Science.gov (United States)

    During winter, larvae of the Antarctic midge, Belgica antarctica (Diptera, Chironomidae), must endure 7–8 months of continuous subzero temperatures, encasement in a matrix of soil and ice, and severely desiccating conditions. This environment, along with the fact that larvae possess a high rate of w...

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

    OpenAIRE

    María V. López van Oosterom; Carolina S. Ocón; Florencia Brancolini; Maroñas, Miriam E.; Eduardo D. Sendra; Alberto Rodrigues Capítulo

    2013-01-01

    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 ba...

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

    International Nuclear Information System (INIS)

    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.

  3. Method refinements for the midge life-cycle, Chironomus dilutus test

    Science.gov (United States)

    Larval stages of non-biting midges can be found in almost any freshwater ecosystem, and one of the commonly tested midges is Chironomus dilutus (Chironomidae, Diptera) which is used for toxicity testing and ecological risk assessment of freshwater contaminants. USEPA, ASTM, Envir...

  4. The diet of the serotine bat: A Comparison between rural and urban environments

    OpenAIRE

    Kervyn, Thierry; Libois, Roland

    2008-01-01

    The diet of four maternity colonies of serotine bats in Southern Belgium was investigated by analysing faecal pellets collected from beneath the roost throughout the activity season. Their diet is composed of Coleoptera Melolonthidae (Melolontha sp., Amphimallon sp., Rhizotrogus sp., Serica brunnea), Coleoptera Scarabaeidae (Aphodius sp., Geotrupes sp.), Coleoptera Carabidae, Diptera Tipulidae, Diptera Chironomidae, Lepidoptera, Hemiptera Pentatomidae, Hymenoptera Ichneumonoidea Ophionidae, T...

  5. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  7. ТАКСОНОМИЧЕСКОЕ ИССЛЕДОВАНИЕ ХИРОНОМИД (DIPTERA, CHIRONOMIDAE) УРАЛА И СОПРЕДЕЛЬНЫХ ТЕРРИТОРИЙ

    OpenAIRE

    Белянина, Светлана; Филинкова, Татьяна

    2014-01-01

    В данной статье приводятся данные по видовому составу и генотипической изменчивости хирономид Урала и сопредельных территорий.

  8. ВИДОВОЙ СОСТАВ И ЭКОЛОГИЧЕСКИЕ ХАРАКТЕРИСТИКИ ХИРОНОМИД (DIPTERA: CHIRONOMIDAE) ВОДОЕМОВ КАЛИНИНГРАДА

    OpenAIRE

    Шевчук, Т.; Винокурова, Н.

    2010-01-01

    Представлены данные о фауне хирономид двух озер в черте Калининграда: Пеньковое и Исаковское. Изучен видовой состав и экологические характеристики популяций. Дана оценка состояния водных экосистем исследованных водоемов на основе полученных данных по количественным характеристикам и видовому разнообразию хирономид....

  9. МОРФОМЕТРИЧЕСКИЕ ПАРАМЕТРЫ ПРЕДИМАГИНАЛНЫХ СТАДИЙ ХИРОНОМИД (DIPTERA, CHIRONOMIDAE) ИЗ ДЕЛЬТЫ ВОЛГИ

    OpenAIRE

    Алексевнина, М.

    2009-01-01

    Приведены данные по длительности развития отдельных возрастных стадий личинок комаров-звонцов из дельты Волги, а также их размеры и массы.

  10. ДОПОЛНЕНИЕ К ФАУНЕ ХИРОНОМИД (DIPTERA, CHIRONOMIDAE) НАЦИОНАЛЬНОГО ПАРКА «ЮГЫД ВА» РЕСПУБЛИКИ КОМИ

    OpenAIRE

    Поздеев, Иван

    2014-01-01

    Приведён аннотированный список хирономид водоёмов и водотоков, расположенных на территории Национального парка «Югыд ва» Республики Коми. Список включает 61 вид из 38 родов и 4 подсемейств: Tanypodinae (5 видов), Diamesinae (4), Orthocladiinae (39) и Chironominae (13). 26 видов впервые указываются для Республики Коми, 2 - для России. Преобладают виды, характеризующиеся голарктическим распространением....

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

    International Nuclear Information System (INIS)

    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

  12. Diversity of macrozoobenthos on Orlice river system

    International Nuclear Information System (INIS)

    There are 2 saprobiology monitoring profiles and 1 faunictic research profile on Orlice river, 5 saprobiology monitoring profiles and 2 faunictic research profile on Divoka Orlice river, 4 saprobiology monitoring profiles on Ticha Orlice river. It was collected 255 taxons of macrozoobentos on long therm research in years 1996-2002. Number of taxons: Turbellaria 3, Oligochaeta 13, Nematomorpha 1, Hirudinea 4, Gastropoda 6, Bivalvia 4, Malacostraca 3, Hydracarina 1, Odonata 4, Ephemeroptera 42, Plecoptera 28, Heteroptera 1, Megaloptera 2, Coleoptera 6, Trichoptera 70, Diptera 16, Diptera - Chironomidae 40, Diptera - Simuliidae 11. On locality Blesno - Orlice was discovered very rare plecoptera species Agnetina elegantula (KLAPALEK, 1905), on locality Chocen - Ticha Orlice was discovered rare chironomidae species Symposiocladius lignicola (KIEFFER, 1915). (authors)

  13. Effects of body size on the diet of Rivulus haraldsiolii (Aplocheiloidei: Rivulidae in a coastal Atlantic Rainforest island stream, southern Brazil

    Directory of Open Access Journals (Sweden)

    Vinícius Abilhoa

    2010-12-01

    Full Text Available The effect of body size on the feeding habits of the little-known killifi sh Rivulus haraldsiolii, collected in a coastal Atlantic Rainforest island stream, was investigated. Samples were collected during a study trip on 13 July 2009 in a brackish stream located in the northern part of Ilha do Mel Island, one of the most important southern Atlantic Forest areas in southern Brazil. The diet included aquatic immature insects (Diptera pupae and Chironomidae, aquatic insects (Hemiptera – Vellidae, microcrustaceans (Cladocera, aquatic ticks (Acarina, gastropods (Pomacea sp., terrestrial insects (Coleoptera, Formicidae and Isoptera, insect fragments, and plant fragments. The species presented an omnivorous feeding habit, and differences in diet could be related to variations in body sizes. Adults (large individuals feed mainly on Formicidae, plant fragments and aquatic ticks, whereas juveniles (small individuals feed basically on aquatic immature insects (Chironomidae and aquatic ticks.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Effects of ozonation treatment on benthic fauna : How does the density of aquatic invertebrates change in the river Knivsta during removal of pharmaceuticals?

    OpenAIRE

    Hagberg, Ludvig

    2016-01-01

    The quantity of pharmaceuticals that end up in aquatic and terrestrial ecosystems are increasing due to a global increase in usage and poor removal efficiency of pharmaceuticals in sewage treatment plants (STP). These compounds may cause great effects on both aquatic and terrestrial ecosystems. Pharmaceuticals are biologically active compounds that may affect non-target organisms. This report focused primarily on if and how the density of Chironomidae (nonbiting midges), Isopoda, Trichoptera ...

  16. Fauna fitotelmata en las bromelias Aechmea fendleri André y Aechmea fendleri y Aechmea fendler del Parque Nacional San Esteban, Venezuela stellata S c h u l t d e l P a r q u e N a c i o n a l S a n E s t e b a n , V

    OpenAIRE

    Jonathan Liria

    2013-01-01

    El presente trabajo caracteriza la asociación de mosquitos y otros invertebrados sobre bromelias del Parque Nacional San Esteban del Estado Carabobo, Venezuela. Se estudiaron 18 plantas de Aechmea fendleri (11) Aechmea fendleri (1 1) Aechmea fendleri y Hohenbergia stellata (7) durante las épocas lluvia (Septiembre 2004) y sequía (Marzo 2005). Fueron colectados un total de 2020 macroinvertebrados. Los taxa más importantes fueron las Familias Chironomidae (43%), Culicidae (25%) y Chaoboridae (6...

  17. Relationship between sugar cane cultivation and stream macroinvertebrate communities

    OpenAIRE

    Juliano José Corbi; Susana Trivinho-Strixino

    2008-01-01

    The aim of this work was to study the influence of the sugar cane cultivation on the macroinvertebrate communities of 11 streams under different land uses. Analysis of the sediment (organic matter contents and metals) and water complemented the study. Ninety six macroinvertebrates taxa were identified, of which 54 were Chironomidae and 42 of other aquatic macroinvertebrates. The streams located in the areas of sugar cane culture and pasture presented low taxa and a great participation of Chir...

  18. Relating actual with subfossil chironomid assemblages. Holocene habitat changes and paleoenvironmental reconstruction of Basa de la Mora Lake (Central Pyrenees)

    Science.gov (United States)

    Tarrats, Pol; Rieradevall, Maria; González-Sampériz, Penélope; Pérez-Sanz, Ana; Valero-Garcés, Blas; Moreno, Ana

    2014-05-01

    Analyses of subfossil and actual macroinvertebrate fauna and Chironomidae larvae (Insecta: Diptera) assemblages of Basa de la Mora Lake (Central Pyrenees, Spain, 1914 m a.s.l.) improves the environmental calibration for lake paleoreconstruction and allow to infer lake habitat changes throughout the Holocene. The results of the actual Chironomidae community are consistent with other mountain lake studies (either in the Pyrenees or other regions), with a few mismatching due to lake specific conditions. The actual and the subfossil Chironomidae taxa present in Basa de la Mora Lake are the same, which is an essential requirement to apply the analogue methods. Although we could not find habitat-specific taxa, significant differences between the different habitats present in the lake were found. This circumstance allowed applying the Modern Analogue Technique (MAT) to infer lake habitat changes. The MAT method relates the actual community, defined from the species abundance matrix and an environmental variable (which is the object of the inference), and the past community, defined from the species abundance matrix downcore. Because the first axis of DCA carried out for the study of the actual Chironomidae larvae explained the assemblage changes between the different habitats, the scores of this first axis were used as representative of the environmental variable (dominant habitat type) to be inferred. The application of the MAT has allowed identifying two periods of lake productivity increase through the Holocene: i) around 2800 cal. yrs BP, which coincides with the first documented human occupation of the area, and ii) the last four centuries, synchronous to the maximum population of mountain areas in the Pyrenees and development of stockbreeding activities.

  19. Feeding preference of the South American endemic anomuran Aegla platensis (Decapoda, Anomura, Aeglidae)

    Science.gov (United States)

    Colpo, Karine Delevati; Ribeiro, Liara Colpo; Wesz, Bruna; Ribeiro, Ludmilla Oliveira

    2012-04-01

    In order to determine the feeding preference of Aegla platensis in streams and the importance of microorganisms in its detritivore diet, we carried out two experiments designed to evaluate the food preferences of A. platensis (1) among leaves with different levels of microbial colonization and (2) among insect larvae (Chironomidae, Simuliidae, Hydropsychidae) and microbially conditioned leaves. A. platensis preferred animal over plant food items; when only leaves were offered, this aeglid preferred the leaves with higher levels of microorganism conditioning.

  20. Efeito de metais Cobre (Cu e Zinco (Zn sobre a comunidade de macroinvertebrados bentônicos em riachos do sul do Brasil = The effect of metals (Cu and Zn on the benthic macroinvertebrate community in streams in southern Brazil

    Directory of Open Access Journals (Sweden)

    Silvia Vendruscolo Milesi

    2008-07-01

    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 ariqueza 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 organismsand 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 bioindicatorpotential of the benthic community in the evaluation of integral quality of the environment.

  1. 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

    Directory of Open Access Journals (Sweden)

    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.

  2. Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil) Avaliação da biodiversidade de macroinvertebrados bentônicos em ecossistemas lóticos de altitude na Serra do Cipó (MG, Brasil)

    OpenAIRE

    GALDEAN N.; Callisto, M.; F. A. R. BARBOSA

    2001-01-01

    Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a cl...

  3. Biodiversity assessment of benthic macroinvertebrates in altitudinal lotic ecosystems of Serra do Cipó (MG, Brazil)

    OpenAIRE

    GALDEAN N.; Callisto, M.; F. A. R. BARBOSA

    2001-01-01

    Five lotic systems of Serra do Cipó, south-east Brazil, were investigated in order to assess the existing diversity of benthic macroinvertebrates, habitats-microhabitats, and the available trophic resources. For each river it was analysed the communities of benthic macroinvertebrates and the composition of some taxonomic groups (Plecoptera, Ephemeroptera, Trichoptera and Diptera Chironomidae): the community with Bivalvia Sphaeriidae, Oligochaeta and Ephemeroptera Baetidae (being supposed a cl...

  4. Freshwater invertebrate fauna of Nuku Hiva island (French Polynesia) : data during a rainy season

    OpenAIRE

    Fossati, Odile; Gibon, François-Marie; Danigo, Anne-Hélène

    1992-01-01

    The streams of Nuku-Hiva Island, Marquesas Archipelago, were sampled during the rainy season in June 1990. The invertebrate fauna was scarce and had a low diversity. Gastropoda and Decapoda accounted for the major part of the biomass. Insects were represented by #Simuliidae$, #Chironomidae$ and a few #Ceratopogonidae$, #Coleoptera$ and #Zygoptera$. #Oligochaeta$ were numerically important. The role of insularity and the effects of hydraulic conditions on this fauna are briefly discussed. (Rés...

  5. Chironomids (Diptera, Nematocera) of Temporary Pools - an Ecological Case Study

    OpenAIRE

    Dettinger-Klemm, Paul-Martin Andreas

    2004-01-01

    The main aim of the present study was to determine how Chironomidae cope with the environmental changes to which temporary pools are exposed. Are the species specifically adapted to the habitat or opportunistic? The problem was approached by: (a) an emergence study done in the Lahnberge mountain range (Marburg, Hesse, Germany) on three pools that were subjected to different lengths of drought (two of which were really temporary an...

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

    OpenAIRE

    Norma Segatti Hahn; Fabiane Cunha

    2005-01-01

    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...

  7. The protective role of endogenous bacterial communities in chironomid egg masses and larvae

    OpenAIRE

    Senderovich, Yigal; Halpern, Malka

    2013-01-01

    Insects of the family Chironomidae, also known as chironomids, are distributed worldwide in a variety of water habitats. These insects display a wide range of tolerance toward metals and organic pollutions. Bacterial species known for their ability to degrade toxicants were identified from chironomid egg masses, leading to the hypothesis that bacteria may contribute to the survival of chironomids in polluted environments. To gain a better understanding of the bacterial communities that inhabi...

  8. Effects of body size on the diet of Rivulus haraldsiolii (Aplocheiloidei: Rivulidae) in a coastal Atlantic Rainforest island stream, southern Brazil

    OpenAIRE

    Vinícius Abilhoa; Jean Ricardo Simões Vitule; Hugo Bornatowski; Fagner Breda de Lara; Glauco Ubiratan Kohler; Luciana Festti; Wanessa Priscila David do Carmo; Igor Kintopp Ribeiro

    2010-01-01

    The effect of body size on the feeding habits of the little-known killifi sh Rivulus haraldsiolii, collected in a coastal Atlantic Rainforest island stream, was investigated. Samples were collected during a study trip on 13 July 2009 in a brackish stream located in the northern part of Ilha do Mel Island, one of the most important southern Atlantic Forest areas in southern Brazil. The diet included aquatic immature insects (Diptera pupae and Chironomidae), aquatic insects (Hemiptera – Vellida...

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

    OpenAIRE

    Albertoni Edélti Faria; Palma-Silva Cleber; Esteves Francisco de Assis

    2003-01-01

    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...

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

    Science.gov (United States)

    Müller, Gerson A; Name, Fernando T; Pacheco, Frederico C L; Marcondes, Carlos B

    2010-12-01

    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 < 0.05). The alternative method was efficient to estimate the diversity of these insects in both species of bromeliads. The higher mobility of immature forms of beetles and dragonflies, and the availability of only one tank in Aechea lindenii, contrasting to several tanks in Vriesea friburgensis that help the suction of these immature, probably influenced the results, which indicated that the suction method should not replace the dismantling in the study of Culicidae and Chironomidae. This method can be useful to get immature forms of Scirtidae and Coenagrionidae in one-tank bromeliads. PMID:21152764

  11. Роль личинок таниподин в составе экологических комплексов хирономид (Diptera, Chironomidae, Tanypodinae) при антропогенном загрязнении

    OpenAIRE

    Сергеева, И.; Аникина, М.; Харитонова, И.

    2009-01-01

    В составе биоиндикационного комплекса хирономид Волжского бассейна в границах Саратовской области таниподины представлены 16 видами. В Волге у Саратова сократилось общее количество видов таниподин. Из состава фауны выбыли индикаторы «чистой» воды. Увеличивается количество видов-индикаторов насыщенных органикой (бытовой сток) водоемов, а также индикаторов токсического загрязнения воды....

  12. 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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

    Directory of Open Access Journals (Sweden)

    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.

  14. Food web structure in a harsh glacier-fed river.

    Directory of Open Access Journals (Sweden)

    Leonie R Clitherow

    Full Text Available Glacier retreat is occurring across the world, and associated river ecosystems are expected to respond more rapidly than those in flowing waters in other regions. The river environment directly downstream of a glacier snout is characterised by extreme low water temperature and unstable channel sediments but these habitats may become rarer with widespread glacier retreat. In these extreme environments food web dynamics have been little studied, yet they could offer opportunities to test food web theories using highly resolved food webs owing to their low taxonomic richness. This study examined the interactions of macroinvertebrate and diatom taxa in the Ödenwinkelkees river, Austrian central Alps between 2006 and 2011. The webs were characterised by low taxon richness (13-22, highly connected individuals (directed connectance up to 0.19 and short mean food chain length (2.00-2.36. The dominant macroinvertebrates were members of the Chironomidae genus Diamesa and had an omnivorous diet rich in detritus and diatoms as well as other Chironomidae. Simuliidae (typically detritivorous filterers had a diet rich in diatoms but also showed evidence of predation on Chironomidae larvae. Food webs showed strong species-averaged and individual size structuring but mass-abundance scaling coefficients were larger than those predicted by metabolic theory, perhaps due to a combination of spatial averaging effects of patchily distributed consumers and resources, and/or consumers deriving unquantified resources from microorganisms attached to the large amounts of ingested rock fragments. Comparison of food web structural metrics with those from 62 published river webs suggest these glacier-fed river food web properties were extreme but in line with general food web scaling predictions, a finding which could prove useful to forecast the effects of anticipated future glacier retreat on the structure of aquatic food webs.

  15. Diversity of macrobenthos in lowland streams: ecological determinants and taxonomic specificity

    Directory of Open Access Journals (Sweden)

    Paweł KOPERSKI

    2010-02-01

    Full Text Available The present study contains the results of an investigation of the relationships between the environmental variables and the taxonomic diversity of common and important groups of benthic macrofauna: Chironomidae, Ephemeroptera, Odonata, Hirudinea and Gastropoda, collected from various types of bottom substrate in seven lowland streams of north-eastern Poland. Four metrics were used to express the diversity of the studied taxa in each sample as the examples of its four different aspects: species richness, rarity, Shannon-Weaver's diversity index and Pielou evenness index. The values of total species richness and Shannon-Weaver index were rarified by functional extrapolation with Michaelis-Menten asymptotic function chosen as a richness estimator. There are high differences in taxonomic diversity of benthic animals between the studied streams. The results of estimation of total species richness and total species diversity are mainly affected by the diversity of the taxon richest in species – larval Chironomidae and, to a lesser extent, Hirudinea. The total taxonomic diversity significantly correlates with the status of riparian vegetation and with the isolation of the sampling site, while the relationship with other environmental parameters, i.e. pollution and seasonality, is not significant. The diversity of Gastropoda and Hirudinea is significantly affected by pollution (positively, water depth and seasonality; whereas the diversity of Ephemeroptera and Chironomidae by the state of riparian vegetation, and that of Odonata by stream width and isolation of the site. The study presents and discusses reduced diversity of certain higher taxa as a result of a reduction in pollution loading to a stream with simultaneous unchanged values of the total diversity.

  16. Biota and biological principles of the aquatic environment

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  18. Fauna bezkręgowa w strumieniach i rzekach miasta Łodzi

    OpenAIRE

    Tszydel, Mariusz; Kruk, Andrzej; Galicka, Wanda; Tybulczyk, Szymon; Pietraszewski, Dariusz; Marszał, Lidia; Janic, Bartosz

    2006-01-01

    In the City of Łódź there are 29 streams and rivers of various sizes, 18 of them named and 11 unnamed, whose total length is 125 km. The aim of the present study was gaining initial knowledge of the abundance and diversity of aquatic macroinvertebrates in water courses in the City of Łódź. Collected aquatic macroinvertebrates were represented by 18 taxons. The highest occurrence was recorded for Dipterans (Chironomidae) (present in all samples), Oligochaeta, Ephemeroptera and Gastropoda. ...

  19. Spatial and seasonal distribution of macroinvertebrates in high altitude reservoir (Beyler Reservoir, Turkey)

    Science.gov (United States)

    Findik, Özlem

    2013-09-01

    A highland reservoir in the West Black Sea region of Turkey which belongs to the Mediterranean climatic zone was examined. Both littoral and profundal zones were sampled from October 2009 to September 2010, to determine taxonomic composition, biodiversity and abundance of benthic invertebrates as well as the seasonal variation of these measures. A total of 35 taxa were identified, of which 12 belong to Chironomidae and 10 to Oligochaeta groups. The highest diversity and abundance of benthic macroinvertebrates were found at the littoral stations. Macroinvertebrates showed significant positive correlations with water temperature and NO2 and NO3 concentrations, and negative correlation with dissolved oxygen.

  20. 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

  1. Invertebrate colonization rates in the tailwater of a Kentucky flood-control reservoir

    Science.gov (United States)

    Swink, W.D.; Novotny, J.F.

    1985-01-01

    Invertebrate colonization on newly introduced rock substrates was examined from July through October 1982 in the tailwater of Barren River Lake, Kentucky. Chironomidae, the dominant taxon of benthic insects, reached full colonization by day 14. Colonization by Oligochaeta, the other major invertebrate taxon, was not completed by the end of the 95-day period of observation. It may have been delayed because insufficient food (periphyton and detritus) had accumulated on the clean rocks. Rapid recolonization of dewatered substrates may be especially critical for maintaining adequate fish food in tailwaters of flood-control reservoir.

  2. Colonização por macroinvertebrados bentônicos em substrato artificial e natural em um riacho da serra de Itatinga, São Paulo, Brasil Colonization by benthic macroinvertebrates in artificial and natural substrates in a mountain stream from Itatinga, São Paulo, Brazil

    OpenAIRE

    Emerson Machado de Carvalho; Virginia Sanches Uieda

    2004-01-01

    Substratos artificial e natural foram comparados quanto ao processo de colonização por macroinvertebrados. No 1º, 3º, 7º, 13º, 21º, 31º e 42º dias de amostragem a riqueza e a abundância dos macroinvertebrados foi analisada. Larvas de Chironomidae foi o grupo mais abundante nos dois substratos durante todo o período amostral (53% em cada substrato), seguido por Oligochaeta (17 no artificial e 18 % no natural), formas imaturas de Ephemeroptera (16 e 11%) e Trichoptera (10 e 11%). O processo de ...

  3. Effects of acid mine drainage on southwestern Pennsylvania stream

    Energy Technology Data Exchange (ETDEWEB)

    Moon, T.C.; Lucostic, C.M.

    1979-01-01

    Physicochemical parameters and benthic macroinvertebrate community structure were studied in a small valley stream in southwestern Pennsylvania, where the pH value below a coal mine effluent discharge was 5.8-7.0. The major factor affecting the benthic community seemed to be ferric hydroxide. Certain taxa were abundant at station sites above the mine discharge, while only those taxa tolerant of polluted conditions, such as Chironomidae and Tubifex, were prevalent at the downstream station sites. An analysis of benthic populations demonstrated environmental stress within the aquatic ecosystem.

  4. 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.

  5. Dieta de espécies de Anostomidae (Teleostei, Characiformes na área de influência do reservatório de Manso, Mato Grosso, Brasil Diet of Anostomidae species (Teleostei, Characiformes in the influence area of Manso Reservoir, Mato Grosso, Brazil

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    Graziela Custodio Balassa

    2004-03-01

    Full Text Available The diet of four species of Anostomidae (Leporinus friderici Bloch, 1794, L. striatus Kner, 1858, L. elongatus Valenciennes, 1849 and Leporinus sp. were investigated in the Manso Reservoir, Mato Grosso State, Brazil. Fish were sampled in three sites: upriver, in the main body of the reservoir, and below the dam. Were analized 276 stomachs. The diet was evaluated using the frequency of ocorrence and volumetric methods. Leporinus friderici showed tendency to herbivory, mainly in the upriver site. In the reservoir and below the dam, it consumed large quantities of fish; Isoptera only in the reservoir. Leporinus striatus and L. elongatus have similar diets, consuming Chironomidae larvae (Diptera, whereas Leporinus sp. was more generalist, feeding similar proportions of vegetable, detritus and insect (Chironomidae and Ephemeroptera. The mouths of the species have different positions: terminal in L. friderici, subterminal in L. elongatus and intermediate in L. striatus and Leporinus sp. The diet overlap values were low, except for L. friderici and Leporinus sp. (0.7 in the upriver, and L. striatus and L. elongatus (0.6 below the dam.

  6. Checklist of the Diptera (Insecta of Finland: an introduction and a summary of results

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    Jere Kahanpää

    2014-09-01

    Full Text Available Nearly thirty-five years have passed since Hackman published his “Check list of the Finnish Diptera” (1980. The number of true flies (Diptera known from Finland has increased by more than two thousand species since then. At the same time, hundreds of erroneous records have been recognized and purged from the checklist. ZooKeys issue 441 provides a new checklist of the Diptera species of the Republic of Finland. This introductory paper presents the rationale behind the project, provides technical documentation on the checklist format and sources used, and summarizes the results. The remaining papers in this issue cover one or more Diptera families in detail. Two electronic appendices are provided: supporting data (additional references to first published records and the previous checklist and a complete list of Finnish Diptera taxa in Darwin Core compliant format for easy computer access and processing. The new checklist records 6920 fly species from Finland, 2932 belonging to the nematoceran or lower flies and 3989 to the suborder Brachycera. The changes since 1980 are most prominent in the Lower Diptera. For example, more than 400 non-biting midges (Chironomidae have been added since 1980, and the number of moth flies (Psychodidae known from Finland has more than tripled. Among the larger families, large increases in known Finnish species are also seen in Cecidomyiidae (161% increase, Pipunculidae (98%, and Chironomidae (90%.

  7. Colonization of artificial substrate by freshwater macroinvertebrates, in the Jacuí River Delta, Rio Grande do Sul State, Brazil

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    Daniel Pereira

    2010-03-01

    Full Text Available Experiments to evaluate the limnic macroinvertebrates that colonize artificial substrates were performed at two experimental stations located in Jacui Channel (CJ and Cais do Porto (PO, both part of the Jacui Delta in Porto Alegre, RS, southern Brazil. Substrates were built in PET bottles containing an internal nylon screen. In CJ, L. fortunei (8229.0 ind.m-2, Chironomidae (188.9 ind.m-2, and Heleobia piscium (39.6 ind.m-2 presented the highest values of average density. In PO, L. fortunei (3233.0 ind.m-2, Chironomidae (288.9 ind.m-2, and Oligochaeta (211.1 ind.m-2 presented the highest values of average density. The freshwater sponge, Trochospongilla paulula, presented an incrustation area of 0.016m2, that corresponded to 31% of the total external substrate surface (PET bottles. Trochospongilla paulula also grew over the golden mussel valves (epizoism. Significant differences between average densities of Oligochaeta verified in the sustrates from CJ (lowest value and PO (highest value were found using the statistics Mann-Whitney Test (p=0.01. Other significant differences (p<0.0001 between the bioincrustation areas of T. paulula in the substrates from CJ (highest value and PO (lowest value were found. The average densities of other taxa in substrates from both CJ and PO did not differ statistically. The substrate was adequate for the sampling of macroinvertebrates, especially Porifera, a group that is difficult to sample.

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

    International Nuclear Information System (INIS)

    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)

  9. 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. PMID:26314044

  10. 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. PMID:26314015

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

    International Nuclear Information System (INIS)

    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

  12. Dynamics and distribution of macrozoobenthos in the Toplica river, a tributary of the Kolubara

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    Živić Ivana

    2002-01-01

    Full Text Available Hydrobiological investigations of the macrozoobenthos were carried out at eight localities in the Toplica river (a right-hand tributary of the Kolubara river from April 2000 to January 2001. The bottom fauna was composed of 19 groups of macroinvertebrates with 85 determined taxa (61 identified to the species level, 24 to the generic level. The most varying groups were the insect orders Trichoptera (20 taxa, Ephemeroptera (15, and Diptera (13, while Isopoda, Decapoda, and insects belonging to orders Collembola, Heteroptera, Megaloptera, and Planipennia were the most uniform. The species Gammarus pulex fossarum Koch and Dugesia gonocephala Duges were the most abundant forms at the river source, and representatives of Ephemeroptera and Gammaridae were the most numerous in its upper course (at the second, third, and fourth locality. The Mollusca and Chironomidae larvae were the most abundant forms at the fifth locality (in the middle course, but no constant dominance of any animal group was recorded at the sixth one, where the dominance alternated among Chironomidae larvae (April, July 2000, Oligochaeta (October 2000 and Mollusca (January 2001. The lower course of the river (the seventh and eighth locality was characterized by the dominance of the species of the phylum Mollusca (Amphimelania holandri Ferussac, Fagotia esperi Ferussac and Theodoxus transversalis Pfeiffer.

  13. Effects of the mosquito larvicides temephos and methoprene on insect populations in experimental ponds

    Science.gov (United States)

    Pinkney, A.E.; McGowan, P.C.; Murphy, D.R.; Lowe, T.P.; Sparling, D.W.; Ferrington, L.C.

    2000-01-01

    The nontarget effects of Abate 4E ? (44.6% temephos) at 0.054 kg of active ingredient (a.i.) per 1 ha and of Altosid Liquid Larvicide ? (5% methoprene) at 0.011 kg a.i./ha were investigated in 18 experimental ponds (average area, 202 m2; maximum depth, 0.7 m) at Patuxent Wildlife Research Center, Laurel, Maryland, USA. Ponds were sprayed three times at 3-week intervals. Six ponds were sprayed with Abate, six with Altosid, and six with distilled water. Two insect-emergence traps per pond collected for 7 d and were then harvested 1 d before each spray and 13 to 14 days afterward. A repeated measures analysis of variance (ANOVA) revealed significant reductions in Shannon diversity, equatability, and numbers of individuals, species, and families in the Abate ponds relative to controls. Significant reductions also occurred in Ephemeroptera, Odonata, Diptera, Chironomidae, and Chaoborus sp. Hester-Dendy samplers were installed before spray one and harvested 16 d after spray three. Based on one-way ANOVA, Shannon diversity, equatability, and number of Ephemeroptera and Chironomidae were significantly reduced in the Abate ponds. Emergence data indicate only isolated cases with significant reductions in the Altosid ponds relative to controls, and the Hester-Dendy data indicate no significant differences between the Altosid and control ponds.

  14. Lacustrine records of continental climate in northwest Greenland through the Holocene and Last Interglacial

    Science.gov (United States)

    McFarlin, J. M.; Axford, Y.; Osburn, M. R.; Lasher, G. E.; Francis, D. R.; Kelly, M. A.; Osterberg, E. C.

    2015-12-01

    Lake sediment records provide opportunities for high-resolution observations of paleoclimate that help to place modern climate change in geologic context. Here we present a terrestrial record of July air temperature for northwest Greenland (Nunatarssuaq, ~25 km east of the Thule Air Base) through the Holocene and a prior warm period, inferred from subfossil insect remains (Chironomidae) preserved in lacustrine sediments. In addition, we discuss ongoing work in characterizing the sources and isotopic composition of leaf waxes preserved in the same sediments. Multiple parallel sediment cores were collected in the summers of 2012 and 2014 from Wax Lips Lake (informal name), a non-glacial lake situated 44 ka) and thus predates the Last Glacial Maximum (LGM). Our results demonstrate temperatures warmer than present through the early and mid Holocene followed by cooling in the late Holocene. Material that pre-dates the LGM contains insect assemblages indicating temperatures warmer than the warmest millennia of the Holocene. We interpret this material as most likely dating to the Last Interglacial Period (MIS 5). Along with assemblages of Chironomidae, we find subfossil Chaoboridae in one section of the pre-LGM sediments, suggesting exceptionally warm conditions based upon the distribution of modern-day Chaoborus. We find abundant n-alkanes and n-acids are preserved in the Holocene and pre-LGM sediments, allowing for complementary compound-specific δD analyses and identification of organic matter source in addition to chironomid derived temperature records.

  15. 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.

  16. Effects of benthic macrofauna bioturbation on the bacterial community composition in lake sediments.

    Science.gov (United States)

    Zeng, Jin; Zhao, Da-Yong; Liu, Peng; Yu, Zhong-Bo; Huang, Rui; Wu, Qinglong L

    2014-08-01

    Benthic macrofauna are considered to be an important part of the lacustrine ecosystem, and bioturbation may greatly affect the biogeochemical processes and microbial activities in sediments. In the present study, the bacterial community composition in sediments inhabited by 3 different types of benthic macrofauna (Corbicula fluminea, Chironomidae larvae, and tubificid worms) in the shallow and eutrophic Lake Taihu was studied to investigate the different effects of bioturbation on the composition of these communities. Microcosms were constructed, and culture-independent methods, including terminal restriction fragment length polymorphism (T-RFLP) and clone library analysis, were performed to evaluate the bacterial communities. Analysis of similarities (ANOSIM) and multidimensional scaling (MDS) analysis of T-RFLP patterns demonstrated that differences in the bacterial community composition between the control and the macrofauna-inhabited sediments were not as great as expected, although the chemical properties of the sediments changed remarkably. Nevertheless, the dominant bacterial group in each type of macrofauna-inhabited sediment was different. Acidobacteria, Betaproteobacteria, and Deltaproteobacteria were the dominant bacterial groups in sediments inhabited by C. fluminea, tubificid worms, and Chironomidae larvae, respectively. The data obtained in this study are helpful for understanding the effects of bioturbation in a shallow, eutrophic lake. PMID:25070418

  17. 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

    Directory of Open Access Journals (Sweden)

    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.

  18. Macroinvertebrate communities associated with macrophyte habitats in a tropical man-made lake (Lake Taabo, Côte d’Ivoire

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    Kouamé M. K.

    2011-02-01

    Full Text Available An ecological study was done on Lake Taabo with the main objective of characterising macroinvertebrate communities associated with the microhabitats created mainly by Eichhornia crassipes and other littoral native macrophytes. We sampled organisms in patches of those aquatic macrophytes. Also, some abiotic variables (temperature, transparency, turbidity, pH, TDS, conductivity, dissolved oxygen, NH$_{4}^{+}$+4, NO$_{3}^{-}$−3, NO$_{2}^{-}$−2, PO$_{4}^{3-}$3−4 and SiO$_{2}^{-}$−2 were measured. Overall, forty-three taxa of macroinvertebrates were identified. Ten of them were exclusively associated with water hyacinth while five were only associated with littoral macrophytes. Macroinvertebrate taxa with some of the highest family richness were Gastropoda, Coleoptera, Heteroptera, Odonata and Diptera. The taxon with highest density in both microhabitats was Chironomidae. Although higher values of taxonomic richness (Rs, the Shannon index (H′ and evenness (J were obtained with the water hyacinth habitat, significant differences between the two microhabitats were not observed. Canonical Correspondence Analysis revealed that samples of E. crassipes collected in the dry season were characterised by Gastropoda and Odonata, as well as higher values of transparency and ammonia-nitrogen. Baetidae, Hydrophilidae, Chironomidae, Ceratopogonidae, Coenagrionidae, Naucoridae and Ostracoda were most abundant in both E. crassipes and littoral macrophyte habitats during the rainy season. This season was characterised by higher levels of nitrates and conductivity.

  19. 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

    Directory of Open Access Journals (Sweden)

    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

  20. Sampling benthic macroinvertebrates in a large flood-plain river: Considerations of study design, sample size, and cost

    Science.gov (United States)

    Bartsch, L.A.; Richardson, W.B.; Naimo, T.J.

    1998-01-01

    Estimation of benthic macroinvertebrate populations over large spatial scales is difficult due to the high variability in abundance and the cost of sample processing and taxonomic analysis. To determine a cost-effective, statistically powerful sample design, we conducted an exploratory study of the spatial variation of benthic macroinvertebrates in a 37 km reach of the Upper Mississippi River. We sampled benthos at 36 sites within each of two strata, contiguous backwater and channel border. Three standard ponar (525 cm(2)) grab samples were obtained at each site ('Original Design'). Analysis of variance and sampling cost of strata-wide estimates for abundance of Oligochaeta, Chironomidae, and total invertebrates showed that only one ponar sample per site ('Reduced Design') yielded essentially the same abundance estimates as the Original Design, while reducing the overall cost by 63%. A posteriori statistical power analysis (alpha = 0.05, beta = 0.20) on the Reduced Design estimated that at least 18 sites per stratum were needed to detect differences in mean abundance between contiguous backwater and channel border areas for Oligochaeta, Chironomidae, and total invertebrates. Statistical power was nearly identical for the three taxonomic groups. The abundances of several taxa of concern (e.g., Hexagenia mayflies and Musculium fingernail clams) were too spatially variable to estimate power with our method. Resampling simulations indicated that to achieve adequate sampling precision for Oligochaeta, at least 36 sample sites per stratum would be required, whereas a sampling precision of 0.2 would not be attained with any sample size for Hexagenia in channel border areas, or Chironomidae and Musculium in both strata given the variance structure of the original samples. Community-wide diversity indices (Brillouin and 1-Simpsons) increased as sample area per site increased. The backwater area had higher diversity than the channel border area. The number of sampling sites

  1. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Radioactive background in principal components of the Jihlava River ecosystem

    International Nuclear Information System (INIS)

    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, 40K, residual β-activity, sup(nat)U, 226Ra and, in some of the samples, also 210Pb, 90Sr and 137Cs. 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)

  4. Paleoecological evidence for abrupt cold reversals during peak Holocene warmth on Baffin Island, Arctic Canada

    Science.gov (United States)

    Axford, Yarrow; Briner, Jason P.; Miller, Gifford H.; Francis, Donna R.

    2009-03-01

    A continuous record of insect (Chironomidae) remains preserved in lake sediments is used to infer temperature changes at a small lake in Arctic Canada through the Holocene. Early Holocene summers at the study site were characterized by more thermophilous assemblages and warmer inferred temperatures than today, presumably in response to the positive anomaly in Northern Hemisphere summer insolation. Peak early Holocene warmth was interrupted by two cold reversals between 9.5 and 8 cal ka BP, during which multiple cold-stenothermous chironomid taxa appeared in the lake. The earlier reversal appears to correlate with widespread climate anomalies around 9.2 cal ka BP; the age of the younger reversal is equivocal but it may correlate with the 8.2 cal ka BP cold event documented elsewhere. Widespread, abrupt climate shifts in the early Holocene illustrate the susceptibility of the climate system to perturbations, even during periods of enhanced warmth in the Northern Hemisphere.

  5. [Macrobenthic community structure and bioassessment for water quality of Banqiao Reservoir in Huaihe River basin].

    Science.gov (United States)

    Sun, Wei-sheng; Gu, Qian-hong; Dong, Jing; Cheng, Qing-qing; Li, Xue-jun; Zhang, Man

    2015-09-01

    In order to demonstrate macrobenthic community structure dynamics and conduct a biological evaluation of water quality in Banqiao Reservoir, we collected seasonal samples from January to November 2014 across 15 sampling sites. A total of 17 species belonging to five families, four classes, and 3 phyla were identified, including 8 chironomidae, 4 oligochaeta and 5 mollusc. Bellamya aeruginosa, Corbicula fluminea, Branchiura sowerbyi, Pelopia sp. and Glyptotendipes sp. were the important species in Banqiao Reservoir. The total density, biomass and biodiversity of marobenthos showed significant spatial and temporal differences. ANOSIM analysis indicated that the macrobenthic community structure also differed significantly among regions and seasons, and the main contributing species were Glyptotendipes sp., Pelopia sp. and B. sowerbyi. The abundance-biomass comparison curves (ABC curves) indicated that the current macrobenthic community in Banqiao Reservoir was stable. Combined with the biodiversity index, biological pollution index (BPI) and Hilsenhoff biotic index (BI), it was suggested that Banqiao Reservoir suffered slight pollution. PMID:26785570

  6. 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. PMID:26322495

  7. From autochthonous to allochthonous resources: seasonal shifts in food use by stream-dwelling YOY Arctic charr Salvelinus alpinus through the ice-free season.

    Science.gov (United States)

    Sánchez-Hernández, J; Gabler, H-M; Amundsen, P-A

    2016-02-01

    Substantial seasonal changes in resource use associated with enhanced water-column use were revealed in stream-living YOY Arctic charr Salvelinus alpinus during the ice-free season. In July, YOY individuals showed a diet dominated by aquatic invertebrates (mainly Chironomidae larvae), but despite the small size of the fish, the abundance of terrestrial insects in their diet increased markedly from July to September (from 1·9 to 62·8%). Similarly, the frequency of surface drifting foragers, i.e. individuals feeding on allochthonous resources, increased from July to September (from 20·6 to 80%); allochthonous resources thus constituting an important energy subsidy for YOY S. alpinus during the late sub-Arctic summer. PMID:26577804

  8. Development and Validation of an Aquatic Fine Sediment Biotic Index

    Science.gov (United States)

    Relyea, Christina D.; Minshall, G. Wayne; Danehy, Robert J.

    2012-01-01

    The Fine Sediment Biotic Index (FSBI) is a regional, stressor-specific biomonitoring index to assess fine sediment (Chironomidae. This reduced the 685 taxa from all data sets to 206. Of these 93 exhibited some sensitivity to fine sediment which we classified into four categories: extremely, very, moderately, and slightly sensitive; containing 11, 22, 30, and 30 taxa, respectively. Categories were weighted and a FSBI score calculated by summing the sensitive taxa found in a stream. There were no orders or families that were solely sensitive or resistant to fine sediment. Although, among the three orders commonly regarded as indicators of high water quality, the Plecoptera (5), Trichoptera (3), and Ephemeroptera (2) contained all but one of the species or species groups classified as extremely sensitive. Index validation with an independent data set of 255 streams found FSBI scores to accurately predict both high and low levels of measured fine sediment.

  9. Plasticidade alimentar em Rivulus pictus Costa (Osteichthtyes, Cyprinodontiformes, Rivulidae de uma pequena lagoa em Brasília, Distrito Federal, Brasil Feeding plasticity of Rivulus pictus Costa (Osteichthyes, Cyprinodontiformes, Rivulidae from a small lake in Brasília, Distrito Federal, Brazil

    Directory of Open Access Journals (Sweden)

    Oscar Akio Shibatta

    2003-12-01

    Full Text Available Rivulus pictus has a wide distribution in Distrito Federal and lives in different environments, including small lakes. The analysis of gastric and intestinal contents showed that most of the 21 ingested food items were from autochthonous origin and characterized the diet of an omnivorous fish with a trend to planktivory. Five feeding items were important in the composition of the alimentary spectrum and revealed that food resources are explored near water surface (Acari, in the water column (Copepoda, Cladocera and Closterium sp. and also in the bottom (Chironomidae. The varied diet and the capacity to explore all levels of the environment evidenced that feeding flexibility is one of the factors that facilitates the survival of this species in different environments.

  10. 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.

  11. Discovering hidden biodiversity: The use of complementary monitoring of fish diet based on DNA barcoding in freshwater ecosystems

    DEFF Research Database (Denmark)

    Jo, Hyunbin; Ventura, Marc; Vidal, Nicolas;

    2015-01-01

    trutta), in 10 Tasmanian lakes and compared the results with those obtained from visual inspection of stomach contents. We obtained 44 unique taxa (OTUs) belonging to 5 phyla, including 7 classes, using the barcode of life approach from cytochrome oxidase I (COI). Compared with visual inspection, 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. The 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...

  12. 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.

  13. Aquatic insect populations in the MUDA rice agroecosystem

    International Nuclear Information System (INIS)

    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)

  14. The macroinvertebrates of Magela Creek, Northern Territory

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Amora, Gizelle; Hamada, Neusa; Fusari, Lívia Maria; Andrade-Souza, Vanderly

    2015-01-01

    Abstract 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 Chironomus striatipennis or Chironomus kiiensis, configuring a species complex but, at the molecular level our studied population is placed in a clade together with Chironomus striatipennis, from South Korea. Bionomic characteristics of the Brazilian Chironomus population differ from the ones of Chironomus 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 Chironomus striatipennis and Chironomus 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

  16. Benthic bioindicators from the lakes of Northern Yakutia (Siberia, Russia) in paleoclimatic research

    Science.gov (United States)

    Tumanov, O. N.; Nazarova, L. B.; Frolova, L. A.; Pestryakova, L. A.

    2012-04-01

    High latitude regions are particularly affected by global climate change. Aquatic ecosystems are known to respond quickly and sensitively to such changes (Carpenter et al., 1992; Findlay et al. 2001; Smol et al., 2005). This effect is especially dramatic in regions with continental climates such as Northern and Eastern Siberia. In 2008, Russian-German expedition investigated 33 lakes of Kolyma river basin, North-Eastern Yakutia. The region of investigation is located in the mouth of Kolyma river between approximately 68°2' and 69°4' N and between 159°8' and 161°9' E. It's a most north-eastern region of Yakutia, so it's suitable for paleolimnological investigations. The investigated lakes are situated along the 200 km transect crossing 3 vegetation zones: polygonal tundra, forest tundra and northern taiga. The main aims were establishing a calibration dataset for paleoenvironmental reconstructions by using aquatic organisms, investigation of limnological variables and the influence of the environmental conditions on distribution of aquatic organisms in Yakutian lakes. The modern benthic fauna of the lakes is represented by 89 taxa from 14 taxonomic groups. The most abundant group was Mollusca. The most taxonomically diverse group was Chironomidae. A unique for this region species were discovered, such as Cincinna kamchatica, Physa jarochnovitschae, Colymbetes dolabratus, Ilybius wasastjernae, Xestochironomus sp., Agrypnia sp. etc. Cluster analysis of taxonomical composition of the benthic fauna of these lakes showed high dependency to vegetation zones. The highest levels of hydrobiological indexes (Shannon, Evenness, species richness) were registered in forest tundra. CCA analysis showed that the most influential factors in species distribution were climate-dependant factors, such as mean Tair of July, pH and water depth. Data from taxonomical analysis of Chironomidae group were used for establishing a calibration dataset for paleoenvironmental reconstructions.

  17. First phase of macroinvertebrate repopulation of Lake Orta (Buccione Basin after liming

    Directory of Open Access Journals (Sweden)

    Angela BOGGERO

    2001-02-01

    Full Text Available The research described here was performed during 1993 and 1994 in the context of studies on the recovery of Lake Orta from acidification after the liming conducted from May 1989 to June 1990. The causes of the pollution were due to the oxidation of ammonium sulphate discharged from a factory producing rayon by a cupro-ammoniacal method and to the loads of heavy metals (Cu, Cr, Ni, Zn derived from plating factories. One year after liming, an increase in pH and a marked decrease in metal concentrations were observed, and as a consequence some qualitative and quantitative changes were observed in 1992-93 in the planctonic communities and in the littoral macrobenthic fauna. This paper presents qualitative and quantitative data on macrobenthos collected along a transect between the littoral and the maximal depth in the Buccione Basin, which was directly affected by the effluents of the rayon factory. The data revealed some quantitative repopulation of this community, especially along the littoral. Qualitatively, however, the macrobenthos was still quite poor, consisting essentially of Oligochaeta and Diptera Chironomidae. The former were rare and mainly represented by Naididae between 15 and 22 m, while the Tubificidae were well represented in the littoral and the profundal zones. As regards the Chironomidae, the genera Procladius and Chironomus gr. thummi extended as far as the maximum depth, while others, such as Ablabesmyia, Parakiefferiella bathophila and Dicrotendipes gr. nervosus were mostly distributed in the littoral layers. Among the other taxonomic groups only the Trichoptera and the Diptera Ceratopogonidae were quantitatively significant. However, many systematic entities typical of the less polluted Italian subalpine lakes are still absent. In fact, the colonisation of Lake Orta by macrobenthic organisms is still influenced by the increased concentrations of heavy metals in the sediment precipitated from the water column. The research

  18. 日本千曲川河中游成年水生昆虫羽化后的沿边扩散与沿岸植被的关系%LATERAL DISPERSAL OF ADULT AQUATIC INSECTS FOLLOWING EMERGENCE FROM THE MIDDLE REACHES OF THE CHIKUMA RIVER ( HONSHU ISLAND, JAPAN) IN RELATION TO WATERFRONT VEGETATION

    Institute of Scientific and Technical Information of China (English)

    Kimio HIRABAYASHI; Goro KIMURA1; Yachiyo FUKUNAGA; Kumiko TSUKADA; Makoto ANDO; Atsushi HATTORI

    2006-01-01

    To clarify the role of waterfront vegetation of floodplains for adult aquatic insects, Trichoptera and Diptera (Tipulidae and Chironomidae), in the middle reaches of the Chikuma River from May to July, an investigation of the number of these insects was conducted by trapping in each type of vegetation using board traps. A total of 2608.5 adults/m2 were collected, and we identified a total of 26 species belonging to three taxa, i. e., seven species of Trichoptera, four species of Tipulidae and 15 species of Chironomidae. The most abundant species was Psychomyia acutipennis in Trichoptera (95.7%). There was a significant difference between the number of P. acutipennis in the all vegetation area (especially, Salix subfragilis ) and the control area (no vegetation)during the investigation periods (P < 0.05, Mann-Whitney U-test). Other taxa did not show a significant difference between the all vegetation area and the control. Moreover, the numbers of adult P. acutipennis showed a significant difference in height on each vegetation. In the case of Vicia villosa varia and V. villosa varia plus dead Phragmites australis, the highest number was caught in the traps set in the boundary between one plant and the plant above (P<0.05, Steel-Dwass Test) in May. On the other hand,in the case of almost all vegetation during the investigation periods (except of S. subfragilis in May, Melilotus officinalis plus dead P. australis in June), the highest number was caught in the traps set up within the vegetation (P < 0.05, Steel-Dwass Test). As a result, a significant difference was observed in the number of trapped P. acutipennis according to the vegetation and its height.It is suggested that the existence of multiple types of vegetation in the floodplain plays an important role for maintaining the diversity of the fauna there.

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

    Science.gov (United States)

    Albertoni, E F; Prellvitz, L J; Palma-Silva, C

    2007-08-01

    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 micro 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. PMID:18094833

  20. Anadromous sea lampreys (Petromyzon marinus) are ecosystem engineers in a spawning tributary

    Science.gov (United States)

    Hogg, Robert S.; Coghlan Jr., Stephen M.; Zydlewski, Joseph; Simon, Kevin S.

    2014-01-01

    Sea lampreys (Petromyzon marinus) disturb the substratum during nest construction and alter the physical habitat, potentially affecting other stream organisms. We quantified differences in depth, velocity, fine-sediment coverage, embeddedness, intragravel permeability and benthic invertebrate assemblages (density and diversity) among nest mounds, nest pits and undisturbed reference locations over a 4-month period after June spawning. In 2010 and 2011, immediate and persistent effects of nest construction were assessed in summer (July) and in autumn (late September to early October), respectively. Randomly selected nests were sampled annually (25 each in summer and autumn). Nest construction increased stream-bed complexity by creating and juxtaposing shallow, swift, rocky habitat patches with deep, slow, sandy habitat patches. Mounds had a 50–143% less cover of fine sediment, and a 30–62% reduction in embeddedness, compared to pits and reference locations. These physical changes persisted into the autumn (almost 4 months). Five insect families contributed 74% of the benthic invertebrate abundance: Chironomidae (27%), Hydropsychidae (26%), Heptageniidae (8%), Philopotamidae (7%) and Ephemerellidae (6%). Densities of Hydropsychidae, Philopotamidae and Heptageniidae were up to 10 times greater in mounds than in pits and adjacent reference habitat. In summer, mounds had twice the density of Chironomidae than did pits, and 1.5 times more than reference habitats, but densities were similar among the habitats in autumn. These results suggest that spawning sea lampreys are ecosystem engineers. The physical disturbance caused by nest-building activity was significant and persistent, increasing habitat heterogeneity and favouring pollution-sensitive benthic invertebrates and, possibly, drift-feeding fish.

  1. Small ecosystem engineers as important regulators of lake's sediment respiration.

    Science.gov (United States)

    Baranov, Victor; Lewandowski, Joerg; Krause, Stefan; Romeijn, Paul

    2016-04-01

    Although shallow lakes are covering only about 1.5% of the land surface of the Earth, they are responsible for sequestration of carbon amounts similar or even larger than those sequestered in all marine sediments. One of the most important drivers of the carbon sequestration in lakes is sediment respiration. Especially in shallow lakes, bioturbation, i.e. the biogenic reworking of the sediment matrix and the transport of fluids within the sediment, severely impacts on sediment respiration. Widespread freshwater bioturbators such as chironomid larvae (Diptera, Chironomidae) are building tubes in the sediment and actively pump water through their burrows (ventilation). In the present work we study how different organism densities and temperatures (5-30°C) impact on respiration rates. In a microcosm experiment the bioreactive resazurin/resorufin smart tracer system was applied for quantifying the impacts of different densities of Chironomidae (Diptera) larvae (0, 1000, 2000 larvae/m2) on sediment respiration. Tracer transformation rates (and sediment respiration) were correlated with larval densities with highest transformation rates occurring in microcosms with highest larval densities. Respiration differences between defaunated sediment and sediment with 1000 and 2000 larvae per m2 was insignificant at 5 °C, and was progressively increasing with rising temperatures. At 30 °C respiration rates of sediment with 2000 larvae per m2 was 4.8 times higher than those of defaunated sediment. We interpret this as an effect of temperature on larval metabolic and locomotory activity. Furthermore, bacterial communities are benefiting from the combination of the high water temperatures and bioirrigation as bacterial community are able to maintain high metabolic rates due to oxygen supplied by bioirrigation. In the context of global climate change that means that chironomid ecosystem engineering activity will have a profound and increasing impact on lake sediment respiration

  2. 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.

  3. Reconstruction of Centennial and Millennial-scale Climate and Environmental Variability during the Holocene in the Central Canadian Arctic

    Science.gov (United States)

    Rolland, N.; Porinchu, D.; MacDonald, G.; Moser, K.

    2007-12-01

    The Arctic and sub-Arctic regions are experiencing dramatic changes in surface temperature, sea-ice extent, glacial melt, river discharge, soil carbon storage and snow cover. According to the IPCC high latitude regions are expected to warm between 4°C and 7°C over the next 100 years. The magnitude of warming and the rate at which it occurs will dwarf any previous warming episodes experienced by latitude regions over the last 11,000 years. It is critical that we improve our understanding of how the Arctic and sub-Arctic regions responded to past periods of warming, especially in light of the changes these regions will be experiencing over the next 100 years. One of the lines of evidence increasingly utilized in multi-proxy paleolimnological research is the Chironomidae (Insecta: Diptera). Also known as non-biting midge flies, chironomids are ubiquitous, frequently the most abundant insects found in freshwater ecosystems and very sensitive to environmental conditions. This research uses Chironomidae to quantitatively characterize climate and environmental conditions of the continental interior of Arctic Canada during the Holocene. Spanning four major vegetation zones (boreal forest, forest-tundra, birch tundra and herb tundra), the surface samples of 80 lakes recovered from the central Canadian Arctic were used to assess the relationship of 22 environmental variables with the chironomid distribution. Redundancy analysis (RDA) identified four variables, total Kjeldahl nitrogen (TKN), pH, summer surface water temperature (SSWT) and depth, which best explain the variance in the distribution of chironomids within these ecoregions. In order to provide new quantitative estimates of SSWT, a 1-component weighted average partial least square (WA-PLS) model was developed (r2jack = 0.76, RMSEP = 1.42°C) and applied downcore in two low arctic continental Nunavut lakes located approximately 50 km and 200 km north of modern treeline. This robust midge-inferred temperature

  4. 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

  5. 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.

  6. Trophic relationships between macroinvertebrates and fish in a pampean lowland stream (Argentina Relaciones tróficas entre los macroinvertebrados y peces en un arroyo de la llanura pampeana (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.Se evaluó la dieta y las relaciones tróficas entre los macroinvertebrados Phyllogomphoides joaquini Rodrigues Capítulo, 1992 y Coenagrionidae (Odonata, Chironomidae (Diptera, Diplodon delodontus (Lamarck, 1919 (Bivalvia: Hyriidae, Pomacea canaliculata (Lamarck, 1822 (Gastropoda: Ampulariidae y los peces Pimelodella laticeps Eigenmann, 1917 (Heptapteridae y Bryconamericus iheringii (Boulenger, 1887 (Characidae en un ecosistema lótico pampásico, sobre la base del contenido estomacal y el análisis de isótopos estables. La estrategia alimentaria fue analizada mediante el método de AMUNDSEN. La contribución relativa de cada categoría alimenticia para los taxa estudiados indicó que

  7. 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

  8. Biological Assessment of Urban and Agricultural Streams in the California Central Valley (Fall 2002 Through Spring 2004)

    Science.gov (United States)

    Bacey, J.; Moncada, A.

    2005-05-01

    California has over 200,000 miles of rivers and streams that are increasingly impacted from human activities. Various agencies in the state have begun to conduct bioassessment to evaluate these impacts. We conducted a pilot study to assess potential aquatic impacts of pesticides and other human activities in two urban creeks and two agricultural creeks in the fall and spring for two years (2002-04) using a modified U.S. EPA EMAP method. All creeks showed highly impacted conditions. Water quality measurements indicated below normal dissolved oxygen levels at 44% and 15% of the sites, and elevated temperatures at 70% and 73% of the urban and agricultural sites, respectively. Physical habitat scores indicated significant impacts. Diazinon and chlorpyrifos were detected at all sites (trace to 0.212 ppb). Pyrethroids were detected in water and sediment in urban sites only (trace to 27.5 ppt). High numbers of chironomidae and very low numbers of pollution intolerant species were detected in the benthic macroinvertebrate community. Urban creeks had a higher number of pollution tolerant species compared to agricultural creeks. All sites were ecologically impacted. Mulitvariate ANOVA of macroinvertebrate metrics revealed a significant difference between urban and agricultural sites (P= 0.002) and between fall and spring seasons (P=0.036).

  9. ПИТАНИЕ ЛЕЩА ЧОГРАЙСКОГО ВОДОХРАНИЛИЩА

    OpenAIRE

    НИКИТЕНКО Е.В.; ЩЕРБИНА Г. X.

    2014-01-01

    Приводятся данные по питанию леща Чограйского водохранилища в 2010 и 2012 гг. Основными объектами потребления Abramis brama являлись личинки и куколки сем. Chironomidae, частота встречаемости которых в среднем составляла 95,4%, моллюсков -13,6%. Из хирономид массовыми в пищевом комке являлись Chironomus muratensis, Procladius gr. choreus, P. gr. ferrugineus, Polypedilum bicrenatum....

  10. Invertebrate communities of the High Arctic ponds in Hornsund

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    Luoto Tomi P.

    2016-03-01

    Full Text Available How environmental conditions influence current distributions of organisms at the local scale in sensitive High Arctic freshwaters is essential to understand in order to better comprehend the cascading consequences of the ongoing climate change. This knowledge is also important background data for paleolimnological assessments of long-term limnoecological changes and in describing the range of environmental variability. We sampled five limnologically different freshwater sites from the Fuglebergsletta marine terrace in Hornsund, southern Svalbard, for aquatic invertebrates. Invertebrate communities were tested against non-climatic environmental drivers as limnological and catchment variables. A clear separation in the communities between the sites was observed. The largest and deepest lake was characterized by a diverse Chironomidae community but Cladocera were absent. In a pond with marine influence, crustaceans, such as Ostracoda, Amphipoda, and calanoid Copepoda were the most abundant invertebrates. Two nutrient-rich ponds were dominated by a chironomid, Orthocladius consobrinus, whereas themost eutrophic pond was dominated by the cladoceran Daphnia pulex, suggesting decreasing diversity along with the trophic status. Overall, nutrient related variables appeared to have an important influence on the invertebrate community composition and diversity, the trophic state of the sites being linked with their exposure to geese guano. Other segregating variables included water color, presence/absence of fish, abundance of aquatic vegetation and lake depth. These results suggest that since most of these variables are climate-driven at a larger scale, the impacts of the ongoing climate change will have cumulative effects on aquatic ecosystems.

  11. The human impact on benthic community structure and dynamics of different ecosystems from Lunca Mureșului Nature Park (West of Romania

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    Andreea A. Marin

    2011-01-01

    Full Text Available The anthropic impact, which takes various forms, changes the water quality parameters anddisturb the living environment of benthic macroinvertebrates. The present study aims to track the waypollution sources influence the macrozoobenthic community. Collecting quantitative samples, at differentseasons, from Mureș River and Cărămidăriei Lake, within the area of Lunca Mureșului Nature Park beforeand after each major pollution source, shows the way pollution affects, both qualitatively andquantitatively, the community of benthic invertebrates. 9 groups of benthic invertebrates were identified,their density, abundance and frequency undergoing changes from one station to another and from oneseason to another. When the river flows through the park, the benthic community reflects strong waterquality degradation of Mureș River. The river, naturally flowing on a long distance allows, through theself-purification process, an improvement in water quality emphasized by the occurrence of somesensitive groups to pollution which disappear completely once the tributary stream Mureșelul and othernon-purified waters from the town of Pecica flow into the river. The seasonal dynamics of dominantgroups (Oligochaeta, Diptera-Chironomidae suggests a similarity, recording high values within theautumn-winter time interval.

  12. 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.

  13. Effects of season and altitude on copper and zinc concentrations in benthos (Chironomids and Gammarids and sediment

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    Arash Javanshir

    2013-04-01

    Full Text Available Concentration of heavy metals in aquatic ecosystems is considered as an important environmantal issue. In this study, the Namrood River located in Firoozkooh (Tehran province, Iran was assessed for the existence of heavy metals. The Namrood river is situated by the main road being by pollutants from tourism and recreational centers, gas stations, sewage of villages, agricultural wastewater and fish culture effluent. The water is extremely contaminated in some parts and possibly contains heavy metals. In the present study, two stations up- and downstream were determined to sample the sediments and Chironomidae and Gammarus pluex in both cold and warm seasons of the year (middle of March and middle of August. The copper and zinc were measured in sediment and benthos. The results showed that copper and zinc concentrations ranged 0.170-0.966 and 0.187-3.846 ppm, respectively. Sediments of the upstream station had the highest copper concentration among the samples in both cold and warm seasons of the year.

  14. Chironomid assemblages along environmental gradients in New York City's drinking water tributaries, New York, USA.

    Science.gov (United States)

    Kratzer, E. B.; Jackson, J. K.; Arscott, D. B.; Aufdenkampe, A. K.; Dow, C. L.; Kaplan, L. A.; Newbold, J. D.; Sweeney, B. W.

    2005-05-01

    Chironomidae are diverse and abundant in streams and rivers and are often included in water quality and pollution evaluations. We examined distribution patterns of chironomid genera from 60 sites in the 2 regions (East and West of the Hudson River) that are the source of New York City's drinking water. These watersheds range from forested to urbanized. Average midge density ranged from 3320-68813/m2 across all sites, and a total of 75 genera were identified over 3 years. Orthocladius and Cricotopus were the most abundant genera in both regions. Tanytarsus and Sublettea were also abundant in the West whereas Micropsectra and Eukiefferiella were abundant in the East. Multivariate analyses suggest that midge assemblages differed along land cover gradients. Nonmetric Multidimensional Scaling explained 73% of the spatial variation in chironomid assemblages from the western region, and 86% of the spatial variation from the eastern region. Western axes were correlated with population density and total roads in the watershed, percent cropland and farmsteads, and numerous other variables associated with agriculture and development. Eastern axes were correlated with wastewater treatment plant discharge, chlorophyll, total roads, and transportation land cover. Some genera-specific abundance responses were associated with certain land cover gradients.

  15. Acute toxicity of cadmium, lead, zinc, and their mixtures to stream-resident fish and invertebrates.

    Science.gov (United States)

    Mebane, Christopher A; Dillon, Frank S; Hennessy, Daniel P

    2012-06-01

    The authors conducted 150 tests of the acute toxicity of resident fish and invertebrates to Cd, Pb, and Zn, separately and in mixtures, in waters from the South Fork Coeur d'Alene River watershed, Idaho, USA. Field-collected shorthead sculpin (Cottus confusus), westslope cutthroat trout (Oncorhynchus clarkii lewisi), two mayflies (Baetis tricaudatus and Rhithrogena sp.), a stonefly (Sweltsa sp.), a caddisfly (Arctopsyche sp.), a snail (Gyraulus sp.), and hatchery rainbow trout (Oncorhynchus mykiss), were tested with all three metals. With Pb, the mayflies (Drunella sp., Epeorus sp., and Leptophlebiidae), a Simuliidae black fly, a Chironomidae midge, a Tipula sp. crane fly, a Dytiscidae beetle, and another snail (Physa sp.), were also tested. Adult westslope cutthroat trout were captured to establish a broodstock to provide fry of known ages for testing. With Cd, the range of 96-h median effect concentrations (EC50s) was 0.4 to >5,329 µg/L, and the relative resistances of taxa were westslope cutthroat trout ≈ rainbow trout ≈ sculpin trout trout trout trout ≈ sculpin trout fry, a pattern of decreasing resistance with increasing fish size was observed. In metal mixtures, the toxicities of the three metals were less than additive on a concentration-addition basis. PMID:22488500

  16. 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.

  17. Carnivory during Ontogeny of the Plagioscion squamosissimus: A Successful Non-Native Fish in a Lentic Environment of the Upper Paraná River Basin

    Science.gov (United States)

    Neves, Mayara Pereira; Delariva, Rosilene Luciana; Guimarães, Ana Tereza Bittencourt; Sanches, Paulo Vanderlei

    2015-01-01

    This study evaluated feeding patterns and ontogenetic variations in a non-native fish species (Plagioscion squamosissimus) in an isolated lake in the Upper Paraná River floodplain. Quarterly samplings were performed from April 2005 to February 2006 using plankton nets to capture larvae, seining nets for juveniles, and gill nets and trammel for adults. Stomach contents (n = 378) were examined according to the volumetric method in which the volume of each food item was estimated using graduated test tubes or a glass counting plate. During early development (larval stage), P. squamosissimus consumed mainly Cladocera and Copepoda. Juveniles showed a more diverse diet, including shrimp (Macrobrachium amazonicum), fish, aquatic insects (Trichoptera, Ephemeroptera, Chironomidae and pupae of Diptera) and plants. It was notable the high proportion of cannibalism (23.3%) in this stage. Adults consumed predominantly shrimp and fish. The use of food resources varied significantly between development stages (ANOSIM; r = 0.458; pcarnivorous habit from the early stages of P. squamosissimus and the predominant use of M. amazonicum by adults have important roles in feeding patterns of the species, suggesting a major contribution to its success and establishment, especially in lentic environments. PMID:26524336

  18. Effect of land use on the composition, diversity and abundance of insects drifting in neotropical streams.

    Science.gov (United States)

    Gimenez, B C G; Lansac-Tôha, F A; Higuti, J

    2015-11-01

    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. PMID:26602342

  19. Relationships between lake water chemistry and benthic macroinvertebrates in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Keith M. SOMERS

    2010-08-01

    Full Text Available Sulphur and nitrogen emissions in the Athabasca Oil Sands Region (AOSR are a threat to regional lentic ecosystems. Benthic macroinvertebrates have been used successfully elsewhere to monitor the impacts of acid emissions on water bodies and the opportunity exists to implement a regional lentic biomonitoring program in the AOSR. Metrics are often used to assess the impacts of anthropogenic stressors because they describe biological conditions through a variety of measures. The selection of appropriate metrics is an integral component of any biomonitoring program and it depends on the in situ relationships between water chemistry and benthic macroinvertebrates. In order to establish these relationships we compared lake water chemistry parameters with benthic macroinvertebrate communities and metric scores from 32 lakes in the AOSR through Redundancy Analyses. Lake acidity correlates positively with Hyallelidae and negatively with Chironomidae and Oligochaeta while dissolved organic carbon is also an important determinant of benthic macroinvertebrate community composition. A number of metrics were strongly correlated with lake acidity and the following compositional metrics proved to be the most suitable for monitoring acidification in the AOSR: % Diptera, % Oligochaeta, % EPT, Total Ephemeroptera and Total Trichoptera.

  20. Breakdown rates and macroinvertebrate colonisation of alder (Alnus glutinosa leaves in an acid lake (Lake Orta, N Italy, before, during and after a liming intervention

    Directory of Open Access Journals (Sweden)

    Giuliano BONOMI

    2001-02-01

    Full Text Available To test the effectiveness of the liming intervention on Lake Orta, the speed of leaves decay and of colonisation processes by macrobenthonic fauna were studied on alder leaves (Alnus glutinosa placed on the bottom of the lake and recovered after appropriate time intervals. Experiments were performed at two sites (North and South and two depths (-3 and –18 m, during three successive winters: 1988-1989 (pre-liming, 1989-1990 (liming, 1990-1991 (post-liming. Two main results emerged: 1 alder leaves, which are known to have a medium to high decaying speed in a number of aquatic environments, behave in Lake Orta as a low speed species. Decaying processes in the three years are significantly different only in station N3, where the mean breakdown rate in 1988- 1989 is more than twice that measured in the two subsequent winters. 2 The species richness of colonising benthic fauna is low: the community is made up almost exclusively of Chironomidae, which form 70 to 100% of the whole population; among them, the genus Phenopsectra is always present, while Tanytarsus was collected only during the first year and in the less deep sampling sites. The mean population abundances were higher before liming.

  1. Holocene temperature history of northern Iceland inferred from subfossil midges

    Science.gov (United States)

    Axford, Yarrow; Miller, Gifford H.; Geirsdóttir, Áslaug; Langdon, Peter G.

    2007-12-01

    The Holocene temperature history of Iceland is not well known, despite Iceland's climatically strategic location at the intersection of major surface currents in the high-latitude North Atlantic. Existing terrestrial records reveal spatially heterogeneous changes in Iceland's glacier extent, vegetation cover, and climate over the Holocene, but these records are temporally discontinuous and mostly qualitative. This paper presents the first quantitative estimates of temperatures throughout the entire Holocene on Iceland. Mean July temperatures are inferred based upon subfossil midge (Chironomidae) assemblages from three coastal lakes in northern Iceland. Midge data from each of the three lakes indicate broadly similar temperature trends, and suggest that the North Icelandic coast experienced relatively cool early Holocene summers and gradual warming throughout the Holocene until after 3 ka. This contrasts with many sites on Iceland and around the high-latitude Northern Hemisphere that experienced an early to mid-Holocene "thermal maximum" in response to enhanced summer insolation forcing. Our results suggest a heightened temperature gradient across Iceland in the early Holocene, with suppressed terrestrial temperatures along the northern coastal fringe, possibly as a result of sea surface conditions on the North Iceland shelf.

  2. 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 behaviour - 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. PMID:26841188

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

    International Nuclear Information System (INIS)

    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/m2 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)

  4. Kesikköprü (Ankara) baraj gölündeki bentik organizma türleri ve mevsimsel değişimleri

    OpenAIRE

    AHISKA, Seyhan

    1999-01-01

       Nisan 1995 - Mayıs 1996 tarihleri arasında Kesiköprü Baraj Gölü (Ankara) 'nde yapılan bu çalışmada, bentik fauna, biyomas değerleri ve mevsimsel değişimler, gölün bazı fiziksel ve kimyasal özellikleri ile birlikte araştırılmıştır. Göldeki bentik faunanın sayısal olarak % 26,88 'ini Chironomidae larvaları, % 32,59' unu Oligochaeta türü ve % 40,5 'ini diğer bentik omurgasız gruplarının oluşturduğu saptanmıştır. Bentik faunanın yaş ağırlığı yıllık orta l...

  5. Late Quaternary paleoclimate of western Alaska inferred from fossil chironomids and its relation to vegetation histories

    Science.gov (United States)

    Kurek, Joshua; Cwynar, Les C.; Ager, Thomas A.; Abbott, Mark B.; Edwards, Mary E.

    2009-05-01

    Fossil Chironomidae assemblages (with a few Chaoboridae and Ceratopogonidae) from Zagoskin and Burial Lakes in western Alaska provide quantitative reconstructions of mean July air temperatures for periods of the late-middle Wisconsin (˜39,000-34,000 cal yr B.P.) to the present. Inferred temperatures are compared with previously analyzed pollen data from each site summarized here by indirect ordination. Paleotemperature trends reveal substantial differences in the timing of climatic warming following the late Wisconsin at each site, although chronological uncertainty exists. Zagoskin Lake shows early warming beginning at about 21,000 cal yr B.P., whereas warming at Burial Lake begins ˜4000 years later. Summer climates during the last glacial maximum (LGM) were on average ˜3.5 °C below the modern temperatures at each site. Major shifts in vegetation occurred from ˜19,000 to 10,000 cal yr B.P. at Zagoskin Lake and from ˜17,000 to 10,000 cal yr B.P. at Burial Lake. Vegetation shifts followed climatic warming, when temperatures neared modern values. Both sites provide evidence of an early postglacial thermal maximum at ˜12,300 cal yr B.P. These chironomid records, combined with other insect-based climatic reconstructions from Beringia, indicate that during the LGM: (1) greater continentality likely influenced regions adjacent to the Bering Land Bridge and (2) summer climates were, at times, not dominated by severe cold.

  6. 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. PMID:26811787

  7. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas.

    Science.gov (United States)

    Freeland-Riggert, Brandye T; Cairns, Stefan H; Poulton, Barry C; Riggert, Christopher 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. PMID:26986207

  8. Occurrence of polycyclic aromatic hydrocarbons below coal-tar-sealed parking lots and effects on stream benthic macroinvertebrate communities

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  10. Reconstructing fish populations using Chaoborus (Diptera: Chaoboridae) remains a review

    Science.gov (United States)

    Sweetman, Jon N.; Smol, John P.

    2006-08-01

    Fish are an important component of many lakes, and a valuable resource in many countries, yet knowledge of how fish populations have fluctuated in the past is very limited. One potential source of information on fisheries dynamics is paleolimnology. This paper reviews the use of the sedimentary remains of the dipteran insect Chaoborus (commonly referred to as the phantom midge) in reconstructing past presence or absence of fish populations. We provide a brief overview of the ecology of Chaoborus larvae, and review the factors believed to be important in determining their distribution and abundance. In particular, we outline the important role fish have in structuring chaoborid assemblages. We highlight several recent studies utilizing Chaoborus remains in reconstructing past fish dynamics, including their use in determining the effects of acidification and piscicide additions on fish populations, and to tracing fish introductions into previously fishless lakes. We conclude by discussing the potential applications of other aquatic invertebrates, such as the Cladocera and Chironomidae, to infer changes in fish populations, and suggest that by integrating the information provided by these different proxies, we may further improve our ability to infer changes in past fish populations.

  11. Extraction of methylmercury from tissue and plant samples by acid leaching

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  12. Using stable isotope analysis in stream mesocosms to study potential effects of environmental chemicals on aquatic-terrestrial subsidies.

    Science.gov (United States)

    Wieczorek, Matthias V; Kötter, Denise; Gergs, René; Schulz, Ralf

    2015-09-01

    While recent research has provided evidence that the emergence of merolimnic insects (species with an aquatic larval stage) provides a considerable energy subsidy to riparian food webs, it has also shown that merolimnic insects may serve as a vector for contaminants. Therefore, riparian food webs may be at risk from either an aquatic-terrestrial transfer of contaminants or from the contaminant-driven reductions of emerging merolimnic insects. The objective of the present study was to develop an integrated stream mesocosms test design capable of identifying these inter-ecosystem boundary effects and to provide a comprehensive approach as a basis for ecotoxicological testing. We chose the widely distributed web-building spider Tetragnatha extensa as a representative species for riparian predators. Trophic aspects of riparian food webs were investigated by stable isotope analysis of carbon (δ(13)C) and nitrogen (δ(15)N). Utilization of stable isotope ratios provided detailed information on the riparian food web structure and the dietary composition of T. extensa. Merolimnic invertebrates (mainly Cloeon spp. and Chironomidae) were found to contribute up to 71 % of T. extensa's diet, demonstrating their importance in riparian food webs in ecotoxicological mesocosm testing. This study provides a conceptual and methodological basis for assessing aquatic insect emergence-related pollutant transfer or effect translation from aquatic to adjacent terrestrial systems. PMID:25586616

  13. Midges as palaeoindicators of lake productivity, eutrophication and hypolimnetic oxygen

    Science.gov (United States)

    Brodersen, Klaus Peter; Quinlan, Roberto

    2006-08-01

    The sedimentary record from lakes can be used as an archive of past environmental changes and for events related to anthropogenic activities in the catchment area. In this paper, we review the more recent studies on zoobenthos responses to changes in lake productivity and to altered sublittoral and hypolimnetic oxygen conditions, as reflected from subfossil midge (Diptera: Chironomidae) assemblages and palaeostratigraphies. We discuss how the importance of different environmental variables is scale dependent in both time and space and we summarize some of the classical and general patterns in chironomid palaeolimnology. The recent advances in quantitative reconstructions using chironomid transfer functions and numerical analyses are presented and compared. A consensus ranking of species trophic optima and respiratory adaptations from published data sets showed good agreement. Factors such as lake depth, stratification patterns, water level change, sediment conditions, submerged vegetation and ecological thresholds are all important for interpretation of palaeolimnological trajectories. We use previously published and new data to document how these factors determine, change or preserve the "lake identity" over time. We conclude that subfossil chironomids have proven to be very effective indicators for lake trophic development (productivity) and hypolimnetic oxygen conditions. Challenges in interpreting the subfossil chironomid record include the interaction between a range of scale-dependent variables and processes.

  14. A 2000-yr-long multi-proxy lacustrine record from eastern Baffin Island, Arctic Canada reveals first millennium AD cold period

    Science.gov (United States)

    Thomas, Elizabeth K.; Briner, Jason P.; Axford, Yarrow; Francis, Donna R.; Miller, Gifford H.; Walker, Ian R.

    2011-05-01

    We generate a multi-proxy sub-centennial-scale reconstruction of environmental change during the past two millennia from Itilliq Lake, Baffin Island, Arctic Canada. Our reconstruction arises from a finely subsectioned 210Pb- and 14C-dated surface sediment core and includes measures of organic matter (e.g., chlorophyll a; carbon-nitrogen ratio) and insect (Diptera: Chironomidae) assemblages. Within the past millennium, the least productive, and by inference coldest, conditions occurred ca. AD 1700-1850, late in the Little Ice Age. The 2000-yr sediment record also reveals an episode of reduced organic matter deposition during the 6th-7th century AD; combined with the few other records comparable in resolution that span this time interval from Baffin Island, we suggest that this cold episode was experienced regionally. A comparable cold climatic episode occurred in Alaska and western Canada at this time, suggesting that the first millennium AD cold climate anomaly may have occurred throughout the Arctic. Dramatic increases in aquatic biological productivity at multiple trophic levels are indicated by increased chlorophyll a concentrations since AD 1800 and chironomid concentrations since AD 1900, both of which have risen to levels unprecedented over the past 2000 yr.

  15. The structure of insect larvae complexes in the soil of shore zone of lake Drukshiai during the first period of Ignalina NPP operation

    International Nuclear Information System (INIS)

    Complexes of insect larvae were investigated in 1986-1988 in five standard points situated 0.2 to 5 km from the nuclear power plant (NPP ) on the shores of Lake Drukshiai and in the control point on the shore of Lake Zheimenis, 50 km from the plant. The greatest larvae abundance and species variety were found on bogged shores of Lake Drukshiai, 5 km from the nuclear power plant. The lowest abundance was found on the eastern sandy shores (Mialka) also 5 km from the plant. The variety of larvae species was the greatest (58) in the control point, their abundance being close to that in Shashkai and canal. After starting the NPP, larvae species variety increased in all standard points 2-8 times, and in the bogged points their abundance also increased 1.5-3.5 times. On the sandy shore of Mialka the amount of larvae reduced nearly 18 times and was at its minimum after starting the plant. Starting the plant influenced also the dominant structure of larvae species variety. Before starting, larvae of the family Chironomidae were eudominant only in one point, whereas after starting the plant they became eudominant in all points except that of Mialka, where larvae of the family Sciomyzidae became eudominant. (author).12 refs., 4 tabs., 1 fig

  16. Fauna fitotelmata en las bromelias Aechmea fendleri André y Aechmea fendleri y Aechmea fendler del Parque Nacional San Esteban, Venezuela stellata S c h u l t d e l P a r q u e N a c i o n a l S a n E s t e b a n , V

    Directory of Open Access Journals (Sweden)

    Jonathan Liria

    2013-04-01

    Full Text Available El presente trabajo caracteriza la asociación de mosquitos y otros invertebrados sobre bromelias del Parque Nacional San Esteban del Estado Carabobo, Venezuela. Se estudiaron 18 plantas de Aechmea fendleri (11 Aechmea fendleri (1 1 Aechmea fendleri y Hohenbergia stellata (7 durante las épocas lluvia (Septiembre 2004 y sequía (Marzo 2005. Fueron colectados un total de 2020 macroinvertebrados. Los taxa más importantes fueron las Familias Chironomidae (43%, Culicidae (25% y Chaoboridae (6% del Orden Diptera, y Scyrtidae (5% del Orden Coleoptera. En Culicidae las especies más abundan- tes fueron: Culex consolador (31%, Cx. neglectus (27% y Wyeomyia celaenocephala (17%. La mayor abundancia y riqueza se encontró en la época de sequía, con el aumento de diversidad en Culicidae. La diversidad y equitabilidad de macroinvertebrados fue mayor H. stellata , pero similares entre estaciones para las comunidades de A. fendleri y A. fendleri y A. fendleri H. stellata .

  17. Assessing the performance of macroinvertebrate metrics in the Challhuaco-Ñireco System (Northern Patagonia, Argentina

    Directory of Open Access Journals (Sweden)

    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.

  18. Colonização de macroinvertebrados bentônicos em detritos foliares em um riacho de primeira ordem na Floresta Atlântica do nordeste brasileiro

    Directory of Open Access Journals (Sweden)

    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%.

  19. Effects of engineered application of Eichhornia crassipes on the benthic macroinvertebrate diversity in Lake Dianchi, an ultra-eutrophic lake in China.

    Science.gov (United States)

    Zhang, Zhiyong; Wang, Zhi; Zhang, Zhenghua; Zhang, Junqian; Guo, Junyao; Li, Enhua; Wang, Xuelei; Liu, Haiqin; Yan, Shaohua

    2016-05-01

    An ecological engineering project with confined growth of 1.5 km(2) of Eichhornia crassipes was implemented to remove pollutants in Lake Dianchi. To assess the ecological effects of this project on benthic macroinvertebrate assemblages, a 1-year investigation at the areas inside and outside E. crassipes mats was conducted from May 2013 to May 2014. All the 10 sampling sites in the areas were grouped into two statistically significant clusters mainly corresponding to inside and outside E. crassipes mat areas (EMAs), by clustering analysis. E. crassipes reduced the densities of pollution indicator taxa (e.g., Oligochaeta and Chironomidae larvae); thus, the total densities of benthic macroinvertebrates at the area inside EMAs (mean 328.2 ind./m(2)) were slightly lower than that at the area outside EMAs (mean 505.6 ind./m(2)). Four functional feeding groups including 38 species of benthic macroinvertebrates were collected at the area inside EMAs, while only three functional feeding groups containing 17 species were collected at the area outside EMAs. The biodiversity indices (Shannon-Weiner, Margalef, Simpson, and Peilou indices) and K-dominance curves also showed higher diversity of benthic macroinvertebrates at the area inside EMAs than at the area outside EMAs. These results suggested that a certain scale of engineering application of E. crassipes was beneficial to benthic macroinvertebrate communities in the ultra-eutrophic Lake Dianchi and it could be used as a pioneer species in ultra-eutrophic lake for pollutant removal. PMID:26780060

  20. A Benthic Macroinvertebrate Multimetric Index for Assessment of the Ecological Integrity of Northeast Streams, Thailand

    Directory of Open Access Journals (Sweden)

    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.

  1. Assessment of benthic macroinvertebrates at Nile tilapia production using artificial substrate samplers.

    Science.gov (United States)

    Moura E Silva, M S G; Graciano, T S; Losekann, M E; Luiz, A J B

    2016-05-17

    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 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. PMID:27191461

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

    International Nuclear Information System (INIS)

    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.

  3. 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.

  4. Successional trends of the benthic macroinvertebrate community in a new southeastern cooling reservoir

    International Nuclear Information System (INIS)

    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/m2 in 1986 to 8948.1--11,694.1 organisms/m2 in 1988). Annual mean biomass also increased (ranging from 0.749--0.907g AFDM/m2 in 1986 to 2074--11,322 g AFDM/m2 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

  5. Differences Found in the Macroinvertebrate Community Composition in the Presence or Absence of the Invasive Alien Crayfish, Orconectes hylas

    Science.gov (United States)

    Freeland-Riggert, Brandye T.

    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. PMID:26986207

  6. 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.

  7. Macroinvertebrates inhabiting the tank leaf terrestrial and epiphyte bromeliads at Reserva Adolpho Ducke, Manaus, Amazonas

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    Sharlene Roberta da Silva Torreias

    2011-12-01

    Full Text Available The aim of this work was to investigate the diversity of macroinvertebrates and also verify if the abundance and diversity of Diptera were influenced by the abiotic factors. The samples were collected from the epiphytic and terrestrial bromeliads G. brasiliensis (1 and 3m in wet and dry seasons at Reserva Adolpho Ducke analyzed total of 144 samples were analyzed from a total of 15,238 individuals collected. These conatined 14,097 insects and, among these, 8,258 were immature Diptera, represented by eight most abundant families: Chironomidae, Ceratopogonidae and Culicidae. The relationship of Diptera diversity was influenced by the seasons and stratifications (p= 0.01; the abundance was influenced by the volume of water (p= 0.02 and the relationship between the season and volume of water in the terrestrial bromeliads was significant (p= 0.01. This study represented the first contribution to knowledge of community of macroinvertebrates associated to bromeliads G. brasiliensis in Central Amazon.

  8. 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.

  9. 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.

  10. Next generation sequencing of fecal DNA reveals the dietary diversity of the widespread insectivorous predator Daubenton's Bat (Myotis daubentonii) in Southwestern Finland.

    Science.gov (United States)

    Vesterinen, Eero J; Lilley, Thomas; Laine, Veronika N; Wahlberg, Niklas

    2013-01-01

    Understanding predator-prey dynamics is a fundamental task in the evaluation of the adaptive capacities of species. However, direct observations or morphological identification of fecal remains do not offer an effective way to study the dietary ecology of elusive species, such as nocturnal insectivorous bats. However, recent advances in molecular techniques have opened a new method for identifying prey species from fecal samples. In this study, we amplified species-specific mitochondrial COI fragments from fecal DNA extractions from 34 individual Daubenton's bats (Myotis daubentonii) collected between 2008 and 2010 from southwestern Finland. Altogether, 128 different species of prey were identified based on a comprehensive local DNA reference library. In our study area, Daubenton's bats feed most frequently on insects of the orders Diptera (found in the diet of 94% individuals), Trichoptera (69%) and Lepidoptera (63%). The most frequent dipteran family in the diet was Chironomidae, which was found in 31 of 34 individuals. Most common prey species were chironomids Microtendipes pedellus (found in 50% of bats), Glyptotendipes cauliginellus (44%), and Procladius ferrugineus (41%). For the first time, an accurate species level list of the diet of the insectivorous Daubenton's bat (Myotis daubentonii) in Finland is presented. We report a generally applicable method for describing the arthropod diet of vertebrate predators. We compare public databases to a national database to highlight the importance of a local reference database. PMID:24312405

  11. An integrative approach to detect subtle trophic niche differentiation in the sympatric trawling bat species Myotis dasycneme and Myotis daubentonii.

    Science.gov (United States)

    Krüger, F; Clare, E L; Greif, S; Siemers, B M; Symondson, W O C; Sommer, R S

    2014-08-01

    Bats are well known for species richness and ecological diversity, and thus, they provide a good opportunity to study relationships and interaction between species. To assess interactions, we consider distinct traits that are probably to be triggered by niche shape and evolutionary processes. We present data on the trophic niche differentiation between two sympatric European trawling bat species, Myotis dasycneme and Myotis daubentonii, incorporating a wide spectrum of methodological approaches. We measure morphological traits involved in foraging and prey handling performance including bite force, weightlifting capacity and wing morphology. We then measure resulting prey consumption using both morphological and molecular diet analyses. These species closely resemble each other in morphological traits, however, subtle but significant differences were apparent in bite force and lift capacity, which are related to differences in basic body and head size. Both morphological and molecular diet analyses show strong niche overlap. We detected subtle differences in less frequent prey items, as well as differences in the exploitation of terrestrial and aquatic-based prey groups. Myotis dasycneme feeds more on aquatic prey, like Chironomidae and their pupal stages, or on the aquatic moth Acentria ephemerella. Myotis daubentonii feeds more on terrestrial prey, like Brachycera, or Coleoptera. This suggests that these bats use different microhabitats within the habitat where they co-occur. PMID:24164379

  12. The influence of urbanisation on macroinvertebrate biodiversity in constructed stormwater wetlands.

    Science.gov (United States)

    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. PMID:26245534

  13. Chironomids' Relationship with Aeromonas Species.

    Science.gov (United States)

    Laviad, Sivan; Halpern, Malka

    2016-01-01

    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, and 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 6-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. PMID:27242751

  14. Extraction of methylmercury from tissue and plant samples by acid leaching.

    Science.gov (United States)

    Hintelmann, Holger; Nguyen, Hong T

    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 CH3 201Hg+. Certified reference materials (CRM) were used to evaluate the efficiency of the procedure. The final digestion method used 5 mL of 4 mol L(-1) HNO3 at 55 degrees 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 CH3 201Hg+ 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. PMID:15662514

  15. 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.

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

    Science.gov (United States)

    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. PMID:26920532

  17. River ecosystem response to prescribed vegetation burning on Blanket Peatland.

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    Lee E Brown

    Full Text Available 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.

  18. Effectiveness of Road-Stream Crossing Improvements and Bank Stabilization in the Manistee River Watershed, MI: Response of the Benthic Macroinvertebrates

    Science.gov (United States)

    Stout, N. Y.; Wright, A. L.; Gressick, N. J.; Snyder, E. B.

    2005-05-01

    The Manistee River Watershed is a unique resource used by many individuals including the Little River Band of Ottawa Indians (LRBOI). However, the presence of excessive sediment from continued erosion of stream banks and poorly designed road-stream crossings threaten habitat quality. The U.S. EPA has recently awarded a grant to the LRBOI to improve road-stream crossings and stabilize stream banks. Our objective is to determine how these improvements affect the physical habitat of the stream and the response of macroinvertebrate assemblages. Initial results from a subset of 10 sites indicate that immediately below a restoration site, there was a decline in abundance and family richness post-restoration. Likely this was due to construction-related deposition of sand, which particularly impacted the Diptera (Simuliidae spp. and Chironomidae spp.). In contrast, fall sampling of sites further from the construction zone exhibited an increase in benthic abundance (from 204 to 816 individuals/m2). The extent to which the construction-generated sand will have impacted reaches further from the restoration site are continuing to be monitored. Although the short-term effects appear to be negative, we believe the ongoing monitoring will document an eventual improvement in the macroinvertebrate community and in overall stream ecosystem integrity.

  19. Does Nutrient Enrichment Alter the Response of Stream Macroinvertebrates to Disturbance?

    Science.gov (United States)

    Gafner, K.; Robinson, C. T.

    2005-05-01

    We examined the influence of nutrient enrichment on the response of benthic macroinvertebrates to disturbance in springbrooks of an alpine floodplain. Individual stones in three different springs were physically disturbed at frequencies of 0, 4, 8 and 16 days, and then collected on day 32. In another experiment, nutrients (slow-release fertilizer pellets) were added to one of two streams, and stones in both treated as in the first experiment. In both experiments, stones were analyzed for periphyton biomass, total invertebrate density, and the density and relative abundance of four common families: Baetidae, Nemouridae, Chironomidae, and Simuliidae. N, P, and C were analyzed for periphyton, benthic sediments and invertebrates in the 2nd experiment to test for stoichiometric changes resulting from nutrient enrichment. In the 1st experiment, disturbance affected the relative abundance of the four families. Fertilization changed the stoichiometry of periphyton, invertebrates and sediments and altered macroinvertebrate assemblages. Here, the effect of disturbance differed between the two streams, and the non-fertilized stream displayed a similar disturbance response pattern by macroinvertebrates as in the 1st experiment. These results suggest that nutrient enrichment alters the effects of physical disturbance on macroinvertebrates by changing food resource stoichiometry and shifting macroinvertebrate assemblage structure.

  20. Macroinvertebrate Communities Differences on Riverine Parts and Reservoirs of Zarrineh River

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    R. Ahmadi

    2012-01-01

    Full Text Available This study was conducted to identify present macro invertebrates fauna in reverine and reservoir parts of the Zarrinehrood River for fisheries purposes. The abundance and species composition of macro invertebrate were analyzed and compared in various parts of the Zarrinehrood River (west Azerbaijan, Iran during November 2008-February 2009 to evaluate the rivers benthic fauna as a resource of fish and fowl feeding. Totally 67 macro invertebrate species were found in Zarrinehrood River. Concerning the macro invertebrate density, a high-density was detected on the summer thanks to the development of bacteria and moderate meta zooplanktons on the rivers bed. The density of Oligochaeta was higher on the polluted sites and dipper zone of the reservoirs but the population of chironomidae larvae increased on the heterotrophic shallow areas. Patchy distribution of Gastropod, Amphipod and Trichoptera occurred in the reverie stations with high water speed and dissolved oxygen. It was concluded that different environmental characteristics and eutrophication degrees of the sampled stations seem to be the main factors that determined the macro invertebrates colonization and abundance. Therefore, preserving better trophy condition can guarantee biodiversity richness in various parts of the Zarrinehrood River.

  1. Solar and atmospheric forcing on mountain lakes.

    Science.gov (United States)

    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. PMID:27220094

  2. Ruffe (Gymnocephalus Cernuus L. Growth and Diet in Lake Dusia (Southern Lithuania

    Directory of Open Access Journals (Sweden)

    Pilinkovskij Andrej

    2014-07-01

    Full Text Available The ruffe, Gymnocephalus cernuus (L., is considered to be a food competitor with many commercially valuable fishes such as bream, Abramis brama (L., roach, Rutilus rutilus (L., pikeperch, Sander lucioperca (L., and perch, Perca fluviatilis L. This paper presents the results of an investigation into the fish community structure of Lake Dusia and the population parameters (morphometry, age, growth, diet of ruffe as one of the prevailing fish species in the lake. The fish community of Lake Dusia was dominated by ruffe, perch, and roach. The ruffe population constituted 64.1% of the fish community of the lake in relative abundance and 36.8% in biomass. An analysis of the ruffe diet revealed that Gammaridae and Chironomidae were the principal components in all age-classes. The ruffe population was comprised mainly of individuals 3+ and 4+ years of age. The mean total length (TL of ruffe was 13.39 ± 1.79 cm (minimum-maximum: 6.12-19.93 cm. The growth in length calculated using the von Bertalanffy equation was Lt = 21.3[1-e-a161(t-0,335]. Ruffe growth rates were found to slow as the fish aged. Ruffe growth variations were linked to population density, fish community structure in the water body, abundance of invertebrates (zooplankton and zoobenthos, and type of water body.

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. 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.

  8. Interspecific interactions between brown trout and slimy sculpin in stream enclosures

    Science.gov (United States)

    Ruetz, C. R., III; Hurford, A.L.; Vondracek, B.

    2003-01-01

    We conducted a 30-d manipulative experiment in Valley Creek, Minnesota, to examine interspecific interactions between juvenile brown trout Salmo trutta and adult slimy sculpin Cottus cognatus. We measured the instantaneous growth of each species in the presence and absence of the other in 1-m2 enclosures. We tested single-species (three slimy sculpins/m2 or three brown trout/m2) and combined-species (three sculpins/m2 and three trout/m2) combinations in each of six riffles. We placed a clay tile in each enclosure to evaluate the effects of fish combinations on benthic macroinvertebrates. Growth of brown trout was unaffected by the presence of slimy sculpins (P = 0.647, power [to detect 50% increase in growth] = 0.92), whereas slimy sculpin growth was less in the presence of brown trout (P = 0.038). Densities of total benthic macroinvertebrates, Chironomidae, Trichoptera, and Physa did not differ among fish combinations (P > 0.3). However, densities of Gammarus pseudolimnaeus were significantly less in the presence of brown trout irrespective of the presence of slimy sculpins (P = 0.024), which could be a causal factor underlying the interaction between brown trout and slimy sculpins. We found asymmetrical competition between brown trout and slimy sculpins in stream enclosures, with brown trout being the superior competitor. Nevertheless, the size of enclosures may have biased our results, making it more likely to detect an effect of brown trout on slimy sculpins than vice versa.

  9. Seasonal variation in Chironomid emergence from coastal pools

    Directory of Open Access Journals (Sweden)

    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.

  10. River ecosystem response to prescribed vegetation burning on Blanket Peatland.

    Science.gov (United States)

    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. PMID:24278367

  11. Contaminant biomonitoring at the Benton Lake National Wildlife Refuge in 1988

    Energy Technology Data Exchange (ETDEWEB)

    Palawski, D.U.; Jones, W.E.; DuBois, K.; Malloy, J.C.

    1991-01-01

    Trace element concentrations in sediment samples from Benton Lake National Wildlife Refuge were not elevated relative to the western U.S. geometric mean concentrations. Boron concentrations in aquatic plants approached the concentration of boron in Mallard (Anas platyrhyncos) diets that reduced hatching success. Among the three invertebrate taxa sampled, only midge larvae (Chironomidae) bioaccumulated selenium. Selenium concentrations in Eared Grebe livers exceeded the levels found in the livers of Mallards that experienced reproductive problems. Four hundred thirty-eight water bird nests were located during nest searches, and 536 eggs were examined from 179 of those nests. A minimum of 8.4% of the eggs laid contained dead embryos, and 0.1% contained abnormal embryos. Rates of embryo death and abnormality were similar to rates of presumably unpolluted natural populations. Mean selenium concentrations in Eared Grebe, Northern Pintail (Anas acuta), Mallard, and American Coot (Fulica americana) eggs exceeded the 3 micrograms/g dry weight concentration typical of natural background levels. However, only one of three deformed bird embryos had a selenium concentration greater than 3 micrograms/g dry weight. Organochlorine residues in bird eggs did not exceed concentrations believed to be harmless.

  12. [Macrobenthos community structure and its relations with environmental factors in Taihu River basin].

    Science.gov (United States)

    Gao, Xin; Niu, Cui-Juan; Hu, Zhong-Jun

    2011-12-01

    An investigation was conducted on the macrobenthos at 37 sampling sites in the Taihu River basin in August 2009 and May 2010. A total of 69 macrobenthos species were collected, of which, 15 species (21.7% of the total) were oligochaetas, 16 species (23.2%) were mollusks, 5 species (7.2%) were crustaceans, 27 species (39.1%) were aquatic insects, and 6 species (8.7%) were polychaetes. Based on the species composition and relative abundance, and by using two-way indicators species analysis (TWINSPAN) and detrended correspondence analysis (DCA), the 37 sampling sites were divided into four groups. In the first group, polychaetes and mollusks such as Nephthys sp. and Corbicula fluminea were the indicator species; in the second group, polychaetes and mollusks such as Grandidierella aihuensis and Semisulcospira libertina were the indicator species; in the third and fourth groups, the indicator species were the annelids such as Limnodrilus hoffmeisteri and the Tubifex tubifex and chironomidae larvae, respectively. The canonical correspondence analysis (CCA) indicated that water conductivity and total nitrogen were the main environmental factors affecting the distribution of macrobenthos, and the factors water depth, diaphaneity, COD(Cr), ammonium nitrogen, nitrate nitrogen, and chlorophyll a also had definite effects. PMID:22384605

  13. Body condition, food habits, and molt status of late-wintering ruddy ducks in California

    Science.gov (United States)

    Hohman, W.L.; Ankney, C.D.; Roster, D.L.

    1992-01-01

    We studied body condition, food habits, and molt status of late-wintering ruddy ducks (Oxyura jamaicensis) using drainwater evaporation ponds in the southern San Joaquin Valley, California. Levels of body fat and protein were similar by sex but varied by age (adults greater than immatures). Masses of breast and leg muscle protein were greatest in adult males and lowest in immature males, but similar in adult and immature females. Fat and protein levels in late-wintering ruddy ducks were independent of their body size. We detected no differences among sex-age classes in the proportion of animal foods consumed. Aquatic invertebrates composed 85% of the diet; midge larvae (Diptera: Chironomidae) and brine flies (Diptera: Ephydridae) were the principal taxa consumed. Molt score by feather region and overall molt score did not vary by sex or age. Light to moderate molt (25 to 50% molting feathers) was recorded in all feather regions. High levels of body fat and protein were attributed to premigratory hyperphagia and consumption of foods with a high protein:energy ratio.

  14. Study on Freshwater Macroinvertebrates of Some Tanzanian Rivers as a Basis for Developing Biomonitoring Index for Assessing Pollution in Tropical African Regions

    Directory of Open Access Journals (Sweden)

    Julius D. Elias

    2014-01-01

    Full Text Available Macroinvertebrates and physicochemical parameters were assessed at 15 sites along five rivers in Kilimanjaro region, Tanzania, with the aim of understanding their ecological status and setting a base to the development of a biological index for tropical regions. Investigated rivers that occur within Pangani basin include Karanga, Rau, Lumbanga, Sere, and Umbwe. Sampling sites were categorized according to the level of water and habitat quality as follows: reference or least impacted (4 sites, moderately impacted (5 sites, and highly impacted (6 sites sites. A total of 12,527 macroinvertebrates belonging to 13 orders and 48 families were recorded. The highest total abundance of 4,110 individuals per m2 was found in Karanga river, while Umbwe river had the lowest with 1,203 individuals per m2. Chironomidae was the most abundant family (2,588 individuals per m2 and the least were Hydridae and Thiaridae, each having 5 individuals per m2. High numbers of taxa were noted among the orders: Ephemeroptera (8, Odonata (8, Diptera (7, and Trichoptera (6. In conclusion, orders with greater diversity of macroinvertebrate families offer a wide range of tolerance to pollution and, thus can potentially be used to develop a biomonitoring index for evaluating pollution in tropical African rivers.

  15. Composition and Longitudinal Patterns of Aquatic Insect Emergence in Small Rivers of Palawan Island, the Philippines

    Science.gov (United States)

    Freitag, Hendrik

    2004-09-01

    This study presents the first emergence trap samples from streams in the Philippines and Greater Sunda. Aquatic insect emergence from two small rivers and longitudinal patterns including estuaries are compared. A decline of total emergence towards estuaries was observed, affecting all major orders. Diptera, namely Chironomidae, dominated all sites. High abundances in Ceratopogonidae, Odonata, and Coleoptera were found, compared to other emergence studies from tropical and temperate latitudes. Ephemeroptera displayed a highly variable contribution to the emergence from Palawan as well as in other comparative studies either supported by the appropriate conditions for certain functional groups or limited by environmental variables such as pH. Trichoptera are likely to tolerate a wider range of environmental conditions and they are consequently able to fill further niches where Ephemeroptera are under-represented. Except for scarce abundances of Plecoptera observed in this and other studies from the tropics, no substantial differences in emergence composition at order level existed between temperate and tropical rivers, however, with a remarkable local variation. Components of riparian and non-aquatic insects and non-emergent fauna contributing to the collections are discussed based on trap features. (

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Remobilization and export of cadmium from lake sediments by emerging insects

    Energy Technology Data Exchange (ETDEWEB)

    Currie, R.S.; Fairchild, W.L.; Muir, D.C.G. [Dept. of Fisheries and Oceans, Winnipeg, Manitoba (Canada). Freshwater Inst.

    1997-11-01

    Emerging insects including, Diptera, Odonata, Ephemeroptera, and Trichoptera were collected from Lake 382 (L382) in 1991 and 1992 to estimate quantitatively the export of Cd by aquatic insects from a natural system having elevated Cd concentrations in the water and sediment. L382 is a Canadian Shield lake, located within the Experimental Lakes Area in northwestern Ontario, that received experimental additions of Cd from 1987 to 1992. Emerging Diptera (mostly Chironomidae), Odonata, and Ephemeroptera had mean Cd concentrations of 1.41, 0.11, and 0.30 {micro}g/g wet weight, respectively. An estimated 1.32 to 3.90 g of Cd per year were exported from the sediments of L382 depending on the estimate of production rates used for these groups of insects. Approximately 0.05 to 0.17% of the whole-lake Cd load in L382 sediments was exported annually or 0.12 to 0.39% of the epilimnion Cd sediment load. Insect emergence may have resulted in greater Cd export from L382 relative to losses via the outflow. Cadmium exported from the sediments by insects may be remobilized and become more available to aquatic organisms or enter the terrestrial ecosystem and become available to insectivores.

  19. Dietary effects on fatty acid composition in muscle tissue of juvenile European eel, Anguilla anguilla (L.)

    Science.gov (United States)

    Prigge, Enno; Malzahn, Arne M.; Zumholz, Karsten; Hanel, Reinhold

    2012-03-01

    The role of intracontinental migration patterns of European eel ( Anguilla anguilla) receives more and more recognition in both ecological studies of the European eel and possible management measures, but small-scale patterns proved to be challenging to study. We experimentally investigated the suitability of fatty acid trophic markers to elucidate the utilization of feeding habitats. Eight groups of juvenile European eels were fed on eight different diets in a freshwater recirculation system at 20°C for 56 days. Three groups were fed on freshwater diets ( Rutilus rutilus, Chironomidae larvae, and Gammarus pulex) and four groups were reared on diets of a marine origin ( Clupea harengus, Crangon crangon, Mysis spec., and Euphausia superba) and one on commercial pellets used in eel aquaculture. Fatty acid composition (FAC) of diets differed significantly with habitat. FAC of eel muscle tissue seemed to be rather insensitive to fatty acids supplied with diet, but the general pattern of lower n3:n6 and EPA:ARA ratios in freshwater prey organisms could be traced in the respective eels. Multivariate statistics of the fatty acid composition of the eels resulted in two distinct groups representing freshwater and marine treatments. Results further indicate the capability of selectively restraining certain fatty acids in eel, as e.g. the n3:n6 ratio in all treatments was <4, regardless of dietary n3:n6. In future studies on wild eel, these measures can be used to elucidate the utilization of feeding habitats of individual European eel.

  20. Bioturbation enhances the aerobic respiration of lake sediments in warming lakes.

    Science.gov (United States)

    Baranov, Viktor; Lewandowski, Jörg; Krause, Stefan

    2016-08-01

    While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m(2) was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming. PMID:27484649

  1. Fauna aquatic insects in sewage maturation ponds of Kashan University of Medical Science 2005.

    Science.gov (United States)

    Dehghani, Rouhollah; Miranzadeh, Mohhamad Bagher; Yosefzadeh, Mehrnoosh; Zamani, Soheyla

    2007-03-15

    Organic materials in maturation ponds, the personal study was carried out to determine the aquatic insects living in the maturation pond of Kashan University of Medical Sciences in 2005. This was a descriptive study, 9 series of sampling including 1032 of larva, nymph and adults were collected and sent to a laboratory. Then they were diagnosed using stereo microscope and morphologic identification key. At of 1032 collected samples from 4 maturation ponds, the orders if Diptera (52%), Hempitera (24%), Ciclopodidade (12%), Hydroacarina (9.5%), Coleptera (0.77%), Aranida (0.67%), Hymenoptera (0.58%), Odonata (0.48%), were determined. The families of Chironomidae and Culicidae from Diptera order, Corixidae, Notonectidae, Cupepodae and Copepodidae families from Hemiptera order, Hydrophilidae family from Coleptera order, Aranidae family from Aranida order, Vospidae family from Hymenoptera order, Anizoptera suborder from Odonata order were determined. Maturation ponds are the artificial places where are appropriate for the growth and development of aquatic insects and also for their predators with taking in to account that some of these insects are the carriers of pathogens, make inconvenience for human and also has significant role in the cycle of changing materials, it is recommended that further specialized studies carry out in this regard. PMID:19069891

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Evaluation of the impact of acid mine drainage on the chemistry and the macrobenthos in the Carolina stream (San Luis, Argentina).

    Science.gov (United States)

    Tripole, Susana; Gonzalez, Patricia; Vallania, Adriana; Garbagnati, Marcela; Mallea, Miguel

    2006-03-01

    The purpose of this study was to evaluate the impact of acid mine drainage on the chemistry and the macrobenthos of the Carolina stream (San Luis - Argentina). Samples were obtained in the years 1997-1998 at two sites: site C(1), located 200 m upstream of the drainage, and site C(2), located 800 m downstream. The system buffer capacity was evaluated in the non - contaminated site by means of the buffer index calculation. The physico - chemical changes observed as a consequence of the contribution of acid mine drainage (AMD) were: a decreasing of pH and an increase in the ionic concentration, especially sulfate and Fe coming from the oxidation produced by chemiolithotrophic bacteria. The values obtained indicated a low buffer capacity and a high intrinsic vulnerability of the system to resist the impact originated by the AMD, producing a remarkable decreasing of pH of the receiving stream. These changes caused modifications in the original benthic community that was replaced by organisms more tolerant to the acid stress. A reduction in the abundance and in the taxonomic richness of the benthic macroinvertebrates was observed when compared with the reference station. An increase in the proportion of Chironomidae and of Acari and a decrease in the proportion of the remaining taxa were observed. The most sensitive groups were Ephemeroptera, Trichoptera and Mollusca. The community was mostly affected by the following variables: pH, conductivity, sulfate and dissolved total Fe. PMID:16565803

  4. Fluvial geomorphology and aquatic-to-terrestrial Hg export are weakly coupled in small urban streams of Columbus, Ohio

    Science.gov (United States)

    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.

  5. Land use effect on invertebrate assemblages in Pampasic streams (Buenos Aires, Argentina).

    Science.gov (United States)

    Solis, Marina; Mugni, Hernán; Hunt, Lisa; Marrochi, Natalia; Fanelli, Silvia; Bonetto, Carlos

    2016-09-01

    Agriculture and livestock may contribute to water quality degradation in adjacent waterbodies and produce changes in the resident invertebrate composition. The objective of the present study was to assess land use effects on the stream invertebrate assemblages in rural areas of the Argentine Pampa. The four sampling events were performed at six sites in four streams of the Pampa plain; two streams were sampled inside a biosphere reserve, and another one was surrounded by extensive livestock fields. The fourth stream was sampled at three sites; the upstream site was adjacent to agricultural plots, the following site was adjacent to an intensive livestock plot and the downstream site was adjacent to extensive breeding cattle plots. Higher pesticide concentrations were found at the site adjacent to agricultural plots and higher nutrient concentrations at the sites adjacent to agricultural and intensive breeding cattle plots. The invertebrate fauna were also different at these sites. Multivariate analysis showed a relationship between nutrient concentrations and taxonomic composition. Amphipoda (Hyalella curvispina) was the dominant group in the reserve and extensive breeding cattle sites, but was not present in the agricultural site. Also, Chironomidae were absent from the agricultural site while present at other sites. Gasteropoda (Biomphalaria peregrina), Zygoptera, and Hirudinea were dominant at the most impacted agricultural and intensive breeding cattle sites. PMID:27581006

  6. Influence of bauxite tailings on the structure of the benthic macroinvertebrate community in an Amazonian Lake (Lago Batata, Pará - Brazil Influência do rejeito de bauxita sobre a estrutura da comunidade de macroinvertebrados bentônicos em um lago amazônico (Lago Batata, Pará, Brasil

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    J. J. L. FONSECA

    1999-08-01

    Full Text Available This research was developed between 1993 and 1996, aiming to study the structure of the benthic macroinvertebrate community, relating it to some abiotic variables, in an amazonian lake (lago Batata, that received for ten years a great amount of bauxite tailings. The benthic macroinvertebrates were collected with a core and the abiotic variables that were measured were: dissolved oxygen, suspended material, depth, transparency (secchi disc, temperature of the water column and total nitrogen, available phosphorus and organic matter in the sediment. With the use of a Principal Components Analysis (PCA, we were able to show that the sampling sites differed regarding the abiotic variables, especially total-N, available-P and organic matter in the sediment, all of which were found in greater concentrations in the natural areas. The PCA concerning the benthic macroinvertebrate community also distinguished the natural sites from the impacted one. The impacted site was positively grouped with the Ephemeroptera (Campsurus sp. and the natural sites were grouped together with the Chironomidae, Chaoboridae, Oligochaeta and Bivalvia. The results achieved in this research made clear that the sites under influence of the bauxite tailings had alterations of their abiotic characteristics and of their benthic macroinvertebrate structure.Esta pesquisa foi desenvolvida entre 1993 e 1996 com o objetivo de estudar a estrutura da comunidade de macroinvertebrados bentônicos, relacionando-a a algumas variáveis abióticas, em um lago amazônico (lago Batata, que recebeu durante dez anos rejeito de bauxita. Os macroinvertebrados bentônicos foram coletados com um coletor tipo core e as variáveis abióticas medidas foram: oxigênio dissolvido, material em suspensão, profundidade, transparência (disco de secchi, temperatura da coluna d’água e nitrogênio total, fósforo disponível e matéria orgânica do sedimento. A partir da aplicação da Análise de Componentes

  7. Fish assemblages in stream stretches occupied by cattail (Typhaceae, Angiospermae stands in Southeast Brazil

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    Fabíola Carla da Rocha

    2009-06-01

    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.Macrófitas são um importante componente de ecossistemas aquáticos lóticos e lênticos. Como consequências da degradação ambiental, espécies de taboas (gênero Typha podem se tornar dominantes em riachos. O objetivo do presente estudo foi investigar a estrutura e alimentação de uma comunidade de peixes em trechos de riachos com influência de Typha sp., bem como a variação temporal na composição, abundância, biomassa

  8. Los macroinvertebrados bentónicos de pozo azul (Cuenca del río Gaira, Colombia y su relación con la calidad del agua The Benthonic Macroinvertebrates of Pozo Azul (Gaira River Basin, Colombia and their Relationship with Water Quality

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    Manjarrés-Hernández Ana

    2003-12-01

    Full Text Available En julio de 2002 se realizó el estudio de algunos parámetros fisicoquímicos y la estructura de la comunidad de macroinvertebrados bentónicos asociados a cuatro coriotipos (piedra, hojarasca, sedimento y macrófitas en el sector de Pozo Azul sobre la cuenca del río Gaira (Magdalena, Colombia. Se discute la relación entre la estructura de la comunidad y la calidad del agua del sector. Los parámetros fisicoquímicos estuvieron determinados en gran medida por las características geográficas del sistema. El agua se caracterizó por estar saturada de oxígeno y por la ausencia de compuestos intermedios de la estabilización de la materia orgánica como nitritos y amonio. Se colectaron 588 individuos distribuidos en 11 órdenes y 38 familias. Los órdenes más representativos fueron Trichoptera, Coleoptera, Diptera y Ephemeroptera, siendo el último de ellos el más abundante. Las familias más representativas fueron Baetidae, Simullidae, Perlidae, Chironomidae e Hydropsychidae, en ese mismo orden de abundancia. Para la relación de la estructura de la comunidad con la calidad del agua se calculó el índice BMWP, adaptado por la Universidad del Valle, Cali, Colombia, que estableció para este caso un agua de óptima calidad y oligosapróbita, según la ecología sapróbita, estado alcanzado luego de la estabilización frente a pequeñas alteraciones inducidas por las actividades del cultivo del café en la zona.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

  9. DISTRIBUTION AND OCCURRENCE OF BENTHIC MACROINVERTEBRATES IN RIVERS WITH RICE CULTURE AREA IN ITAJAÍ VALLEY - SC = DISTRIBUIÇÃO E OCORRÊNCIA DE MACROINVERTEBRADOS BENTÔNICOS EM RIOS NAS ÁREAS COM CULTURA ORIZÍCOLA NO VALE DO ITAJAÍ-SC

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    Joseline Molozzi

    2009-01-01

    Full Text Available Rice is one of the main cereals grown in Brazil. The handling of the rice culture may impact in the river downstream of the farming. The main goal of this research was to evaluate the distribution and occurrence of benthic macroinvertebrates in rivers with rice plantations. This research was developed in the cities of Gaspar and Agrolândia, in Itajaí River Basin, Santa Catarina, Brazil. In Gaspar City, macroinvertebrate data and environmental information were collected quarterly, in August/04, November/04 and February/05. In Agrolândia City, they were also collected quarterly in October/04, January/05 and April/05. Benthic macroinvertebrates samples were collected using Surber sampler. The macroinvertebrates were identified at family level. Diversity was estimated using Shannon, Margalef and Evenness Indices. To compare the diversity among these sites, T Student Test was used. Richness and Dominance were also determinated. 21.831 organisms were collected at the six sites. 73% were Diptera with predominance of Chironomidae family with 14.956 individuals. Site 4 had the lowest diversity and the highest dominance. In rivers under influence of the rice culture it is observed predominance of taxons resistant to pollution. Taxons more sensitive to pollution were hardly found at the six sites, demonstrating the inappropriate conditions for their development. = O arroz é um dos principais cereais cultivados no Brasil. No manejo desta cultura é possível que ocorra um impacto no corpo hídrico à jusante das lavouras. Este trabalho teve por objetivo estudar a distribuição e ocorrência de macroinvertebrados bentônicos em rios nas áreas com cultura orizícola. O estudo foi desenvolvido nos municípios de Gaspar e Agrolândia, localizados na bacia do Itajaí, SC. As coletas foram realizadas trimestralmente, em agosto e novembro de 2004 e fevereiro de 2005 em Gaspar, outubro de 2004, janeiro e abril de 2005 em Agrolândia. As amostras de

  10. 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

  11. 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

    2011-03-01

    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.A maioria dos peixes da família Rivulidae são popularmente conhecidos como anuais por completarem todo seu ciclo biológico em pequenos corpos de água temporários que secam obrigatoriamente em determinados períodos do ano causando a morte dos indivíduos adultos. Possuem características biológicas peculiares como pequeno porte, maturação sexual precoce, reprodução contínua, um elaborado padrão de corte e uma grande capacidade reprodutiva entre os peixes. Os rivulídeos se encontram amplamente distribuídos nas Américas do Norte, Central e Sul. Este trabalho analisou a dieta e a biologia

  12. Habitat diversity and benthic functional trophic groups at Serra do Cipó, Southeast Brazil Diversidade de habitats e grupos tróficos funcionais na Serra do Cipó, sudeste do Brasil

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    M. CALLISTO

    2001-05-01

    Full Text Available The assessment of the diversity of habitats and the characterisation of the functional trophic groups of benthic macroinvertebrate communities of some rivers of Serra do Cipó (MG were the main objectives of this study. The available trophic resources and the types of substrata were characterised along with the structure and composition of their using functional trophic groups. Serra do Cipó is a watershed divisor of the São Francisco and Doce River basins, including a series of streams and rivers, of good water quality and well preserved ecological characteristics. Samples were collected in Cipó, Peixe and Preto do Itambé rivers, besides the Indaiá and Capão da Mata streams at 26 sampling stations, during the rainy (February and dry (October seasons of 1998, using "Kicking nets" of 0.125 mm mesh size. The group of collectors (Baetidae, Leptophlebiidae and Leptohyphidae was the most abundant, followed by collector-predators (Hydrophilidae, Ceratopogonidae, Chironomidae-Tanypodinae, and detritivorous-herbivores (Oligochaeta. The riparian vegetation, together with the aquatic macrophytes, are the substrata containing the highest richness of functional trophic groups and the higher habitat diversity. The results suggest that the use of functional trophic groups, together with habitat evaluation, are efficient tools in the evaluation of the diversity of benthic macroinvertebrates, particularly in altitudinal lotic ecosystems.Este trabalho teve por objetivo avaliar a diversidade de habitats e caracterizar os grupos tróficos funcionais das comunidades de macroinvertebrados bentônicos em alguns rios na Serra do Cipó, MG. Foram caracterizados os recursos tróficos disponíveis e os tipos de substrato nos habitats amostrados, a composição de grupos tróficos funcionais que os utilizam e a estrutura da comunidade de macroinvertebrados bentônicos. A Serra do Cipó constitui-se em um divisor de águas das bacias do Rio São Francisco e do Rio

  13. Diet of four annual killifishes: an intra and interspecific comparison

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    Gabriel Laufer

    2009-03-01

    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.Nós examinamos a dieta de 4 peixes anuais, Austrolebias viarius, Austrolebias cheradophilus, Austrolebias luteoflammulatus e Cynopoecilus melanotaenia, que habitam poças temporárias do sudeste do Uruguai, através da análise de conteúdo estomacal. Os peixes foram capturados em cinco poças temporárias da bacia da lagoa Castillos, na região de Humedales del Este. Nós identificamos 13099 itens de presas estraídos de 669 estômagos das quatro espécies. No sistema estudado, peixes anuais representam os predadores de topo mais

  14. Evaluación del Riego Ambiental del Insecticida Metamidofos en Bioensayos con Cuatro Organismos Acuáticos no Destinatarios Environmental Risk Assessment of the Insecticide Metamidophos in Bioassays with Four Non-Target Aquatic Organisms

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    José Iannacone O

    2007-06-01

    Full Text Available El objetivo de este trabajo fue evaluar el efecto ecotoxicológico del metamidofos, en dos formulaciones de diferente categoría toxicológica [Monofos®, categoría Ia (extremadamente peligroso y Tamaron®, categoría Ib (altamente peligroso] sobre cuatro organismos acuáticos no destinatarios: la lombriz roja Chironomus calligraphus (Goeldi, 1905 (Diptera:Chironomidae, el erizo negro Tetrapygus niger Molina, 1782 (Echinodermata: Arbaciidae, el neón tetra Paracheirodon innesi (Rabout, 1940 (Osteichthyes: Characidae y la trucha Oncorhynchus mykiss (Walbaum, 1792 (Osteichthyes: Salmonidae. Ambas formulaciones del metamidofos provocaron un alto riesgo sobre el ambiente acuático, al encontrarse efectos sobre las larvas de C. calligraphus (Clase Ia, CL50 a 48 h = 1,32 mg i.a. L-1 y Clase Ib, CL50 a 48 h = 4,5 mg i.a. L-1, sobre la fertilización de T. niger (Class Ia, CI50 a 1 h = 1423 mg i.a. L-1 y Clase Ib, CI50 a 1 h = 608 mg i.a. L-1, en P. innesi (Clase Ia, CL50 a 96 h = 20,56 mg i.a. L-1 y Clase Ib, CL50 a 96 h = 10,13 mg i.a. L-1 y en O. mykiss (Clase Ib, CL50 a 96 h = 19,12 mg i.a. L-1. La secuencia de sensibilidad al metamidofos en ambas formulaciones fue: C. calligraphus > O. mykiss ≈ P. innesi > T. niger. En adición, se evaluaron dos efectos subletales en P. innesi, inmovilización y nado extraño, y finalmente, incremento de movimiento opercular en O. mykiss. Los cuocientes de riesgo (CR indicaron en todos los casos un alto riesgo del metamidofos en el ambiente acuático.The aim of this research was to evaluate the ecotoxicological effect of methamidophos using two formulations of different toxicological class [Monofos®, class Ia (extremely dangerous and Tamaron®, class Ib (highly dangerous] on four non-target aquatic organisms: bloodworm Chironomus calligraphus (Goeldi, 1905 (Diptera: Chironomidae, black sea urchin Tetrapygus niger Molina, 1782 (Echinodermata: Arbaciidae, neon tetra Paracheirodon innesi (Rabout, 1940

  15. Benthic community structure in the Gorgan Bay (Southeast of the Caspian Sea, Iran: Correlation to water physiochemical factors and heavy metal concentration of sediment

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    Mahmood Saghali

    2013-11-01

    Full Text Available Macrobentos frequency and biomass was investigated in the Gorgan Bay in 2011. Five sampling sites were chosen to collect benthos and sediment from the Bay using a Van Veen grab sampler. Samples were collected seasonally. Macrobenthos were indentified and their biomass was recorded. Sediment heavy metals concentration were measured using Atomic Absorption Spectroscopy. A total of 11 families belonging to three phyla of invertebrates were found. The phyla were Annelids (Nereidae, Naididae, Ampharetidae, Lumbriculidae, Tubificidae and Amphiporidae, Arthropods (Pontogammaridae, Balanidae and Chironomidae and Mollusks (Cardiidae and Scrobicularidae. Lumbriculidae (413 individuals m-2, corresponding to 18.7% and Cardiidae (55.2 g m-2, corresponding to 82.4% had the highest frequency and biomass, respectively. Annelids with an average of 1557 individuals m-2 was the most frequent groups, while, mollusks with the average of 141 g per m2 had the highest biomass. Results showed that macrobenthos frequency in summer was significantly higher than those of the other seasons, however, in the case of biomass, there was a significantly higher biomass in the spring than the other seasons. The maximum metal concentration was related to Zn and Pb, whereas, Cr and Cd had the lowest values. There was no significant difference in Zn and Cr concentrations among the sampling seasons. Pb concentration in winter was significantly lower than the other seasons, whereas, Cd concentrations in the spring and summer were significantly lower than the autumn and winter. There were some correlations between benthos frequency and water physiochemical characteristics and sediment heavy metal levels. This study indicated that benthic fauna of the Gorgan Bay and the Caspian Sea are not similar. Also, results showed that benthic fauna communities are affected by sediment heavy metal concentrations and water physiochemical characteristics, however, different benthos groups show

  16. 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.

  17. 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.

  18. Aquatic ecosystems of the lower Pecos drainage, October-December, 1980

    International Nuclear Information System (INIS)

    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

  19. Trace DNA from insect skins: a comparison of five extraction protocols and direct PCR on chironomid pupal exuviae.

    Science.gov (United States)

    Kranzfelder, Petra; Ekrem, Torbjørn; Stur, Elisabeth

    2016-01-01

    Insect skins (exuviae) are of extracellular origin and shed during moulting. The skins do not contain cells or DNA themselves, but epithelial cells and other cell-based structures might accidentally attach as they are shed. This source of trace DNA can be sufficient for PCR amplification and sequencing of target genes and aid in species identification through DNA barcoding or association of unknown life stages. Species identification is essential for biomonitoring programs, as species vary in sensitivities to environmental factors. However, it requires a DNA isolation protocol that optimizes the output of target DNA. Here, we compare the relative effectiveness of five different DNA extraction protocols and direct PCR in isolation of DNA from chironomid pupal exuviae. Chironomidae (Diptera) is a species-rich group of aquatic macroinvertebrates widely distributed in freshwater environments and considered a valuable bioindicator of water quality. Genomic DNA was extracted from 61.2% of 570 sampled pupal exuviae. There were significant differences in the methods with regard to cost, handling time, DNA quantity, PCR success, sequence success and the ability to sequence target taxa. The NucleoSpin(®) Tissue XS Kit, DNeasy(®) Blood and Tissue kit, and QuickExtract(™) DNA Extraction Solution provided the best results in isolating DNA from single pupal exuviae. Direct PCR and DTAB/CTAB methods gave poor results. While the observed differences in DNA isolation methods on trace DNA will be relevant to research that focuses on aquatic macroinvertebrate ecology, taxonomy and systematics, they should also be of interest for studies using environmental barcoding and metabarcoding of aquatic environments. PMID:26186122

  20. The effect of sewage effluent on the physico-chemical and biological characteristics of the Sand River, Limpopo, South Africa

    Science.gov (United States)

    Seanego, K. G.; Moyo, N. A. G.

    Population growth in urban areas is putting pressure on sewage treatment plants. The improper treatment of sewage entering the aquatic ecosystems causes deterioration of the water quality of the receiving water body. The effect of sewage effluent on the Sand River was assessed. Eight sampling sites were selected, site 1 and 2 were upstream of the sewage treatment plant along the urbanised area of Polokwane, whilst sites 3, 4, 5, 6, 7 and 8 were downstream. The physico-chemical parameters and coliform counts in the water samples were determined. The suitability of the water for irrigation was also determined. Hierarchical average linkage cluster analysis produced two clusters, grouping two sites above the sewage treatment works and six sites downstream of the sewage effluent discharge point. Principal component analysis (PCA) identified total nitrogen, total phosphorus, conductivity and salinity as the major factors contributing to the variability of the Sand River water quality. These factors are strongly associated with the downstream sites. Canonial correspondence analysis (CCA) indicated the macroinvertebrates, Chironomidae, Belastomatidae, Chaoborus and Hirudinea being strongly associated with nitrogen, phosphorus, conductivity and temperature. Escherichia coli levels in the Polokwane wastewater treatment works maturation ponds, could potentially lead to contamination of the Polokwane aquifer. The Sodium Adsorption Ratio was between 1.5 and 3.0 and residual sodium carbonate was below 1.24 Meq/l, indicating that the Sand River water is still suitable for irrigation. The total phosphorus concentrations fluctuated across the different site. Total nitrogen concentrations showed a gradual decrease downstream from the point of discharge. This shows that the river still has a good self-purification capacity.

  1. Dietary habits of invasive Ponto-Caspian gobies in the Croatian part of the Danube River basin and their potential impact on benthic fish communities.

    Science.gov (United States)

    Piria, Marina; Jakšić, Goran; Jakovlić, Ivan; Treer, Tomislav

    2016-01-01

    Invasive Ponto-Caspian (P-C(1)) gobies have recently caused dramatic changes in fish assemblage structures throughout the Danube basin. While their presence in the Croatian part of the basin has been noted and distribution studied, their dietary habits and impacts on native fish communities have, until now, been unknown. In 2011, 17 locations in the Sava River Basin were sampled for fish and 15 for benthic invertebrates. Fish population monitoring data, available for nine seasons (2003-2006 and 2010-2014) and 12 locations, were used to analyse the impacts of P-C gobies on benthic fish abundance. Gut content analysis indicates that the monkey goby Neogobius fluviatilis diet is very diverse, but dominated by Trichoptera, Chironomidae, Bivalvia and Odonata. The diet overlaps considerably with the round goby Neogobius melanostomus diet, although Gastropoda are dominant in the latter's diet. Small fish and Gammarus sp. dominate the bighead goby Ponticola kessleri diet. Comparison of gut content with the prey available in the environment indicates that monkey and round gobies exhibit preference for Trichoptera, Megaloptera and Coleoptera, and bighead goby for Trichoptera, Gammarus sp. and Pisces. P-C gobies in the Sava River are spreading upstream, towards the reaches with lower fish diversity. Analyses indicate potentially positive impacts of P-C gobies' presence on some fish populations: round and bighead goby on Balkan golden loach Sabanejewia balcanica and monkey goby on common carp Cyprinus carpio, crucian carp Carassius carassius, burbot Lota lota and Balkan loach Cobitis elongata. However, there are also indications that bighead and round goby could adversely impact the native chub Squalius cephalus and zingel Zingel zingel populations, respectively. As P-C gobies are still in the expansionary period of invasion and the ecosystem still adapting to new circumstances, continued monitoring of fish population dynamics in the Sava basin is needed to determine the

  2. Chironomids’ Relationship with Aeromonas Species

    Science.gov (United States)

    Laviad, Sivan; Halpern, Malka

    2016-01-01

    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, and 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 6-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. PMID:27242751

  3. Indirect effects of bioinsecticides on the nontarget fauna: The Camargue experiment calls for future research

    Science.gov (United States)

    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.

  4. EVALUACIÓN DE COMUNIDADES DE MACROINVERTEBRADOS ASOCIADOS A TRES ESPECIES DE MACRÓFITAS ACUÁTICAS EN LA LAGUNA DE MORONACOCHA, IQUITOS

    Directory of Open Access Journals (Sweden)

    Zoila Perea Saavedra

    2011-12-01

    Full Text Available El objetivo fue evaluar la riqueza y abundancia de macroinvertebrados acuáticos asociados a tres especies de macrófitas acuáticas del Lago Moronacocha. Los muestreos se realizaron entre los meses de mayo y julio del 2009; se realizaron colectas mensuales de 27 muestras de cada macrófita, tomándose adicionalmente medidas de parámetros fisicoquímicos: temperatura, oxígeno y pH. Las muestras de Pistia stratiotes (huama y Echinocloa crassipes (putu putu, fueron colectadas con una red de bentos (20 x 30 cm y 180 µm de abertura de malla, mientras que los ejemplares de Echinocloa polystachya (gramalote fueron colectados manualmente.No se encontraron diferencias estadísticas significativas en cuanto la riqueza y abundancia entre las tres macrófitas  evaluadas (P>0.05. Se encontró una abundancia de 1538 individuos, siendo las familias más abundantes en la colecta: Chironomidae, Noteridae y Haplotaxidae, siendo además Hydrophilidae, Elmidae y Planorbidae abundantes solo para Pistia stratiotes. De las 31 familias reportadas en este estudio, 17 estuvieron presentes en las tres macrófitas evaluadas.  Los valores promedio de T° (26,4 °C y pH (6,7 registrados se encontraron dentro de los límites adecuados. Concluyendo que la composición de macroinvertebrados acuáticos en el Lago Moronacocha, no está influenciada por el tipo de macrófita que existe en ella.

  5. Bioindicación de la calidad del agua con lógica difusa Sugeno y macroinvertebrados acuáticos de la Sabana de Bogotá Bioindication of water quality in the Bogota Sabana using fuzzy logic Sugeno and aquatic microinvertebrates

    Directory of Open Access Journals (Sweden)

    Ospina Rodulfo

    2002-11-01

    Full Text Available

    Se presenta una implementación de la metodología de lógica difusa Sugeno que permite el cálculo de la calidad biológica del agua en la Sabana de Bogotá, Colombia. Se emplearon un total de 28 sitios correspondientes a 9 subcuencas de la Sabana de Bogotá. Los organismos utilizados para la implementación del modelo de lógica Sugeno fueron: Leptoceridae e Hydrobiosidae como indicadores de aguas limpias, Planariidae y Amphipoda como indicadores aguas contaminadas y como indicadores de aguas muy contaminadas se seleccionaron Psychodidae y Syrphidae. Adicionalmente se incluyo la familia Chironomidae. Los resultados obtenidos con la aplicación de la lógica Sugeno fueron confrontados con los valores del índice fisicoquímico (Cfq para comprobar el nivel de confiabilidad de la metodología de 1ógica Sugeno, observándose una correlación altamente significativa.

    An application of the Sugeno-rype fuzzy logic to calculate biological water quality in Bogota, Colombia is presented 28 sites corresponding to 9 watersheds in the Bogota area were used. The organisms selected were: Leptoceridae and Hidrobiosidae as indicators of dean waters, Planariidae and Amphipoda as indicators of polluted waters and Psychodida and Syrphidae as indicators of highly polluted waters Chironomids were also included. In order to prove the degree of reliability of Sugeno-type fuzzy logic, the results obtained were compared with values for the Cfq index, and a highly significant correlation was obtained.

  6. Colonisation of leaf litter by aquatic invertebrates in an Atlantic Forest stream.

    Science.gov (United States)

    Oliveira, V C; Gonçalves, E A; Alves, R G

    2014-05-01

    Riparian vegetation along streams in the Atlantic Forest in Brazil contributes to the formation of a highly heterogeneous leaf litter in streambeds. To investigate the structure and composition of the aquatic invertebrate community during the process of leaf decomposition of two plant species present along the banks of the stream studied, 21 plastic mesh bags containing 2.5g (dry weight) of leaf matter from each species (Alchornea glandulosa (Vell) and Cabralea canjerana End. and Poeppig), for a total of 5.0g, were placed in the streambed. Three bags were removed after 3, 6, 9, 12, 24, 48 and 96 days. The taxonomic density was negatively correlated with the remaining weight. The high density of collector organisms, such as Chironomidae, Oligochaeta and Amphipoda, on the last day of incubation, probably occurred due to the increased amount of fine organic matter in the more advanced decomposition stages. The highest α diversity (Shannon-Wiener) values were observed for the 3rd and 96th days of the experiment, while the β diversity values showed that these days presented the highest variation in the taxonomic composition, thus presenting a different faunistic composition. This study showed that the trophic structure and composition of aquatic invertebrates changes during the decomposition of leaf litter. The faunistic abundance and diversity observed in this study indicate that the entrance of material from plants growing along streams provides favorable conditions for the colonisation and establishment of invertebrates in lower-order streams, and thus points to the need to preserve riparian vegetation. PMID:25166310

  7. Benthic Macro-Fauna Composition and Abundance in Sombreiro River, Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    E.N. Ezekiel

    2011-04-01

    Full Text Available The benthic macro-fauna composition and abundance in sombreiro was studied for a period of two years (August 2007 - July2009. A total of twenty-eight species belonging to fourteen (14 families, six (6 classes and three (3 phyla were recorded in Sombreiro River. The phylum Annelida dominated with two classes (Oligochaeta and Polychaeta. Oligochaeta was represented by two families (Naididae and Lumbricidae and seven species having 25% by composition. Polychaeta was represented by seven families (Nereidae, Nepthyidae, Capitellidae, Eucinidae, Glyceridae, Arenicolidae and Syllidae and thirteen species having 46.4% by composition. The Phylum arthropoda was represented by two classes (Crustacea and inseita. Two families (Gammaridae and Penaidae having two species consisting of 7.2% were recorded, for the class crustacea. The class insecta was represented by one family (Chironomidae with one species consisting of 3.6%. The phylum Mollusca was represented by two classes (Gastropoda and Bivalvia. Gastropoda had two species with 7.2% composition and Bivalvia has three species with10.7% composition. Oligochaeta was the highest and constituted 62.0%. The others were Polychaeta (23.9%, Insecta (6.7%, Gastropoda (3.9%, Bivalvia (2.2% and Crustacea (1.3%. The mean diversity(S ranged between 11 species. Mean abundance of individuals (N was 985. Mean Margalef index (d value was 1.339. The mean value for Shannon-Wienner (H was 0.956. Mean Pielou’s index of relative density or evenness index (E was 0.986. Mean SimpsIn’s Dominance index (C was 0.623.

  8. 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.

  9. 20th century human pressures drive reductions in deepwater oxygen leading to losses of benthic methane-based food webs

    Science.gov (United States)

    Belle, Simon; Millet, Laurent; Verneaux, Valérie; Lami, Andrea; David, Etienne; Murgia, Laurie; Parent, Claire; Musazzi, Simona; Gauthier, Emilie; Bichet, Vincent; Magny, Michel

    2016-04-01

    Freshwater lakes play a key role in the global carbon cycle as sinks (organic carbon sequestration) and sources (greenhouse gas emissions). Understanding the carbon cycle response to environmental changes is becoming a crucial challenge in the context of global warming and the preponderance of human pressures. We reconstructed the long-term (1500 years) evolution of trophic functioning of the benthic food web, based on methanotrophic ancient DNA and chironomid isotope analyses). In addition, human land use is also reconstructed in three different lakes (eastern France, Jura Mountains). Our findings confirm that the benthic food web can be highly dependent on methane-derived carbon (up to 50% of the chironomid biomass) and reveal that the activation of this process can correspond to a natural functioning or be a consequence of anthropic perturbation. The studied lakes also showed a similar temporal evolution over the last century with the disappearance of the profundal aquatic insects (Chironomidae, Diptera), considered as keystone for the whole lake food web (e.g., coupling benthic-pelagic), inducing a potential collapse in the transfer of methane to top consumers. This functional state, also called the dead zone expansion, was caused by the change in human land-use occurring at the beginning of the 20th century. The strong modification of agro-pastoral practices (e.g., fertilization practices, intensive grazing, and sewage effluent) modified the influx of nutrients (by diffuse and/or point-source inputs) and induced a significant increase in the trophic status and organic matter sedimentation to reach unprecedented values. Further studies should be planned to assess dead zone expansion and, according to the regime shift theory, to provide environmental tipping points for sustainable resource management.

  10. A comparison of sampling techniques and summary indices for assessment of water quality in the Yamaska River, Québec, based on benthic macroinvertebrates.

    Science.gov (United States)

    Barton, D R; Metcalfe-Smith, J L

    1992-06-01

    The Yamaska River drainage basin in Quebec, Canada, is intensively farmed and heavily polluted with poorly treated domestic and industrial wastes. We investigated the responses of the resident and colonizing components of the benthic macroinvertebrate community to municipal/industrial versus agricultural pollution in the basin, and evaluated the performances of seven diversity and biotic indices for assessing water quality. Samples of riffle-dwelling, infaunal and colonizing invertebrates were collected from 13 stations representing a wide range of types and degrees of pollution using Surber, scoop and artificial substrate samplers. The data were summarized using the indices S (number of taxa), N (number of individuals), H' (Shannon-Wiener's diversity index), D (Simpson's diversity index), BBI (Belgian Biotic Index), TBI (a modification of Hilsenhoff's Biotic Index), % CHIR (percentage of arthropods consisting of Chironomidae) and %OLIGO (percentage of total organisms consisting of Oligochaeta). Different components of the community generated somewhat different assessments and were, therefore, complementary. Community composition, expressed as the percentage of individuals contributed by major taxonomic groups, reflected the kinds of stresses at a station more consistently than did any of the indices. S and TBI came closest to ranking control, agricultural and municipal/industrial sites in accordance with our a priori classification, both between months and among sampling methods. %OLIGO usually separated municipal/industrial sites from control sites. Other indices were found to be less sensitive, accurate or temporally stable, or were otherwise inappropriate for use with certain sampling methods or for certain types of pollution. With most of our samples, all of the summary indices suggested that the impact of agricultural practices on stream ecosystems may be as severe as the impacts of municipal and industrial wastes. PMID:24234488

  11. 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)

    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 CdCl2, 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.

  12. Chironomus group classification according to the mapping of polytene chromosomes

    Science.gov (United States)

    Salleh, Syafinaz; Kutty, Ahmad Abas

    2013-11-01

    Chironomus is one of the important genera in Chironomidae family since they are widely diverse and abundance in aquatic ecosystem. Since Chironomus is very diverse, taxonomic work on this genus is very difficult and incomplete. Objective of this study is to form group classification of Chironomus according to the polytene chromosome mapping. The specific characteristics of polytene chromosomes in the salivary gland appeared to be particularly promising for taxonomic diagnosis of chironomid species. Chironomid larvae were collected from pristine sites at Sg. Langat and cultured in laboratory to reach fourth instar stage. The salivary glands were removed from larvae and chromosomes were stained with aceto orcein. Results showed that polytene chromosomes of Chironomus comprise of three long metacentric or submetacentric arms (BF, CD and AE arms) and one short acrocentric (G arm). In regards to nucleolar organizing region (NOR), Balbiani ring (BR), puffings and chromosome rearrangement, a number of four groups of different banding patterns were found. Two groups called as G group A and B have common NOR on arm BF and BR on arm G. However, group A has rearrangement pattern on arm CD and not in group B. This makes group B separated from group A. Another two groups called as groups C and D do not have common NOR on arm BF and also BR on arm G. Groups C and D were separated using arms G and arm AE. At arm G, only group C rearrangement pattern at unit 23c whereas group D was found to have large NOR at arm G and as well as arm AE, only group D has rearrangement pattern at unit 12c. This study indicates that chromosome arrangement could aid in revealing Chironomus diversity.

  13. 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. PMID:21915593

  14. Benthic macroinvertebrates as bioindicators of water quality in an Atlantic forest fragment

    Directory of Open Access Journals (Sweden)

    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.

  15. Interplay of anthropogenic and natural disturbance impacts on the hyporheic ecology

    Science.gov (United States)

    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.

  16. [Agricultural land use impacts on aquatic macroinvertebrates in small streams from La Vieja river (Valle del Cauca, Colombia].

    Science.gov (United States)

    Giraldo, Lina Paola; Chará, Julián; Zúñiga, Maria del Carmen; Chará-Serna, Ana Marcela; Pedraza, Gloria

    2014-04-01

    The expansion of the agricultural frontier in Colombia has exerted significant pressure on its aquatic ecosystems during the last few decades. In order to determine the impacts of different agricultural land uses on the biotic and abiotic characteristics of first and second order streams of La Vieja river watershed, we evaluated 21 streams located between 1,060 and 1,534 m asl in the municipalities of Alcalá, Ulloa, and Cartago (Valle del Cauca, Colombia). Seven streams were protected by native vegetation buffers, eight had influence of coffee and plantain crops, and six were influenced by cattle ranching. Habitat conditions, channel dimensions, water quality, and aquatic macroinvertebrates were studied in each stream. Streams draining cattle ranching areas had significantly higher dissolved solids, higher phosphorus, higher alkalinity, higher conductivity, and lower dissolved oxygen than those covered by cropland and forests. Coarse substrates and diversity of flow regimes were significantly higher in cropland and protected streams when compared to streams affected by cattle ranching, whereas the percent of silt and slow currents was significantly higher in the latter. A total of 26,777 macroinvertebrates belonging to 17 orders, 72 families and 95 genera were collected. The most abundant groups were Diptera 62.8%, (Chironomidae 49.6%, Ceratopogonidae 6.7%), Mollusca 18.8% (Hydrobiidae 7.2%, Sphaeriidae 9.6%) and Trichoptera 5.7% (Hydropsychidae 3.7%). The Ephemeroptera, Trichoptera, and Plecoptera orders, known for their low tolerance to habitat perturbation, had high abundance in cropland and forested streams, whereas Diptera and Mollusca were more abundant in those impacted by cattle ranching. Results indicate that streams draining forests and croplands have better physical and biological conditions than those draining pastures, and highlight the need to implement protective measures to restore the latter. PMID:25189079

  17. Mesh-size effects on drift sample composition as determined with a triple net sampler

    Science.gov (United States)

    Slack, K.V.; Tilley, L.J.; Kennelly, S.S.

    1991-01-01

    Nested nets of three different mesh apertures were used to study mesh-size effects on drift collected in a small mountain stream. The innermost, middle, and outermost nets had, respectively, 425 ??m, 209 ??m and 106 ??m openings, a design that reduced clogging while partitioning collections into three size groups. The open area of mesh in each net, from largest to smallest mesh opening, was 3.7, 5.7 and 8.0 times the area of the net mouth. Volumes of filtered water were determined with a flowmeter. The results are expressed as (1) drift retained by each net, (2) drift that would have been collected by a single net of given mesh size, and (3) the percentage of total drift (the sum of the catches from all three nets) that passed through the 425 ??m and 209 ??m nets. During a two day period in August 1986, Chironomidae larvae were dominant numerically in all 209 ??m and 106 ??m samples and midday 425 ??m samples. Large drifters (Ephemerellidae) occurred only in 425 ??m or 209 ??m nets, but the general pattern was an increase in abundance and number of taxa with decreasing mesh size. Relatively more individuals occurred in the larger mesh nets at night than during the day. The two larger mesh sizes retained 70% of the total sediment/detritus in the drift collections, and this decreased the rate of clogging of the 106 ??m net. If an objective of a sampling program is to compare drift density or drift rate between areas or sampling dates, the same mesh size should be used for all sample collection and processing. The mesh aperture used for drift collection should retain all species and life stages of significance in a study. The nested net design enables an investigator to test the adequacy of drift samples. ?? 1991 Kluwer Academic Publishers.

  18. 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

  19. Impact of urbanization on the ecology of Mukuvisi River, Harare, Zimbabwe

    Science.gov (United States)

    Moyo, N. A. G.; Rapatsa, M. M.

    2016-04-01

    The main objective in this study was to compare the physico-chemical characteristics and biota of a river (Mukuvisi) passing through an urban area to that of a non-urbanised river (Gwebi). Five sites in the Mukuvisi River and five sites in the Gwebi River were sampled for water physico-chemical parameters (pH, conductivity, DO, BOD, TDS, ammonia, Cl, SO42-, PO42-, NO33-, F-, Pb, Cu, Fe, Mn, Zn and Cr) once every month between August, 2012-August, 2013. Cluster analysis based on the physico-chemical parameters grouped the sites into two groups. Mukuvisi River sites formed their own grouping except for one site which was grouped with Gwebi River sites. Principal Component Analysis (PCA) was used to extract the physico-chemical parameters that account for most variations in water quality in the Mukuvisi and Gwebi Rivers. PCA identified sulphate, chloride, fluoride, iron, manganese and zinc as the major factors contributing to the variability of Mukuvisi River water quality. In the Gwebi river, sulphate, nitrate, fluoride and copper accounted for most of the variation in water quality. Canonical Correspondence Analysis (CCA) was used to explore the relationship between physico-chemical parameters and macroinvertebrate communities. CCA plots in both Mukuvisi and Gwebi Rivers showed significant relationships between macroinvertebrate communities and water quality variables. Phosphate, ammonia and nitrates were correlated with Chironomidae and Simulidae. Gwebi River had higher (P < 0.05, ANOVA) macroinvertebrates and fish diversity than Mukuvisi River. Clarias gariepinus from the Mukuvisi River had high liver histological lesions and low AChE activity and this led to lower growth rates in this river.

  20. Aspectos da biologia de Buenoa platycnemis (Fieber (Insecta, Heteroptera, Notonectidae da Restinga de Maricá, Rio de Janeiro On the biology of Buenoa platycnemis (Fieber (Insecta, Heteroptera, Notonectidae at Restinga de Maricá, Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Jorge Luiz Nessimian

    2000-03-01

    Full Text Available A monthly quantitative study on B. platycnemis (Fieber, 1851 was carried out in a sand dune marsh, on the littoral of Rio Janeiro State. The aims of this study were to correlate the life cycle of the species with the seasonal regime of the water body, defining steps of the annual cycle, age strueture, and to indicate oviposition sites and trophic relations. The species shows a marked seasonal tendency. The major steps of the life cycle obtained were an invernal (weak with a predominance of imagines, followed by another of population expansion, characterized by the absence of adults, massive eclosions and predominance of low instar nymphs. Probably, B. platycnemis has a sensibility to water levei variation and might be intluenced by the concentration of Spirogyra sp. (Chlorophyceae in the water column. In relation to oviposition, B. platycnemis has not shown preference for any macrophyte, since eggs were found in Rhynchosphora corymbosa (Linnaeus Britton (Cyperaceae, Eleocharis sellowiana Kunth. (Cyperaceae and Nymphoides indica (Linnaeus O. Kuntze. (Menyanthaceae. The observed predators of B. platycnemis were Anax amazilli (Burmeister, 1839 (Aeshinidae, Eryihemis crédula (Hagen, 1861 (Libellulidae and other Odonata, nymphs and adults of Belostoma candidulum Montandon, 1903 (Belostomatidae, Notonecta (Paranecta disturbata Hungerford, 1926, Buenoa antigone antigone (Ki-rkaldy, 1899 (Notonectidae, besides Curicta cf. tibialis (Martin, 1898 and Ranatra horvalhi Montandon, 1910 (Nepidae. Larvae of Sayomyia sp. (Chaoboridae, Chiro-nomus spp. and Labrundinia sp. (Chironomidae, Callibaetis gutlatus Navás, 1915 (Baetidae, cladocerans and copepods are potential prey of B. platycnemis, while ostracodes were refused.

  1. 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.)

  2. Results of Macroinvertebrate Sampling Conducted at 33 SRS Stream Locations, July--August 1993

    International Nuclear Information System (INIS)

    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)

  3. Late Holocene Climate Change Inferred From Varved Proglacial Lake Sediments on Northeastern Baffin Island, Arctic Canada

    Science.gov (United States)

    Thomas, E. K.; Briner, J. P.; Axford, Y.

    2007-12-01

    The Arctic has a disproportionately large response to changes in radiative forcing of climate, and glaciers and arctic lacustrine ecosystems respond sensitively to these changes. Lacustrine ecosystems throughout the Arctic are undergoing rapid regime shifts, including dramatically increased primary productivity and changing aquatic floral and faunal assemblages. Our work on organic lake sediments from northeast Baffin Island shows a large increase in primary productivity, changes in insect (Chironomidae) assemblages including the disappearance of cold stenotherms, and a rise in chironomid-inferred summer water temperatures of at least 1.5°C over the past 50 years, reaching temperatures that were unprecedented in the past 5000 years. Here, we pursue the use of varve thickness, an abiotic temperature proxy, to expand our understanding of late Holocene temperature changes on northeast Baffin Island. We obtained a 14C- and 239+240Pu-dated surface core/percussion core pair from a proglacial lake. Together these cores span > 8000 years and the sediments are varved, as verified by the 239+240Pu analysis, for at least the past 700 years. Magnetic susceptibility was high during the early Holocene, decreased to near-zero values during the mid-Holocene and increased during the past 2500 years to reach the highest values seen in the record around 1000 years ago. Loss-on- ignition had an opposite trend, with the highest values in the mid-Holocene. Sedimentation rate was constant during most of the Holocene (0.03 cm yr -1) and increased during the past 1000 years to 0.05 cm yr -1. These parameters indicate that following the absence of an active glacier during the middle Holocene, glacier activity initiated ~2500 years ago and reached peak activity over the last 1000 years. Our ongoing work to obtain a varve-thickness record for at least the last 700 years, and its calibration to a nearby weather station, will be presented.

  4. Under siege: Isolated tributaries are threatened by regionally impaired metacommunities.

    Science.gov (United States)

    Merriam, Eric R; 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 5km 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. PMID:27101452

  5. The food spectrum of the cardinal - tetra (Paracheirodon axelrodi, Characidae in its natural habitat Estratégias alimentares do cardinal-tetra (Paracheirodon axelrodi, Characidae em seu ambiente natural

    Directory of Open Access Journals (Sweden)

    Ilse Walker

    2004-01-01

    Full Text Available The cardinal tetra (Paracheirodon axelrodi is the most intensively commercialized ornamental fish from the Rio Negro Basin (Amazonas State, Brasil. Analysis of the stomach and gut contents of fish caught in their natural habitats show conclusively that the cardinal is essentially a predator, feeding on the mesofauna that adheres to submerged litter, roots and waterplants. Microcrustacea and chironomid larvae (Diptera were the most frequently ingested prey, while algae intake was relatively infrequent. It is argued that the relatively small size of the cardinals captured in their natural habitat is due to the annual migrations imposed by the inundation cycles, rather than to resource limitation, because it is known from earlier investigations of similar habitats, that these plant substrates are densely colonized by the aquatic mesofauna. Cardinals raised in captivity are larger and have higher rates of growth.O cardinal (Paracheirodon axelrodi é o peixe ornamental comercializado com maior intensidade na Bacia do Rio Negro (Estado do Amazonas, Brasil. Análise do conteúdo estomacal de peixes capturados nos seus habitats naturais mostra, que o cardinal é essencialmente um predador, alimentando-se da mesofauna que está colonizando a liteira submersa, arbustos submersos, raízes flutuantes e plantas aquáticas. As presas principais são microcrustáceos e larvas de quironomídeos (Chironomidae, Diptera, enquanto ingestão de algas é pouco freqüente. Considera-se que o tamanho relativamente pequeno de cardinais capturados nos ambientes naturais é devido as migrações anuais que acompanham os ciclos anuais de enchente e vazante, e não à falta de recursos; já que é conhecido de ambientes parecidos de outros rios da região, que estes substratos aquáticos são densamente colonizados pela mesofauna. Cardinais criados em cativeiros tem taxas de crescimento mais altas e são de tamanho maiores.

  6. 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

  7. 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.

  8. Avaliação rápida da integridade ecológica em riachos urbanos na bacia do rio Corumbá no Centro-Oeste do Brasil

    Directory of Open Access Journals (Sweden)

    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.

  9. 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

  10. Experimental acidification of two biogeochemically-distinct neotropical streams: Buffering mechanisms and macroinvertebrate drift

    International Nuclear Information System (INIS)

    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 (HCO3−) 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 HCO3− was an important buffering mechanism in both streams. Base cation, Fe2+, 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-solute poorly

  11. Caracterización de la artropofauna terrestre del humedal Jaboque (Bogotá, Colombia

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    Amat García Germán

    2005-07-01

    Full Text Available En el humedal Jaboque, se estudió la diversidad y la estructura trófica de la artropofauna asociada a las comunidades de vegetación Juncus effusus, Juncus effusus-Polygonum punctatum, Schoenoplectus californicus y Typha latifolia. La composición y riqueza asociada a la comunidad Bidens laevis y la composición de los insectos antófilos relacionados a algunas plantas. Se identificaron en total 212 morfoespecies, distribuidas en 48 familias y siete órdenes. A lo largo del estudio se colectaron 8.944 individuos que presentan una biomasa seca de 9757,8 mg. El órden Diptera y sus familias
    Ephydridae, Chironomidae y Muscidae son taxas, con predominio a nivel de riqueza, abundancia y biomasa. Entre las comunidades de vegetación consideradas se aprecia una artropofauna variable en composición, diversidad de morfoespecies y diversidad trófica. Se encontraron seis tipos
    de patrones de distribución, con familias especialistas en cuanto a la selección de hábitats y con valores de abundancia relativa global bajos (0–1% hasta familias generalistas en cuanto a selección de hábitats (4–5 comunidades de vegetación y con valores de abundancia relativa altos
    (>5%. Se encontró un total de 16 morfoespecies de insectos presentando contenido polínico. Estas morfoespecies pertenecen a las familias Muscidae, Syrphidae, Dolichopodidae, Tephritidae, Tipulidae, Sciaridae, Heleomyzidae, Sciomyzidae y Chrysomelidae. Los dípteros y sus familias Muscidae y Syrphidae registraron las mayores riquezas de morfoespecies, abundancias, número de familias vegetales visitadas, además de demostrar una alta capacidad de movilidad. Las compuestas con estrategia de polinización entomófila y las gramíneas con estrategia anemófila presentaron las mayores riquezas de insectos visitantes florales.

  12. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    International Nuclear Information System (INIS)

    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

  13. 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

  14. 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

  15. Macroinvertebrates as tadpole food: importance and body size relationships Macroinvertebrados como alimento de girinos: importância e relações com tamanho de corpo

    Directory of Open Access Journals (Sweden)

    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

  16. 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., Jr.; 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

  17. Fauna cavernícola brasileira: composição e caracterização preliminar

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    Eleonora Trajano

    1986-01-01

    Full Text Available In this study a number of caves from various Brazilian limestone regions were surveyed. The information gathered expands and improves that of our preliminary article, allowing a reasonable good picture of the Brazilian cave fauna. There doesn't seem to be any striking difference between the composition of the Brazilian cave fauna and that of the other tropical regions that have been studied. Animals commonly found throughout the studied area include: Phalangopsidae crickets, Reduviidae heteropterans, Polydesmida and Juliformida millipedes, Opilionida Laniatores, and spiders, particularly Scytodidae, Ctenidae, Theridiosomatidae and Pholcidae. Among the vertebrates the commonest are barts and catfishes. Amblypygi are common in all regions except São Paulo State, which is outside the group geographical distribution. Cockroaches are frequent in the warm caves to the north of Vale do Ribeira (São Paulo State where these animals are rarely seen. The cave fauna of the Vale do Ribeira is better Known than that of other Brazilian regions. Those small secretive species often found in Vale do Ribeira are probable also common elsewhere: beetles (partilarly the Carabidae, Leiodidae Catopinae, and, to a lesser exyent, the Pselaphidae and Otilodactylidae; dipterans (in special Chironomidae and Keroplatidae; and typically soil animals like collembolans and earthwormos. The sandstone cave fauna is basically the same found in limestone. The only difference seems to be the larger amount of batguano found in the former, conditioning larger populations of guano-feeding arthropods such as crickets and juliformid millipedes. The fauna of the entrance and twilight zone is characterized by the predominance of the Arachnida like opilionids Goniosominae and spiders Pholcidae, and heteropterans Reduviidae; the only typical dipteran of this fauna is the larval form of the fungus gnat Neoditomyia sp. (Mycetophiloidea. It was also observed a stratification within the

  18. 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

  19. 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

  20. 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.