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Sample records for salmonis copepoda caligidae

  1. Moulting in the chalimus larva of the salmon louse Lepeophtheirus salmonis (Copepoda, Caligidae)

    NARCIS (Netherlands)

    Bron, J.E.; Shinn, A.P.; Sommerville, C.

    2000-01-01

    The ultrastructure of moulting in the chalimus phase of the parasitic caligid copepod Lepeophtheirus salmonis is described for the first time. The major features of the moult sequence correspond to those of other Crustacea, save for the absence of a distinguishable intermoult as defined by reduced

  2. Moulting in the chalimus larva of the salmon louse Lepeophtheirus salmonis (Copepoda, Caligidae)

    OpenAIRE

    Bron, J. E.; Shinn, A.P.; Sommerville, C.

    2000-01-01

    The ultrastructure of moulting in the chalimus phase of the parasitic caligid copepod Lepeophtheirus salmonis is described for the first time. The major features of the moult sequence correspond to those of other Crustacea, save for the absence of a distinguishable intermoult as defined by reduced epidermal activity and a cessation of cuticle production. This latter may be explained cither in terms of a continuous moulting process related to the constant food supply available to a parasite or...

  3. The Salmon Louse Lepeophtheirus salmonis (Copepoda: Caligidae life cycle has only two Chalimus stages.

    Directory of Open Access Journals (Sweden)

    Lars A Hamre

    Full Text Available Each year the salmon louse (Lepeophtheirussalmonis Krøyer, 1838 causes multi-million dollar commercial losses to the salmon farming industry world-wide, and strict lice control regimes have been put in place to reduce the release of salmon louse larvae from aquaculture facilities into the environment. For half a century, the Lepeophtheirus life cycle has been regarded as the only copepod life cycle including 8 post-nauplius instars as confirmed in four different species, including L. salmonis. Here we prove that the accepted life cycle of the salmon louse is wrong. By observations of chalimus larvae molting in incubators and by morphometric cluster analysis, we show that there are only two chalimus instars: chalimus 1 (comprising the former chalimus I and II stages which are not separated by a molt and chalimus 2 (the former chalimus III and IV stages which are not separated by a molt. Consequently the salmon louse life cycle has only six post-nauplius instars, as in other genera of caligid sea lice and copepods in general. These findings are of fundamental importance in experimental studies as well as for interpretation of salmon louse biology and for control and management of this economically important parasite.

  4. A review of the population biology and host-parasite interactions of the sea louse Lepeophtheirus salmonis (Copepoda: Caligidae).

    Science.gov (United States)

    Tully, O; Nolan, D T

    2002-01-01

    Lepeophtheirus salmonis is a specific parasite of salmonids that occurs in the Atlantic and Pacific Oceans. When infestations are heavy fish mortality can occur although the factors that are responsible for causing epizootics, especially in wild salmonid populations are still largely unknown. Over the past 20 years this parasite has caused significant economic losses in farmed salmon production and possibly in wild salmonid populations locally. Understanding the connectivity between populations is crucial to an understanding of the epidemiology of infections and for management of infections in aquaculture. Data from genetics, pesticide resistance, larval dispersal models and spatial and temporal patterns of infestation in wild and farmed hosts suggests a spatially highly structured metapopulation the components of which have different levels of connectivity, probabilities of extinction and influence on the development of local infestations. The population structure is defined mainly by the dispersal dynamics of the planktonic stages and the behaviour of the host. Until recently virtually nothing was known about the relationship between the parasite and the host, or how the host may influence lice at local or population level. Typically, impacts on the host have usually been reported in terms of pathological lesions caused by attachment and feeding of the adult stages, as well as localised mild epithelial responses to juvenile attachment. However many studies report pathology associated with severe infestation. Recent new studies on the host-parasite interactions of L. salmonis have shown that this parasite induces stress-related responses systemically in the host skin and gills and that the stress response and immune systems are modulated. In the second part of this review, these new studies are presented, together with results from other host-parasite model systems where data for caligid sea lice are missing. One of the most revealing methods reported recently is

  5. New records of Caligidae (Copepoda, Siphonostomatoida) from the Philippines.

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    Maran, Balu Alagar Venmathi; Cruz-Lacierda, Erlinda R; Ohtsuka, Susumu; Nagasawa, Kazuya

    2016-10-11

    Parasitic copepods, especially sea lice (Caligidae) are causing economic problems in both aquaculture and to wild fishes around the world, but their study in at least some of the southeastern Asian countries, is still scanty. Here we provide new information on the distribution of 11 known species of parasitic copepods collected from 11 marine fish hosts from Iloilo, central part of the Philippines. Two species of the genus Anuretes Heller, 1865 and nine species of the genus Caligus Müller, 1785 were found to infest these hosts, i.e. Anuretes branchialis Rangnekar, 1953 from Platax orbicularis (Forsskål, 1775); A. plectorhynchi Yamaguti, 1936 from P. orbicularis and Plectorhinchus pictus (Tortonese, 1936); Caligus absens Ho, Lin et Chen, 2000 from Priacanthus macracanthus Cuvier in Cuvier & Valenciennes, 1829; C. asymmetricus Kabata, 1965 and C. coryphaenae (Steenstrup & Lütken, 1861) from Auxis thazard (Lacepède, 1800); C. bonito Wilson, 1905 from Coryphaena hippurus Linnaeus, 1758; C. cordyla Pillai, 1963 from Megalaspis cordyla (Linnaeus, 1758); C. cornutus Heegaard, 1962 from Sphyraena jello Cuvier in Cuvier & Valenciennes, 1829; C. epinepheli Yamaguti, 1936 from Scomberoides commersonnianus Lacepède, 1801; C. kanagurta Pillai, 1961 from Decapterus kurroides Bleeker, 1855, D. macarellus (Cuvier in Cuvier & Valenciennes, 1833) and C. hippurus; and C. rotundigenitalis Yü, 1933 from Scatophagus argus (Linnaeus, 1766). Attachment sites included the gill filaments and the body surface. Prevalence and mean intensity of caligids are provided in addition to an update on the checklist of caligids of the Philippines. Although reports on caligids in the Philippines are few, the published records indicate that sea lice are widely distributed throughout the archipelago.

  6. The sea louse Lepeophtheirus acutus (Caligidae, Siphonostomatoida, Copepoda) as a pathogen of aquarium-held elasmobranchs.

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    Kik, M J L; Janse, M; Benz, G W

    2011-10-01

    Lepeophtheirus acutus Heegaard, 1943 (Caligidae, Siphonostomatoida, Copepoda), was collected from or observed on four of six elasmobranch species held at Burgers' Zoo (Arnhem, The Netherlands). Circumstantial evidence suggested that a zebra shark, Stegostoma fasciatum (Hermann), from the wild carried the infection into the facility, where copepods reproduced and colonized additional hosts. Copepods typically attached on and about the eyes, in the mouth and occasionally about the cloaca and on the claspers. Severe ocular lesions were associated with infections on zebra sharks, a grey reef shark, Carcharhinus amblyrhynchos (Bleeker), whitetip reef sharks, Triaenodon obesus (Rüppell), and giant shovelnose ray, Rhinobatos typus Bennett, while blacktip reef sharks, Carcharhinus melanopterus (Quoy & Gaimard), and blacktip sharks, Carcharhinus limbatus (Valenciennes), living in infested aquaria showed no sign of infection. Water treatments using trichlorfon were considered primarily responsible for the eradication of copepods from hosts and infested aquaria. This case is the first report of a copepod infection being closely associated with disease and death of an aquarium-held elasmobranch. Given its ability to infect a wide variety of elasmobranchs and promote life-threatening lesions on some hosts, L. acutus should be considered a dangerous pathogen of captive elasmobranchs. © 2011 Blackwell Publishing Ltd.

  7. Caligus sclerotinosus (Copepoda: Caligidae), a serious pest of cultured red seabream Pagrus major (Sparidae) in Korea.

    Science.gov (United States)

    Venmathi Maran, B A; Oh, Sung-Yong; Soh, Ho Young; Choi, Hee Jung; Myoung, Jung-Goo

    2012-09-10

    Caligid copepods (Crustacea) known as sea lice are pests of cultured fish, causing serious diseases and economic losses in fish aquaculture worldwide. One species, Caligus sclerotinosus Roubal, Armitage & Rohde, 1983 (Caligidae), is considered a serious pest of the highly prized red seabream Pagrus major (Temminck and Schlegel, 1843) (Sparidae) cultured in Japan. Recently, in neighboring Korea, red seabream culture has intensified and almost replaced yellow tail culture. However, until now, there have been no reports on infection of this sea louse from red seabream in Korea. We surveyed 120 (20 fish per month) P. major from a sea ranched Tongyeong Marine Research Center aquaculture facility, Gyeongsangnamdo, Korea for six months in 2011 (June to November). We recorded severe infection by the sea louse C. sclerotinosus on the skin of P. major. Prevalence was 100%, mean intensity 7.06, maximum intensity 49, and minimum intensity 2. Adult females (624), males (219) and few chalimi (5) were observed and identified by their morphology. As an average of all our collections, less than 0.6% of individuals were chalimi. We suggest, therefore, that adults of C. sclerotinosus undergo ontogenetic host switching after their final moult. No infection of C. sclerotinosus was found on wild P. major collected from Tongyeong and Yeosu fish markets on the southern coast of Korea. Severe infection by this sea louse may cause secondary infections of the host. This copepod is already reported from Australia and Japan and hence, this is the first report from Korea. We expect this pest to have an impact on Korean red seabream fisheries equally serious to that being experienced in Japan. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Ectoparasitic sea lice, Caligus minimus (Otto 1821, Copepoda: Caligidae) on Brawn wrasse, Labrus merula L. in Izmir Bay, Aegean Sea

    OpenAIRE

    TANRIKUL, Tansel T.; Fatih Percin

    2012-01-01

    This paper reports on the species of Caligus minimus of the genus Caligus (Siphonosto - matoida: Caligidae), parasitic on marine fish, brawn wrasse (Labrus merula), genus Labridae, of Izmir Bay, Aegean Sea. The sea lice, C. minimus, is identified from the gill and external surfaces of the brawn wrasse (total length, 30 cm; weight, 210 gr.), particularly on its head. The entire collection of sea lice consists of 11-12 specimens, all of which are female. Ectoparasitic copepods especially belong...

  9. New records of sea lice (Copepoda: Caligidae) from marine fishes in Jaramijó, an area with potential for sea-cage aquaculture in Ecuador.

    Science.gov (United States)

    Morales-Serna, Francisco Neptali; Caña-Bozada, Víctor; Mera-Loor, Geormery; Loor-Andrade, Peggy; Fajer-Ávila, Emma J; Ho, Ju-Shey

    2015-02-20

    Farming of finfish in sea cages is gaining popularity worldwide. These systems are a suitable environment for the emergence, establishment and transmission of parasites or pathogens, such as sea lice (Copepoda: Caligidae), known to cause serious diseases and economic losses in finfish aquaculture worldwide. In coastal waters of Jaramijó, Ecuador, there are plans to culture spotted rose snapper (Lutjanus guttatus) and longfin yellowtail (Seriola rivoliana); however, the information about the occurrence of sea lice on fish from this country is scarce. To address this problem, a parasitological survey of economically important fish caught by artisanal fishermen was conducted between June 2013 and May 2014. A total of 608 fish belonging to 66 species were examined. Sea lice were found on 23 fish species. The diversity of these parasites consisted of 22 species of Caligus and 5 species of Lepeophtheirus. Most sea lice species (66%) occurred in a single fish species only, with low infection levels. The most frequently encountered species were Caligus asperimanus Pearse, 1951, Caligus mutabilis Wilson, 1905 and Caligus rufimaculatus Wilson, 1905. Taxonomic remarks are presented for some of the species recorded during this survey. All but two sea lice records are new to Ecuador, considerably expanding the geographical range of some species.

  10. Ectoparasitic sea lice, Caligus minimus (Otto 1821, Copepoda: Caligidae on Brawn wrasse, Labrus merula L. in Izmir Bay, Aegean Sea

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    Tansel T. Tanrikul

    2012-04-01

    Full Text Available This paper reports on the species of Caligus minimus of the genus Caligus (Siphonosto - matoida: Caligidae, parasitic on marine fish, brawn wrasse (Labrus merula, genus Labridae, of Izmir Bay, Aegean Sea. The sea lice, C. minimus, is identified from the gill and external surfaces of the brawn wrasse (total length, 30 cm; weight, 210 gr., particularly on its head. The entire collection of sea lice consists of 11-12 specimens, all of which are female. Ectoparasitic copepods especially belong to the Caligidae family, the most common crustacean parasites on fish. C. minimus can be found in Atlantic coasts, British waters, the North Sea, and the Mediterranean Sea. C. minimus ectoparasite is a host and mainly recorded on Perciformes, such as Dicentrarchus labrax, Pagellus bogaraveo, Umbrina cirrosa, and Mugil cephalus. Recently, in both sides of the Aegean Sea, C. minimus has been identified from cultured marine fish, mainly D. labrax. The intensity of the infection is apparent on adult fish, especially during the winter and early spring. C. minimus is the first record on brawn wrasse caught by gill nets from the Urla coasts in Izmir Bay, Aegean Sea in March 2010.

  11. A new Lepeophtheirus (Copepoda: Siphonostomatoida: Caligidae from Isla del Coco National Park, Costa Rica, Eastern Tropical Pacific

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    Eduardo Suárez-Morales

    2012-11-01

    Full Text Available Among the several groups of copepods that are teleost parasites, the siphonostomatoid family Caligidae is by far the most widespread and diverse. With more than 108 nominal species, the caligid genus Lepeophtheirus von Nordmann is one of the most speciose. There are no reports of this genus in Costa Rican waters. A new species of Lepeophtheirus is herein described based on female specimens collected from plankton samples in waters off Bahía Wafer, isla del Coco, an oceanic island in the Eastern Tropical Pacific. The new species, L. alvaroi sp. nov., has some affinities with other congeners bearing a relatively short abdomen, a wider than long genital complex and a 3-segmented exopod of leg 4. it differs from most of these species by the presence of an unbranched maxillular process and by the relative lengths of the terminal claws of leg 4, with two equally long elements. it is most closely related to two other Eastern Pacific species: L. dissimulatus Wilson, 1905 and L. clarionensis Shiino, 1959. it differs from these species by the proportions and shape of the genital complex, the shape of the sternal furca, the relative length of the maxillar segments, the absence of a pectiniform process on the distal maxillar segment, the length of leg 4 and the armature of leg 5. The new species represents the first Lepeophtheirus described from Costa Rican waters of the Pacific. The low diversity of this genus in this tropi- cal region is explained by its tendency to prefer hosts from temperate latitudes. Until further evidence is found, the host of this Lepeophtheirus species remains unknown.Entre los varios grupos de copépodos que son parásitos de teleósteos, la familia sifonostomatoide Caligidae incluye los más dispersos y diversos. Con más de 108 especies nominales, el género de calígidos Lepeophtheirus von Nordmann es uno de los más diversos. No existen registros previos de este género en aguas de Costa Rica. Se describe una nueva especie de

  12. Sex-biased gene expression and sequence conservation in Atlantic and Pacific salmon lice (Lepeophtheirus salmonis).

    Science.gov (United States)

    Poley, Jordan D; Sutherland, Ben J G; Jones, Simon R M; Koop, Ben F; Fast, Mark D

    2016-07-04

    Salmon lice, Lepeophtheirus salmonis (Copepoda: Caligidae), are highly important ectoparasites of farmed and wild salmonids, and cause multi-million dollar losses to the salmon aquaculture industry annually. Salmon lice display extensive sexual dimorphism in ontogeny, morphology, physiology, behavior, and more. Therefore, the identification of transcripts with differential expression between males and females (sex-biased transcripts) may help elucidate the relationship between sexual selection and sexually dimorphic characteristics. Sex-biased transcripts were identified from transcriptome analyses of three L. salmonis populations, including both Atlantic and Pacific subspecies. A total of 35-43 % of all quality-filtered transcripts were sex-biased in L. salmonis, with male-biased transcripts exhibiting higher fold change than female-biased transcripts. For Gene Ontology and functional analyses, a consensus-based approach was used to identify concordantly differentially expressed sex-biased transcripts across the three populations. A total of 127 male-specific transcripts (i.e. those without detectable expression in any female) were identified, and were enriched with reproductive functions (e.g. seminal fluid and male accessory gland proteins). Other sex-biased transcripts involved in morphogenesis, feeding, energy generation, and sensory and immune system development and function were also identified. Interestingly, as observed in model systems, male-biased L. salmonis transcripts were more frequently without annotation compared to female-biased or unbiased transcripts, suggesting higher rates of sequence divergence in male-biased transcripts. Transcriptome differences between male and female L. salmonis described here provide key insights into the molecular mechanisms controlling sexual dimorphism in L. salmonis. This analysis offers targets for parasite control and provides a foundation for further analyses exploring critical topics such as the interaction

  13. Diversity of sea lice (Copepoda: Caligidae) parasitic on marine fishes with commercial and aquaculture importance in Chamela Bay, Pacific coast of Mexico by using morphology and DNA barcoding, with description of a new species of Caligus.

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    Morales-Serna, Francisco Neptalí; Pinacho-Pinacho, Carlos Daniel; Gómez, Samuel; de León, Gerardo Pérez-Ponce

    2014-02-01

    The occurrence of parasitic copepods of the family Caligidae on wild and cultured marine fishes from Chamela Bay, on the Pacific coast of Mexico, is reported. A total of 16 species of Caligus and 1 species of Lepeophtheirus were found on 19 wild fish species. The description of Caligus chamelensis n. sp. parasitizing Kyphosus elegans is presented. Among the species of Caligus reported here, Caligus serratus is the most common since it was found infecting 11 fish species. On cultured fish, Lutjanus gutattus and L. peru, only one species of Caligus, C. sclerotinosus was collected. DNA barcodes [mitochondrial cytochrome c oxidase subunit I (COI) gene sequences] were obtained for the majority of the sea lice species herein reported. The molecular analyses support the recognition of the new species and suggest that neither Caligus nor Lepeophtheirus are monophyletic. COI is shown to be a good candidate for parasitic copepod species identification, although a more robust reference database is needed to expand our ability to accomplish a molecular identification. © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. Copepoda: Siphonostomatoida

    African Journals Online (AJOL)

    1987-04-13

    Apr 13, 1987 ... algunas especies de copepodos parasitos de peces de. Iitoral mediterraneo. Misc. Zool. 5: 161-171. SCOTT, T. 1901. Notes on some parasites of fishes. Rep. Fish. Board. Scott. 19: 120-153. WILSON, C.B. 1905. North American parasitic copepods belonging to the family Caligidae. Pt.I. The Caliginae. Proc.

  15. Purification of Piscirickettsia salmonis and partial characterisation of antigens

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    Barnes, M.N.; Landolt, M.L.; Powell, D.B.; Winton, J.R.

    1998-01-01

    Piscirickettsia salmonis is the etiological agent of salmonid rickettsial septicemia, an economically significant disease affecting the salmon aquaculture industry. As with other rickettsial pathogens, antigenic analysis of P. salmonis has been limited by the inherent difficulties of purifying an intracellular organism away from host cell material. In this report, we describe the use of diatrizoate meglumine and diatrizoate sodium (DMDS) density gradient centrifugation to purify P. salmonis grown in chinook salmon embryo (CHSE-214) cells. Plaque assay titers and total protein assays confirmed that viable P. salmonis was consistently concentrated in a visible band within the DMDS density gradient at a density of 1.15 to 1.16 g ml-1. Recovery of purified, viable organisms from DMDS density gradients varied from 0.6 to 3%. Preparations of uninfected CHSE-214 cells, CHSE-214 cells infected with P. salmonis, and gradient-purified P. salmonis were compared using sodium dodecyl sulfate polyacrylamide gel electrophoresis to assess the degree of purification and to identify P. salmonis-specific proteins. Although gradient-purified P. salmonis preparations were not completely free of host cell material, 8 bacterial proteins were identified. Polyclonal rabbit antiserum was used in an immunoblot of proteins from purified P. salmonis to identify 3 major and 5 minor antigens. The major antigens of 56, 30 and 20 kDa were potential candidates for experimental vaccines and development of novel diagnostic assays.

  16. Histopathological changes induced by copepoda parasites ...

    African Journals Online (AJOL)

    Histopathological changes induced by copepoda parasites infections on the gills of economically important fish mugilidae ( Liza falcipinnis and Mugil cephalus ) from Ganvie area of Lac Nokoue, Republic of Benin.

  17. The developmental stages of Pseudodiaptomus hessei (Copepoda ...

    African Journals Online (AJOL)

    The developmental stages of Pseudodiaptomus hessei (Copepoda: Calanoida). H.L. Jerling, T.H. Wooldridge. Abstract. Nauplii and copepodid developmental stages of the estuarine copepod, Pseudodiaptomus hessei, are described and illustrated. Five post-embryonic naupliar and five copepodid stages (excluding adults) ...

  18. In vitro culture of the flagellate protozoan Hexamita salmonis

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    Uzmann, J.R.; Hayduk, S.H.

    1963-01-01

    Trophozoites of Hexamita salmonis, asserted pathogen of juvenile salmonid fishes, were isolated from two species of Pacific salmon hosts and cultured repeatedly in an organic medium saturated with nitrogen. Primary isolates and serial subcultures usually exhibited five- to tenfold population increases per passage.

  19. The Proteome of Biologically Active Membrane Vesicles from Piscirickettsia salmonis LF-89 Type Strain Identifies Plasmid-Encoded Putative Toxins

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    Cristian Oliver

    2017-09-01

    Full Text Available Piscirickettsia salmonis is the predominant bacterial pathogen affecting the Chilean salmonid industry. This bacterium is the etiological agent of piscirickettsiosis, a significant fish disease. Membrane vesicles (MVs released by P. salmonis deliver several virulence factors to host cells. To improve on existing knowledge for the pathogenicity-associated functions of P. salmonis MVs, we studied the proteome of purified MVs from the P. salmonis LF-89 type strain using multidimensional protein identification technology. Initially, the cytotoxicity of different MV concentration purified from P. salmonis LF-89 was confirmed in an in vivo adult zebrafish infection model. The cumulative mortality of zebrafish injected with MVs showed a dose-dependent pattern. Analyses identified 452 proteins of different subcellular origins; most of them were associated with the cytoplasmic compartment and were mainly related to key functions for pathogen survival. Interestingly, previously unidentified putative virulence-related proteins were identified in P. salmonis MVs, such as outer membrane porin F and hemolysin. Additionally, five amino acid sequences corresponding to the Bordetella pertussis toxin subunit 1 and two amino acid sequences corresponding to the heat-labile enterotoxin alpha chain of Escherichia coli were located in the P. salmonis MV proteome. Curiously, these putative toxins were located in a plasmid region of P. salmonis LF-89. Based on the identified proteins, we propose that the protein composition of P. salmonis LF-89 MVs could reflect total protein characteristics of this P. salmonis type strain.

  20. Host specificity of Lepeophtheirus crassus (Wilson and Bere) (Copepoda: Caligidae) parasitic on the marlin sucker Remora osteochir (Cuvier) in the Atlantic Ocean.

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    Ho, Ju-shey; Collete, Bruce B; Madinabeitia, Ione

    2006-10-01

    Three species of remoras--Remora brachyptera (Lowe), Remora osteochir (Cuvier), and Remora remora (Linnaeus)--were collected from 4 species of billfishes--Istiophorus platypterus (Shaw), Makaira nigricans Lacepéde, Tetrapturus albidus Poey, and Tetrapturus pfluegeri Robins and de Sylva--on board a Japanese long-liner Shoyo Maru during her cruise in 2002 across the Atlantic. However, only the marlin sucker (R. osteochir) was found to carry a parasitic copepod, Lepeophtheirus crassus (Wilson and Bere, 1936). Although 12 species of parasitic copepods have been reported from billfishes around the world ocean, none of them is L. crassus. Thus, L. crassus is considered a parasite specific to the marlin sucker.

  1. The discovery of male Caligus brevicaudatus Scott, 1901 (Copepoda: Caligidae) parasitic on tub gurnard, Chelidonichthys lucerna (Linnaeus) from the eastern Mediterranean.

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    Demirkale, Ibrahim; Ozak, Argun Akif; Boxshall, Geoffrey Allan

    2015-09-17

    Caligus brevicaudatus Scott, 1901, a common but poorly known species of parasitic copepod, is redescribed from newly collected specimens of both sexes. The new material was collected from the body surface of tub gurnards, Chelidonichthys lucerna (Linnaeus), caught in eastern Mediterranean waters off the Turkish coast. Inadequately described female structures from earlier descriptions are redescribed and illustrated in detail and the male of C. brevicaudatus is described for the first time. The new material of C. brevicaudatus is compared with material collected by A. Scott and stored in the collections of the Natural History Museum, London. In addition, a voucher specimen of Caligus uranoscopi Vaissière, 1955, stored in the collections of the Muséum National d'Histoire Naturelle in Paris is re-examined. Caligus uranoscopi is recognised as a junior subjective synonym of C. brevicaudatus since it does not differ in any substantive characters.

  2. Redescriptions of two species of Lepeophtheirus (Copepoda, Siphonostomatoida, Caligidae parasitic on teleost marine fishes from the coastal zone of the State of Rio de Janeiro, Brazil

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    José Luis Luque

    2000-12-01

    Full Text Available Two species of Lepeophtheirus Nordmann, 1832 parasitic on the ariid fish Netuma barba Lacépède, 1803, and the bothiid fish Paralichthys sp. from the coastal zone of the State of Rio de Janeiro, are redescribed and illustrated: L. bagri Dana, 1852, and L. monacanthus Heller, 1865. New junior synonyms for these species are proposed: L. marginatus syn.n., L. christianensis syn.n. and L. platensis syn.n. of L. bagri and L. unispinosus syn.n. of L. monacanthus.

  3. Broth medium for the successful culture of the fish pathogen Piscirickettsia salmonis .

    Science.gov (United States)

    Yañez, A J; Valenzuela, K; Silva, H; Retamales, J; Romero, A; Enriquez, R; Figueroa, J; Claude, A; Gonzalez, J; Avendaño-Herrera, R; Carcamo, J G

    2012-01-24

    Piscirickettsiosis or salmonid rickettsial septicaemia (SRS) caused by Piscirickettsia salmonis constitutes one of the main problems in farmed salmonid and marine fishes. Since the first reports of the disease, it has been successfully isolated and maintained in eukaryotic cell--culture systems, but these systems are time-consuming, the media are costly, and eliminating heavily contaminated host cell debris is difficult. In this report, we describe a marine-based broth supplemented with L-cysteine, named AUSTRAL-SRS broth, that facilitates superior growth of P. salmonis strains. Strains reached an optical density of approximately 1.8 when absorbance was measured at 600 nm after 6 d incubation at 18°C. Several passages (n = 6) did not alter the culture kinetics. We report for the first time the purification of DNA, lipopolysaccharide (LPS) and whole membrane protein obtained from P. salmonis grown in this liquid medium, and thus provide a suitable platform to simplify the preparation of P. salmonis cells for genetic and serological studies. Moreover, the results of the cytopathic effect test showed that P. salmonis grown in AUSTRAL-SRS broth maintained their virulence properties, inducing apoptosis after 3 d. This makes the medium a good candidate for the successful growth of P. salmonis and an excellent basis for the development of low cost vaccines.

  4. COPEPODA: SUMBU KELANGSUNGAN BIOTA AKUATIK DAN KONTRIBUSINYA UNTUK AKUAKULTUR

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    Media Fitri Isma Nugraha

    2011-12-01

    Full Text Available Ulasan ini mencoba memperkenalkan dan manfaat jasad renik copepoda untuk domain manusia. Perannya sebagai basal kehidupan akuatik dan taksa vertebrata lainnya sering dilupakan, pada ulasan ini pula akan mengenalkan jasanya pada akuakultur. Copepoda digolongkan dalam Phylum Crustacean, yang berukuran sangat kecil sekitar 60-200 μm. Copepoda menghuni hampir setiap lapisan perairan dari permukaan sampai dasar lautan. Jasad renik ini dijadikan sebagai indikator kesuburan perairan, juga sebagai konsumen tingkat pertama yang memberikan gizi berupa EPA dan DHA pada setiap jenis biota perairan. Sejarah manusia pertama kali mengenal copepoda pasca kesuksesan ekspedisi Challenger 1872-1876. Kepedulian kita dalam mengenal spesies ini berarti telah membantu dalam mewujudkan keseimbangan ekosistem. Atas dasar kepedulian dan untuk keseimbangan alam dan lingkungan, maka multi institusional yang bergerak dalam domain akuakultur telah mengoleksi dan mengembangbiakkan satu sub spesies dari copepoda ini di dalam sebuah bak terkontrol, dan dijadikan sebagai sumber pakan alami larva kultivan.

  5. Mechanism behind Resistance against the Organophosphate Azamethiphos in Salmon Lice (Lepeophtheirus salmonis.

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    Kiranpreet Kaur

    Full Text Available Acetylcholinesterase (AChE is the primary target for organophosphates (OP. Several mutations have been reported in AChE to be associated with the reduced sensitivity against OP in various arthropods. However, to the best of our knowledge, no such reports are available for Lepeophtheirus salmonis. Hence, in the present study, we aimed to determine the association of AChE(s gene(s with resistance against OP. We screened the AChE genes (L. salmonis ace1a and ace1b in two salmon lice populations: one sensitive (n=5 and the other resistant (n=5 for azamethiphos, a commonly used OP in salmon farming. The screening led to the identification of a missense mutation Phe362Tyr in L. salmonis ace1a, (corresponding to Phe331 in Torpedo californica AChE in all the samples of the resistant population. We confirmed the potential role of the mutation, with reduced sensitivity against azamethiphos in L. salmonis, by screening for Phe362Tyr in 2 sensitive and 5 resistant strains. The significantly higher frequency of the mutant allele (362Tyr in the resistant strains clearly indicated the possible association of Phe362Tyr mutation in L. salmonis ace1a with resistance towards azamethiphos. The 3D modelling, short term survival experiments and enzymatic assays further supported the imperative role of Phe362Tyr in reduced sensitivity of L. salmonis for azamethiphos. Based on all these observations, the present study, for the first time, presents the mechanism of resistance in L. salmonis against azamethiphos. In addition, we developed a rapid diagnostic tool for the high throughput screening of Phe362Tyr mutation using High Resolution Melt analysis.

  6. Evidence of exotoxin secretion of Piscirickettsia salmonis, the causative agent of piscirickettsiosis.

    Science.gov (United States)

    Rojas, M E; Galleguillos, M; Díaz, S; Machuca, A; Carbonero, A; Smith, P A

    2013-08-01

    Piscirickettsia salmonis is the aetiological agent of piscirickettsiosis, a disease which affects a variety of teleost species and that is particularly severe in salmonid fish. Bacterial-free supernatants, obtained from cultures of three isolates of Piscirickettsia salmonis, were inoculated in Atlantic salmon, Salmo salar L., and in three continuous cell lines in an effort to determine the presence of secretion of extracellular products (ECPs) by this microorganism. Although steatosis was found in some liver samples, no mortalities or clinical signs occurred in the inoculated fish. Clear cytotoxicity was observed after inoculation in the cell lines CHSE-214 and ASK, derived from salmonid tissues, but not in MDBK, which is of mammalian origin. The degree of cytotoxicity of the ECPs was different among the P. salmonis isolates tested. The isolate that evidenced the highest cytotoxicity in its ECPs exhibited only an intermediate virulence level after challenging fish with bacterial suspensions of the three P. salmonis isolates. Almost complete inhibition of the cytotoxic activity of ECPs was seen after proteinase K treatment, indicating their peptidic nature, and a total preclusion of the cytotoxicity was shown after their incubation at 50 °C for 30 min. Results show that P. salmonis can produce ECPs and at least some of them are thermolabile exotoxins that probably play a role in the pathogenesis of piscirickettsiosis. © 2013 Blackwell Publishing Ltd.

  7. Genomic Prediction Accuracy for Resistance Against Piscirickettsia salmonis in Farmed Rainbow Trout.

    Science.gov (United States)

    Yoshida, Grazyella M; Bangera, Rama; Carvalheiro, Roberto; Correa, Katharina; Figueroa, René; Lhorente, Jean P; Yáñez, José M

    2018-02-02

    Salmonid rickettsial syndrome (SRS), caused by the intracellular bacterium Piscirickettsia salmonis, is one of the main diseases affecting rainbow trout (Oncorhynchus mykiss) farming. To accelerate genetic progress, genomic selection methods can be used as an effective approach to control the disease. The aims of this study were: (i) to compare the accuracy of estimated breeding values using pedigree-based best linear unbiased prediction (PBLUP) with genomic BLUP (GBLUP), single-step GBLUP (ssGBLUP), Bayes C, and Bayesian Lasso (LASSO); and (ii) to test the accuracy of genomic prediction and PBLUP using different marker densities (0.5, 3, 10, 20, and 27 K) for resistance against P. salmonis in rainbow trout. Phenotypes were recorded as number of days to death (DD) and binary survival (BS) from 2416 fish challenged with P. salmonis A total of 1934 fish were genotyped using a 57 K single-nucleotide polymorphism (SNP) array. All genomic prediction methods achieved higher accuracies than PBLUP. The relative increase in accuracy for different genomic models ranged from 28 to 41% for both DD and BS at 27 K SNP. Between different genomic models, the highest relative increase in accuracy was obtained with Bayes C (∼40%), where 3 K SNP was enough to achieve a similar accuracy to that of the 27 K SNP for both traits. For resistance against P. salmonis in rainbow trout, we showed that genomic predictions using GBLUP, ssGBLUP, Bayes C, and LASSO can increase accuracy compared with PBLUP. Moreover, it is possible to use relatively low-density SNP panels for genomic prediction without compromising accuracy predictions for resistance against P. salmonis in rainbow trout. Copyright © 2018 Yoshida et al.

  8. Surveillance of the Sensitivity towards Antiparasitic Bath-Treatments in the Salmon Louse (Lepeophtheirus salmonis.

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    Peder A Jansen

    Full Text Available The evolution of drug resistant parasitic sea lice is of major concern to the salmon farming industry worldwide and challenges sustainable growth of this enterprise. To assess current status and development of L. salmonis sensitivity towards different pesticides used for parasite control in Norwegian salmon farming, a national surveillance programme was implemented in 2013. The programme aims to summarize data on the use of different pesticides applied to control L. salmonis and to test L. salmonis sensitivity to different pesticides in farms along the Norwegian coast. Here we analyse two years of test-data from biological assays designed to detect sensitivity-levels towards the pesticides azamethiphos and deltamethrin, both among the most common pesticides used in bath-treatments of farmed salmon in Norway in later years. The focus of the analysis is on how different variables predict the binomial outcome of the bioassay tests, being whether L. salmonis are immobilized/die or survive pesticide exposure. We found that local kernel densities of bath treatments, along with a spatial geographic index of test-farm locations, were significant predictors of the binomial outcome of the tests. Furthermore, the probability of L. salmonis being immobilized/dead after test-exposure was reduced by odds-ratios of 0.60 (95% CI: 0.42-0.86 for 2014 compared to 2013 and 0.39 (95% CI: 0.36-0.42 for low concentration compared to high concentration exposure. There were also significant but more marginal effects of parasite gender and developmental stage, and a relatively large random effect of test-farm. We conclude that the present data support an association between local intensities of bath treatments along the coast and the outcome of bioassay tests where salmon lice are exposed to azamethiphos or deltamethrin. Furthermore, there is a predictable structure of L. salmonis phenotypes along the coast in the data, characterized by high susceptibility to pesticides

  9. North-south diversity of Scolecithricidae species (Copepoda: Calanoida) in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalakrishnan, T.C.; Balachandran, T.

    The effectiveness of north-south hydrographical barriers in restricting the distributions of Scolecithricidae species (Copepoda:Calanoida) in the euphotic zone of the Indian Ocean was studied. Twenty seven species belonging to 7 genera were...

  10. A note on chromosomes of Pontellopsis herdmani and Pontella princeps (Copepoda) from the Laccadive sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.; Goswami, S.C.

    Pontellopsis herdmani and Pontella princeps (Pontellidae, Calanoida, Copepoda) showed a diploid number of 20 and a haploid number of 10 chromosomes during the spermatogonial metaphase and metaphase II stages. The chromosomes were in the size range...

  11. Isolation and Characterization of Serum Extracellular Vesicles (EVs from Atlantic Salmon Infected with Piscirickettsia Salmonis

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    Leidy Lagos

    2017-12-01

    Full Text Available Secretion of extracellular vesicles (EVs is a common feature of both eukaryotic and prokaryotic cells. Isolated EVs have been shown to contain different types of molecules, including proteins and nucleic acids, and are reported to be key players in intercellular communication. Little is known, however, of EV secretion in fish, or the effect of infection on EV release and content. In the present study, EVs were isolated from the serum of healthy and Piscirickettsia salmonis infected Atlantic salmon in order to evaluate the effect of infection on EV secretion. P. salmonis is facultative intracellular bacterium that causes a systemic infection disease in farmed salmonids. EVs isolated from both infected and non-infected fish had an average diameter of 230–300 nm, as confirmed by transmission electron microscopy, nanoparticle tracking, and flow cytometry. Mass spectrometry identified 180 proteins in serum EVs from both groups of fish. Interestingly, 35 unique proteins were identified in serum EVs isolated from the fish infected with P. salmonis. These unique proteins included proteasomes subunits, granulins, and major histocompatibility class I and II. Our results suggest that EV release could be part of a mechanism in which host stimulatory molecules are released from infected cells to promote an immune response.

  12. Pengujian Dua Pasang Primer Universal Untuk Amplifikasi Gen Cytochrome Oxidase I Copepoda

    OpenAIRE

    Sumampow, Thalita C. P

    2015-01-01

    Copepoda merupakan zooplankton kaya manfaat dengan diversitas yang sangat tinggi dan terdiri dari banyak spesies kriptik. Identifikasi cepat, akurat, dan hemat dapat dilakukan dengan menggunakan teknik DNA Barcoding. Kesuksesan teknik tersebut sangat dipengaruhi oleh penggunaan primer yang tepat. Tujuan penelitian ini adalah untuk menguji kemampuan dua pasang primer universal, yakni LCO1490-HCO2198 dan FF2d-FR1d, mengamplifikasi gen COI Copepoda. Dalam penelitian ini, pasangan primer LCO1490-...

  13. A new species of Quinquelaophonte (Copepoda: Harpacticoida from Argentina

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    Michel Sciberras

    2014-10-01

    Full Text Available Quinquelaophonte aestuarii sp. nov. (Copepoda, Harpacticoida from Bahía Blanca estuary is the first record of Quinquelaophonte Wells, Hicks & Coull, 1982 in Argentina and its southernmost location in the world. The setal formula (P2: exopod 1.2.3-endopod 1.2.0; P3: exopod 1.2.3-endopod 2.2.1; P4: exopod 1.2.3-endopod 1.2.0 of the last segment of P2-P4, in both the exopod and the endopod, distinguishes this species from all known species in Quinquelaophonte, except for Quinquelaophonte varians Bjornberg, 2010. The new species differs from the latter in the setal formula of the antennule, the mouth parts and maxillipeds, the absence of an inner seta on the second exopod segment of P2, the length of the second exopod segment of P4 and in the shape of baseoendopod setae of P5.

  14. Transcriptomic responses to emamectin benzoate in Pacific and Atlantic Canada salmon lice Lepeophtheirus salmonis with differing levels of drug resistance.

    Science.gov (United States)

    Sutherland, Ben J G; Poley, Jordan D; Igboeli, Okechukwu O; Jantzen, Johanna R; Fast, Mark D; Koop, Ben F; Jones, Simon R M

    2015-02-01

    Salmon lice Lepeophtheirus salmonis are an ecologically and economically important parasite of wild and farmed salmon. In Scotland, Norway, and Eastern Canada, L. salmonis have developed resistance to emamectin benzoate (EMB), one of the few parasiticides available for salmon lice. Drug resistance mechanisms can be complex, potentially differing among populations and involving multiple genes with additive effects (i.e., polygenic resistance). Indicators of resistance development may enable early detection and countermeasures to avoid the spread of resistance. Here, we collect sensitive Pacific L. salmonis and sensitive and resistant Atlantic L. salmonis from salmon farms, propagate in laboratory (F1), expose to EMB in bioassays, and evaluate either baseline (Atlantic only) or induced transcriptomic differences between populations. In all populations, induced responses were minor and a cellular stress response was not identified. Pacific lice did not upregulate any genes in response to EMB, but downregulated degradative enzymes and transport proteins at 50 ppb EMB. Baseline differences between sensitive and now resistant Atlantic lice were much greater than responses to exposures. All resistant lice overexpressed degradative enzymes, and resistant males, the most resistant group, overexpressed collagenases to the greatest extent. These results indicate an accumulation of baseline expression differences related to resistance.

  15. An isolate of Piscirickettsia salmonis from white seabass is fully virulent for coho salmon

    Science.gov (United States)

    House, M.L.; Hedrick, R.P.; Winton, J.R.; Fryer, J.L.

    2006-01-01

    The virulence of the WSB-98 isolate of Piscirickettsia salmonis from white seabass Atractoscion nobilis was compared with that of the American Type Culture Collection type strain LF-89, which was originally isolated from coho salmon Oncorhynchus kisutch in Chile. In controlled laboratory challenges of juvenile coho salmon, the isolate from white seabass exhibited virulence that was equal to or greater than that of LF-89. The cumulative percent mortality (CPM) was similar between groups of coho salmon receiving an intraperitoneal injection of WSB-98 at 104.5 tissue culture infectious dose with 50% endpoint (TCID50)/fish (CPM = 98%) or an injection of LF-89 at 104.8 TCID50/fish (CPM = 95%). The mean day to death of 9.3 d for WSB-98 and 18.6 d for LF-89, however, differed significantly (P < 0.0001) between the two isolates. The virulence of an isolate of P. salmonis from white seabass for a salmonid species is consistent with the hypothesis that nonsalmonids can serve as natural marine hosts for the bacterium and potential sources for infection of salmonids. ?? Copyright by the American Fisheries Society 2006.

  16. Prevalence, geographic distribution and phenotypic differences of Piscirickettsia salmonis EM-90-like isolates.

    Science.gov (United States)

    Saavedra, J; Hernandez, N; Osses, A; Castillo, A; Cancino, A; Grothusen, H; Navas, E; Henriquez, P; Bohle, H; Bustamante, F; Bustos, P; Mancilla, M

    2017-08-01

    Early reports accounted for two main genotypes of Piscirickettsia salmonis, a fish pathogen and causative agent of piscirickettsiosis, placing the single isolate EM-90 apart from the prototypic LF-89 and related isolates. In this study, we provide evidence that, contrary to what has been supposed, the EM-90-like isolates are highly prevalent and disseminated across Chilean marine farms. Molecular analysis of 507 P. salmonis field isolates derived from main rearing areas, diverse hosts and collected over 6 years, revealed that nearly 50% of the entire collection were indeed typed as EM-90-like. Interestingly, these isolates showed a marked host preference, being recovered exclusively from Atlantic salmon (Salmo salar) samples. Although both strains produce undistinguishable pathological outcomes, differences regarding growth kinetics and susceptibility to the antibiotics and bactericidal action of serum could be identified. In sum, our results allow to conclude that the EM-90-like isolates represent an epidemiologically relevant group in the current situation of piscirickettsiosis. Based on the consistency between genotype and phenotype exhibited by this strain, we point out the need for genotypic studies that may be as important for the Chilean salmon industry as the continuous surveillance of antimicrobial susceptibility patterns. © 2017 The Authors Journal of Fish Diseases Published by John Wiley & Sons Ltd.

  17. Cletocamptus goenchim sp. nov., a new harpacticoid (Copepoda: Harpacticoida) from India

    Digital Repository Service at National Institute of Oceanography (India)

    Gomez, S.; Ingole, B.; Sawant, M.; Singh, R.

    ; ENP, endopod; P1(P2-P4)EXP(ENP)1(2, 3) denotes the proximal (middle, distal) exopodal (endopodal) segment of P1, P2, P3 or P4. Taxonomic account Family CANTHOCAMPTIDAE Sars, 1906 (incertae sedis) sensu Por, 1986 Genus Cletocamptus Shmankevich... of Environmental Biology 31: 819-826. Por, F. D. 1986. A re-evaluation of the Cletodidae Sars, Lang (Copepoda, Harpacticoida). Syllogeus 58: 420–425. Ranga Reddy, Y., & Y. Radhakrishna. 1979. A new record of Cletocamptus deitersi (Richard, 1895) (Copepoda...

  18. Cladocera and Copepoda (Crustacea Fauna of Çatalan Dam Lake (Adana, Turkey.

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    Ahmet Turan Aladağ

    2015-12-01

    Full Text Available Çatalan Baraj Gölü’nün (Adana Copepoda ve Cladocera (Crustacea faunası. Çatalan baraj gölünün Cladocera ve Copepoda (Crustacea faunası Temmuz 2001 ve Haziran 2002 tarihleri arasında aylık periyotlarla alınan örneklerin incelenmesiyle belirlendi. Örneklerin değerlendirilmesi sonucunda, Çatalan baraj gölünde kladoserlerden 8, kopepodlardan ise 2 olmak üzere toplam 10 tür saptanmıştır

  19. Genomic-based restriction enzyme selection for specific detection of Piscirickettsia salmonis by 16S rDNA PCR-RFLP

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    Dinka eMandakovic

    2016-05-01

    Full Text Available The gram negative facultative bacterium P. salmonis is the etiological agent of Salmonid Rickettsial Septicaemia (SRS, a severe disease that causes important economic losses in the global salmon farmer industry. Despite efforts to control this disease, the high frequency of new epizootic events indicate that the vaccine and antibiotics treatments have limited effectiveness, therefore the preventive and diagnostic approaches must be improved. A comparison of several methodologies for SRS diagnostic indicate differences in their specificity and its capacity to detect other bacteria coexisting with P. salmonis in culture media (contamination and fish samples (coinfection, aspects relevant for research, vaccine development and clinical diagnostic. By computer-simulation analyses, we identified a group of restriction enzymes that generate unique P. salmonis 16S rDNA band patterns, distinguishable from all other bacteria. From this information, we designed and developed a PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism assay, which was validated using 16S rDNA universal primers and restriction enzyme PmaCI for the amplification and digestion, respectively. Experimental validation was performed by comparing the restriction pattern of P. salmonis with the restriction patterns generated by bacteria that cohabit with P. salmonis (fish bacterial isolates and culture media contaminants. Our results indicate that the restriction enzyme selection pipeline was suitable to design a more specific, sensible, faster and cheaper assay than the currently used P. salmonis detection methodologies.

  20. Cyclopidae des eaux souterraines de Portugal et de l’île de Majorque (Crustacea, Copepoda)

    NARCIS (Netherlands)

    Lescher-Moutoué, Françoise

    1981-01-01

    Eight species of Cyclopidae (Copepoda) are recorded from continental groundwaters of the Iberian peninsula and Mallorca. The six species from Portugal constitute the first records of subterranean Cyclopidae from that country. Thermocyclops oblongatus is new to the Iberian peninsula, and the range of

  1. On the ecological role of Copepoda in the Suez Canal marine ...

    African Journals Online (AJOL)

    On the ecological role of Copepoda in the Suez Canal marine ecosystem. Hamed El-Serehy, Sawsan Aboul-Ezz, Amein Samaan, Nasser Saber. Abstract. Species-specific abundance of copepods was determined at monthly intervals at 10 stations in the Suez Canal water between June 1994 and May 1995. Sampling ...

  2. Br anchiopoda and Copepoda (Crustacea in Mongolian Saline Lakes

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    Miguel Alonso

    2010-06-01

    Full Text Available Thi s paper presents a very complete inventory of the branchiopods and copepods that inhabit the salt lakes (salinity >3‰ of Mongolia. The inventory was based on samples collected from 108 salt lakes over the course of seven limnological expeditions in most of the Mongolian territory between 2005 and 2009. The salinity of the lakes ranged from 3.4 to 76‰ S. A total of 43 taxa were identifi ed: 7 Anostraca, 1 Spinicaudata, 1 Notostraca, 1 Leptodoridae, 1 Ctenopoda, 15 Anomopoda and 17 Copepoda. Thirteen taxa are limited to the Asiatic portion and the rest are known throughout the Palearctic region. One taxon, Phallocryptus sp. has not yet been described in scientifi c literature. The taxonomic position of Artemia sp. in Mongolia has still not been clarifi ed. All of the species are eurysaline and, except for Artemia sp. and Cletocamptus retrogressus , which are the most halophile, they can live in waters with less than 10‰ S. Thirty-three species appear only in mesosaline waters (3–20‰ S, fi ve do not exceed the mesosaline level (50‰ S and fi ve can live in hypersaline waters (>50‰ S.

  3. Factors influencing the long-term dynamics of larval sea lice density at east and west coast locations in Scotland.

    Science.gov (United States)

    Harte, Anna J; Bowman, Alan S; Salama, Nabeil K G; Pert, Campbell C

    2017-03-21

    Sea lice (Copepoda: Caligidae) are marine copepods that parasitize finfish, and in cases of high infestation can result in severe epithelial damage and mortality. In Scotland, 2 species of sea louse, Lepeophtheirus salmonis and Caligus elongatus, pose a significant economic burden to the marine Atlantic salmon aquaculture industry and potentially impact wild salmonids. The purpose of this study was to determine how the density of pelagic sea lice is affected by external variables, in order to improve our understanding of sea lice dynamics. Long-term data from 2 sampling sites on the east and west coasts of Scotland were modelled independently in conjunction with environmental and anthropogenic variables. Statistical analysis identified that at the east coast site, the most influential factor affecting lice density was salinity. On the west coast, salinity, rainfall and farmed salmon production year were most influential. Molecular and morphological techniques also showed that the individuals recorded on the east coast were C. elongatus, a generalist copepod parasite, whereas only the salmonid-specific L. salmonis were found on the west. These results reiterate the role of environmental factors in influencing sea lice dynamics, and that salmonids are the primary hosts of sea lice on the west coast, but there could be non-salmonid host species as well as salmonid species influencing east coast sea lice densities.

  4. Piscirickettsia salmonis Imbalances the Innate Immune Response to Succeed in a Productive Infection in a Salmonid Cell Line Model.

    Directory of Open Access Journals (Sweden)

    Claudio A Álvarez

    Full Text Available Piscirickettsia salmonis is a facultative intracellular bacterium that causes the disease called "salmon rickettsial syndrome". Attempts to control this disease have been unsuccessful, because existing vaccines have not achieved the expected effectiveness and the antibiotics used fail to completely eradicate the pathogen. This is in part the product of lack of scientific information that still lacks on the mechanisms used by this bacterium to overcome infected-cell responses and survive to induce a productive infection in macrophages. For that, this work was focused in determining if P. salmonis is able to modify the expression and the imbalance of IL-12 and IL-10 using an in vitro model. Additionally, we also evaluated the role the antimicrobial peptide hepcidin had in the control of this pathogen in infected cells. Therefore, the expression of IL-10 and IL-12 was evaluated at earlier stages of infection in the RTS11 cell line derived from Oncorhynchus mykiss macrophages. Simultaneously, the hepcidin expression and location was analyzed in the macrophages infected with the pathogen. Our results suggest that IL-10 is clearly induced at early stages of infection with values peaking at 36 hours post infection. Furthermore, infective P. salmonis downregulates the expression of antimicrobial peptide hepcidin and vesicles containing this peptide were unable to merge with the infective bacteria. Our results suggest that P. salmonis is able to manipulate the behavior of host cytokines and likely might constitute a virulence mechanism that promotes intracellular bacterial replication in leukocytes cells lines of trout and salmon. This mechanism involves the generation of an optimum environment for the microorganism and the downregulation of antimicrobial effectors like hepcidin.

  5. Immunization strategies against Piscirickettsia salmonis infections. Review of vaccination approaches and modalities and their associated immune response profiles.

    Directory of Open Access Journals (Sweden)

    Oystein Evensen

    2016-11-01

    Full Text Available Salmonid rickettsial septicemia is a serious, infectious disease in Chilean salmon farming caused by Piscirickettsia salmonis, causing heavy losses to the salmonid industry. P. salmonis belongs to the Gammaproteobacteria, order Thiotrichales. SRS was first described in Chile in 1989, and infection with P. salmonis has since been described from a high number of fish species and in several geographic regions globally. P. salmonis infection of salmonids causes multifocal, necrotic areas of internal organs like liver, kidney and spleen. Histologically and immunologically the tissue response is formation of granulomas, often with central suppuration. The exact sequence of infection is not known but bacteria likely gain access to internal organs through mucosal surfaces and when infected, fish carry bacteria in macrophages. It has not been fully determined if the bacterium resides in the cytosol or hide within vesicular structures intracellularly, although there are indications that in vitro infection results in actin reorganization and formation of actin-coated vesicle within which the bacterium resides. Protection against lethal challenge is well documented in lab scale experiments but protection from vaccination has proven more difficult to attain long term under field conditions. Current vaccination protocols include whole cell, inactivated and adjuvanted vaccines for injection for primary immunization followed by oral boost where timing of boost delivery is followed by measuring circulating antibody levels against the pathogen. Documentation also exist that there is correlation between antibody titers and protection against mortality. Future vaccination regimes will likely also include live, attenuated vaccines or other technologies such as DNA vaccination. So far there is no documentation available for live vaccines and for DNA vaccines, studies have been unsuccessful under laboratory conditions.

  6. Improvement of the sediment ecosystem following diversion of an intertidal sewage outfall at the Fraser river estuary, Canada, with emphasis on Corophium salmonis (Amphipoda).

    Science.gov (United States)

    Arvai, J L; Levings, C D; Harrison, P J; Neill, W E

    2002-06-01

    Primary treated sewage effluent from the city of Vancouver, Canada was deposited directly onto the intertidal ecosystem of Sturgeon bank, Fraser river estuary between 1962 and 1988. In response to the degraded sediment conditions an azoic zone developed near the discharge outfall. Effluent discharges into the intertidal zone were almost completely stopped in 1988 with the construction of a submerged outfall. Our studies, conducted between 1994 and 1996, showed considerable improvement in the environment of the mudflat ecosystem, including increased dissolved oxygen, decreased sediment chlorophyll, decreased organic material in the sediment, reduced heavy metals in surficial sediment and increased grain size. The amphipod Corophium salmonis, important in the food web for juvenile salmon and other fish species, recolonized the previously azoic location. At reference stations, C. salmonis density was similar to that observed in previous surveys two decades earlier. Our data strongly suggest that improvement or sediment conditions near the former sewage outfall was a major factor enabling colonization by C. salmonis.

  7. Phylogenomic analysis of Copepoda (Arthropoda, Crustacea) reveals unexpected similarities with earlier proposed morphological phylogenies.

    Science.gov (United States)

    Eyun, Seong-Il

    2017-01-19

    Copepods play a critical role in marine ecosystems but have been poorly investigated in phylogenetic studies. Morphological evidence supports the monophyly of copepods, whereas interordinal relationships continue to be debated. In particular, the phylogenetic position of the order Harpacticoida is still ambiguous and inconsistent among studies. Until now, a small number of molecular studies have been done using only a limited number or even partial genes and thus there is so far no consensus at the order-level. This study attempted to resolve phylogenetic relationships among and within four major copepod orders including Harpacticoida and the phylogenetic position of Copepoda among five other crustacean groups (Anostraca, Cladocera, Sessilia, Amphipoda, and Decapoda) using 24 nuclear protein-coding genes. Phylogenomics has confirmed the monophyly of Copepoda and Podoplea. However, this study reveals surprising differences with the majority of the copepod phylogenies and unexpected similarities with postembryonic characters and earlier proposed morphological phylogenies; More precisely, Cyclopoida is more closely related to Siphonostomatoida than to Harpacticoida which is likely the most basally-branching group of Podoplea. Divergence time estimation suggests that the origin of Harpacticoida can be traced back to the Devonian, corresponding well with recently discovered fossil evidence. Copepoda has a close affinity to the clade of Malacostraca and Thecostraca but not to Branchiopoda. This result supports the hypothesis of the newly proposed clades, Communostraca, Multicrustacea, and Allotriocarida but further challenges the validity of Hexanauplia and Vericrustacea. The first phylogenomic study of Copepoda provides new insights into taxonomic relationships and represents a valuable resource that improves our understanding of copepod evolution and their wide range of ecological adaptations.

  8. Microcrustaceans (Branchipoda and Copepoda) of Wetland Impoundments on the Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    DeBiase, Adrienne E; Taylor, Barbara E

    2005-09-21

    The United States Department of Energy’s Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders, larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.

  9. Spatial distribution and secondary production of Copepoda in a tropical reservoir: Barra Bonita, SP, Brazil

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    MJ. Santos-Wisniewski

    Full Text Available The present paper aims to describe the spatial distribution of zooplankton copepods, their biomass and instantaneous secondary production, in Barra Bonita, a large eutrophic, polymitic reservoir (22° 29' S and 48° 34' W on the Tietê River, of the Paraná basin. Sampling was carried out during two seasons: dry winter and rainy summer. Species composition, age structure and numerical density of each copepod species population were analyzed at 25 sampling stations. Secondary production was calculated for Copepoda, the dominant group in zooplankton communities, taking Calanoida and Cyclopoida separately. Copepoda represented the largest portion of the total zooplankton biomass, the dominant species being Notodiaptomus iheringi among the Calanoida and Mesocyclops ogunnus and Thermocyclops decipiens among the Cyclopoida. The production of Copepoda was higher during the rainy summer (23.61 mgDW.m-3.d-1 in January 1995 than during the dry winter season (14 mgDW.m-3.d-1 in August 1995, following the general pattern of abundance for the whole zooplankton community. Among the copepods, Cyclopoida production was higher than that of Calanoida, a pattern commonly observed for tropical lakes and reservoirs. Barra Bonita copepods are very productive, but there was a great degree of spatial heterogeneity, related to the physical and chemical conditions, particularly the level of nutrients and also to phytoplankton biomass.

  10. A screening of multiple classes of pharmaceutical compounds for effect on preadult salmon lice Lepeophtheirus salmonis.

    Science.gov (United States)

    Aaen, S M; Horsberg, T E

    2016-10-01

    The salmon louse, Lepeophtheirus salmonis Krøyer, is the major obstacle facing a sustainable future for farmers of salmonids in the North Atlantic Ocean. Medicinal compounds have been the most utilized tool to prevent salmon lice infestation; however, the active compounds have become less effective or considered environmentally unfriendly in the past years. Novel medicinal compounds are thus highly desired. In two experiment series, 26 medicinal compounds were screened for their efficacy against salmon lice, in a 30-min exposure and 24-h exposure, respectively. Pyriprole, imidacloprid, cartap and spinetoram were effective at 50 mg L(-1) in the short-time exposure. In the 24-h exposure, pyriprole, propoxur, cartap, imidacloprid, fenoxycarb, pyriproxyfen, nitenpyram, spinetoram, spiromesifen and diflubenzuron induced a high level of immobilization at 5 mg L(-1) . The EC50 values of the effective compounds were calculated in further titration studies for both exposure periods. Several physiological and biochemical pathways were discovered as possible targets for medicinal intervention against the salmon louse. © 2016 John Wiley & Sons Ltd.

  11. A model for sea lice (Lepeophtheirus salmonis dynamics in a seasonally changing environment

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    Matthew A. Rittenhouse

    2016-09-01

    Full Text Available Sea lice (Lepeophtheirus salmonis are a significant source of monetary losses on salmon farms. Sea lice exhibit temperature-dependent development rates and salinity-dependent mortality, but to date no deterministic models have incorporated these seasonally varying factors. To understand how environmental variation and life history characteristics affect sea lice abundance, we derive a delay differential equation model and parameterize the model with environmental data from British Columbia and southern Newfoundland. We calculate the lifetime reproductive output for female sea lice maturing to adulthood at different times of the year and find differences in the timing of peak reproduction between the two regions. Using a sensitivity analysis, we find that sea lice abundance is more sensitive to variation in mean annual water temperature and mean annual salinity than to variation in life history parameters. Our results suggest that effective sea lice management requires consideration of site-specific temperature and salinity patterns and, in particular, that the optimal timing of production cycles and sea lice treatments might vary between regions.

  12. Early East Asian art history in Vienna and its trajectories: Josef Strzygowski, Karl With, Alfred Salmony

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    Julia Orell

    2015-12-01

    Full Text Available In 1912 Josef Strzygowski founded the ‘Section for East Asian Art History’ at the University of Vienna, which attracted many students who would continue their careers in museums and at universities and thus established East Asian art history as an academic field. This paper examines these early art historical engagements with East Asian art: First, I discuss the role of East Asian art in Strzygowski’s agenda of broadening art history’s geographical scope beyond Europe and in his argument about the dominance of ‘Nordic’ artistic traditions in Europe and in Asia. Secondly, I introduce the work of two early students at the ‘Section for East Asian Art History’ in Vienna, Karl With and Alfred Salmony. Their respective approaches to East Asian art exemplify a range of methodological concerns of their time, from stylistic narratives, the concept of ars una, comparative frameworks, to ideas about cultural or national ‘purity’ in the arts, and an interest in cross-cultural adaption and transformation of motifs and symbolism.

  13. Presencia de Piscirickettsia salmonis en Truchas de Cultivo (Oncorhynchus mykiss) en Junín, Perú

    OpenAIRE

    Yunis A., Jefferson; Laboratorio de Histología, Embriología y Patología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Anicama D., Jahir; Laboratorio de Histología, Embriología y Patología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Manchego S., Alberto; Laboratorio de Microbiología y Parasitología Veterinaria, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima; Sandoval C., Nieves; Laboratorio de Histología, Embriología y Patología Animal, Facultad de Medicina Veterinaria, Universidad Nacional Mayor de San Marcos, Lima

    2015-01-01

    El objetivo de este estudio fue determinar la posible presencia de Piscirickettsia salmonis en truchas de cultivo (Oncorhynchus mykiss) en la cuenca del río Mantaro, Junín, Perú, mediante la prueba de inmunofluorescencia indirecta (IFI). Se obtuvieron 180 truchas en forma aleatoria de tres piscigranjas, se beneficiaron, se les realizó la necropsia y se recolectaron muestras de riñón y bazo. Los tejidos fueron sometidos a la prueba de inmunofluorescencia indirecta (IFI). Todas las muestras res...

  14. Maternal inheritance of deltamethrin resistance in the salmon louse Lepeophtheirus salmonis (Krøyer is associated with unique mtDNA haplotypes.

    Directory of Open Access Journals (Sweden)

    Greta Carmona-Antoñanzas

    Full Text Available Parasitic infections by the salmon louse, Lepeophtheirus salmonis (Krøyer, cause huge economic damage in salmon farming in the northern hemisphere, with combined treatment costs and production losses in 2014 having been estimated at US$ 350 million for Norway (annual production 1.25 million tonnes. The control of L. salmonis relies significantly on medicinal treatments, supplemented by non-pharmacological approaches. However, efficacy losses have been reported for several delousing agents, including the pyrethroid deltamethrin. The aim of the present study was to analyse the genetic basis of deltamethrin resistance in L. salmonis. Deltamethrin median effective concentrations (EC50 were 0.28 μg L-1 in the drug susceptible L. salmonis strain IoA-00 and 40.1 μg L-1 in the pyrethroid resistant strain IoA-02. IoA-00 and IoA-02 were crossed to produce families spanning one parental and three filial generations (P0, F1-F3. In three families derived from P0 crosses between an IoA-00 sire and an IoA-02 dam, 98.8% of F2 parasites (n = 173 were resistant, i.e. remained unaffected after exposure to 2.0 μg L-1 deltamethrin. F3 parasites from these crosses showed a deltamethrin EC50 of 9.66 μg L-1. In two families of the inverse orientation at P0 (IoA-02 sire x IoA-00 dam, 16.7% of F2 parasites were resistant (n = 84, while the deltamethrin EC50 in F3 animals was 0.26 μg L-1. The results revealed a predominantly maternal inheritance of deltamethrin resistance. The 15,947-nt mitochondrial genome was sequenced and compared among six unrelated L. salmonis strains and parasites sampled from wild salmon in 2010. IoA-02 and three further deltamethrin resistant strains, established from isolates originating from different regions of Scotland, showed almost identical mitochondrial haplotypes. In contrast, the mitochondrial genome was variable among susceptible strains and L. salmonis from wild hosts. Deltamethrin caused toxicity and depletion of whole body ATP

  15. Identification of genomic islands in Chilean Piscirickettsia salmonis strains and analysis of gene expression involved in virulence.

    Science.gov (United States)

    Lagos, F; Cartes, C; Vera, T; Haussmann, D; Figueroa, J

    2017-10-01

    Piscirickettsia salmonis, an agent of Piscirickettsiosis, is the cause of major losses in the Chilean salmon industry. We identified, characterized and bioinformatically analysed genomic islands in field strains of P. Salmonis, using the bioinformatic software PIPS, that uses the characteristics of the islands of pathogenicity to identify them. We analysed nine partially sequenced genomes in different new field strains, and compared them with the LF-89 (Type strain) genome, selecting a genomic island present in all of them. We then evaluated the relative expression of three genes present in that island. From the obtained results, we conclude that the expression of the tcf gene is directly proportional to the cytopathogenicity in vitro of the bacteria; the product of the dnsa gene could contribute to its pathogenicity, but would be potentiated by one or more factors. The product of the gene liso is necessary for the virulence process and could have functions in early stages of infection. Regarding the strains, the IBM-040 strain showed a significant increase in the expression of all the genes in the study. Contrarily, LF-89 only presented a significant increase in expression of the gene liso, which correlates with the cytopathogenicity in vitro observed in the SHK-1 cells. © 2017 John Wiley & Sons Ltd.

  16. Search and analysis of genes involved in antibiotic resistance in Chilean strains of Piscirickettsia salmonis.

    Science.gov (United States)

    Cartes, C; Isla, A; Lagos, F; Castro, D; Muñoz, M; Yañez, A; Haussmann, D; Figueroa, J

    2017-08-01

    Piscirickettsia salmonis is the pathogen causing Piscirickettsiosis. For treatment, the industry mainly uses oxytetracycline and florfenicol, so it is essential to understand the degree of susceptibility of this pathogen to these drugs. But this is still unknown for a large number of P. salmonis strains, as are the molecular mechanisms responsible for greater or lesser susceptibility. However, genes that confer resistance to these antimicrobials have been reported and characterized for this and other bacterial species, among which are membrane proteins that take out the drug. Our results identified differences in the degree of susceptibility to both antibiotics among different Chilean isolated of these bacteria. We analysed 10 available genomes in our laboratory and identified ~140 genes likely to be involved in antibiotic resistance. We analysed six specific genes, which suggests that some of them would eventually be relevant in conferring resistance to both antibiotics, as they encode for specific transporter proteins, which increase the number of transcripts when grown in media with these antibiotics. Our results were corroborated with EtBr permeability analysis, which revealed that the LF-89 strain accumulates this compound and has a reduced capacity to expulse it compared with the field strains. © 2016 John Wiley & Sons Ltd.

  17. First report of reduced sensitivity towards hydrogen peroxide found in the salmon louse Lepeophtheirus salmonis in Norway

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    Kari Olli Helgesen

    2015-05-01

    Full Text Available Reduced sensitivity towards chemotherapeutants in the salmon louse Lepeophtheirus salmonis (Krøyer is an increasing problem for the fish farming industry. Most fish farmers are dependent on chemical treatments in order to maintain salmon lice numbers below permitted levels. However parasites showing reduced sensitivity contribute to complicating this task. Hydrogen peroxide (H2O2 is used as a delousing agent in bath treatments and until recently treatment failures due to reduced H2O2-sensitivity have not been documented in Norway. The aim of the current study was to develop a bioassay protocol suitable for testing H2O2-sensitivity in L. salmonis. If failed treatments were found to be caused by parasite insensitivity to H2O2 the possibility of this reduced sensitivity being hereditary was looked into. The results show that bioassays permit differentiation between strains of salmon lice with regards to H2O2-sensitivity, coinciding with treatment efficacies. Up to ten times variance in sensitivity between two strains was recorded. The progeny of the least sensitive salmon lice also showed reduced sensitivity to H2O2 in a bioassay, which indicates that reduced sensitivity towards H2O2 is hereditary. The current study presents the first case report of reduced sensitivity towards H2O2 in salmon lice in Norway. This change in sensitivity imposes a threat to the Norwegian fish farming industry and should be monitored closely.

  18. The effect of light on the settlement of the salmon louse, Lepeophtheirus salmonis, on Atlantic salmon, Salmo salar L.

    Science.gov (United States)

    Browman, H I; Boxaspen, K; Kuhn, P

    2004-12-01

    The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic copepod that infests both wild and farmed salmonid fish. Salmon lice are a major disease problem in the farming of Atlantic salmon, Salmo salar L., and the possibility of salmon lice playing a role in the decline of wild anadromous stocks has also been raised. Lepeophtheirus salmonis can detect a range of stimuli (pressure/moving water, chemicals and light) in the external environment. However, the response thresholds to various stimuli, and the spatial and temporal scales over which they operate in the context of host location, are largely unknown. In this context, we attempted to determine whether salmon lice copepodids settle onto hosts more effectively, or at different locations on the fish's body, under different qualities of light. Lice settlement trials were conducted under three lighting conditions; L1: unpolarized under ultraviolet A (UVA)-through visible; L2: unpolarized without UVA (control); L3: 100% linearly polarized without UVA. A dark control was also conducted. No statistically significant difference in lice settlement was found. While changes in light intensity are involved in host detection at spatial scales on the order of metres, the results presented here suggest that it is not the primary sensory modality underlying host location at smaller spatial scales (cm to mm).

  19. Development of the salmon louse Lepeophtheirus salmonis and its effects on juvenile sockeye salmon Oncorhynchus nerka.

    Science.gov (United States)

    Jakob, E; Sweeten, T; Bennett, W; Jones, S R M

    2013-11-06

    Responses of sockeye salmon Oncorhynchus nerka during infection with Lepeophtheirus salmonis were assessed in controlled laboratory trials. Juvenile salmon were exposed to 100 copepodids fish-1 (Trials 1 and 2) or 300 copepodids fish-1 (Trial 3) at mean weights of approximately 40, 80 and 135 g, respectively. Infections occurred on all salmon in all trials, and mean abundances (infection densities) ranged between 3.3 and 19.4 lice fish-1 (0.08 and 0.44 lice g-1 fish) in Trial 1, between 7.2 and 18.3 (0.09 and 0.22) in Trial 2 and between 19.5 and 60.7 (0.15 and 0.46) in Trial 3. A cumulative mortality of 24.4% occurred in Trial 3. At attachment sites on gills, we observed hyperplasia of basal epithelial cells and fusion of secondary lamellae occasionally associated with a cellular infiltrate. At attachment sites on fins, partial to complete skin erosion occurred, with limited evidence of hyperplasia or inflammation. Scale loss and abrasions coincided with pre-adult lice around 20 d post infection (dpi). Plasma osmolality was significantly elevated in exposed fish in Trials 1 (21 dpi), 2 (15 and 36 dpi) and 3 (20 dpi), whereas haematocrit was significantly depressed in exposed fish in Trials 1 (21 and 28 dpi) and 3 (20 dpi). Plasma cortisol was significantly elevated in exposed fish at 20 dpi (Trial 3). Physiological changes and mortality were related to the intensity of infection and became most prominent with pre-adult stages, suggesting patterns of infection and response in sockeye salmon similar to those reported for Atlantic and Chinook salmon.

  20. Gene silencing reveals multiple functions of Na+/K+-ATPase in the salmon louse (Lepeophtheirus salmonis).

    Science.gov (United States)

    Komisarczuk, Anna Z; Kongshaug, Heidi; Nilsen, Frank

    2018-01-12

    Na+/K+-ATPase has a key function in a variety of physiological processes including membrane excitability, osmoregulation, regulation of cell volume, and transport of nutrients. While knowledge about Na+/K+-ATPase function in osmoregulation in crustaceans is extensive, the role of this enzyme in other physiological and developmental processes is scarce. Here, we report characterization, transcriptional distribution and likely functions of the newly identified L. salmonis Na+/K+-ATPase (LsalNa+/K+-ATPase) α subunit in various developmental stages. The complete mRNA sequence was identified, with 3003 bp open reading frame encoding a putative protein of 1001 amino acids. Putative protein sequence of LsalNa+/K+-ATPase revealed all typical features of Na+/K+-ATPase and demonstrated high sequence identity to other invertebrate and vertebrate species. Quantitative RT-PCR analysis revealed higher LsalNa+/K+-ATPase transcript level in free-living stages in comparison to parasitic stages. In situ hybridization analysis of copepodids and adult lice revealed LsalNa+/K+-ATPase transcript localization in a wide variety of tissues such as nervous system, intestine, reproductive system, and subcuticular and glandular tissue. RNAi mediated knock-down of LsalNa+/K+-ATPase caused locomotion impairment, and affected reproduction and feeding. Morphological analysis of dsRNA treated animals revealed muscle degeneration in larval stages, severe changes in the oocyte formation and maturation in females and abnormalities in tegmental glands. Thus, the study represents an important foundation for further functional investigation and identification of physiological pathways in which Na+/K+-ATPase is directly or indirectly involved. Copyright © 2018. Published by Elsevier Inc.

  1. Feeding spectra of Arctodiaptomus salinus (Calanoida, Copepoda) using fatty acid trophic markers in seston food in two salt lakes in South Siberia (Khakasia, Russia)

    NARCIS (Netherlands)

    Tolomeev, A.; Sushchik, N.N.; Gulati, R.D.; Makhutova, O.N.; Kalacheva, G.S.; Zotina, T.A.

    2010-01-01

    During two vegetation seasons (2004–2005), we compared feeding spectra of Arctodiaptomus salinus (Calanoida, Copepoda) populations inhabiting two neighboring salt lakes, Shira and Shunet, Khakasia, Russia, using fatty acid (FA) trophic markers. Sestonic FA composition in two lakes moderately

  2. A new species of Hemicyclops (Crustacea, Copepoda, Poecilostomatoida, Clausidiidae) associated with hermit crabs in Curaçao

    NARCIS (Netherlands)

    Stock, Jan H.

    1992-01-01

    STOCK, J. H. 1992. A new species of Hemicyclops (Crustacea, Copepoda, Poecilostomatoida, Clausidiidae) associated with hermit crabs in Curaçao. Stud. Nat. Hist. Caribbean Region 71, Amsterdam 1992: 69-78. Hemicyclops geminatus n. sp. is described from the upper infralittoral zone of Curaçao

  3. Over de eerste vondsten van twee Pennella-soorten (Crustacea: Copepoda) en van Conchoderma virgatum (Spengler) (Crustacea: Cirripedia) in Nederland

    NARCIS (Netherlands)

    Huwae, P.H.M.

    1986-01-01

    On 30 November 1941 a sunfish Mola mola (L.) was found on the beach near Schoorl (Province of Noord-Holland). The fish was parasitized by a specimen of Pennella filosa (L.) (Crustacea, Copepoda) on which a specimen of Conchoderma virgatum (Crustacea: Cirripedia) had attached itself. This is the

  4. A new species of Notodiaptomus Kiefer (Crustacea, Copepoda, Calanoida, Diaptomidae from Brazil

    Directory of Open Access Journals (Sweden)

    T Matsumura-Tundisi

    Full Text Available Description of a new species of Diaptomidae (Crustacea, Copepoda, Calanoida Notodiaptomus oliveirai is given from the material obtained at a reservoir at Barra Bonita, SP in 1992. The new species is very similar to Notodiaptomus henseni Dahl 1894 although both species can be found in the same locality, constituting two distinct populations. Notodiaptomus oliveirai seems to be endowed with great adaptability to changes in environmental conditions, extending its distribution to all the hydrographic basins in the state of São Paulo.

  5. Disease resistance in Atlantic salmon (Salmo salar: coinfection of the intracellular bacterial pathogen Piscirickettsia salmonis and the sea louse Caligus rogercresseyi.

    Directory of Open Access Journals (Sweden)

    Jean Paul Lhorente

    Full Text Available BACKGROUND: Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1 coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2 coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. METHODOLOGY: In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI of P. salmonis (primary pathogen or coinfection with C. rogercresseyi (secondary pathogen. Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish. Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. MAIN FINDINGS: C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545. Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23 ± 0.07; h2LC = 0.17 ± 0.08; h2HC = 0.24 ± 0.07. A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99 ± 0.01 but not between the single and coinfection treatments (rg SI-LC = -0.14 ± 0.33; rg SI-HC = 0.32 ± 0.34. CONCLUSIONS/SIGNIFICANCE: C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future

  6. Disease resistance in Atlantic salmon (Salmo salar): coinfection of the intracellular bacterial pathogen Piscirickettsia salmonis and the sea louse Caligus rogercresseyi.

    Science.gov (United States)

    Lhorente, Jean Paul; Gallardo, José A; Villanueva, Beatriz; Carabaño, María J; Neira, Roberto

    2014-01-01

    Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1) coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2) coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI) of P. salmonis (primary pathogen) or coinfection with C. rogercresseyi (secondary pathogen). Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish). Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545). Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23 ± 0.07; h2LC = 0.17 ± 0.08; h2HC = 0.24 ± 0.07). A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99 ± 0.01) but not between the single and coinfection treatments (rg SI-LC = -0.14 ± 0.33; rg SI-HC = 0.32 ± 0.34). C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future research on salmon farming, selective breeding and conservation.

  7. Nutritional Immunity Triggers the Modulation of Iron Metabolism Genes in the Sub-Antarctic Notothenioid Eleginops maclovinus in Response to Piscirickettsia salmonis

    Directory of Open Access Journals (Sweden)

    Danixa Martínez

    2017-09-01

    Full Text Available Iron deprivation is a nutritional immunity mechanism through which fish can limit the amount of iron available to invading bacteria. The aim of this study was to evaluate the modulation of iron metabolism genes in the liver and brain of sub-Antarctic notothenioid Eleginops maclovinus challenged with Piscirickettsia salmonis. The specimens were inoculated with two P. salmonis strains: LF-89 (ATCC® VR-1361™ and Austral-005 (antibiotic resistant. Hepatic and brain samples were collected at intervals over a period of 35 days. Gene expression (by RT-qPCR of proteins involved in iron storage, transport, and binding were statistically modulated in infected fish when compared with control counterparts. Specifically, the expression profiles of the transferrin and hemopexin genes in the liver, as well as the expression profiles of ferritin-M, ferritin-L, and transferrin in the brain, were similar for both experimental groups. Nevertheless, the remaining genes such as ferritin-H, ceruloplasmin, hepcidin, and haptoglobin presented tissue-specific expression profiles that varied in relation to the injected bacterial strain and sampling time-point. These results suggest that nutritional immunity could be an important immune defense mechanism for E. maclovinus against P. salmonis injection. This study provides relevant information for understanding iron metabolism of a sub-Antarctic notothenioid fish.

  8. Effectiveness of emamectin benzoate for treatment of Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, Canada.

    Science.gov (United States)

    Jones, Patti G; Hammell, K Larry; Dohoo, Ian R; Revie, Crawford W

    2012-12-03

    Emamectin benzoate (an avermectin chemotherapeutant administered to fish as an in-feed treatment) has been used to treat infestations of sea lice Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, New Brunswick, Canada, since 1999. This retrospective study examined the effectiveness of 114 emamectin benzoate treatment episodes from 2004 to 2008 across 54 farms. Study objectives were to establish whether changes in the effectiveness of emamectin benzoate were present for this period, examine factors associated with treatment outcome, and determine variables that influenced differences in L. salmonis abundance after treatment. The analysis was carried out in 2 parts: first, trends in treatment effectiveness and L. salmonis abundance were explored, and second, statistical modelling (linear and logistic regression) was used to examine the effects of multiple variables on post-treatment abundance and treatment outcome. Post-treatment sea lice abundance increased in the later years examined. Mean abundance differed between locations in the Bay of Fundy, and higher numbers were found at farms closer to the mainland and lower levels were found in the areas around Grand Manan Island. Treatment effectiveness varied by geographical region and decreased over time. There was an increased risk for unsuccessful treatments in 2008, and treatments applied during autumn months were more likely to be ineffective than those applied during summer months.

  9. Microcrustaceans (Branchiopoda and Copepoda) of Wetland Ponds and Impoundments on the Savannah River Site, Aiken, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Adrienne E. DeBiase; Barbara E. Taylor

    2005-09-21

    The United States Department of Energy's Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders, larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.

  10. A new species of Acantholochus (Copepoda: Bomolochidae parasitic on Centropomus undecimalis (Osteichthyes: Centropomidae from the coastal zone of the State of Rio de Janeiro, Brazil

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    Tavares Luiz ER

    2003-01-01

    Full Text Available A new species of Acantholochus Cressey, 1984 (Copepoda: Bomolochidae parasitic on the gills of common snook, Centropomus undecimalis, from the coastal zone of the State of Rio de Janeiro, Brazil, is described and illustrated. The new species differs from all other species of Acantholochus by the presence of only one inner seta on middle segment of the second and third endopods.

  11. Zooplankton (Cladocera, Copepoda dynamics in the River Danube upstream and downstream of Budapest, Hungary

    Directory of Open Access Journals (Sweden)

    Vadadi-Fülöp, Cs.

    2009-11-01

    Full Text Available The spatial distribution and seasonal dynamics of zooplankton (Cladocera, Copepoda were studied in the River Danube near Budapest, Hungary. The investigated river section was relatively poor in plankton, nauplii dominated. A total of 36 species was recorded of which Acanthocyclops robustus, Thermocyclops crassus, Bosmina longirostris were the most abundant. There was a downstream increase in copepod densities, however, no other remarkable differences could be observed between the profiles upstream and downstream of the capital. Generally, the streamline was characterized by lower densities and lower number of taxa as compared to the river bank; nevertheless, there were differences between the left and the right banks both upstream or downstream as well. Seasonal dynamics was defined by a marked late winter–spring aspect and abundance peaks were found to be characteristic for Danube with high densities in May–June and August–September. Examining the relationship between zooplankton density and the hydrological regime, it can be concluded that zooplankton production in the main channel is of minor importance, rather floodplain areas and adjacent water bodies seem to be important sources of plankton biomass.

  12. Comparative pathogenesis of piscirickettsiosis in Atlantic salmon (Salmo salar L.) post-smolt experimentally challenged with LF-89-like and EM-90-like Piscirickettsia salmonis isolates.

    Science.gov (United States)

    Rozas-Serri, M; Ildefonso, R; Peña, A; Enríquez, R; Barrientos, S; Maldonado, L

    2017-10-01

    Piscirickettsiosis (SRS) is the most prevalent bacterial disease in Chilean salmon aquaculture and is responsible for high economic losses. The aim of this study was to comparatively characterize the pathogenesis of SRS in post-smolt Atlantic salmon during the early and late stages of infection with Piscirickettsia salmonis LF-89-like (PS-LF-89) and EM-90-like (PS-EM-90) using a cohabitation challenge. The pathogenesis of cohabitant fish infected with the two isolates was relatively different due to cohabitant fish infected with PS-EM-90 showing higher cumulative mortality and shorter time until death compared with PS-LF-89 fish. PS-LF-89 caused an SRS infection characterized by kidney and liver lesions, whereas PS-EM-90 caused systemic and haemorrhagic disease characterized by kidney, liver, heart, brain, skeletal muscle and intestine lesions. Decreased serum concentration of total proteins and albumin as well as increased serum ALT, AST and creatinine levels in fish infected with both isolates confirmed that changes in liver and kidney function occurred during infection. Tissue damage, expressed as an SRS histoscore, showed a strong positive correlation with the bacterial load expressed as abundance of P. salmonis 16S rRNA transcripts in the livers and kidneys of fish affected with either isolate, but the correlation was significantly higher in fish infected with PS-EM-90. The results contribute to improving the understanding of the bacteria-host interaction. © 2017 John Wiley & Sons Ltd.

  13. Genomic characterization and phylogenetic position of two new species in Rhabdoviridae infecting the parasitic copepod, salmon louse (Lepeophtheirus salmonis.

    Directory of Open Access Journals (Sweden)

    Arnfinn Lodden Økland

    Full Text Available Several new viruses have emerged during farming of salmonids in the North Atlantic causing large losses to the industry. Still the blood feeding copepod parasite, Lepeophtheirus salmonis, remains the major challenge for the industry. Histological examinations of this parasite have revealed the presence of several virus-like particles including some with morphologies similar to rhabdoviruses. This study is the first description of the genome and target tissues of two new species of rhabdoviruses associated with pathology in the salmon louse. Salmon lice were collected at different Atlantic salmon (Salmo salar farming sites on the west coast of Norway and prepared for histology, transmission electron microscopy and Illumina sequencing of the complete RNA extracted from these lice. The nearly complete genomes, around 11,600 nucleotides encoding the five typical rhabdovirus genes N, P, M, G and L, of two new species were obtained. The genome sequences, the putative protein sequences, and predicted transcription strategies for the two viruses are presented. Phylogenetic analyses of the putative N and L proteins indicated closest similarity to the Sigmavirus/Dimarhabdoviruses cluster, however, the genomes of both new viruses are significantly diverged with no close affinity to any of the existing rhabdovirus genera. In situ hybridization, targeting the N protein genes, showed that the viruses were present in the same glandular tissues as the observed rhabdovirus-like particles. Both viruses were present in all developmental stages of the salmon louse, and associated with necrosis of glandular tissues in adult lice. As the two viruses were present in eggs and free-living planktonic stages of the salmon louse vertical, transmission of the viruses are suggested. The tissues of the lice host, Atlantic salmon, with the exception of skin at the attachment site for the salmon louse chalimi stages, were negative for these two viruses.

  14. A method for stable gene knock-down by RNA interference in larvae of the salmon louse (Lepeophtheirus salmonis).

    Science.gov (United States)

    Eichner, Christiane; Nilsen, Frank; Grotmol, Sindre; Dalvin, Sussie

    2014-05-01

    The salmon louse (Lepeophtheirus salmonis), an ectoparasitic copepod of salmonid fish, is a major threat to aquaculture in Norway, Ireland, Scotland and Canada. Due to rise in resistance against existing pesticides, development of novel drugs or vaccines is necessary. Posttranscriptional gene silencing by RNA interference (RNAi), when established in a high throughput system is a potential method for evaluation of molecular targets for new medical compounds or vaccine antigens. Successful use of RNAi has been reported in several stages of salmon lice. However, when we employed a previously described protocol for planktonic stages, no reproducible down-regulation of target genes was gained. In the present study, we describe a robust method for RNAi, where nauplius larvae are soaked in seawater added double stranded RNA (dsRNA). In order to test for when dsRNA may be introduced, and for the efficacy and duration of RNAi, we performed a series of experiments on accurately age determined larvae, ranging from the hatching egg to the copepodid with a salmon louse coatomer and a putative prostaglandin E synthase gene. Presumptive knock-down was monitored by real time PCR. Significant gene silencing was obtained only when nauplius I larvae were exposed to dsRNA during the period in which they molted to nauplius II. A knock down effect could be detected 2days after soaking, and it remained stable until the last measurement, on day 12. Soaking nauplius I larvae, knock-down was verified for six additional genes with a putative role in molting. For one chitinase, a loss-of-function phenotype with abnormal swimming was obtained. Hence, RNAi, induced in the nauplius, may facilitate studies of the molecular biology of the louse, such as the function of specific genes in developmental processes and physiology, host recognition, host-parasite interaction, and, in extension, the engineering of novel medicines. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Delousing efficiency of farmed ballan wrasse (Labrus bergylta) against Lepeophtheirus salmonis infecting Atlantic salmon (Salmo salar) post-smolts.

    Science.gov (United States)

    Leclercq, Eric; Davie, Andrew; Migaud, Hervé

    2014-08-01

    Cleaner-fish (wrasse, Labridae) are increasingly deployed within the Atlantic salmon (Salmo salar L.) industry as a biological control against sea-lice (Lepeophtheirus salmonis Krøyer). Two tank-based trials were performed to test the effect of farmed ballan wrasse (Labrus bergylta Ascanius) body mass and supplementary feeding on the delousing of Atlantic salmon post-smolts with an initial infection level of ∼12 lice salmon(-1) and a ∼5% wrasse:salmon ratio. Sea-louse levels below 0.5 lice salmon(-1) were obtained within 84 h, and preferential preying upon larger motile stages was found. The wrasse body mass and the availability of fresh, opened blue mussels (Mytilus edulis L.) did not significantly affect delousing efficiency. The functional predator response was linear, showing no minimum prey density threshold for sea-louse foraging and no satiation plateau, in spite of the high consumption rates measured. Sea-louse infection levels declined following a one-phase exponential decay model, with a standardised decline time constant of 0.8-1.3% h(-1) for each wrasse stocked per 100 salmon. Farmed ballan wrasse are confirmed as highly effective therapeutic and preventive biological controls against sea-lice. The study supports the current minimum hatchery size target (10 mm total length) and the use of supplementary feeding to sustain the wrasse stocks in operation. The functional predator response and the standardised decline time constant of sea-louse abundance are proposed as useful indicators of delousing efficiency. © 2013 Society of Chemical Industry.

  16. Copepoda: Poecilostomatoida

    African Journals Online (AJOL)

    1987-03-13

    Mar 13, 1987 ... Hawke 1978) and nasal fossae (Yamashita 1980). The parasites are generally less than 1 mm long and can only be found using a dissection microscope at a low magnification of approximately 20 X. For sampling ergasilids, the fish is killed and the gills removed. Individual arches are separated, kept wet in.

  17. Copepoda: Kroyeriidae

    African Journals Online (AJOL)

    1998-10-28

    Oct 28, 1998 ... 1822) from the following localities: Puerto Rico (Caribbean. Sea), Florida (Atlantic Ocean) and Madagascar (Indian. Ocean). This is the first report of K. dispar from the east coast of South Africa. K. dispar can be distinguished from other Kroyeria species by an unusually wide cephalothorax, armature of the ...

  18. Lernanthropidae: Copepoda

    African Journals Online (AJOL)

    1996-12-03

    Dec 3, 1996 ... ular spines, rostral spines, sternal furca, adhesion pads, buccal stylets and lunules (Kabata 1979), are .... ridges sometimes has small patches of ornamented integu- ment (oi) (Figure 3); (3) in some species an ... round patches of ornamented integument (oi) are present mid- way on the inner surface of the ...

  19. Taxonomic resolutions based on 18S rRNA genes: a case study of subclass copepoda.

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    Shu Wu

    Full Text Available Biodiversity studies are commonly conducted using 18S rRNA genes. In this study, we compared the inter-species divergence of variable regions (V1-9 within the copepod 18S rRNA gene, and tested their taxonomic resolutions at different taxonomic levels. Our results indicate that the 18S rRNA gene is a good molecular marker for the study of copepod biodiversity, and our conclusions are as follows: 1 18S rRNA genes are highly conserved intra-species (intra-species similarities are close to 100%; and could aid in species-level analyses, but with some limitations; 2 nearly-whole-length sequences and some partial regions (around V2, V4, and V9 of the 18S rRNA gene can be used to discriminate between samples at both the family and order levels (with a success rate of about 80%; 3 compared with other regions, V9 has a higher resolution at the genus level (with an identification success rate of about 80%; and 4 V7 is most divergent in length, and would be a good candidate marker for the phylogenetic study of Acartia species. This study also evaluated the correlation between similarity thresholds and the accuracy of using nuclear 18S rRNA genes for the classification of organisms in the subclass Copepoda. We suggest that sample identification accuracy should be considered when a molecular sequence divergence threshold is used for taxonomic identification, and that the lowest similarity threshold should be determined based on a pre-designated level of acceptable accuracy.

  20. A selection study on a laboratory-designed population of salmon lic (Lepeophtheirus salmonis using organophosphate and pyrethroid pesticides.

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    Elena Myhre Jensen

    Full Text Available Resistance towards antiparasitic agents in the salmon louse (Lepeophtheirus salmonis is a widespread problem along the Norwegian coast, reducing treatments efficacies and slowing down the envisioned expansion of Norwegian salmon production. The present study was conducted in order to assess the efficacies of two of the most widely used anti-parasitic substances-azamethiphos and deltamethrin-as well as assessing the benefit of having a resistant genotype compared to being fully sensitive when exposed to one of these substances. Atlantic salmon were exposed to a mix of salmon lice copepodids from a fully sensitive, a double resistant and a multi-resistant strain. Once the lice reached pre-adult stages, one group was exposed to 100 μg/L azamethiphos for 60 minutes, the other to 2 μg/L deltamethrin for 30 minutes, and the last was kept in a seawater control. Detached lice were collected at a series of time points following exposure, and all lice (immobilized and surviving were analysed for both pyrethroid (sensitive "S" and resistant "R" and azamethiphos (fully sensitive "SS", heterozygous resistant "RS" and fully resistant "RR" resistance markers. We found that the efficacies of deltamethrin on parasites with genotype S and R were 70.3 and 13.2%, respectively. The overall efficacy of the deltamethrin treatment was 32.3%. The efficacies of azamethiphos on parasites with genotype SS, RS and RR were 100, 80 and 19.1%, respectively. The overall efficacy of the azamethiphos treatment was 80.4%. Survival analyses revealed that the median survival time in deltamethrin-sensitive and-resistant parasites were 16.8 and >172 hours, respectively. The differences were even more pronounced in the azamethiphos-treated group, where SS, RS and RR parasites survived for 0.26, 6.6 and >172 hours, respectively. The substantial differences in survival between sensitive and resistant lice following treatment demonstrate the ability of medicinal treatments to drive

  1. Original observations of Desmozoon lepeophtherii, a microsporidian hyperparasite infecting the salmon louse Lepeophtheirus salmonis, and its subsequent detection by other researchers

    Directory of Open Access Journals (Sweden)

    Freeman Mark A

    2011-12-01

    Full Text Available Abstract A microsporidian hyperparasite, Desmozoon lepeophtherii, of the parasitic copepod Lepeophtheirus salmonis (salmon louse, infecting farmed Atlantic salmon (Salmo salar, was first discovered in the west of Scotland in 2000. Heavily infected salmon lice are easily recognised as they have large opaque inclusions distributed throughout the body. The prevalence of salmon lice with visible signs of microsporidiosis can be up to 10% of the population from certain farm sites. The microsporidian was also isolated from the host Atlantic salmon suggesting it may have a two host life cycle. The authors believe that the infection in immunocompetent salmon may be latent, becoming acute during periods of infection with another pathogen or during sexual maturation. Since its first discovery in Scotland, Desmozoon lepeophtherii has been subsequently reported from Norway, and more recently from the Pacific coast of North America.

  2. Physiological consequences of the salmon louse (Lepeophtheirus salmonis) on juvenile pink salmon (Oncorhynchus gorbuscha): implications for wild salmon ecology and management, and for salmon aquaculture.

    Science.gov (United States)

    Brauner, C J; Sackville, M; Gallagher, Z; Tang, S; Nendick, L; Farrell, A P

    2012-06-19

    Pink salmon, Oncorhynchus gorbuscha, are the most abundant wild salmon species and are thought of as an indicator of ecosystem health. The salmon louse, Lepeophtheirus salmonis, is endemic to pink salmon habitat but these ectoparasites have been implicated in reducing local pink salmon populations in the Broughton Archipelago, British Columbia. This allegation arose largely because juvenile pink salmon migrate past commercial open net salmon farms, which are known to incubate the salmon louse. Juvenile pink salmon are thought to be especially sensitive to this ectoparasite because they enter the sea at such a small size (approx. 0.2 g). Here, we describe how 'no effect' thresholds for salmon louse sublethal impacts on juvenile pink salmon were determined using physiological principles. These data were accepted by environmental managers and are being used to minimize the impact of salmon aquaculture on wild pink salmon populations.

  3. A Novel and Validated Protocol for Performing MIC Tests to Determine the Susceptibility of Piscirickettsia salmonis Isolates to Florfenicol and Oxytetracycline

    Directory of Open Access Journals (Sweden)

    Sergio Contreras-Lynch

    2017-07-01

    Full Text Available This paper presents a validated protocol, using a novel, specifically formulated medium, to perform broth microdilution antimicrobial susceptibility assays of the salmonid bacterial pathogen Piscirickettsia salmonis. The minimum inhibitory concentrations (MIC for florfenicol and oxytetracycline against 58 P. salmonis isolates recovered from various outbreaks occurred in Chilean salmonid farms were determined using this protocol. Normalized resistance interpretation (NRI analysis was applied to these data to calculate appropriate protocol-specific epidemiological cut-off values. These cut-off values allow the isolates to be categorized as either fully susceptible wild type (WT members of this species, or as manifesting reduced susceptibility non-wild type (NWT. The distribution of MIC values of florfenicol was bimodal and the distribution of the normalized values for the putative WT observation had a standard deviation of 0.896 log2 μg mL-1. This analysis calculated a cut-off value of ≤0.25 μg mL-1 and categorized 33 (56% of the isolates as manifesting reduced susceptibility to florfenicol. For the oxytetracycline MIC data the NRI analysis also treated the distribution as bimodal. The distribution of the normalized values for the putative WT observation had a standard deviation of 0.951 log2 μg mL-1. This analysis gave a cut-off value of ≤0.5 μg mL-1 and categorized five isolates (9% as manifesting reduced susceptibility to oxytetracycline. The susceptibility testing protocol developed in this study was capable of generating MIC data from all the isolates tested. On the basis of the precision of the data it generated, and the degree of separation of values for WT and NWT it achieved, it is argued that this protocol has the performance characteristics necessary for it to be considered as a standard protocol.

  4. Transcriptome Analysis of the Intracellular Facultative Pathogen Piscirickettsia salmonis: Expression of Putative Groups of Genes Associated with Virulence and Iron Metabolism.

    Directory of Open Access Journals (Sweden)

    Alvaro Machuca

    Full Text Available The intracellular facultative bacteria Piscirickettsia salmonis is one of the most important pathogens of the Chilean aquaculture. However, there is a lack of information regarding the whole genomic transcriptional response according to different extracellular environments. We used next generation sequencing (NGS of RNA (RNA-seq to study the whole transcriptome of an isolate of P. salmonis (FAVET-INBIOGEN using a cell line culture and a modified cell-free liquid medium, with or without iron supplementation. This was done in order to obtain information about the factors there are involved in virulence and iron acquisition. First, the isolate was grown in the Sf21 cell line; then, the bacteria were cultured into a cell-free liquid medium supplemented or not with iron. We identified in the transcriptome, genes associated with type IV secretion systems, genes related to flagellar structure assembly, several proteases and sigma factors, and genes related to the development of drug resistance. Additionally, we identified for the first time several iron-metabolism associated genes including at least two iron uptake pathways (ferrous iron and ferric iron uptake that are actually expressed in the different conditions analyzed. We further describe putative genes that are related with the use and storage of iron in the bacteria, which have not been previously described. Several sets of genes related to virulence were expressed in both the cell line and cell-free culture media (for example those related to flagellar structure; such as basal body, MS-ring, C-ring, proximal and distal rod, and filament, which may play roles in other basic processes rather than been restricted to virulence.

  5. Filtration of sea louse, Lepeophtheirus salmonis, copepodids by the blue mussel, Mytilus edulis, and the Atlantic sea scallop, Placopecten magellanicus, under different flow, light and copepodid-density regimes.

    Science.gov (United States)

    Bartsch, A; Robinson, S M C; Liutkus, M; Ang, K P; Webb, J; Pearce, C M

    2013-03-01

    Population management of Lepeophtheirus salmonis in Canada currently relies on chemotherapeutants to remove attached stages of the ectoparasite. However, some populations of L. salmonis are developing resistance to chemotherapeutants making alternate management measures necessary. This article explores the ability of filter-feeding shellfish [i.e. blue mussels (Mytilus edulis) and Atlantic sea scallops (Placopecten magellanicus)] to consume the copepodid stages of L. salmonis in the laboratory under static and flowing water conditions, with variable copepodid densities, and with the aid of a light attractant. Mytilus edulis consumed copepodids under both static and flowing water conditions, and the proportion of individuals ingested was similar at low and high copepodid densities, suggesting that M. edulis was not saturated at the concentrations tested. Also, M. edulis consumed more copepodids when a light attractant was present, suggesting that lights may be useful to concentrate widely dispersed copepodids around cultured shellfish in the field. Finally, P. magellanicus consumed the same number of copepodids as an equivalent total wet weight of M. edulis. During each of the four separate experiments, shellfish consumed between 18 and 38% of the copepodids presented per hour, suggesting that both species are well suited for low level removal of copepodids over time. © Her Majesty the Queen in Right of Canada 2013.

  6. Phylogeny of the taxon Paralaophontodes Lang (Copepoda, Harpacticoida, Laophontodinae, including species descriptions, chorological remarks, and a key to species

    Directory of Open Access Journals (Sweden)

    Kai Horst George

    2017-03-01

    Full Text Available A detailed phylogenetic analysis of the taxon Paralaophontodes Lang (Copepoda, Harpacticoida, Laophontodinae Lang based on morphological characters is presented. The monophylum Paralaophontodes is supported by 16 unambiguous autapomorphies such as the presence of characteristic dorsal processes on cephalothorax and body somites, a 5-segmented male antennule, the loss of the syncoxal seta on the maxilliped, and the endopodal strengthening of the first swimming leg. The corresponding extensive phylogenetic evaluation includes the description of Paralaophontodes anjae sp. n. from a beach on Chiloé Island (Chile, the re-description of Laophontodes armatus Lang, and the re-establishment of Paralaophontodes robustus (Bŏzić, the displacement of Laophontodes armatus, L. hedgpethi Lang and L. psammophilus Soyer to Paralaophontodes, a discussion on relationships within that taxon, remarks on its geographical distribution, and a key to the species.

  7. Diversity of the free-living marine and freshwater Copepoda (Crustacea) in Costa Rica: a review.

    Science.gov (United States)

    Morales-Ramírez, Álvaro; Suárez-Morales, Eduardo; Corrales-Ugalde, Marco; Garrote, Octavio Esquivel

    2014-01-01

    The studies on marine copepods of Costa Rica started in the 1990's and focused on the largest coastal-estuarine systems in the country, particularly along the Pacific coast. Diversity is widely variable among these systems: 40 species have been recorded in the Culebra Bay influenced by upwelling, northern Pacific coast, only 12 in the Gulf of Nicoya estuarine system, and 38 in Golfo Dulce, an anoxic basin in the southern Pacific coast of the country. Freshwater environments of Costa Rica are known to harbor a moderate diversity of continental copepods (25 species), which includes 6 calanoids, 17 cyclopoids and only two harpacticoids. Of the +100 freshwater species recorded in Central America, six are known only from Costa Rica, and one appears to be endemic to this country. The freshwater copepod fauna of Costa Rica is clearly the best known in Central America. Overall, six of the 10 orders of Copepoda are reported from Costa Rica. A previous summary by 2001 of the free-living copepod diversity in the country included 80 marine species (67 pelagic, 13 benthic). By 2009, the number of marine species increased to 209: 164 from the Pacific (49% of the copepod fauna from the Eastern Tropical Pacific) and 45 from the Caribbean coast (8% of species known from the Caribbean Basin). Both the Caribbean and Pacific species lists are growing. Additional collections of copepods at Cocos Island, an oceanic island 530 km away of the Pacific coast, have revealed many new records, including five new marine species from Costa Rica. Currently, the known diversity of marine copepods of Costa Rica is still in development and represents up to 52.6% of the total marine microcrustaceans recorded in the country. Future sampling and taxonomic efforts in the marine habitats should emphasize oceanic environments including deep waters but also littoral communities. Several Costa Rican records of freshwater copepods are likely to represent undescribed species. Also, the biogeographic relevance

  8. Space-time cluster analysis of sea lice infestation (Caligus clemensi and Lepeophtheirus salmonis) on wild juvenile Pacific salmon in the Broughton Archipelago of Canada.

    Science.gov (United States)

    Patanasatienkul, Thitiwan; Sanchez, Javier; Rees, Erin E; Pfeiffer, Dirk; Revie, Crawford W

    2015-06-15

    Sea lice infestation levels on wild chum and pink salmon in the Broughton Archipelago region are known to vary spatially and temporally; however, the locations of areas associated with a high infestation level had not been investigated yet. In the present study, the multivariate spatial scan statistic based on a Poisson model was used to assess spatial clustering of elevated sea lice (Caligus clemensi and Lepeophtheirus salmonis) infestation levels on wild chum and pink salmon sampled between March and July of 2004 to 2012 in the Broughton Archipelago and Knight Inlet regions of British Columbia, Canada. Three covariates, seine type (beach and purse seining), fish size, and year effect, were used to provide adjustment within the analyses. The analyses were carried out across the five months/datasets and between two fish species to assess the consistency of the identified clusters. Sea lice stages were explored separately for the early life stages (non-motile) and the late life stages of sea lice (motile). Spatial patterns in fish migration were also explored using monthly plots showing the average number of each fish species captured per sampling site. The results revealed three clusters for non-motile C. clemensi, two clusters for non-motile L. salmonis, and one cluster for the motile stage in each of the sea lice species. In general, the location and timing of clusters detected for both fish species were similar. Early in the season, the clusters of elevated sea lice infestation levels on wild fish are detected in areas closer to the rivers, with decreasing relative risks as the season progresses. Clusters were detected further from the estuaries later in the season, accompanied by increasing relative risks. In addition, the plots for fish migration exhibit similar patterns for both fish species in that, as expected, the juveniles move from the rivers toward the open ocean as the season progresses The identification of space-time clustering of infestation on wild

  9. Detection of emamectin benzoate tolerance emergence in different life stages of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar L.

    Science.gov (United States)

    Jones, P G; Hammell, K L; Gettinby, G; Revie, C W

    2013-03-01

    Emamectin benzoate has been used to treat sea lice, Lepeophtheirus salmonis, infestations on farmed Atlantic salmon, Salmo salar. Recent evidence suggests a reduction in effectiveness in some locations. A major challenge in the detection of tolerance emergence can be the typically low proportion of resistant individuals in a population during the early phases. The objectives of this study were to develop a method for determining differences in temporal development of tolerance between sea lice life stages and to explore how these differences might be used to improve the monitoring of treatment effectiveness in a clinical setting. This study examined two data sets based on records of sea lice abundance following emamectin benzoate treatments from the west coast of Scotland (2002-2006) and from New Brunswick, Canada (2004-2008). Life stages were categorized into two groups (adult females and the remaining mobile stages) to examine the trends in mean abundance and treatment effectiveness. Differences in emamectin benzoate effectiveness were found between the two groups by year and location, suggesting that an important part of monitoring drug resistance development in aquatic ectoparasites may be the need to focus on key life stages. © 2013 Blackwell Publishing Ltd.

  10. Horizontal and vertical distribution of sea lice larvae (Lepeophtheirus salmonis) in and around salmon farms in the Bay of Fundy, Canada.

    Science.gov (United States)

    Nelson, E J; Robinson, S M C; Feindel, N; Sterling, A; Byrne, A; Pee Ang, K

    2017-11-21

    The sea louse, Lepeophtheirus salmonis, is parasitic to salmonid species in the Northern Hemisphere and has become a widespread biological and economic problem for the salmon farming industry. A better understanding is needed of their spatial distribution and early life history to disrupt the life cycle of the sea louse. In this study, sea lice larval densities within salmon farms, between salmon farms and reference sites, and at various depths were quantified using both plankton pumps and plankton nets. Farm sites exhibited significantly higher densities than reference sites; however, these densities dropped an order of magnitude at a distance of 100 m from the cages. The majority of the larvae captured in the study were nauplii (93%), and densities ranged from 0 to 10 larvae/m3 . Free-swimming sea lice larvae were found to exhibit a diel cycle where nauplii larvae were in deeper waters (10-17 m) during the day and in surface waters (1-6 m) during the night. The results of this study suggest that the early life-history stages of sea lice originate from and may remain close to active salmon farms, creating a self-sustaining population. © 2017 Her Majesty the Queen in Right of Canada. Journal of Fish Diseases © 2017 John Wiley & Sons Ltd Reproduced with the permission of the Minister of Fisheries and Oceans of Canada.

  11. The efficacy of emamectin benzoate against infestations of Lepeophtheirus salmonis on farmed Atlantic salmon (Salmo salar L) in Scotland, 2002-2006.

    Science.gov (United States)

    Lees, Fiona; Baillie, Mark; Gettinby, George; Revie, Crawford W

    2008-02-06

    Infestations of the parasitic copepod Lepeophtheirus salmonis, commonly referred to as sea lice, represent a major challenge to commercial salmon aquaculture. Dependence on a limited number of theraputants to control such infestations has led to concerns of reduced sensitivity in some sea lice populations. This study investigates trends in the efficacy of the in-feed treatment emamectin benzoate in Scotland, the active ingredient most widely used across all salmon producing regions. Study data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. An epi-informatics approach was adopted whereby available farm records, descriptive epidemiological summaries and statistical linear modelling methods were used to identify factors that significantly affect sea lice abundance following treatment with emamectin benzoate (SLICE(R), Schering Plough Animal Health). The results show that although sea lice infestations are reduced following the application of emamectin benzoate, not all treatments are effective. Specifically there is evidence of variation across geographical regions and a reduction in efficacy over time. Reduced sensitivity and potential resistance to currently available medicines are constant threats to maintaining control of sea lice populations on Atlantic salmon farms. There is a need for on-going monitoring of emamectin benzoate treatment efficacy together with reasons for any apparent reduction in performance. In addition, strategic rotation of medicines should be encouraged and empirical evidence for the benefit of such strategies more fully evaluated.

  12. A new species of Anchistrotos Brian, 1906 (Copepoda: Cyclopoida: Taeniacanthidae) from the filamentous shrimpgoby Myersina filifer (Valenciennes) (Perciformes: Gobiidae) in Korean waters.

    Science.gov (United States)

    Moon, Seong Yong; Lee, Jeong-Hoon; Kim, Doo Nam

    2015-10-01

    A new species of Anchistrotos Brian, 1906 (Copepoda: Cyclopoida: Taeniacanthidae), parasitic in the branchial cavities of the filamentous shrimpgoby Myersina filifer (Valenciennes) (Perciformes: Gobiidae) from Korea is described. The new species is most closely related to A. tangi Venmathi Maran, Moon & Adday, 2014, but differs from it by the following combination of characters in the adult female: the U-shaped rostrum, the distal margin of the anal somite lacks patches of spinules, the proximal segment of the maxilliped is without seta, and the maxilliped claw is armed with long and small naked setae. This is the tenth species of the genus and a key is provided to distinguish all nominal species.

  13. Sublittoral Harpacticoida (Crustacea, Copepoda from the Magellan Straits and the Beagle Channel (Chile. Preliminary results of abundance and generic diversity

    Directory of Open Access Journals (Sweden)

    Kai Horst George

    1999-12-01

    Full Text Available Samples of meiofauna were collected with a Multicorer during the Magellan `Victor Hensen´ Campaign of RV `Victor Hensen´ in 1994 at 62 stations along the Magellan Straits and the Beagle Channel. Seventeen samples were analysed in the framework of a larger project. Only 69 species of Harpacticoida are known from Chile so far, all of them inhabiting the littoral zone. The Magellan Campaign of RV `Victor Hensen´ provided the first opportunity to obtain sublittoral samples of meiobenthos of Chilean coasts. In these samples the Copepoda were represented by 4 of its orders: Calanoida, Cyclopoida, Poecilostomatoida and Harpacticoida, the latter exhibiting the highest abundances. Representatives of 19 harpacticoid families (6 of which are new for Chilean waters were identified in the samples. The species found in 15 of these families belong to 28 genera of which 18 are new to the Chilean fauna. With respect to taxa composition and distribution, the following preliminary results can be presented: the number of new families and new genera for the southern tip of South America increased considerably; a relatively high similarity between the Magellan Straits/Beagle Channel and areas of corresponding northern latitudes can be observed; the Magellan Straits and Beagle Channel show considerable differences with respect to taxa composition and diversity of the harpacticoid fauna.

  14. Sublittoral and bathyal Harpacticoida (Crustacea, Copepoda of the Magellan region. Composition, distribution and species diversity of selected major taxa

    Directory of Open Access Journals (Sweden)

    Kai Horst George

    2005-12-01

    Full Text Available Two expeditions, undertaken in 1994 and 1996, provided quantitatively sampled material of sublittoral and bathyal meiobenthos from the Paso Ancho of the Straits of Magellan, the Beagle Channel, and the Patagonian continental slope (Chile. To investigate whether these distinct geographic areas might also be characterised by different harpacticoid assemblages, qualitative and quantitative analyses of Copepoda Harpacticoida were carried out. At supraspecific level 25 harpacticoid families were found, as well as several species that could not yet be assigned to any major harpacticoid taxon. Due to the high amount of collected Harpacticoida, detailed investigations at species level had to be restricted to six taxa, namely the Ancorabolidae, Argestidae, Cletodidae, Diosaccinae, Paramesochridae, and Paranannopinae. The corresponding specimens were assigned to 122 species in 52 genera. More than 80% of them are new to science. Qualitative comparisons of both species composition and species distribution allow the three areas to be distinguished in terms of species richness. However, statistical analyses confirm these results only partly. Similarity analyses applying non-metrical multidimensional scaling, as well as diversity analyses using the rarefaction method, suggest that the observed differences in distribution and diversity patterns are due to small-scale, local conditions, which may overlay possible large-scale ones.

  15. A new species of Wellsopsyllus (Copepoda, Harpacticoida, Paramesochridae) from the deep Southern Ocean and remarks on its biogeography

    Science.gov (United States)

    Kottmann, Johanna; Kihara, Terue Cristina; Glatzel, Thomas; Veit-Köhler, Gritta

    2013-03-01

    The new deep-sea copepod species of the family Paramesochridae (Copepoda, Harpacticoida) presented here was collected during the scientific ANtarctic benthic DEEP-sea biodiversity cruise II (ANDEEP II) to the Weddell Abyssal Plain and western Weddell Sea and the CROZet natural iron bloom and EXport experiment (CROZEX cruise) to the Crozet Isles in the Indian Ocean. The new species has been allocated to the subgenus Wellsopsyllus within the genus Wellsopsyllus Kunz, 1981, based on the 1-segmented endopods and 3-segmented exopods of swimming legs 2-4. Furthermore, the new species shows a 1-segmented exopod of the antenna. Wellsopsyllus ( W.) antarcticus sp. n. can be distinguished from its congeners by its small body size, the presence of two setae on the distal segment of the endopod of the first swimming leg, by the very small furcal rami, the extremely reduced endopods of second and third swimming legs, the reduced mandibular palp and maxillula, as well as by the size and armature of the fifth and sixth swimming legs in both sexes. Difficulties of the placement of the new species into a suitable genus show an insufficiency in the present family classification. In the future, a revision of the genus Wellsopsyllus is essential. With its presence in the western Weddell Sea and the Indian Ocean, the new species may have a wide distribution range. Furthermore, it is the first abyssal species of the genus Wellsopsyllus sampled outside of the Scotia Sea.

  16. In silico characterization of the insect diapause-associated protein couch potato (CPO) in Calanus finmarchicus (Crustacea: Copepoda).

    Science.gov (United States)

    Christie, Andrew E; Roncalli, Vittoria; Lona, Paola Batta; McCoole, Matthew D; King, Benjamin L; Bucklin, Ann; Hartline, Daniel K; Lenz, Petra H

    2013-03-01

    Couch potato (CPO) is an RNA-binding protein involved in the regulation of nervous system development and adult diapause in insects. Within insects, this protein is highly conserved, yet it has not been identified in another large arthropod group, the Crustacea. Here, functional genomics was used to identify putative CPO homologs in the copepod Calanus finmarchicus, a planktonic crustacean that undergoes seasonal diapause. In silico mining of expressed sequence tag (EST) and 454 pyrosequencing data resulted in the identification of two full-length CPO proteins, each 205 amino acids long. The two C. finmarchicus CPOs (Calfi-CPO I and II) are identical in sequence with the exception of three amino acids, and are predicted to possess a single RNA recognition motif (RRM). Sequence comparison of the two Calfi-CPOs with those of insects shows high levels of amino acid conservation, particularly in their RRMs. Using the C. finmarchicus sequences as queries, ESTs encoding partial CPOs were identified from two other crustaceans, the parasitic copepod Lernaeocera branchialis and shrimp Penaeus monodon. Surprisingly, no convincing CPO-encoding transcripts were identified from crustacean species with very large (>100,000) EST datasets (e.g. Litopenaeus vannamei, Daphnia pulex and Lepeophtheirus salmonis), suggesting that CPO transcript/protein may be expressed at very low levels or absent in some crustaceans. RNA-Seq data suggested stage-specific expression of CPO in C. finmarchicus, with few transcripts present in eggs (which represent mixed embryonic stages) and adults, and high levels in nauplii and copepodites; stages exhibiting high CPO expression are consistent with a role for it in neuronal development. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Enhanced transcriptomic responses in the Pacific salmon louse Lepeophtheirus salmonis oncorhynchi to the non-native Atlantic Salmon Salmo salar suggests increased parasite fitness.

    Science.gov (United States)

    Braden, Laura M; Sutherland, Ben J G; Koop, Ben F; Jones, Simon R M

    2017-01-30

    Outcomes of infections with the salmon louse Lepeophtheirus salmonis vary considerably among its natural hosts (Salmo, Oncorhynchus spp.). Host-parasite interactions range from weak to strong host responses accompanied by high to low parasite abundances, respectively. Parasite behavioral studies indicate that the louse prefers the host Atlantic Salmon (Salmo salar), which is characterized by a weak immune response, and that this results in enhanced parasite reproduction and growth rates. Furthermore, parasite-derived immunosuppressive molecules (e.g., proteases) have been detected at higher amounts in response to the mucus of Atlantic Salmon relative to Coho Salmon (Oncorhynchus kisutch). However, the host-specific responses of the salmon louse have not been well characterized in either of the genetically distinct sub-species that occur in the Atlantic and Pacific Oceans. We assessed and compared the transcriptomic feeding response of the Pacific salmon louse (L. salmonis oncorhynchi,) while parasitizing the highly susceptible Atlantic Salmon and Sockeye Salmon (Oncorhynchus nerka) or the more resistant Coho Salmon (Oncorhynchus kisutch) using a 38 K oligonucleotide microarray. The response of the louse was enhanced both in the number of overexpressed genes and in the magnitude of expression while feeding on the non-native Atlantic Salmon, compared to either Coho or Sockeye Salmon. For example, putative virulence factors (e.g., cathepsin L, trypsin, carboxypeptidase B), metabolic enzymes (e.g., cytochrome B, cytochrome C), protein synthesis enzymes (e.g., ribosomal protein P2, 60S ribosomal protein L7), and reproduction-related genes (e.g., estrogen sulfotransferase) were overexpressed in Atlantic-fed lice, indicating heightened parasite fitness with this host species. In contrast, responses in Coho- or Sockeye-fed lice were more similar to those of parasites deprived of a host. To test for host acclimation by the parasite, we performed a reciprocal host transfer

  18. A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis

    Science.gov (United States)

    2014-01-01

    Background The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing. Results With the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure. Conclusions To our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance

  19. Gene expression analyses of immune responses in Atlantic salmon during early stages of infection by salmon louse (Lepeophtheirus salmonis revealed bi-phasic responses coinciding with the copepod-chalimus transition

    Directory of Open Access Journals (Sweden)

    Afanasyev Sergey

    2011-03-01

    Full Text Available Abstract Background The salmon louse (Lepeophtheirus salmonis Krøyer, an ectoparasitic copepod with a complex life cycle causes significant losses in salmon aquaculture. Pesticide treatments against the parasite raise environmental concerns and their efficacy is gradually decreasing. Improvement of fish resistance to lice, through biological control methods, needs better understanding of the protective mechanisms. We used a 21 k oligonucleotide microarray and RT-qPCR to examine the time-course of immune gene expression changes in salmon skin, spleen, and head kidney during the first 15 days after challenge, which encompassed the copepod and chalimus stages of lice development. Results Large scale and highly complex transcriptome responses were found already one day after infection (dpi. Many genes showed bi-phasic expression profiles with abrupt changes between 5 and 10 dpi (the copepod-chalimus transitions; the greatest fluctuations (up- and down-regulation were seen in a large group of secretory splenic proteases with unknown roles. Rapid sensing was witnessed with induction of genes involved in innate immunity including lectins and enzymes of eicosanoid metabolism in skin and acute phase proteins in spleen. Transient (1-5 dpi increase of T-cell receptor alpha, CD4-1, and possible regulators of lymphocyte differentiation suggested recruitment of T-cells of unidentified lineage to the skin. After 5 dpi the magnitude of transcriptomic responses decreased markedly in skin. Up-regulation of matrix metalloproteinases in all studied organs suggested establishment of a chronic inflammatory status. Up-regulation of putative lymphocyte G0/G1 switch proteins in spleen at 5 dpi, immunoglobulins at 15 dpi; and increase of IgM and IgT transcripts in skin indicated an onset of adaptive humoral immune responses, whereas MHCI appeared to be down-regulated. Conclusions Atlantic salmon develops rapid local and systemic reactions to L. salmonis, which, however

  20. A new species of Pseudomacrochiron Reddiah, 1969 (Crustacea: Copepoda: Macrochironidae) associated with scyphistomae of the moon jellyfish Aurelia sp. (Cnidaria: Scyphozoa) off Japan.

    Science.gov (United States)

    Tang, Danny; Yasuda, Akira; Yamada, Satoshi; Nagasawa, Kazuya

    2012-02-01

    A new species of the Macrochironidae Humes & Boxshall, 1996 (Copepoda: Cyclopoida), Pseudomacrochiron aureliae n. sp., is described based on adult specimens extracted from the gastrovacular cavity of the scyphistomae of Aurelia sp. (Cnidaria: Scyphozoa) collected in the Seto Inland Sea and Ise Bay off the coast of Japan. The new species differs from its congeners by having the following combination of characters: a caudal ramus with a length to width ratio of 3.1; an accessory flagellum on caudal setae II, III and VI; three apical setae on the maxillule; only setae I and II on the maxillary basis; two short spines on the female maxilliped claw (endopod); an armature of III, I, 4 on the terminal exopodal segment of leg 3; an armature of I, II, 2 on the terminal endopodal segment of leg 3; an armature of II, I, 4 on the terminal exopodal segment of leg 4; and a short free exopodal segment of leg 5 (length to width ratio of 1.4) armed with a long seta and short spine. P. aureliae n. sp. is the first member of the genus reported from off Japan and from the scyphistomae of its scyphozoan host.

  1. The zooplankton of Santa Catarina continental shelf in southern Brazil with emphasis on Copepoda and Cladocera and their relationship with physical coastal processes El zooplancton de la plataforma continental de Santa Catarina, sur de Brasil con énfasis en Copepoda y Cladocera y sus relaciones con procesos físicos costeros

    Directory of Open Access Journals (Sweden)

    Renata Domingos-Nunes

    2012-11-01

    Full Text Available Very few studies have been carried out to exclusively investigate the zooplankton community of Santa Catarina State continental shelf, despite the economic and ecological importance of the area. This coastal region of southern Brazil presents highly relevant oceanographic processes, such as the strong influence of continental inputs, resurgence in the Cabo de Santa Marta Grande and River Plata plume water to the south. Two sampling cruises were carried out, in December 2005 and May 2006, in order to study temporal hydrological variations, and their influence on the biota of the region. Zooplankton samples for analysis were obtained by oblique hauls with Bongo nets at 33 sampling stations arranged in profiles perpendicular to the coast on each cruise. The predominant groups found in the samples were Copepoda, Cladocera, Salpidae and Chaetognatha, which presented higher densities at the stations closer to the coast. In the case of the December 2005 cruise, the salinity and temperature gradients perpendicular to the coast, promoted by the continental inputs to the north of the area and by the upwelling to the south, determined the limits of distribution of Acartia lilljeborgi and Penilia avirostris. However, the temperature and salinity gradients longitudinal to the coast determined on the May 2006 cruise did not explain the species distribution, indicating that biotic forcing mechanisms may have been active in the ecology of the system during this period.A pesar de la importancia económica y ecológica del área todavía no habían sido realizados estudios exclusivamente destinados a la investigación de la comunidad zooplanctónica de la plataforma continental del Estado de Santa Catarina. Esta región costera del sur de Brasil presenta procesos oceanográficos de alta relevancia, tales como fuerte influencia de aportes continentales, resurgencia en el Cabo de Santa Marta Grande y la pluma de agua del río Plata en el sur. Se efectuaron dos

  2. Macrozooplâncton da Zona Econômica Exclusiva do Nordeste do Brasil (segunda expedição oceanográfica - REVIZEE/NE II com ênfase em Copepoda (Crustacea

    Directory of Open Access Journals (Sweden)

    Eliane Aparecida Holanda Cavalcanti

    2004-09-01

    Full Text Available Objetivando-se caracterizar a densidade, abundância relativa, freqüência de ocorrência, diversidade específica e associação de espécies do macrozooplâncton oceânico da "Zona Econômica Exclusiva" foi realizado o presente estudo. A região prospectada encontra-se localizada entre os paralelos 7º28'56"S - 34º32'45"W, referente a segunda expedição oceanográfica do Programa REVIZEE/NE, realizada pelo Noc. Antares da DHN/Marinha do Brasil. As amostras foram coletadas com rede de plâncton tipo bongo com malha de 300 e 500µm, no período de 31/01 a 07/02/97 em 21 estações, totalizando 42 amostras. Foram identificados 78 taxa. A densidade total dos organismos (exceto Copepoda variou de 2,31 a 6,06 org.m-3 (estações 55 e 56 e, para os Copepoda de 0,99 a 4,75 org.m-3 (estações 48 e 57. Em termos de freqüência de ocorrência Crustacea e Chaetognatha foram muito freqüentes; Cnidaria e Teleostei (ovos e larvas freqüentes; Mollusca, Annelida e Chordata pouco freqüentes e Protozoa raros. A diversidade específica variou de 0,648 a 4,037 ind.bits-1. A equitabilidade variou de 0,279 a 1,0. Os baixos valores de diversidade e equitabilidade ocorreram devido à dominância de Undinula vulgaris (Dana, 1849 e Calanopia americana F. Dahl, 1894. A análise cofenética revelou um r The present study was performed with the objective to characterise the density, relative abundance, frequency of occurrence, specific diversity and species associations of the oceanic macrozooplankton of the "Exclusive Economic Zone". The area under investigation is located between 7º28'56"S - 34º32'45"W and 3º21'08"S - 38º40'29"W, sampled during the second oceanographic expedition REVIZEE/NE on board OV Antares of the Brazilian Navy. Twenty-one samples were taken with bongo type plankton net with 300µm mesh size between 0 and 200 m depth. 63 (sixty and three taxa were identified. Total density varied from 2,31 to 6,06 ind.m-3 (station 55 and 56 for the whole

  3. A new genus of Ectinosomatidae (Copepoda, Harpacticoida from sublittoral sediments in Ubatuba, São Paulo State, Brazil, including an updated key to genera and notes on Noodtiella Wells, 1965

    Directory of Open Access Journals (Sweden)

    Terue Kihara

    2009-08-01

    Full Text Available Both sexes of a new genus and species of Ectinosomatidae (Copepoda, Harpacticoida from sublittoral sediments collected on the inner continental shelf in Ubatuba, São Paulo State (Brazil are described in detail. Chaulionyx gen. n. (type species: C. paivacarvalhoi sp. n. differs from all known genera in the presence of a conspicuous bifid spine on the prehensile P1 endopod. It can be differentiated from other genera with a prehensile endopod (Halophytophilus Brian, 1919; Bradyellopsis Brian, 1925; Klieosoma Hicks & Schriever, 1985 by the presence of distinctive subrectangular middorsal pores on the urosomites and the unarmed male sixth legs. The genus Lineosoma Wells, 1965 is recognized as a paraphyletic taxon and relegated to a junior subjective synonym of Noodtiella Wells, 1965. Arenosetella pectinata Chappuis, 1954a is removed from its floating position in Ectinosomoides Nicholls, 1945, transferred to the genus Noodtiella as N. pectinata comb. n. and considered the senior subjective synonym of N. toukae Mitwally & Montagna, 2001. Dichotomous keys are provided for the identification of the 18 valid species of Noodtiella and the 21 valid genera of the family Ectinosomatidae. Halophytophilus aberrans Wells & Rao, 1987 is placed species incertae sedis in the family.

  4. (Copepoda: Siphonostomatoida) from southern Africa

    African Journals Online (AJOL)

    1988-08-22

    Aug 22, 1988 ... The three segments each bear 7-4-10 setae successively. The terminal segment bears one bifid seta. Second antenna three-segmented. (Figure 2a). Basal segment stout and about twice as long as second segment. Third segment transformed into a stout, sclerotized hook articulating laterally with second.

  5. (Copepoda, Harpacticoida) from South Africa

    African Journals Online (AJOL)

    1976-12-09

    ? and 200, K-31017, in the Zoologisches. Institut und Zoologisches Museum, Hamburg. Further paratypes in the Zoologisches Museum der UniversiHit. Kiel, Federal Republic of Germany. Type-locality: Langvlei, Wilderness ...

  6. Estrutura da assembléia de microcrustáceos (Cladocera e Copepoda em um reservatório do semi-árido Neotropical, Barragem de Pedra, Estado da Bahia, Brasil - DOI: 10.4025/actascibiolsci.v31i1.538 Structure of microcrustaceans assemblage (Cladocera and Copepoda from reservoir Neotropical semiarid, Pedra Dam, Bahia, Brazil - DOI: 10.4025/actascibiolsci.v31i1.538

    Directory of Open Access Journals (Sweden)

    Nadson Ressyé Simões

    2009-04-01

    Full Text Available Na região semi-árida, os reservatórios desempenham importante papel para o desenvolvimento regional, o que resulta no aumento da pressão antrópica no seu entorno, acarretando mudanças na qualidade da água. O conhecimento do zooplâncton fornece informações básicas sobre a estrutura trófica pelágica. O objetivo deste trabalho foi caracterizar a assembléia de microcrustáceos planctônicos (copépodes e cladóceros no reservatório Barragem da Pedra, em dois períodos distintos (chuvoso e seco/2003. As amostragens foram realizadas em quatro pontos do Reservatório Barragem de Pedra, com uma rede de plâncton (malha de 70 µm, por meio de arrastos verticais do fundo para a superfície. Foram encontradas 12 espécies de microcrustáceos. As espécies dominantes foram Notodiaptomus iheringi e Daphnia gessneri. A densidade de indivíduos adultos variou de 4.303 a 7.423 ind. M-3 em janeiro e de 669 a 7.272 ind. M-3 em julho. O índice de diversidade de Shannon variou de 1,90 bit. ind.-1 em julho a 2,71 bit. ind.-1 em janeiro. Maiores densidades de indivíduos, índice de diversidade e equabilidade foram encontrados na estação chuvosa. A estrutura da comunidade de microcrustáceos diferiu entre as estações seca e chuvosa e correlacionou-se significativamente com as variáveis físicas e químicas da água.In the semiarid region, the reservoirs perform important role for the regional development, which results in the increase of the anthropogenic pressure, causing changes in the water quality. The knowledge of the zooplankton structure supplies basic information for the ecology, zoology, limnology and biogeography of these organisms. The objective of this study was to characterize the plankton microcrustaceans assemblage (Copepoda and Cladocera in the Pedra Dam Reservoir (PDR in two distinct periods (rainy and dry/2003. The samplings were carried out in four station of the PDR, using plankton net (70µm of mesh, by vertical hauls from

  7. (Copepoda, Notodelphyidae) from Pyura stolonifera (Echinodermata ...

    African Journals Online (AJOL)

    The genus Doropygus has long been plagued by morphological and taxonomic confusion. Descriptions are often lound to be inadequate and finer morphological variations result in laborious and unnecessary description of new species. Although the genus is known to be cosmopolitan in its distribution, only four species ...

  8. Copepoda parasites in economically important fish, Mugilidae ...

    African Journals Online (AJOL)

    FUNMILAYO

    1Federal College of Fisheries and Marine Technology, Ahmadu Bello Way, Victoria Island, Lagos State, Nigeria. 2Laboratory of Parasitological and Ecology of parasites, Department of .... parts per thousand, but highest in station 2 (Djdje) with. 0.8 and 29.5 parts per thousand salinity levels respect- tively. The highest ...

  9. The developmental stages of Pseudodiaptomus hessei (Copepoda ...

    African Journals Online (AJOL)

    1988-06-15

    Jun 15, 1988 ... A. Body in ventral view; B. Antennule; C. Antenna; D. Mandible; E. Maxi11ule. one basipodite segment bearing a strong masticatory process and four setae. Subsequent stages have two basi- podite segments. Two strong spines are present on the first with the addition of one seta in Stages 4 to 6. Stage 3.

  10. On Choniostoma and Heptalobus (Copepoda, Choniostomatidae)

    NARCIS (Netherlands)

    Stock, J.H.

    1958-01-01

    In the course of a study of prawns infected by epicarid isopods, I observed some specimens of Spirontocaris lilljeborgi (Dan.) showing deformations of the carapax very similar to those caused by parasitic isopods (fig. 1). In this case, however, the swellings of the carapax were not caused by

  11. Distribution and biogeography of the Paradiaptominae (Copepoda ...

    African Journals Online (AJOL)

    They are endemic to Africa with the exception of four species, Metadiaptomus asiaticus (Asia and Mongolia), M. gauthieri (Africa and Madagascar), Paradiaptomus greeni (India and Sri Lanka) and Neolovenula alluaudi (Canary Islands, North Africa, Baltic and Mediterranean countries). The North African species ...

  12. Copepoda parasites in economically important fish, Mugilidae ...

    African Journals Online (AJOL)

    FUNMILAYO

    of economically important fish, both from the wild and fish farms, thus making them difficult to market. In this study, copepod parasitic investigation was carried out in gills of 856 fish mugilidae (Mugil cephalus and Liza falcipinnis) in three stations (Ganvie, Djdje and Zogbo) of Lac Nokoue lagoon. In the three stations, three ...

  13. Zur Biologie von Paramphiascella fulvofasciata (Copepoda, Harpacticoida)

    Science.gov (United States)

    Dahms, Hans-Uwe

    1986-09-01

    The benthic harpacticoid copepod Paramphiascella fulvofasciata Rosenfield & Coull was collected from holdfasts of Laminaria hyperborea from a subtidal area of Helgoland (North Sea). All developmental stages of P. fulvofasciata are raptorial feeders. The feeding of the nauplii is advanced by a marginal setule-crest of the labrum which prevents food-particles from being swept away. The oral appendages of the copepodites circumscribe a frustal space ventral to the mouth which facilitates uptake of food-particles. The nauplii are not able to swim and perform stalking movements with their antennal endopodites. Good swimming ability as well as digging-in-behaviour and negative phototaxis of the copepodites indicate epi- as well as inbenthic mode of life. Several life-cycle characters are described. Precopula lasts ca. one day. The mean egg-number is 27, and mean egg-diameter is 87 × 75 µm. The number of nauplii per egg (double)-sac amounts to 25 30. Developmental time at 19°C is 6 9 days (nauplii) and 20 24 days (copepodites). The whole developmental period lasts 28 days. The maximal lifespan in the laboratory is 193 days. Sex-ratio is almost balanced. Females produce egg-sacs more than 3.5 times during their life period. Seasonal effects on reproductive activity have not been detected in laboratory cultures.

  14. Histopathological changes induced by copepoda parasites ...

    African Journals Online (AJOL)

    User

    2014-01-13

    Jan 13, 2014 ... oceanographic alterations induced by climatic changes and temperature dependent can influence parasitic-host interaction (Abalaka et al., 2010). In conclusion, the resultant hypertrophy of the underlying epithelial reducing the surface area for effective respiration could lead to suffocation, particularly at ...

  15. Diversity of the Monstrilloida (Crustacea: Copepoda.

    Directory of Open Access Journals (Sweden)

    Eduardo Suárez-Morales

    Full Text Available Monstrilloid copepods are protelean parasites of different groups of marine benthic invertebrates. Only their first naupliar, preadult, and adult phases are planktonic. Monstrilloids are currently represented by more than 115 nominal species contained in four genera. Its taxonomic knowledge has been hampered by nomenclatural and descriptive problems derived from their peculiar ontogeny and poor definitions of taxa. One of the most important difficulties is that of matching males to females. The only reliable methods to link the sexes of a species are the confirmation of particular apomorphies shared by both sexes, finding both sexes in the same host or as a pre-copulatory male-female pair in the plankton, or by the use of molecular markers. A general overview of the morphology of the group and its life cycle is provided herein. Recently, upgraded descriptive standards have been established and the relevance of redescribing taxa based on type and museum specimens has been demonstrated. The rate of species description per decade has had several peaks between 1840 and 2010: (1971-1980, 1991-2000, 2001-2010, each related to the activity of a few researchers. An analysis of the world distribution of published records of the Monstrilloida revealed that the Northeast Atlantic is the best studied region (45% of all records, followed by the Northwestern Atlantic (17%; the least surveyed areas include regions of the southern hemisphere (less than 3%. The Northeast Atlantic region harbors the highest number of known species (32 nominal species, followed by the Caribbean Sea/Gulf of Mexico (24, the Mediterranean/Black Sea (19, Indonesia-Malaysia-Philippines region (17, Japanese waters (17, and the Brazil-Argentina area (16. Other than these generalized patterns, little can be concluded concerning the biogeography of the group. Many species records are doubtful or improbable, and purportedly cosmopolitan nominal species are being revealed as species complexes yet to be studied.

  16. Groundwater crustaceans of Spain, 13 (Copepoda Calanoida)

    NARCIS (Netherlands)

    Bowman, Thomas E.

    1990-01-01

    Two calanoid copepods were collected from groundwaters in Spain by the University of Amsterdam Expeditions in 1983—84 and 1985. Copidodiaptomus numidicus was found in southwestern Spain, in provincias Huelva and Sevilla. Mixodiaptomus laciniatus, previously known in Spain only from the Pyrenees, was

  17. How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere.

    Science.gov (United States)

    Costello, Mark J

    2009-10-07

    Fishes farmed in sea pens may become infested by parasites from wild fishes and in turn become point sources for parasites. Sea lice, copepods of the family Caligidae, are the best-studied example of this risk. Sea lice are the most significant parasitic pathogen in salmon farming in Europe and the Americas, are estimated to cost the world industry euro300 million a year and may also be pathogenic to wild fishes under natural conditions. Epizootics, characteristically dominated by juvenile (copepodite and chalimus) stages, have repeatedly occurred on juvenile wild salmonids in areas where farms have sea lice infestations, but have not been recorded elsewhere. This paper synthesizes the literature, including modelling studies, to provide an understanding of how one species, the salmon louse, Lepeophtheirus salmonis, can infest wild salmonids from farm sources. Three-dimensional hydrographic models predicted the distribution of the planktonic salmon lice larvae best when they accounted for wind-driven surface currents and larval behaviour. Caligus species can also cause problems on farms and transfer from farms to wild fishes, and this genus is cosmopolitan. Sea lice thus threaten finfish farming worldwide, but with the possible exception of L. salmonis, their host relationships and transmission adaptations are unknown. The increasing evidence that lice from farms can be a significant cause of mortality on nearby wild fish populations provides an additional challenge to controlling lice on the farms and also raises conservation, economic and political issues about how to balance aquaculture and fisheries resource management.

  18. Modeling the Transmission of Piscirickettsia salmonis in Farmed Salmon

    Science.gov (United States)

    Cisternas, Jaime; Moreno, Adolfo

    2007-05-01

    Farming Atlantic salmon is an economic activity of growing relevance in the southern regions of Chile. The need to increase efficiency and reach production goals, as well as restrictions on the use of water resources, had led in recent years to certain practices that proved prone to bacterial infections among the fish. Our study focuses on the impact of rickettsial bacteria in farmed salmon, and the possibility of controlling its incidence once it is established along the salmon life cicle. We used compartmental models to separate fish in their maturation stages and health status. The mathematical analysis will involve differential equations with and without delays, and linear stability principles. Our goal was to build a simple model that explains the basic mechanisms at work and provides predictions on the outcome of different control strategies.

  19. Two new species of Leptopsyllus from Korea (Copepoda, Harpacticoida, Paramesochridae)

    Science.gov (United States)

    Back, Jinwook; Lee, Wonchoel

    2017-01-01

    Abstract Two new species of Leptopsyllus are described from the subtidal zone of Korea. Both species were assigned to the subgenus Leptopsyllus (Leptopsyllus) T. Scott, 1894, based on following three characters: two-segmented rami of P1, absence of endopod on P2 and P3, and presence of one-segmented endopod of P4. L. (L.) pundius sp. n. is most closely related to L. (L.) punctatus Mielke, 1894, however clearly distinguishable from it based on mandibular exopod with two setae, shape of P6, and caudal seta III ornamented with spinules in the new species. L. (L.) koreanus sp. n. is clearly distinguishable from its congeners by the second segment of P1 endopod armed with one element, male baseoendopod of P5 with one seta, and one segmented endopod of mandibular palp. The world distribution and updated key to the species of the genus Leptopsyllus are provided. PMID:28769625

  20. A new species of Schizopera (Copepoda: Harpacticoida: Miraciidae from Colombia

    Directory of Open Access Journals (Sweden)

    Juan M. Fuentes-Reinés

    2014-09-01

    Full Text Available Objective. The present contribution aims at the description of a new species of the genus Schizopera. Materials and methods. Water samples were collected in littoral areas with mangrove and macrophytes, and in the limnetic zone. Twenty five liters of water were taken. Water samples were filtered with a zooplankton net (45μm and preserved in 70% ethanol. The filtered samples were concentrated to 100 ml and examined in a Bogorov camera. Copepods were separated. Observations and drawings of S. evelynae sp. nov. were made at a magnification of 1000X. Results. Schizopera evelynae sp. nov. seems to be closely related to S. giselae Jiménez -Álvarez 1988 and to S. pratensis Noodt 1958 based on the armature formula of P1-P4, but can be separated from these two species based on the relative length of P1ENP, length/width ratio of P1ENP2, relative length of the outer proximal and distal spines on P4EXP3, shape of the exopod and relative length of the exopodal setae of the female P5, shape and length/width ratio of the male P2ENP2, and male P5 baseoendopodal lobe:exopod length ratio. A key to the species of Schizopera from America is given. Conclusion. A new species of the genus Schizopera is described. The Colombian material shares most characters with S. giselae and S. pratensis.

  1. Desiccation Resistance in Tigriopus californicus(Copepoda, Harpacticoida)

    Science.gov (United States)

    Powlik, James J.; Lewis, Alan G.

    1996-10-01

    In field populations and controlled laboratory microcosms, the supralittoral copepod Tigriopus californicusdemonstrated the ability to recover populations from evaporated splashpools. The response to either seawater or rainwater introduction occurred mainly within 24 h, regardless of copepod abundance or substrate material (mixed sediment or dried samples of the alga Enteromorpha compressa). As a proportion of available individuals, the response was quite consistent over all life-history stages. However, egg-carrying females andadult males showed the greatest net increase in individual numbers due to their abundance in source (dried) materials. Enteromorpha compressatreatments hydrated with seawater yielded significantly greater re-animation ( Pdried splashpools probably still yields sufficient numbers of effective intra-pool recolonization. Such a response may be more practical for population endurance in ephemeral supralittoral habitats than reliance on environmental influences (waves, precipitation or transport on coincident invertebrates) or the deposition of encysted eggs.

  2. Monstrilloida (Crustacea: Copepoda) from the Beagle Channel, South America

    NARCIS (Netherlands)

    Suárez-Morales, E.; Ramírez, F.C.; Derisio, C.

    2008-01-01

    Monstrilloid copepods were collected during zooplankton surveys in the Beagle Channel at the southernmost end of South America. These specimens represent two species of Monstrillopsis, one of them undescribed, and one new species of Monstrilla. Monstrillopsis igniterra n. sp. is related to forms of

  3. Two New Species of Clausidiidae (Copepoda, Poecilostomatoida from Korea

    Directory of Open Access Journals (Sweden)

    Hwang, Hosung

    2016-04-01

    Full Text Available Two new species of Clausidiidae, each belonging to the genera Clausidium Kossmann, 1875 and Hippomolgus G. O. Sars, 1917, are described from Korea. Clausidium maximus n. sp. is an associate of a burrowing decapod of the genus Callianassa living on the Korean coast of the Yellow Sea and has, as diagnostic characters, two inner setae on the second endopodal segment of legs 2-4, nine elements on the third exopodal segment of leg 4, an inner seta on the second exopodal segment of male leg 1, and a relatively large body size, exceeding 2.0 mm in the female. Hippomolgus limiticus n. sp. was found in the bottom sediments in the East China Sea. It is similar to H. furcifer G. O. Sars, but distinghuishable from the latter species by having shorter caudal rami, 4-segmented female maxilliped, and inner coxal spine (instead of seta on legs 2 and 3. This is the first record on the genera Clausidium and Hippomolgus in the West Pacific.

  4. A new Bomolochus (Copepoda parasitica) from the California Grunion

    NARCIS (Netherlands)

    Stock, J.H.

    1955-01-01

    The grunion, Leuresthes tenuis (AYRES) (family Atherinidae), a fish with a distribution limited to coastal southern California, U.S.A., and Lower California, Mexico, yielded the recently described copepod Caligus olsoni PEARSE, 1953, and still another parasitic copepod which proved to be an

  5. Distribution of scolecithricidae (Copepoda: Calanoida) in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Gopalakrishnan, T.C.; Devi, K.S.

    Ecology and zoogeography of the frequently occurring and widely distributed planktonic copepods collected during the International Indian Ocean Expedition, Scolecithrix danae, Scolecithricella bradyi, S. tenuiserrata, S. abyssalis, Scaphocalanus...

  6. Aspects of the pathology of Lamproglena clariae (Copepoda ...

    African Journals Online (AJOL)

    Epithelial hyperplasia, resulting in fusion of gill lamellae and necrosis of the host tissue in the vicinity of the parasite were revealed through histological examination. No correlation was evident between the infestation intensity and fish haematocrit values. Although results showed that L. clariae causes localized infestation, ...

  7. Molecular effects of diethanolamine exposure on Calanus finmarchicus (Crustacea: Copepoda).

    Science.gov (United States)

    Hansen, Bjørn Henrik; Altin, Dag; Booth, Andy; Vang, Siv-Hege; Frenzel, Max; Sørheim, Kristin Rist; Brakstad, Odd Gunnar; Størseth, Trond R

    2010-08-15

    Alkanolamines are surface-active chemicals used in a wide range of industrial, agricultural and pharmaceutical applications and products. Of particular interest is the use of alkanolamines such as diethanolamine (DEA) in the removal of CO(2) from natural gas and for CO(2) capture following fossil fuel combustion. Despite this widespread use, relatively little is known about the ecotoxicological impacts of these compounds. In an attempt to assess the potential effects of alkanolamines in the marine environment, a key species in the North Atlantic, the planktonic copepod Calanus finmarchicus, was studied for molecular effects following sublethal exposure to DEA. DEA-induced alterations in transcriptome and metabolome profiling were assessed using a suppression subtractive hybridization (SSH) gene library method and high resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR), respectively. Effects were observed on transcription of genes reportedly involved in lipid metabolism, antioxidant systems, metal binding, and amino acid and protein catabolism. These effects were accompanied by altered expression of fatty acid derivates, amino acids (threonine, methionine, glutamine, arginine, alanine and leucine) and cholines (choline, phosphocholine and glycerophosphocholine). Together, SSH and HR-MAS NMR offer complementary screening tools for the assessment of molecular responses of C. finmarchicus to DEA and can be used in the study of other chemicals and organisms. Concentration-response and time-response relationships between DEA exposure and single gene transcription were investigated using quantitative PCR. Specific relationships were found between DEA exposure and the transcription of genes involved in protein catabolism (ubiquitin-specific protease-7), metal ion homeostasis (ferritin) and defence against oxidative stress (gamma-glutamylcysteine synthase, glutathione synthase and Cu/Zn-superoxide dismutase). At the lowest alkanolamine concentration used in these experiments, which corresponded to 0.5% of the LC(50) concentration, no transcriptional effects were observed, giving information regarding the lower molecular effect level. Finally, similar transcription patterns were observed for a number of different genes following exposure to DEA, which indicates analogous mechanisms of toxicity and response. (c) 2010 Elsevier B.V. All rights reserved.

  8. Copepoda associated with West Indian Actiniaria and Corallimorpharia

    NARCIS (Netherlands)

    Stock, Jan H.

    1975-01-01

    The present material has been collected at three occasions: during a stay on Curaçao and Bonaire (Netherlands Antilles) in 1958/59, and again in 1973/74, and during a visit in 1963 to La Parguera, Puerto Rico. The copepods recorded here as associates of Actiniaria and Corallimorpharia

  9. Spatial distribution of Nemesis lamna Risso 1826 (Copepoda ...

    African Journals Online (AJOL)

    The selection of a specific site of attachment by a copepod parasite is determined by a set of mostly unknown factors. The spatial distribution of Nemesis lamna on the gill filaments of white sharks Carcharodon carcharias was investigated. The complete set of left gills of 11 hosts was examined and the location, orientation ...

  10. Molecular effects of diethanolamine exposure on Calanus finmarchicus (Crustacea: Copepoda)

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Bjorn Henrik, E-mail: bjorn.h.hansen@sintef.no [SINTEF Materials and Chemistry, Marine Environmental Technology, Brattorkaia 17B, N-7465 Trondheim (Norway); Altin, Dag [BioTrix, N-7022 Trondheim (Norway); Booth, Andy; Vang, Siv-Hege; Frenzel, Max; Sorheim, Kristin Rist; Brakstad, Odd Gunnar [SINTEF Materials and Chemistry, Marine Environmental Technology, Brattorkaia 17B, N-7465 Trondheim (Norway); Storseth, Trond R. [SINTEF Fisheries and Aquaculture, N-7465 Trondheim (Norway)

    2010-08-15

    Alkanolamines are surface-active chemicals used in a wide range of industrial, agricultural and pharmaceutical applications and products. Of particular interest is the use of alkanolamines such as diethanolamine (DEA) in the removal of CO{sub 2} from natural gas and for CO{sub 2} capture following fossil fuel combustion. Despite this widespread use, relatively little is known about the ecotoxicological impacts of these compounds. In an attempt to assess the potential effects of alkanolamines in the marine environment, a key species in the North Atlantic, the planktonic copepod Calanus finmarchicus, was studied for molecular effects following sublethal exposure to DEA. DEA-induced alterations in transcriptome and metabolome profiling were assessed using a suppression subtractive hybridization (SSH) gene library method and high resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR), respectively. Effects were observed on transcription of genes reportedly involved in lipid metabolism, antioxidant systems, metal binding, and amino acid and protein catabolism. These effects were accompanied by altered expression of fatty acid derivates, amino acids (threonine, methionine, glutamine, arginine, alanine and leucine) and cholines (choline, phosphocholine and glycerophosphocholine). Together, SSH and HR-MAS NMR offer complementary screening tools for the assessment of molecular responses of C. finmarchicus to DEA and can be used in the study of other chemicals and organisms. Concentration-response and time-response relationships between DEA exposure and single gene transcription were investigated using quantitative PCR. Specific relationships were found between DEA exposure and the transcription of genes involved in protein catabolism (ubiquitin-specific protease-7), metal ion homeostasis (ferritin) and defence against oxidative stress ({gamma}-glutamylcysteine synthase, glutathione synthase and Cu/Zn-superoxide dismutase). At the lowest alkanolamine concentration used in these experiments, which corresponded to 0.5% of the LC{sub 50} concentration, no transcriptional effects were observed, giving information regarding the lower molecular effect level. Finally, similar transcription patterns were observed for a number of different genes following exposure to DEA, which indicates analogous mechanisms of toxicity and response.

  11. A checklist of the marine Calanoida (Crustacea, copepoda) of Nigeria.

    African Journals Online (AJOL)

    This paper is based on analysis of a total of 725 zooplankton samples collected during series of surveys of the marine ecosystem of the continental shelf along the Nigeria Gulf of Guinea, between 1999 and 2010. The list encompasses a total of 55 species of Calanoida in 14 families and 27 genera. At the genus level, the ...

  12. INFECTIOUS SALMON ANEMIA

    Directory of Open Access Journals (Sweden)

    M. Yu. Shchelkanov

    2017-01-01

    Full Text Available The aim of this work consists in the analysis of modern scientific conceptions about infectious salmon anemia (ISA etiologically linked with ISAV (infectious salmon anemia virus (Orthomyxoviridae, Isavirus. ISA is deadly disease of Salmonidae fishes.Discussion. ISA began to extend actively among salmon breeding farms since the extremity of the XX century and poses nowadays serious threat of fishing industry as there are no not only anti-ISAV chemopreparates and effective vaccines, but also scientifically based ideas of ISAV ecology. In the offered review data on the discovery history, taxonomical status, virion morphology and genome structure as well as ecology of ISAV, clinical features, pathogenesis and laboratory diagnostics, actions in the epizootic foci for the prevention of further distribution and prophylaxis of ISA, arrangement for protection against salmon louses and utilized approaches to anti-ISAV vaccines development are discussed. There is very important that ISAV is capable to be transferred by salmon louses – pelagic crustaceans (Copepoda: Caligidae that allows to classify ISAV as arbovirus ecological group which are transferred due to biological transmission by arthropods (copepods to vertebrate animals (salmons. It is the only example known so far when representatives of Crustacea act as a vector for arboviruses.Conclusion. Investigation of ISAV ecology turns into one of "touchstones" allowing to judge technological readiness of mankind to master resources of the World Ocean. 

  13. Increased susceptibility to infectious salmon anemia virus (ISAv) in Lepeophtheirus salmonis – infected Atlantic salmon

    Science.gov (United States)

    The salmon louse and infectious salmon anemia virus (ISAv) are the two most significant pathogens of concern to the Atlantic salmon (Salmo salar) aquaculture industry. However, the interactions between sea lice and ISAv, as well as the impact of a prior sea lice infection on the susceptibility of th...

  14. Effect of exposure on salmon lice Lepeophtheirus salmonis population dynamics in Faroese salmon farms

    DEFF Research Database (Denmark)

    Patursson, Esbern J.; Simonsen, Knud; Visser, Andre

    2017-01-01

    of the freshwater exchange rate, the tidal exchange rate and dispersion by tidal currents. Salmon farms were ranked according to the rate of increase in the average numbers of salmon lice per fish. In a multiple linear regression, physical exposure together with temperature were shown to have a significant effect...

  15. Autogenous vaccination for control of yersiniosis (Yersiniosis salmonis in the salmonid aquaculture in Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Cvetkovik Aleksandar

    2009-05-01

    Full Text Available The aim of this study was to produce an autogenous vaccine from Yersinia ruckeri isolate and to test it’s efficacy in field conditions. Colonies of Yersinia ruckeri biotype I isolated from rainbow trout with haemorrhagic septicemia were cultivated in TSB and inactivated with formalin. The vaccine was diluted and administered by immersion of rainbow trout fry (~ 4.5 g BW in the vacinal suspension. The experimental infection was done 28 days post vaccination by immersing the fry in infectious suspension of the same isolate. Mortality of the control and vaccinated fish was 87% and 11%, respectively. Vaccinated fish showed high level of gained specific resistance to the infection (RPS 87,4%.

  16. Effects of salmon lice Lepeophtheirus salmonis onwild sea trout Salmo trutta—a literature review

    OpenAIRE

    Thorstad, Eva Bonsak; Todd, Christopher D.; Uglem, Ingebrigt; Bjørn, Pål Arne; Gargan, Patrick G.; Vollset, Knut Wiik; Halttunen, Elina; Kålås, Steinar; Berg, Marius; Finstad, Bengt

    2015-01-01

    - Salmon farming increases the abundance of salmon lice, which are ectoparasites of salmonids in the sea. Here we review the current knowledge on the effects of salmon lice on wild sea trout. Salmon lice feed on host mucus, skin and muscle, and infestation may induce osmoregulatory dysfunction, physiological stress, anaemia, reduced feeding and growth, increased susceptibility to secondary infections, reduced disease resistance and ultimately mortality of individual sea trou...

  17. Effects of salmon lice Lepeophtheirus salmonis onwild sea trout Salmo trutta—a literature review

    OpenAIRE

    Thorstad, Eva Bonsak; Todd, Christopher D.; Uglem, Ingebrigt; Bjørn, Pål Arne; Gargan, Patrick G.; Vollset, Knut Wiik; Halttunen, Elina; Kålås, Steinar; Berg, Marius; Finstad, Bengt

    2015-01-01

    Salmon farming increases the abundance of salmon lice, which are ectoparasites of salmonids in the sea. Here we review the current knowledge on the effects of salmon lice on wild sea trout. Salmon lice feed on host mucus, skin and muscle, and infestation may induce osmoregulatory dysfunction, physiological stress, anaemia, reduced feeding and growth, increased susceptibility to secondary infections, reduced disease resistance and ultimately mortality of individual sea trout. Wi...

  18. Effects of salmon lice Lepeophtheirus salmonis on wild sea trout Salmo trutta—a literature review

    OpenAIRE

    Thorstad, Eva Bonsak; Todd, Christopher D.; Uglem, Ingebrigt; Bjørn, Pål Arne; Gargan, Patrick G.; Vollset, Knut Wiik; Halttunen, Elina; Kålås, Steinar; Berg, Marius; Finstad, Bengt

    2015-01-01

    Salmon farming increases the abundance of salmon lice, which are ectoparasites of salmonids in the sea. Here we review the current knowledge on the effects of salmon lice on wild sea trout. Salmon lice feed on host mucus, skin and muscle, and infestation may induce osmoregulatory dysfunction, physiological stress, anaemia, reduced feeding and growth, increased susceptibility to secondary infections, reduced disease resistance and ultimately mortality of individual sea trout. Wi...

  19. Selective breeding program for sea lice Lepeophtheirus salmonis (Kroyer 1838) at the USDA's National Cold Water Marine Aquaculture Center

    Science.gov (United States)

    Sea lice are likely the most economically costly pathogen that has faced the salmon farming industry over the past 40 years. Recent economic estimates put the annual cost of sea lice at $742 million USD in 2012. With the rise of resistance to multiple drugs used to treat sea lice, there has been a s...

  20. Large scale modelling of salmon lice (Lepeophtheirus salmonis infection pressure based on lice monitoring data from Norwegian salmonid farms

    Directory of Open Access Journals (Sweden)

    Anja B. Kristoffersen

    2014-12-01

    Full Text Available Infection by parasitic sea lice is a substantial problem in industrial scale salmon farming. To control the problem, Norwegian salmonid farms are not permitted to exceed a threshold level of infection on their fish, and farms are required to monitor and report lice levels on a weekly basis to ensure compliance with the regulation. In the present study, we combine the monitoring data with a deterministic model for salmon lice population dynamics to estimate farm production of infectious lice stages. Furthermore, we use an empirical estimate of the relative risk of salmon lice transmission between farms, that depend on inter-farm distances, to estimate the external infection pressure at a farm site, i.e. the infection pressure from infective salmon lice of neighbouring farm origin. Finally, we test whether our estimates of infection pressure from neighbouring farms as well as internal within farm infection pressure, predicts subsequent development of infection in cohorts of farmed salmonids in their initial phase of marine production. We find that estimated external infection pressure is a main predictor of salmon lice population dynamics in newly stocked cohorts of salmonids. Our results emphasize the importance of keeping the production of infectious lice stages at low levels within local networks of salmon farms. Our model can easily be implemented for real time estimation of infection pressure at the national scale, utilizing the masses of data generated through the compulsory lice monitoring in salmon farms. The implementation of such a system should give the salmon industry greater predictability with respect to salmon lice infection levels, and aid the decision making process when the development of new farm sites are planned.

  1. Local and systemic gene expression responses of Atlantic salmon (Salmo salar L. to infection with the salmon louse (Lepeophtheirus salmonis

    Directory of Open Access Journals (Sweden)

    Nilsen Frank

    2008-10-01

    Full Text Available Abstract Background The salmon louse (SL is an ectoparasitic caligid crustacean infecting salmonid fishes in the marine environment. SL represents one of the major challenges for farming of salmonids, and veterinary intervention is necessary to combat infection. This study addressed gene expression responses of Atlantic salmon infected with SL, which may account for its high susceptibility. Results The effects of SL infection on gene expression in Atlantic salmon were studied throughout the infection period from copepodids at 3 days post infection (dpi to adult lice (33 dpi. Gene expression was analyzed at three developmental stages in damaged and intact skin, spleen, head kidney and liver, using real-time qPCR and a salmonid cDNA microarray (SFA2. Rapid detection of parasites was indicated by the up-regulation of immunoglobulins in the spleen and head kidney and IL-1 receptor type 1, CD4, beta-2-microglobulin, IL-12β, CD8α and arginase 1 in the intact skin of infected fish. Most immune responses decreased at 22 dpi, however, a second activation was observed at 33 dpi. The observed pattern of gene expression in damaged skin suggested the development of inflammation with signs of Th2-like responses. Involvement of T cells in responses to SL was witnessed with up-regulation of CD4, CD8α and programmed death ligand 1. Signs of hyporesponsive immune cells were seen. Cellular stress was prevalent in damaged skin as seen by highly significant up-regulation of heat shock proteins, other chaperones and mitochondrial proteins. Induction of the major components of extracellular matrix, TGF-β and IL-10 was observed only at the adult stage of SL. Taken together with up-regulation of matrix metalloproteinases (MMP, this classifies the wounds afflicted by SL as chronic. Overall, the gene expression changes suggest a combination of chronic stress, impaired healing and immunomodulation. Steady increase of MMP expression in all tissues except liver was a remarkable feature of SL infected fish. Conclusion SL infection in Atlantic salmon is associated with a rapid induction of mixed inflammatory responses, followed by a period of hyporesponsiveness and delayed healing of injuries. Persistent infection may lead to compromised host immunity and tissue self-destruction.

  2. Local and systemic gene expression responses of Atlantic salmon (Salmo salar L.) to infection with the salmon louse (Lepeophtheirus salmonis).

    Science.gov (United States)

    Skugor, Stanko; Glover, Kevin Alan; Nilsen, Frank; Krasnov, Aleksei

    2008-10-23

    The salmon louse (SL) is an ectoparasitic caligid crustacean infecting salmonid fishes in the marine environment. SL represents one of the major challenges for farming of salmonids, and veterinary intervention is necessary to combat infection. This study addressed gene expression responses of Atlantic salmon infected with SL, which may account for its high susceptibility. The effects of SL infection on gene expression in Atlantic salmon were studied throughout the infection period from copepodids at 3 days post infection (dpi) to adult lice (33 dpi). Gene expression was analyzed at three developmental stages in damaged and intact skin, spleen, head kidney and liver, using real-time qPCR and a salmonid cDNA microarray (SFA2). Rapid detection of parasites was indicated by the up-regulation of immunoglobulins in the spleen and head kidney and IL-1 receptor type 1, CD4, beta-2-microglobulin, IL-12beta, CD8alpha and arginase 1 in the intact skin of infected fish. Most immune responses decreased at 22 dpi, however, a second activation was observed at 33 dpi. The observed pattern of gene expression in damaged skin suggested the development of inflammation with signs of Th2-like responses. Involvement of T cells in responses to SL was witnessed with up-regulation of CD4, CD8alpha and programmed death ligand 1. Signs of hyporesponsive immune cells were seen. Cellular stress was prevalent in damaged skin as seen by highly significant up-regulation of heat shock proteins, other chaperones and mitochondrial proteins. Induction of the major components of extracellular matrix, TGF-beta and IL-10 was observed only at the adult stage of SL. Taken together with up-regulation of matrix metalloproteinases (MMP), this classifies the wounds afflicted by SL as chronic. Overall, the gene expression changes suggest a combination of chronic stress, impaired healing and immunomodulation. Steady increase of MMP expression in all tissues except liver was a remarkable feature of SL infected fish. SL infection in Atlantic salmon is associated with a rapid induction of mixed inflammatory responses, followed by a period of hyporesponsiveness and delayed healing of injuries. Persistent infection may lead to compromised host immunity and tissue self-destruction.

  3. Epibiotic ciliates Scyphidia sp. and diatoms on Tigriopus fulvus (Copepoda: Harpacticoida exoskeleton

    Directory of Open Access Journals (Sweden)

    Luigi Pane

    2014-12-01

    Full Text Available Several microorganisms – epibionts – can adhere to living supports taking advantage for their survival, feeding and movement. Epibiosis occurs particularly in aquatic environments, on both benthic and planktonic organisms, among which copepods and cladocerans represent an important living support. The harpacticoid copepod Tigriopus fulvus, living in the splashpools of rocky coasts, was studied to recognize the occurrence of epibionts on the exoskeleton surface using scanning electon microscopy techniques. The first evidence of ciliate Scyphidia sp. on Tigriopus fulvus has been described and the occurrence of algae Cocconeis sp. has been observed as well. Epibionts were found to adhere to antennae, a site linked to the exploitation of water currents carrying food particles to mouthparts and to swimming legs. The reason of the occurrence on swimming legs is less clear and needs further observations. Pertinent results are described and discussed and the influence of epibionts on life cycle and behavior of Tigriopus fulvus is considered.

  4. Epidemiology of Pennella sp. (Crustacea: Copepoda, in exploited Illex coindetii stock in the NE Atlantic

    Directory of Open Access Journals (Sweden)

    S. Pascual

    2001-12-01

    Full Text Available The spatio-temporal distribution of the mesoparasitic copepod Pennella sp. on the short-finned squid Illex coindetii was studied monthly during 1993 in the southeastern North Atlantic (Galician waters, NW Spain. A total of 600 individuals were analysed separately considering two areas (north and west with different hydrographical characteristics. Six pennellid stages were found: a copepodite, four chalimus stages and the free-living adult male and female. Epidemiology was assessed using the parasite demographic parameters. The results revealed a marked seasonal pattern in the number of parasites in squid samples from the northern area. This seasonal pattern was not detected in squids from the western area. The observed frequency distributions of parasites on the host population were aggregative at each sampling area. Infection values were extraordinarily high when they are compared with published host-parasite records for other representatives of the genus Pennella. Advantages of the parasite aggregation pattern and possible explanations of the seasonality variations in the number of parasites observed in squid samples from the northern area are discussed.

  5. On two new species of the genus Acanthochondria Oakley (Crustacea Copepoda) found in Japan

    NARCIS (Netherlands)

    Shiino, S.M.

    1964-01-01

    Acanthochondria Oakley is a genus of parasitic copepods, the members of which usually cling to the gills or gill arches of fishes, or to the mucous membrane of their buccal cavity, or to the inner surface of their operculum. Two new species of this genus recently obtained in Japan are described here

  6. @iPseudocyclops lakshmi@@, a new species (Pseudocyclopidae: Calanoidea: Copepoda) from the Laccadives, India

    Digital Repository Service at National Institute of Oceanography (India)

    Haridas, P.; Madhupratap, M.; Ohtsuka, S.

    @iPseudocyclops lakshmi@@, new species, is described from the Kadmat and Agatti atolls of the Laccadives, India, along with its dimorphic males. Characters separating the new species from the rest of its congeners are discussed. This species...

  7. To Swim or Not to Swim: Potential Transmission of Balaenophilus manatorum (Copepoda: Harpacticoida in Marine Turtles.

    Directory of Open Access Journals (Sweden)

    Francesc Domènech

    Full Text Available Species of Balaenophilus are the only harpacticoid copepods that exhibit a widespread, obligate association with vertebrates, i.e., B. unisetus with whales and B. manatorum with marine turtles and manatees. In the western Mediterranean, juveniles of the loggerhead sea turtle, Caretta caretta are the only available hosts for B. manatorum, which has been found occurring at high prevalence (>80% on them. A key question is how these epibionts are transmitted from host to host. We investigated this issue based on experiments with live specimens of B. manatorum that were cultured with turtle skin. Specimens were obtained from head-started hatchlings of C. caretta from the western Mediterranean. Hatched nauplii crawled only on rough substrates and lacked the ability to swim. Only copepodites IV and V, and adults, were able to perform directional swimming. Legs 2, 3 and 4 played a major role in swimming and were only well-developed in these stages. Nauplii reared in wells with turtle skin readily fed on this item. Late copepodites and adults also fed on turtle skin but did not consume other potential food items such as fish skin, baleen plates or planktonic algae. Evidences suggest that the transmission of B. manatorum should rely on hosts' bodily contacts and/or swimming of late developmental stages between spatially close hosts. The possibility of long-ranged dispersal is unlikely for two reasons. First, all developmental stages seem to depend on turtle skin as a food resource. Second, the average clutch size of ovigerous females was small (< 70 eggs for free-living phases to successfully contact turtles that occur at very low densities (< 0.6 turtles·km-2 in the western Mediterranean. The high prevalence of B. manatorum in loggerhead turtles in this area raises the question whether these turtles have contacts, or tend to closely aggregate, more than is currently believed.

  8. Copepoda associated with West Indian Invertebrates – IV The genera Octopicola, Pseudanthessius and Meomicola (Cyclopoida, Lichomolgidae)

    NARCIS (Netherlands)

    Stock, Jan H.; Humes, Arthur G.; Gooding, Richard U.

    1963-01-01

    Our thanks are due to the following for their identifications of host animals: Dr. W. ADAM, Muséum Royal d’Histoire Naturelle, Brussels (cephalopods from Curaçao); Dr. GILBERT L. VOSS, University of Miami Marine Laboratory, Florida (cephalopods from Barbados); Mrs. R. E. TEAGLE, British Museum

  9. Early life history of Neocalanus plumchrus (Calanoida: Copepoda) in the western subarctic Pacific

    Science.gov (United States)

    Fujioka, Hidefumi A.; Machida, Ryuji J.; Tsuda, Atsushi

    2015-09-01

    The life history of copepods during nauplius stages has rarely been studied, because of difficulties in identification. This study describes the development of an identification method that uses integrated microscopic analysis and real-time PCR based method to distinguish and estimate the abundance of pelagic calanoida nauplii, Neocalanus plumchrus, and to determine their phenology and ontogenetic vertical migration (OVM) in the Oyashio region. The overall approach of identification included: classify field samples of calanoida nauplii into six developmental stages by microscopic analysis, determining the Cq values from each representative nauplii by real-time PCR using specie specific probe and primer pair for N. plumchrus, calculating the |ΔCq| values from the standard curve, distinguish N. plumchrus nauplii by the criterion of |ΔCq| ⩽ 2, and calculate the abundance of N. plumchrus nauplii using results obtained from microscopic analysis and real-time PCR. Validation of the method showed that our real-time PCR based approach could identify N. plumchrus nauplii in field samples with as low as 9% of underestimation, the effect of which is negligibly low on the investigation. The results showed that early nauplius stages (first and second nauplius stages: N1 and N2, respectively) were observed during the period from October 2009 to May 2010. Spawning females were also observed during the same period, and these results confirm that the spawning period of N. plumchrus is at least 8 months long. N3 was the most dominant stage in October 2009, January, and March 2010, the distribution depth of N3 was between 500 m and 2000 m in October 2009 and their vertical distribution range was extended until April 2010. Late stages (N4-N6) were rarely observed during the period from October 2009 to March 2010, and they occurred abundantly from the surface layer (0-20 m) in April 2010. The dominance of N3 from October to March and the sudden occurrence of later stages in April indicate arrested development of N3 in the mesopelagic layer.

  10. Copepoda of the family Lamippidae from the western Atlantic and the Caribbean

    NARCIS (Netherlands)

    Stock, Jan H.

    1973-01-01

    The Lamippidae form a rather homogeneous family of copepods endoparasitic on octocorals. The great majority of the species (17 out of 24) is described from the Mediterranean Sea. These species are relatively well-known, thanks to the efforts of DE ZULUETA (1908, 1910, 1911) and BOULIGAND (various

  11. Distribution of @iPleuromamma@@ spp (Copepoda-Calanoida) in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.

    Distribution of common marine copepods of genus @iPleuromamma@@ Giesbrecht was studied. Two species, @iP. indica@@ Wolfenden and @iP. gracilis@@ were present in surface and vertical samples (0-500 m). The former was dominant (98.17%) and @i...

  12. Distribution of some Calanoida (Crustacea: Copepoda from the Yucatán Peninsula, Belize and Guatemala

    Directory of Open Access Journals (Sweden)

    Gerd-Oltmann Brandorff

    2012-03-01

    Full Text Available Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A total of 32 samples with totally six species contained calanoid copepods: one estuarine pseudodiaptomid and five freshwater diaptomids. Pseudodiaptomus marshi was found at different salinities. It is confirmed that the commonest diaptomids in the Yucatan Peninsula are Arctodiaptomus dorsalis and Mastigodiaptomus nesus. The former was also recorded from Lake Amatitlan. Mastigodiaptomus nesus is as widespread as A. dorsalis but it is absent from the Lake Peten area in Guatemala. Mastigodiaptomus reidae was found in two shallow habitats, these specimens differ from those from the type locality by having a set of peculiar large spine-like processes on the last thoracic and the urosome segments of the females. Leptodiaptomus siciloides was found only in Lake Ayarza with high salinity. Prionodiaptomus colombiensis occurred in the highlands of Guatemala in Lago de Güija and in the Peten area in Laguna Sacpuy. We contributed with our occurrence records to a better knowledge of the geographic distribution of some calanoid copepods. Morphological findings in some species are of value for taxonomic differentiation between species.El sur de México y América Central tienen varios cuerpos de agua con diferente morfología, composición química y una interesante fauna de zooplancton procedente de América del Norte o del Sur. Un grupo de 63 muestras, fueron tomadas en 2005 y 2008 para conocer la cantidad de copépodos calanoides en los cuerpos de agua del karst Península de Yucatán, Belice y Guatemala. Se utilizó literatura antigua y reciente para la identificación de los especímenes a nivel de especie y se preparon dibujos con un microscopio y una cámara lúcida. En un total de 32 muestras se obtuvieron seis especies de copépodos calanoides: un pseudodiaptomidos estuarino y cinco diaptomidos de agua dulce. Pseudodiaptomus marshi fue encontrado a diferentes salinidades. Además, se confirmó que los diaptomidos más comunes en la Península de Yucatán fueron: Arctodiaptomus dorsalis y Mastigodiaptomus nesus. El primero se registró también en el lago de Amatitlán. Mastigodiaptomus nesus está ampliamente distribuido al igual que A. dorsalis, pero se encuentra ausente en el área del Lago Petén en Guatemala. Mastigodiaptomus reidae fue localizado en dos hábitats poco profundos, éstos especímenes difieren de los tipos de la localidad, por tener un grupo de espinas de gran tamaño en la última parte de la caja toráxica y los segmentos del urosoma de las hembras. Leptodiaptomus siciloides se encontró sólo en el Lago Ayarza, el cual contiene alta salinidad. Prionodiaptomus colombiensis se localizó en las tierras altas de Guatemala en el Lago de Güija y en la zona del Petén en Laguna Sacpuy. Se contribuye con registros de presencia de especies para un mejor conocimiento de la distribución geográfica de algunos copépodos calanoides. De la misma forma, los hallazgos morfológicos en algunas especies son de gran valor taxonómico para la diferenciación de especies.

  13. Three new species of Bomolochidae (Copepoda, Cyclopoida) from Tropical Atlantic Tunnies

    NARCIS (Netherlands)

    Vervoort, W.

    1965-01-01

    Dr. J. F. Aldrin, Sous Direction de Pêche, Abidjan, Côte d'Ivoire, during an extensive survey of tropical Atlantic Tunnies, discovered the presence of Cyclopoid Copepods of the family Bomolochidae in the nasal fossae of three species of tunnies, viz., Euthynnus alleteratus (Rafinesque), Auxis

  14. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda

    Directory of Open Access Journals (Sweden)

    Patricio De los Ríos Escalante

    2012-12-01

    Full Text Available Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902, which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. gracilipes collected in Riñihue lakes, with a third population of B. gracilipes collected in shallow ponds in Salar de Surire. Titicaca and Riñihue lakes are stable environments, whereas Salar de Surire is an extreme environment. These ponds present an extreme environment due to high exposure to solar radiation and high salinity levels. The results of the study revealed differences among the three populations. These results agree well with systematic descriptions in the literature on differences between the populations of Titicaca and Riñihue lakes, and population of Salar de Surire differs slightly from the other two populations. It is probable that the differences between the population of Salar de Surire and the other two populations result from the extreme environment in Salar de Surire. High exposure to solar radiation, high salinity and extreme variations in temperature enhance genetic variations that are consequently expressed in morphology.

  15. Copepoda (Siphonostomatoida) associated with Ophiuroidea in Jamaica, Puerto Rico, and Barbados

    NARCIS (Netherlands)

    Humes, A.G.

    1998-01-01

    Three new siphonostomatoid copepods are associated with Ophiuroidea in the tropical western Atlantic. Collocheres vervoorti spec. nov., from Ophiothrix angulata in Jamaica, has an elongate, gently tapered genital double-somite in the female and the second segment of leg 5 has a distal outer notch.

  16. Two new species of Harpacticoid Copepods (Copepoda, Harpacticoida, Canthocamptidae) from Montenegro (Balkan Peninsula)

    NARCIS (Netherlands)

    Karanovic, Tomislav

    1997-01-01

    In the present paper two new species of harpacticoid copepods (family Canthocamptidae) are described from several subterranean localities in Montenegro, Crmnica region. Moraria jana n.sp. is most similar to M. catalana Chappuis & Kiefer, 1952. It is also alike M. brevipes (Sars, 1863). Elaphoidella

  17. Cyclopidae (Crustacea, Copepoda) from the upper Paraná River floodplain, Brazil.

    Science.gov (United States)

    Lansac-Tôha, F A; Velho, L F M; Higuti, J; Takahashi, E M

    2002-02-01

    Cyclopid copepods from samples of fauna associated with aquatic macrophytes and plancton obtained in lotic and lentic environments were obtained from the upper Paraná River floodplain (in the states of Paraná and Mato Grosso do Sul, Brazil). Macrophytes were collected in homogeneous stands and washed. Plankton samples, taken from the water column surface and bottom, were obtained using a motor pump, with a 70 microns mesh plankton net for filtration. Twelve taxa of Cyclopidae were identified. Among them, Macrocyclops albidus albidus, Paracyclops chiltoni, Ectocyclops rubescens, Homocyclops ater, Eucyclops solitarius, Mesocyclops longisetus curvatus, Mesocyclops ogunnus, and Microcyclops finitimus were new finds for this floodplain. Eight species were recorded exclusively in aquatic macrophyte samples. Among these species, M. albidus albidus and M. finitimus presented greatest abundances. Only four species were recorded in plankton samples, and Thermocyclops minutus and Thermocyclops decipiens are limited to this type of habitat. Among these four species, T. minutus is the most abundant, especially in lentic habitats.

  18. Cyclopidae (Crustacea, Copepoda from the upper Paraná River floodplain, Brazil

    Directory of Open Access Journals (Sweden)

    F. A. LANSAC-TÔHA

    Full Text Available Cyclopid copepods from samples of fauna associated with aquatic macrophytes and plancton obtained in lotic and lentic environments were obtained from the upper Paraná River floodplain (in the states of Paraná and Mato Grosso do Sul, Brazil. Macrophytes were collected in homogeneous stands and washed. Plankton samples, taken from the water column surface and bottom, were obtained using a motor pump, with a 70 mum mesh plankton net for filtration. Twelve taxa of Cyclopidae were identified. Among them, Macrocyclops albidus albidus, Paracyclops chiltoni, Ectocyclops rubescens, Homocyclops ater, Eucyclops solitarius, Mesocyclops longisetus curvatus, Mesocyclops ogunnus, and Microcyclops finitimus were new finds for this floodplain. Eight species were recorded exclusively in aquatic macrophyte samples. Among these species, M. albidus albidus and M. finitimus presented greatest abundances. Only four species were recorded in plankton samples, and Thermocyclops minutus and Thermocyclops decipiens are limited to this type of habitat. Among these four species, T. minutus is the most abundant, especially in lentic habitats.

  19. A new species of Metacyclops Kiefer, 1927 (Copepoda, Cyclopidae, Cyclopinae) from the Chihuahuan desert, northern Mexico

    Science.gov (United States)

    Mercado-Salas, Nancy F.; Suárez-Morales, Eduardo; Maeda-Martínez, Alejandro M.; Silva-Briano, Marcelo

    2013-01-01

    Abstract A new species of the freshwater cyclopoid copepod genus Metacyclops Kiefer, 1927 is described from a single pond in northern Mexico, within the binational area known as the Chihuahuan Desert. This species belongs to a group of Metacyclops species with a 3443 spine formula of swimming legs. It is morphologically similar to Metacyclops lusitanus Lindberg, 1961 but differs from this and other congeners by having a unique combination of characters, including a caudal rami length/width proportion of 3.5–3.8, a innermost terminal seta slightly longer than the outermost terminal seta, intercoxal sclerites of legs 1-4 naked, a strong apical spine of the second endopodal segment of leg 1 and one row of 6-8 small spinules at the insertion of this spine. The finding of this species represents also the first record of the genus in Mexico and the third in North America, where only two other species, Metacyclops gracilis (Lilljeborg, 1853)and Metacyclops cushae Reid, 1991 have been hitherto reported. This is also the first continental record of a species of Metacyclops from an arid environment in the Americas. This species appears to be endemic to the Chihuahuan Desert, thus emphasizing the high endemicity of this area. PMID:23794845

  20. Redescription of Pseudodiaptomus jonesi (Copepoda: Calanoida) with notes on its distribution

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Haridas, P.

    Pseudodiaptomus jonesi Pillai 1970 is redescribed; several previously undescribed features are included and a few errors in the original description corrected. This species is assignable to the Ramosus group and Hickmani-subgroup. The present record...

  1. Mating behaviour of Pseudodiaptomus annandalei (Copepoda Calanoida) with emphasis on rejection rate

    Science.gov (United States)

    Dur, G.; Souissi, S.; Schmitt, F. G.; Hwang, J. S.; Cheng, S. H.

    2009-04-01

    Mating behaviour has important consequences at both individual and population levels. Reproductive fitness is of paramount importance to sustain the success of planktonic copepod populations in aquatic environments. The calanoid copepod Pseudodiaptomus annandalei has one of the largest geographical ranges for Indo-Pacific Pseudodiaptomidae. It is also of great importance in fish culture pounds south of Taiwan. However, the mating behavior of this species has never been studied. Mating and predatory behaviour are conceptually the same. In both cases, the encounter and the interactions occur between two individuals with opposite characteristics: predator-prey for predation; male-female for mating. The mating behaviour may be defined as a sequence of encounter, pursuit, capture and copulation. Several observed behaviour suggest that both sexes asses and choose among available mates before the copulation. Pre-copulatory mate choice in copepods may manifest as mate guarding where males attached to CV females until their final moult, complicated pre-copulatory dance and escaping. During our preliminary observations, we notice that P. annandalei females escape by shaking, often violently, the males that have caught them. Consequently for such a species the act of mating may be visualized as a chain of six events (i.e. search, encounter, pursuit, capture, selective dance, copulation).Within this chain, encounter, capture and copulation are conditional events depending on the successful conclusion of their preceding events in the chain. In this study, we examined the different step in the mating behaviour of the scarcely studied sub-tropical copepod, Pseudodiaptomus annandalei, collected from the Danshuei estuary (North Taiwan). The individuals were observed using a 3D optical system to obtain simultaneous front and side views. Males, when placed in the water where females had previously swum in, showed significant increase of their swimming velocities. Additionally, their swimming trajectories are more convoluted, indicating that males explore larger volume of fluid to increase the probability to encounter a female. The mate finding behaviour appears to depend not only on chemical signal but also on hydromechanical signals. Some males exhibited shifts of direction when females were passing by. When male intercepted a chemical trail left by a female, they initiate tracking behaviour racing up the trail with increasing speed. Males pursued pheromone trails up to 24 sec old and 10 mm long. Most studies of mating behaviour have focused on detection and sometimes pursuit, but few have addressed the other components of successful mating, namely, capture and copulation. Moreover, mate choice issue has largely been ignored in regards to pelagic copepods. Consequently very few are known about the plasticity of rejection rates as a function of mate encounter rates. The second aim of this experiment is to describe the process used by female to select their mate and to fill the gap in the quantification of mating success. Once caught by a male, P. annandalei's females entered in intensive dance which sometimes lead to shake off the males suggesting a female mate choice. The three-dimensional trajectories described by the couple during this event were characterized by fast loops and intense jumps. Individual's access to mates may be affected by operational sex ratios, causing strong variation in mating success. We finally manipulated adult sex ratios of the brackish copepod P. annandalei, to examine the influence of population sex ratio on mating success of P. annandalei in a final set of experiment concluding the investigation. It should be notice that, to our knowledge, it the first quantification ever done before. The plasticity of rejection rate was therefore investigated as a function of sex-ratio and mate encounter rate. The encounter rate reached maximum value for balanced proportion of male and female and decreased as the sex ratio unbalanced. Higher value of success was nevertheless observed for a pro-male sex-ratio.

  2. A new species of Acartia (Copepoda, Calanoida) from Cochin Harbour, India, and adjacent areas

    Digital Repository Service at National Institute of Oceanography (India)

    Abraham, S.

    During the course of a study of the family Acartiidae of Cochin harbour and its neighbourhood, a species of Acartia different from all other known species of Acartia, was found. Its characteristics, habitat and seasonal distribution form the theme...

  3. Distribution of some Calanoida (Crustacea: Copepoda) from the Yucatán Peninsula, Belize and Guatemala

    OpenAIRE

    Gerd-Oltmann Brandorff

    2012-01-01

    Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A total of...

  4. Distribution of some Calanoida (Crustacea: Copepoda) from the Yucatán Peninsula, Belize and Guatemala

    OpenAIRE

    Brandorff,Gerd-Oltmann

    2012-01-01

    Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A tota...

  5. Two new species of the genus Emertonia Wilson, 1932 from Korean waters (Copepoda, Harpacticoida, Paramesochridae)

    Science.gov (United States)

    Back, Jinwook; Lee, Wonchoel

    2017-01-01

    Abstract Two new species of the genus Emertonia were found from the west coast of Korea. The first new species, E. koreana sp. n., is closely related to E. acutifurcata. However, the new species is clearly distinguished by the presence of two modified pinnate setae on the P5 baseoendopodal lobe. All body somites of the new species except for the last two urosomites have strongly developed hyaline frills forming quadrilateral lappets. The second new species, E. simplex sp. n., superficially resembles E. mielkei in the structure of antennary exopod (with five setae), and the shape of P5. However, this new species differs from its congener mainly by having a caudal ramus 3.5 times as long as width, and P1 enp-2 with two claw-like setae. In addition, a key to the worldwide species of Emertonia is provided. PMID:29290714

  6. Molecular phylogeny of Oncaeidae (Copepoda using nuclear ribosomal internal transcribed spacer (ITS rDNA.

    Directory of Open Access Journals (Sweden)

    Iole Di Capua

    Full Text Available Copepods belonging to the Oncaeidae family are commonly and abundantly found in marine zooplankton. In the Mediterranean Sea, forty-seven oncaeid species occur, of which eleven in the Gulf of Naples. In this Gulf, several Oncaea species were morphologically analysed and described at the end of the XIX century by W. Giesbrecht. In the same area, oncaeids are being investigated over seasonal and inter-annual scales at the long-term coastal station LTER-MC. In the present work, we identified six oncaeid species using the nuclear ribosomal internal transcribed spacers (ITS rDNA and the mitochondrial cytochrome c oxidase subunit I (mtCOI. Phylogenetic analyses based on these two genomic regions validated the sisterhood of the genera Triconia and the Oncaea sensu stricto. ITS1 and ITS2 phylogenies produced incongruent results about the position of Oncaea curta, calling for further investigations on this species. We also characterised the ITS2 region by secondary structure predictions and found that all the sequences analysed presented the distinct eukaryotic hallmarks. A Compensatory Base Change search corroborated the close relationship between O. venusta and O. curta and between O. media and O. venusta already identified by ITS phylogenies. The present results, which stem from the integration of molecular and morphological taxonomy, represent an encouraging step towards an improved knowledge of copepod biodiversity: The two complementary approaches, when applied to long-term copepod monitoring, will also help to better understanding their genetic variations and ecological niches of co-occurring species.

  7. On Collocheres Canu, 1893, and Leptomyzon Sars, 1915, two synonymous genera of Copepoda

    NARCIS (Netherlands)

    Stock, Jan H.

    1966-01-01

    Deux espèces nouvelles du genre Collocheres, C. breei (Méditerranée occidentale, hôte Ophioderma longicauda) et C. uncinatus (Golfe d’Aqaba, hôtes Heterometra savignyi et Oligometra serripinna) ont été décrites. Certains caractères de ces nouvelles espèces, et une étude critique des espèces déjà

  8. Distribution of Pleuromamma (Copepoda: Metridiidae) along a north-south transect in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, S.C.; Gajbhiye, S.N.; Padmavati, G.

    abundant in the upper 200 m. The adults were more at deeper depths. The vertical segregation among co-occurring species was observed in the zooplankton collections taken during day. However, there was considerable overlap at night. Sexual segregation...

  9. Selective feeding of Eurytemora affinis (Copepoda, Calanoida) in temperate estuaries: model and field observations

    NARCIS (Netherlands)

    Tackx, M.L.M.; Herman, P.M.J.; Gasparini, S.; Irigoien, X.; Billionesa, R.; Daroa, M.H.

    2003-01-01

    The copepod Eurytemora affinis generally lives under estuarine conditions, where the suspended particulate matter (SPM) is strongly dominated by non-living particles. This article investigates as to how far E. affinis is capable of feeding selectively on phytoplankton under these extreme

  10. Marine Flora and Fauna of the Northeastern United States. Copepoda: Lernaeopodidae and Sphyriidae.

    Science.gov (United States)

    Ho, Ju-Shey

    This report is part of a sub-series to aid biology students, biologists, biological oceanographers, and informed laymen in the identification and study of marine flora and fauna of the Northeastern United States. Contents of this report include: (1) Introduction; (2) Glossary; (3) Key to the marine lernaeopodoid copepods of the Northeastern United…

  11. Bathymetric distribution of Pleuromamma (Copepoda, Calanoida) species in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.

    Based on the analysis of 204 zooplankton samples from the stratified depths in the Indian Ocean collected during the International Indian Ocean Expedition (IIOE), the distribution of the genus Pleuromamma indica, P. gracilis, P. piseki, P...

  12. Ecology of Pleuromamma indica Wolfenden (Copepoda - Calanoida) in the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswathy, M.; Iyer, H.K.

    Pleuromamma indica was the only species among the 7 species of the genus, recorded in the area, to be present in 2 restricted areas, one near the mouth of the Gulf of Oman in the Arabian Sea and the other in the Bay of Bengal. High productivity...

  13. Pseudocyclops lakshmi, a new species (Pseudocyclopidae: Calanoidea: Copepoda) from the Laccadives, India

    Digital Repository Service at National Institute of Oceanography (India)

    Haridas, P.; Madhupratap, M.; Ohtsuka, S.

    stream_size 13 stream_content_type text/plain stream_name Proc_Biol_Soc_Wash_1994_107_151.pdf.txt stream_source_info Proc_Biol_Soc_Wash_1994_107_151.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  14. A new species of Mesocyclops (Copepoda, Cyclopoida, Cyclopidae from Southeastern Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo SUÁREZ-MORALES

    2001-08-01

    Full Text Available The taxonomical status of several neotropical species of Mesocyclops is still uncertain. Furthermore, several new species with a restricted distributional range have been described recently in this region. From littoral zooplankton samples collected in the lowlands of the State of Tabasco, Southeastern Mexico, male and female specimens of a previously unknown species of Mesocyclops were found. This new species is described herein based on both sexes and following the upgraded standards set for the taxonomic study of this genus, including SEM analysis. The new species differs from its congeners by a combination of several characters: the unique shape of the antennular hyaline membrane, the ornamentation of both maxillule and maxilla, the ornamentation of the fourth swimming leg, the shape and structure of the genital receptacle, and the ornamentation of the furcal rami. It is most closely related to other neotropical species such as M. meridianus Kiefer, 1926 and M. pseudomeridianus Defaye & Dussart, 1989. This is the eleventh species of Mesocyclops known from Mexico, and also the third new species described upon Mexican material. Due to the affinity of the Tabasco fauna with the Caribbean and the South American copepod faunas, the new species is expected to have a relatively wide geographical distribution in the neotropical region.

  15. Copepoda associated with West Indian Invertebrates – III The Genus Anthessius (Cyclopoida, Myicolidae)

    NARCIS (Netherlands)

    Stock, Jan H.; Humes, Arthur G.; Gooding, Richard U.

    1963-01-01

    For the identification of certain of the mollusks with which the copepods to be described were associated we wish to thank Dr. RUTH D. TURNER, Museum of Comparative Zoölogy, Harvard College, Cambridge, and Mr. C. J. VAN EEKEN, Zoölogisch Museum, Amsterdam. We also express our appreciation to Mr. J.

  16. A new species of Peltidium Philippi, 1839 (Crustacea, Copepoda, Harpacticoida from the Pacific coast of Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Suarez-Morales

    2013-08-01

    Full Text Available During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, P. nayarit sp. n. is described herein. It resembles P. nichollsi Geddes and P. lerneri Geddes from Bahamas but also the widespread P. speciosum Thompson & Scott and P. purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific.

  17. A new species of Peltidium Philippi, 1839 (Crustacea, Copepoda, Harpacticoida) from the Pacific coast of Mexico

    Science.gov (United States)

    Suárez-Morales, Eduardo; Jarquín-González, Jani

    2013-01-01

    Abstract During the analysis of phytal meiobenthic samples collected from a rocky-sandy beach in the state of Nayarit, in the Mexican Pacific, several specimens of harpacticoid copepods were obtained and taxonomically examined. These specimens were found to represent an undescribed species of the peltidiid genus Peltidium Philippi, 1839. The new species, Peltidium nayarit sp. n. is described herein. It resembles Peltidium nichollsi Geddes and Peltidium lerneri Geddes from Bahamas but also the widespread Peltidium speciosum Thompson & Scott and Peltidium purpureum Philippi. The new species from the Mexican Pacific differs from its known congeners by its possession of a unique combination of characters, including a modified pectinate seta on the antennary exopod, three terminal setae on the second endopodal segment of leg 1, third exopodal segment of leg 1 with three elements, inner terminal claw twice as long as outer claw, female fifth leg with 5 exopodal setae, exopodal setae I-III stout, spinulose and seta IV being as long as seta V. This is the second species of the family known to be distributed in the Eastern Tropical Pacific and in Mexico. Pending additional data, the distribution of this species appears to be restricted to this area of the Mexican Pacific. PMID:24003319

  18. Cyclopidae (Crustacea, Copepoda from the upper Paraná River floodplain, Brazil

    Directory of Open Access Journals (Sweden)

    LANSAC-TÔHA F. A.

    2002-01-01

    Full Text Available Cyclopid copepods from samples of fauna associated with aquatic macrophytes and plancton obtained in lotic and lentic environments were obtained from the upper Paraná River floodplain (in the states of Paraná and Mato Grosso do Sul, Brazil. Macrophytes were collected in homogeneous stands and washed. Plankton samples, taken from the water column surface and bottom, were obtained using a motor pump, with a 70 mum mesh plankton net for filtration. Twelve taxa of Cyclopidae were identified. Among them, Macrocyclops albidus albidus, Paracyclops chiltoni, Ectocyclops rubescens, Homocyclops ater, Eucyclops solitarius, Mesocyclops longisetus curvatus, Mesocyclops ogunnus, and Microcyclops finitimus were new finds for this floodplain. Eight species were recorded exclusively in aquatic macrophyte samples. Among these species, M. albidus albidus and M. finitimus presented greatest abundances. Only four species were recorded in plankton samples, and Thermocyclops minutus and Thermocyclops decipiens are limited to this type of habitat. Among these four species, T. minutus is the most abundant, especially in lentic habitats.

  19. Two (cosoccurring new Karllangia species (Copepoda: Ameiridae) from the Caribbean mast of Costa Rica

    OpenAIRE

    Mielke, Wolfgang

    2016-01-01

    Se halló dos especies nuevas de copépodos del género Karllangia coexistiendo en playa Manzanillo,' costa caribeña de Costa Rica Se halló dos especies nuevas de copépodos del género Karllangia coexistiendo en playa Manzanillo,' costa caribeña de Costa Rica

  20. Resting eggs of zooplankton (copepoda and cladocera) from the Kiel Bay and adjacent waters (southwestern Baltic)

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Nehring, S.; Lenz, J.

    stream_size 11 stream_content_type text/plain stream_name Mar_Biol_125_77.pdf.txt stream_source_info Mar_Biol_125_77.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  1. Identification of the molecular components of a Tigriopus californicus (Crustacea, Copepoda) circadian clock.

    Science.gov (United States)

    Nesbit, Katherine T; Christie, Andrew E

    2014-12-01

    Copepods of the genus Tigriopus have been proposed as marine models for investigations of environmental perturbation. One rapidly increasing anthropogenic stressor for intertidal organisms is light pollution. Given the sensitivity of circadian rhythms to exogenous light, the genes/proteins of a Tigriopus circadian pacemaker represent a potential system for investigating the influences of artificial light sources on circadian behavior in an intertidal species. Here, the molecular components of a putative Tigriopus californicus circadian clock were identified using publicly accessible transcriptome data; the recently deduced circadian proteins of the copepod Calanus finmarchicus were used as a reference. Transcripts encoding homologs of all commonly recognized ancestral arthropod core clock proteins were identified (i.e. CLOCK, CRYPTOCHROME 2, CYCLE, PERIOD and TIMELESS), as were ones encoding proteins likely to modulate the core clock (i.e. CASEIN KINASE II, CLOCKWORK ORANGE, DOUBLETIME, PROTEIN PHOSPHATASE 1, PROTEIN PHOSPHATASE 2A, SHAGGY, SUPERNUMERARY LIMBS and VRILLE) or to act as inputs to it (i.e. CRYPTOCHROME 1). PAR DOMAIN PROTEIN 1 was the only circadian-associated protein not identified in Tigriopus; it appears absent in Calanus too. These data represent just the third full set of molecular components for a crustacean circadian pacemaker (Daphnia pulex and C. finmarchicus previously), and only the second obtained from transcribed sequences (C. finmarchicus previously). Given Tigriopus' proposed status as a model for investigating the influences of anthropogenic stressors in the marine environment, these data provide the first suite of gene/protein targets for understanding how light pollution may influence circadian physiology and behavior in an intertidal organism. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Effects of seven diets on the population dynamics of laboratory cultured Tisbe holothuriae Humes (Copepoda, Harpacticoida)

    Science.gov (United States)

    Miliou, H.; Moraïtou-Apostolopoulou, M.

    1991-09-01

    The harpacticoid copepod Tisbe holothuriae was collected from Saronicos Gulf (Greece) and reared under constant laboratory conditions. In order to study the effects of food on the population dynamics, seven diets were tested: the seaweed Ulva; five artificial compound feeds: the liquid Fryfood® (Waterlife), a powder of Mytilus, yeast, soya and Spirulina, respectively; and a mixed diet consisting of Ulva and Fryfood. The life cycle parameters (mortality, sex ratio, generation time, offspring production) were measured, and the demographic variables [mean generation time (T), net reproductive rate (Ro), and intrinsic rate of natural increase (rm)] were determined. As to their efficiency regarding population dynamics, the diets ranked as follows: (1) Ulva+Fryfood, (2), Ulva, (3) Fryfood, (4) Mytilus, (5) soya, (6) yeast, and (7) Spirulina. In this order they cause a progressive increase of both larval mortality and generation time, a progressive decrease of sex ratio, number of offspring per egg sac, number of egg sacs per female and, consequently, of Ro and rm. The observed differences between diets were most pronounced with respect to offspring production. Of the compound diets, those containing animal extracts were more efficient than those containing vegetable materials. Ulva plays an important role in the nutrition of T. holothuriae, favouring offspring production as well as larval survival, development and pigmentation. Ulva in combination with Fryfood led to a greater copepodid survival and offspring production. This mixed diet proved to be the most favourable for rearing the Greek population of t. holothuriae, resulting in an efficient intrinsic rate of natural increase (rm=0.304) of the population.

  3. Differences in behavioral responses of Eurytemora affinis (Copepoda, Calanoida) adults to salinity variations

    OpenAIRE

    Michalec, François Gaël; Souissi, Sami; Dur, Gaël; Mahjoub, Mohamed Sofiene; Schmitt, François G; Hwang, Jiang-Shiou

    2010-01-01

    Abstract Estuarine copepods undergo strong and frequent salinity variations caused by alternating tides. Salinity is known to be a major parameter in the ecology of copepods from brackish waters but its effects on small scale behavior are relatively unclear. In this study we used 2-dimensional laboratory filming techniques to record swimming paths of the three reproductive stages (i.e. male, non-ovigerous female and ovigerous female) of E. affinis from the Seine estuary, under diff...

  4. Ultrastructural Evidence of Lumnescent glad openings in Metridia gerlachei giesbrecht, 1902 (Copepoda: Clanoida

    Directory of Open Access Journals (Sweden)

    P. Romano

    2009-01-01

    Full Text Available The luminescence is a feature of several marine planktonic organisms, such as bacteria, algae, cnidaria, ctenophores, crustaceans and pyrosomes, in particular, alot of pelagic crustaces have got luminescent organs (Ghirendelli, 1981, Gruner, 1994 useful for trophic, reproductive or defense purposes. Several calanoid copepods are luminescent and possess variously distribuited epidermal glands. In this paper the occurrence of luminescent gland openings in adults and copepodids of Metridia gerlachei sampled during the Italian Oceanographic Campaign in Antarctica 1987-88 in Terra Nova Bay (Ross Sea is described by using scanning electron microscopy (SEM techniques. The openings of cephalothorax luminescent gland has been observed and described with the aim to complete what is known about this subject (Pinero de Verdinelli, 1981, the occurrence of a gland opening, not previously described, has been reported. Considering the extreme characteristics of the environment also that this species seems to prefer to live in low-light waters (Crli et al., 1990, 1992a as the constant light conditions during the Antarctic summer restrict its occurrence in surface waters, luminescent structures could have an adaptive significance both for reproduction and defence.

  5. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda)

    OpenAIRE

    Patricio de los Ríos Escalante

    2012-01-01

    Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902), which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S) and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. graci...

  6. Parabrachiella jarai sp. nov. (Crustacea: Copepoda: Siphonostomatoida) parasitic on Sillago sihama (Actinopterygii: Perciformes: Sillaginidae).

    Science.gov (United States)

    Piasecki, Wojciech; Młynarczyk, Magdalena; Hayward, Craig J

    2010-05-01

    The presently reported study provides a detailed morphological description of the female and the male of a new species of the genus Parabrachiella-Parabrachiella jarai sp. nov. The parasites were sampled from marine fish, silver sillago, Sillago sihama (Perciformes: Sillaginidae), captured in Malaysia in 1994 and Hong Kong in 1995. The new species bears some resemblance to Parabrachiella lata (Song et Chen, 1976) but differs from it in details of second antenna, mandible, and maxilliped. The genus Parabrachiella currently covers 67 species including those recently transferred from Neobrachiella Kabata, 1979. An amended generic diagnosis is proposed for Parabrachiella and Thysanote. Some members of Parabrachiella are herewith transferred to Thysanote and some Thysanote are now placed in Parabrachiella. Copyright 2009 Elsevier Inc. All rights reserved.

  7. A new species of Euchirella (fam. Aetideidae) from the "Dana"-collections (Copepoda, Calanoida)

    NARCIS (Netherlands)

    Vaupel-Klein, von J.C.

    1980-01-01

    SUMMARY Euchirella paulinae spec. nov. is described and illustrated in extenso ; various structures are outlined in detail for the first time. The external morphology of the new species is discussed with reference to the other species of the genus. Some brief remarks are made about the anatomical

  8. On Scambicornus Heegard, 1944, a senior synonym of Preherrmannella Seymour Sewell, 1949 (Copepoda, Cyclopoida)

    NARCIS (Netherlands)

    Stock, J.H.

    1964-01-01

    During the preparation of a report dealing with poecilostomes associated with holothurians, it was found desirable to obtain more information concerning a number of genera formerly described. Through the courtesy of Dr. T.Wolff of the Zoologisk Museum of Copenhagen, I was able to reexamine the

  9. Vertical distribution, feeding and vulnerability to tactile predation in Metridia longa (Copepoda, Calanoida)

    KAUST Repository

    Vestheim, Hege

    2013-12-01

    We assessed the vertical distribution and feeding of the calanoid copepod Metridia longa in the Oslofjord, Norway during winter and spring 2006. Adult females of Metridia longa inhabited the whole 200 m deep-water column. Their distribution was shallower at night than during the day. Enumeration of egested faecal pellets suggested that feeding activity was greater at night than during the day and that more pellets were produced by individuals collected at shallow depths vs. by individuals found deeper. There was no pronounced difference between months in feeding activity. Although the hypothesis is that they prey on Calanus eggs and nauplii, scanning of Metridia faecal pellets by PCR using Calanus-specific primers did not confirm the presence of any Calanus prey DNA. Most pellets had a greenish colour, implying herbivorous feeding. Feeding is related to swimming, and the actively swimming Metridia would presumably be vulnerable to tactile invertebrate predators. However, predation experiments where the carnivorous copepod Pareuchaeta norvegica was offered similar-sized Metridia and Calanus proved that Pareuchaeta consumed the less-active Calanus, but not the Metridia. © 2013 Copyright Taylor and Francis Group, LLC.

  10. Effect of diurnal temperature difference on lipid accumulation and development in Calanus sinicus (Copepoda: Calanoida)

    Science.gov (United States)

    Zhou, Konglin; Sun, Song

    2017-07-01

    Calanus sinicus, the dominant copepod in the Yellow Sea, develops a large oil sac in late spring to prepare for over-summering in the Yellow Sea Cold Water Mass (YSCWM). The lipid accumulation mechanism for the initiation of over-summering is unknown. Here, we cultured C3 copepodites at four constant temperatures (10, 13, 16, and 19°C) and at three temperature regimes that mimicked the temperature variations experienced during diurnal vertical migration (10-13°C, 10-16°C, and 10-19°C) for 18 days to explore the effects of temperature differences on copepod development and lipid accumulation. C. sinicus stored more lipid at low than at high temperatures. A diurnal temperature difference (10-16°C and 10-19°C) promoted greater lipid accumulation (1.9-2.1 times) than a constant temperature of either 16°C or 19°C, by reducing the energy cost at colder temperatures and lengthening copepodite development. Thereafter, the lipid reserve supported gonad development after final molting. Only one male developed in these experiments. This highly female-skewed sex ratio may have been the result of the monotonous microalgae diet fed to the copepodites. This study provides the first evidence that diurnal temperature differences may promote lipid accumulation in C. sinicus, and provides a foundation for future investigations into the mechanisms involved in over-summering in the YSCWM.

  11. Distribution of eurytemora affinis (copepoda: calanoida) in relation to salinity: Field and laboratory observations

    DEFF Research Database (Denmark)

    Von Vaupel-Klein, J.C.; Weber, Roy E.

    1975-01-01

    The occurrence of the euryhaline copepod Eurytemora affinis in relation to salinity is investigated in the western Wadden Sea which shows salinities increasing from east (where E. affinis-loaden fresh water from the IJsselmeer is sluiced) to west (where Wadden Sea water admixes with saline North...... Sea water). Population densities in excess of those in the IJsselmeer show that E. affinis maintains a complete and reproductive population in the Wadden Sea below about 22.5% S at which its numbers decrease precipitously. The finding that E. affinis extends to higher salinities at low compared...... to high temperature correlates with a longer survival demonstrated by tolerance experiments under the former conditions. Laboratory experiments demonstrate that the upper salinity tolerance limit varies in parallel with the salinity to which E. affinis is preaclimated. Accllimation tolerance experiments...

  12. Tychidion guyanense n. gen., n. sp. (Copepoda, Cyclopoida) associated with an annelid off Guyana

    NARCIS (Netherlands)

    Humes, A.G.

    1973-01-01

    In his original description of the worm Lamellibrachia barhami, found in a depth of 1125 m in the northeastern Pacific, Webb (1969: 31) mentioned "as yet unidentified copepods which live in quite large numbers in interlamellar pockets in the tentacular crown". Webb regarded the worm host as a

  13. Eight new species of ascidicolous copepods from the eastern coast of Korea (Crustacea, Copepoda, Cyclopoida)

    Science.gov (United States)

    Kim, Il-Hoi; Moon, Seong Yong

    2011-03-01

    Eight new species of copepods associated with shallow-water ascidians are described from the eastern coast of Korea. They are Ascidicola secundus n. sp. from a Pyura sp., Enteropsis nudus n. sp. from Pyura sacciformis (Drasche), Mycophilus capillatus n. sp. from a compound ascidian, Bonnierilla yangpoensis n. sp. from Phallusia cf. nigra Savigny, Janstockia truncata n. sp. from Chelyosoma siboja Oka, Pholeterides pilosa n. sp. from a compound ascidian, Pachypygus spinosus n. sp. from a solitary ascidian, and Paranotodelphys unguifer n. sp. from Ascidia samea Oka.

  14. Distribution of some Calanoida (Crustacea: Copepoda from the Yucatán Peninsula, Belize and Guatemala

    Directory of Open Access Journals (Sweden)

    Gerd-Oltmann Brandorff

    2012-03-01

    Full Text Available Southern Mexico and Central America have many water bodies of different morphology and water chemistry with an interesting zooplankton fauna, originating from North or South America. A set of 63 samples, taken in 2005 and 2008, from water bodies of the Yucatan Peninsula karst, Belize and Guatemala, were studied for the content of calanoid copepods. Old and recent literature was used to determine animals to species level. Drawings were prepared with a microscope and a camera lucida. A total of 32 samples with totally six species contained calanoid copepods: one estuarine pseudodiaptomid and five freshwater diaptomids. Pseudodiaptomus marshi was found at different salinities. It is confirmed that the commonest diaptomids in the Yucatan Peninsula are Arctodiaptomus dorsalis and Mastigodiaptomus nesus. The former was also recorded from Lake Amatitlan. Mastigodiaptomus nesus is as widespread as A. dorsalis but it is absent from the Lake Peten area in Guatemala. Mastigodiaptomus reidae was found in two shallow habitats, these specimens differ from those from the type locality by having a set of peculiar large spine-like processes on the last thoracic and the urosome segments of the females. Leptodiaptomus siciloides was found only in Lake Ayarza with high salinity. Prionodiaptomus colombiensis occurred in the highlands of Guatemala in Lago de Güija and in the Peten area in Laguna Sacpuy. We contributed with our occurrence records to a better knowledge of the geographic distribution of some calanoid copepods. Morphological findings in some species are of value for taxonomic differentiation between species.

  15. Asi Nehri (Hatay, Türkiye Cladocera ve Copepoda (Crustacea Faunası.

    Directory of Open Access Journals (Sweden)

    Münir Ziya Lugal Göksu

    2015-12-01

    Full Text Available Bu araştırmada, Doğu Akdeniz Bölgesinin önemli bir akarsuyu olan Asi Nehri’nin, Hatay (Türkiye sınırları içinde kalan bölümündeki Kopepoda ve Kladosera (Crustacea faunası, 1 yıl süreyle (1996 Eylül - 1997 Ağustos kalitatif yönden incelenmiştir. Örnekler, çalışma alanındaki 5 istasyondan aylık dönemlerde, göz açıklığı 60 µm olan plankton kepçesi ile toplanmış ve %4’lük formaldehit ile korunmuştur. Araştırmada, Kladosera grubuna dahil 15 tür ve Kopepoda grubuna dahil 7 tür olmak üzere, toplam 22 tür tanımlanmıştır. Kladosera grubundan Bosmina longirostris (O.F.Muller, 1785 yılın büyük bölümünde; Kopepoda grubundan Nitocra hibernica (Brady, 1880 12 ay süresince ve Cyclops vicinus Uljanıne, 1975 türü ise 11 ay boyunca gözlenmiştir

  16. First record of the Asian diaptomid Neodiaptomus schmackeri (Poppe & Richard, 1892 (Crustacea: Copepoda: Calanoida in Europe

    Directory of Open Access Journals (Sweden)

    Giuseppe Alfonso

    2014-06-01

    Full Text Available Albania, as well as a great part of the Balkan area in general, still suffers a lack of environmental studies especially in limnological research. The Dumre plateau, in Central Albania, is characterized by an extraordinary high number of karst lakes in a small geographic area. Despite their environmental peculiarity, very few biological data are to date available for these lakes, none on the zooplankton. For this reason, 15 water bodies located in the central area of the plateau were selected for a preliminary limnological survey carried out in the years 2008-2011. Neodiaptomus schmackeri (Poppe & Richard, 1892, a diaptomid calanoid copepod characterized by a South-Eastern Palearctic - Oriental distribution, and the most widely spread Neodiaptomus species in Asia, was found in 8 lakes of the Dumre area. This finding represents the first record of the species, and of the entire genus Neodiaptomus, for Europe. Several environmental variables were measured to characterize the lakes, and the co-occurring planktonic crustaceans were also identified. Taxonomical drawings and descriptions of the main morphological features of both sexes are herein provided in order to compare the Albanian populations of N. schmackeri with those of the native distribution area of the species. The possible causes which determined the occurrence of this non-indigenous species in several Dumre lakes are discussed.

  17. Seasonal variability of planktonic copepods (Copepoda: Crustacea in a tropical estuarine region in Brazil

    Directory of Open Access Journals (Sweden)

    Cristina de Oliveira Dias

    2009-12-01

    Full Text Available The Caravelas River estuary and adjacent coastal region were studied during the rainy and dry seasons of 2003-2004 to assess the copepod community structure. Abiotic and biotic parameters were measured, and the total density, frequency and percentage of copepod taxa were determined for each sampling period. Copepod densities showed significant differences between sampling periods, with higher densities in the rainy seasons (Mean: 90,941.80 ind.m-3; S.D.: 26,364.79. The sampling stations located to the north and south, in the coastal region adjacent to the Caravelas River estuary presented the lowest copepod density values. The copepod assemblage was composed mainly of estuarine and estuarine/coastal copepods. The seasonal variations in temperature and salinity influenced the abundance of species during the rainy and dry seasons, with the following dominant species alternating: Paracalanus quasimodo Bowman, 1971 in the rainy season of 2003, Parvocalanus crassirostris Dahl, 1894 in the dry season of 2003 and Acartia lilljeborgii Giesbrecht, 1892 in the rainy and dry seasons of 2004. Non-parametric multidimensional scaling indicated differences in copepod assemblages between sampling periods, but not between sampling stations.

  18. Redescription and first records from Brazil of Diacyclops uruguayensis Kiefer (Crustacea, Copepoda, Cyclopidae

    Directory of Open Access Journals (Sweden)

    Janet W. Reid

    1998-01-01

    Full Text Available Diacyclops uruguayensis Kiefer, 1935 is redescribed from specimens from Santa Catarina and Ceará, Brazil. These new records represent a significant range extension from southern Uruguay.

  19. Infestação experimental em girinos de Rana catesbeiana Shaw por copepoditos de Lernaea cyprinacea Linnaeus (Copepoda, Lernaeidae Experimental, infestation of Rana catesbeiana Shaw tadpoles by copepodids of Lernaea cyprinacea Linnaeus (Copepoda, Lernaeidae

    Directory of Open Access Journals (Sweden)

    Maurício Laterça Martins

    1995-09-01

    Full Text Available The Lernaea cyprinacea Linnaeus, 1758 copepodids experimental contamination on the Rana catesbeiana Shaw, 1802 ladpoles was analized. Sixty percent (12 of infested tadpoles was found parasitized. High mortality range, lower appetence, equilibrium loss and apathy were observed. The parasites showed the preference for the mouth and cloaca: in 72 hours lhe egg saes had already developed.

  20. A new record and redescription of Schizopera (Schizopera knabeni (Copepoda: Harpacticoida: Miraciidae from north-western Mexico Un registro nuevo y redescripción completa de Schizopera (Schizopera knabeni (Copepoda: Harpacticoida: Miraciidae del noroeste de México

    Directory of Open Access Journals (Sweden)

    Samuel Gómez

    2008-06-01

    Full Text Available Specimens of Schizopera Sars, 1905 were found during sampling in 2 brackish systems in central and southern Sinaloa (north-western Mexico. The specimens turned out to belong to Schizopera (Schizopera knabeni Lang, 1965 which was originally described from Monterey Bay (the type locality and is known from Cocodrie (Louisiana. Amendments to Lang's (1965 original description and Fiers and Rutledge's (1990 partial redescription are given.Durante una serie de muestreos se hallaron ejemplares del género Schizopera Sars, 1905 en 2 sistemas salobres en el centro y sur de Sinaloa (México. El material recolectado resultó ser Schizopera (Schizopera knabeni Lang, 1965, una especie de copépodo harpacticoide originalmente descrita de material recolectado en la Bahía de Monterey (localidad tipo y hallada también en Cocodrie (Louisiana, EUA. Se proporcionan enmiendas a la descripción original de Lang (1965 y a la redescripción parcial de Fiers y Rutledge (1990.

  1. First record and redescription of Tisbella pulchella (Copepoda: Harpacticoida from the eastern tropical Pacific Primer registro y redescripción de Tisbella pulchella (Copepoda: Harpacticoida del Pacífico tropical este

    Directory of Open Access Journals (Sweden)

    Francisco Neptalí Morales-Serna

    2008-06-01

    Full Text Available Specimens of the genus Tisbella Gurney, 1927 were found during a series of sampling campaigns in 2 brackish systems in southern Sinaloa (north-western Mexico. The specimens were identified as Tisbella pulchella (Wilson, 1932, a species of harpacticoid copepod originally described from material collected from the Woods Hole region (USA and found also in the Bermuda Islands. A thorough comparison between the material collected in Mexican coastal systems in the eastern tropical Pacific and previous redescriptions of the type material is presented. It is shown that the only differences between the most accurate and detailed redescription available and the present description is in the number of setae of the arthrite and palp of the maxillule, and in the number of accessory setae of the maxilliped. Some notes on the biogeography of the species are presented and it is concluded that T. pulchella is the most widely distributed species within the genus.Se encontraron ejemplares del género Tisbella Gurney, 1927 durante una serie de muestreos de meiofauna en 2 sistemas costeros del sur de Sinaloa (noroeste de México. Los organismos fueron identificados como Tisbella pulchella (Wilson, 1932, una especie de copépodo harpacticoide originalmente descrita a partir de material recolectado en la región de Woods Hole (EUA y también registrada en las islas Bermuda. Se presenta una comparación de los especímenes recolectados en sistemas costeros mexicanos del Pacífico tropical este y las redescripciones disponibles del material tipo. Se observó que las únicas diferencias observadas entre la redescripción más detallada de la especie y la presente descripción es el número de setas del artrito y palpo de la maxíllula y el número de setas accesorias del maxilípedo. Finalmente se dan algunas notas acerca de su biogeografía y se concluye que T. pulchella es la especie con la distribución más amplia del género.

  2. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda Diferencias morfométricas en dos especies hermanas Boeckella gracilipes y Boeckella titicacae (Crustacea, Copepoda

    Directory of Open Access Journals (Sweden)

    Patricio De los Ríos Escalante

    2012-12-01

    Full Text Available Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902, which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. gracilipes collected in Riñihue lakes, with a third population of B. gracilipes collected in shallow ponds in Salar de Surire. Titicaca and Riñihue lakes are stable environments, whereas Salar de Surire is an extreme environment. These ponds present an extreme environment due to high exposure to solar radiation and high salinity levels. The results of the study revealed differences among the three populations. These results agree well with systematic descriptions in the literature on differences between the populations of Titicaca and Riñihue lakes, and population of Salar de Surire differs slightly from the other two populations. It is probable that the differences between the population of Salar de Surire and the other two populations result from the extreme environment in Salar de Surire. High exposure to solar radiation, high salinity and extreme variations in temperature enhance genetic variations that are consequently expressed in morphology.Los copépodos calanoideos son abundantes en aguas continentales sudamericanas e incluyen especies de amplia distribución geográfica como Boeckella gracilipes (Daday, 1902 que se encuentra desde Ecuador hasta la isla de Tierra del Fuego. Esta especie vive bajo varias condiciones ambientales, y se encuentra en lagos oligotróficos en la Patagonia (39-54°S y en lagunas superficiales de montaña al norte de los 39°S. El objetivo del presente trabajo es realizar un estudio comparativo morfométrico de machos de B. titicacae colectado en el lago Titicaca y B. gracilipes colectado en el lago Riñihue, ambos son ambientes estables, con una tercera población colectada en lagunas superficiales en el Salar de Surire. Estas lagunas tienen condiciones ambientales extremas debido a alta exposición a la radiación solar y altos niveles de salinidad. Los resultados del presente estudio encontraron diferencias entre las tres poblaciones. Estos resultados concordarían con las descripciones sistemáticas en la literatura sobre las diferencias de las poblaciones de los lagos Titicaca y Riñihue, y la población del salar de Surire tuvo leves diferencias respecto a las dos poblaciones anteriores. Es probable que las diferencias entre la población del Salar de Surire y las otras dos se deban a alta exposición a la radiación solar, salinidad y condiciones extremas de temperatura que acelera las diferencias genéticas las que se expresan en diferencias morfológicas.

  3. Morphometric differences in two calanoid sibling species, Boeckella gracilipes and B. titicacae (Crustacea, Copepoda) Diferencias morfométricas en dos especies hermanas Boeckella gracilipes y Boeckella titicacae (Crustacea, Copepoda)

    OpenAIRE

    Patricio de los Ríos Escalante

    2012-01-01

    Calanoid copepods are abundant in South American inland waters and include widespread species, such as Boeckella gracilipes (Daday, 1902), which occurs from the Ecuador to Tierra del Fuego Island. This species occurs under various environmental conditions, and is found in oligotrophic lakes in Patagonia (39-54°S) and in shallow mountain lakes north of 39°S. The aim of the present study is to conduct a morphometric comparison of male specimens of B. titicacae collected in Titicaca and B. graci...

  4. Expanded description of Lamproglena monodi (Copepoda: Lernaeidae, parasitizing native and introduced fishes in Brazil Descrição expandida de Lamproglena monodi (Copepoda: Lernaeidae, parasita de peixes nativos e introduzidos no Brasil

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    Rodney Kozlowiski de Azevedo

    2012-09-01

    Full Text Available An occurrence of the copepod Lamproglena monodi Capart, 1944, parasitizing freshwater fishes in Brazil is presented, along with new morphological data. This crustacean was originally described parasitizing several cichlids in Africa. In the present study, the crustaceans were collected from the body surface and gills of two fish species native to Brazil [Astronotus ocellatus (Agassiz, 1831 and Cichla ocellaris Bloch and Schneider, 1801] and two introduced species [Oreochromis niloticus (Linnaeus, 1758 and Tilapia rendalli (Boulenger, 1897]. The Brazilian specimens exhibited some morphometric intraspecies differences in relation to the specimens from Congo-Kinshasa and Egypt.A ocorrência e novos dados morfológicos do copépode Lamproglena monodi Capart, 1944 parasitando peixes dulcícolas no Brasil são apresentados. Este crustáceo foi originalmente descrito parasitando vários ciclídeos da África. No presente trabalho, os crustáceos foram coletados das brânquias e superfície do corpo dos peixes nativos do Brasil [Astronotus ocellatus (Agassiz, 1831 e Cichla ocellaris Bloch e Schneider, 1801 e duas espécies introduzidas Oreochromis niloticus (Linnaeus, 1758 e Tilapia rendalli (Boulenger, 1897]. Os espécimes coletados no Brasil apresentaram algumas diferenças morfométricas intraespecíficas em relação aos espécimes do Congo-Kinshasa e Egito.

  5. Phylogeography of Calanus helgolandicus and the Black Sea copepod Calanus euxinus, with notes on Pseudocalanus elongatus (Copepoda, Calanoida)

    Science.gov (United States)

    Unal, Ebru; Frost, Bruce W.; Armbrust, Virginia; Kideys, Ahmet E.

    2006-08-01

    Calanus helgolandicus is a widespread epipelagic copepod species whose geographical range extends from the temperate Atlantic Ocean to the northern Mediterranean Sea. Calanus euxinus, recently designated as a distinct species though closely related to C. helgolandicus, occurs in the Black Sea. Very subtle morphological differences distinguish the two species. Pseudocalanus elongatus has a similar geographic range including North Atlantic Ocean, Mediterranean Sea and the Black Sea. In this study, population genetic variation of C. helgolandicus, C. euxinus and P. elongatus was investigated using DNA sequence variation of 540 base pair ( Calanus spp.) and 575 base pair ( P. elongatus) regions of mitochondrial cytochrome oxidase I (mtCOI) gene. C. helgolandicus was collected from the English Channel, the Adriatic Sea, and C. euxinus was collected from various regions of the Black Sea. P. elongatus was collected from the English Channel and the Black Sea. Intraspecific differentiation in mtCOI was <1% for all species; mtCOI sequence variation between C. helgolandicus and C. euxinus was <0.5%. The absence of substantial genetic differentiation between C. helgolandicus and C. euxinus is particularly striking in comparison to other close species pairs in these genera. Statistically significant haplotype frequency differences were determined for different locations of the Black Sea, English Channel, and Adriatic Sea Calanus populations ( χ2=3.94, P<0.0001). The haplotype diversity was high for all species: C. euxinus ( h=0.92), C. helgolandicus ( h⩽0.80), P. elongatus ( h⩽0.60). No haplotype sharing was reported for different locations of P. elongatus, whereas the presence of haplotype sharing between C. helgolandicus and C. euxinus was remarkable. The size distribution in terms of prosome length measurements was found to be region-specific. The lack of phylogenetic differentiation between the Calanus species pair may suggest ancestral polymorphisms. The morphological and genetic similarities between C. euxinus and C. helgolandicus raise new questions about the status of C. euxinus as a different species.

  6. Complementary description of Ergasilus arthrosis Roberts, 1969 (Copepoda: Poecilostomatoida: Ergasilidae), a new parasite of cichlid teleosts in southeast Mexico.

    Science.gov (United States)

    Jiménez-García, María Isabel; Suárez-Morales, Eduardo

    2017-01-01

    During a parasitological survey of the ichthyofauna of Lake Catemaco, a freshwater system in the Mexican State of Veracruz, the widespread copepod Ergasilus arthrosis Roberts, 1969 was recovered from two cichlid teleosts, Mayaheros urophthalmus (Günther) and Oreochromis sp. This is the first confirmed record of this copepod species outside of the United States and from Mexico; its finding as a parasite of cichlids represents an expansion of the known host range for this copepod. The local prevalence and intensity of infection of E. arthrosis was highest in M. urophthalmus. The infection prevalence of E. arthrosis on M. urophthalmus (60%) was higher than that known for other ergasilids on cichlids. Ergasilus arthrosis can be distinguished from its closest congener E. lizae Krøyer, 1863 by the morphometry of the antennary segments, the ventral ornamentation of the thoracic sclerites and by details of the antennulary setation, but also by its habitat and host preferences. Taxonomic illustrations and morphological details of the specimens examined are also provided together with comments on the variability of this species.

  7. Drought-associated absence of alien invasive anchorworm, Lernaea cyprinacea (Copepoda: Lernaeidae, is related to changes in fish health

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    Rachel L. Welicky

    2017-12-01

    Full Text Available Recently, Mozambique tilapia (Oreochromis mossambicus Peters, 1852 were listed on the IUCN Red List as near-threatened as their populations are at risk due to hybridization. Another factor that potentially contributes to their population decline is that they are regularly infected by the invasive parasitic copepod anchorworm, Lernaea cyprinacea Linnaeus, 1758. Considering anchorworm-infected Mozambique tilapia are common, understanding their condition with respect to infection is difficult as uninfected fish from the same localities have been unavailable for comparison. A severe drought in southern Africa has created hypersaline environments in the Phongolo River floodplain of north-eastern South Africa, such that freshwater parasites cannot survive and uninfected fish are now found. To determine how infection influences host health, infected and uninfected Mozambique tilapia were collected before and during drought conditions, from Nyamiti pan of the Phongolo River floodplain. Anchorworm-infected fish prevalence was recorded, and anchorworms were collected from hosts and identified to the species level using molecular data of the 18S rRNA gene. For each fish, intensity of anchorworm infection, total length, and weights of the gutted body, liver, spleen, and gonads were recorded. Gutted condition factor, hepato-, spleeno-, and gonado-somatic index values per fish, and prevalence of infection per collection were determined. A rapid health assessment was also conducted to determine a health score for each fish. Molecular analyses confirmed the anchorworm studied was L. cyprinacea. Prior to and during drought, prevalence of infection was 100%, and 0%, respectively. Before drought, fish had significantly reduced hepato-, spleeno-, and gonado-somatic index values, and higher health assessment scores, yet significantly higher gutted condition. Anchorworm intensity was indirectly correlated with fish liver and gonad condition. This study demonstrates that host condition and health varies greatly with respect to drought and infection, and provides the necessary data for follow-up studies in post-drought conditions. Keywords: Alien invasive, Cichlidae, Fish parasites, Host condition, Tilapia, 18S ribosomal DNA

  8. A new species of Parategastes Sars, 1904 from the Thale Noi Lake, southern Thailand (Copepoda, Harpacticoida, Tegastidae

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    Thanida Saetang

    2015-09-01

    Full Text Available Parategastes pholpunthini sp. n. is described and illustrated based on material collected in the Thale Noi Lake, Phatthalung province, southern Thailand. This species can be distinguished from its congeners by the number segments of female antennule, the lengths of rami and basis of P1, the shape of middle inner seta of P4 exp-3, shape of P5, and relative lengths of spine at apically of baseoendopod of P5. The differences among Parategastes species are pointed out and they are compared with the new species. An identification key to species of the genus Parategastes are proposed.

  9. A new species of Harpacticella Sars, 1908 (Copepoda, Harpacticoida, from a tidal pool on Jeju Island, Korea

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    Seunghan Lee

    2014-10-01

    Full Text Available A new species of the genus Harpacticella Sars, 1908 is described from a tidal pool on Jeju Island, Korea. Harpacticella jejuensis sp. n. is closely related to H. itoi Chang & Kim, 1991, with regard to the structure of P1 exp-1 and enp-1, the length of P1 exp-1 and exp-2, and the setal number of the P5 exopod in males. However, the new species is clearly distinguishable from H. itoi by the combined following characters: six setae on the P5 exopod in females, one naked seta on the inner margin of P1 exp-2, the short endopod of P1 compared to the exopod, and a naked long seta on the proximal inner margin of the P5 exopod of males. The mtCOI partial sequence is provided as a DNA barcode for the new species.

  10. Life histories and seasonal dynamics of common boreal pelagic copepods (Crustacea, Copepoda inhabiting an oligotrophic Fennoscandian lake

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    Svein Birger WÆRVÅGEN

    2010-08-01

    Full Text Available The annual seasonal abundance and spatial distribution of four widespread pelagic copepods, the Palaeartic calanoid Eudiaptomus gracilis, the cyclopoids Mesocyclops leuckarti and Thermocyclops oithonoides, and the Holartic Cyclops scutifer were investigated in Lake Gjerstadvann, an oligotrophic boreal lake. Important ecological traits such as life cycles, pelagic microhabitats and wintering strategies varied strongly between the investigated copepods, and influenced seasonal succession in the plankton community. Fish predation did not seem to affect copepod abundances, except perhaps the two lage-sized, less abundant species, the Palaeartic calanoid Heterocope saliens and the Holartic cyclopoid Cyclops abyssorum. Life cycles varied from one (C. scutifer to three (M. leuckarti and E. gracilis complete generations per year, primarily related to habitat temperatures. Wintering took place as late instars (C. scutifer, C. abyssorum or cop V and adults (E. gracilis in the plankton, late instars in profundal (T. oithonoides or littoral (M. leuckarti sediment diapause, and embryonic diapause in sediment egg bank (H. saliens. C. scutifer and C. abyssorum exhibited delayed development in the profundal waters during winter, which could be characterised as so-called "active diapause". C. scutifer, T. oithonoides, and C. abyssorum in Lake Gjerstadvann were probably negatively affected by acidified waters. M. leuckarti seemed to be the most acid-tolerant of these species being able to endure pH slightly below 5.0, whereas T. oithonoides was usually absent at such pH levels. The calanoid species H. saliens and E. gracilis were extremely tolerant towards acidic environments. The yearly differences in population abundance as indicated by the fluctuations in the diapausing populations were probably due to environmental variations in water chemistry occurring during the most vulnerable ontogenetic stages, i.e., eggs and nauplii. Even if the pelagic ecosystem in boreal and oligotrophic lakes may appear homogeneous, a whole array of life histories and dormancy patterns has evolved among copepods.

  11. Postembryonic stages of Nucellicola holmanae Lamb et al., 1996 (copepoda, poecilostomatoida), an endoparasite of the dog whelk Nucella lapillus (gastropoda)

    Science.gov (United States)

    Lamb, E. J.; Boxshall, G. A.; Mill, P. J.; Grahame, J.

    1998-06-01

    The external morphology of the first three larval stages of Nucellicola holmanae is described. These stages were cultured from eggs found with the adults in the viscera of dog whelks collected from Robin Hood's Bay, North Yorkshire. The nauplius develops within the whelk. It moults to a metanauplius which is released as a free-swimming stage. The metanauplius moults to a free copepodid stage which exhibits a combination of characters typical of the first, second and third copepodid stages of other poecilostomatoid copepods. The infective copepodid stage which locates and penetrates the host is visible through the integument of this free-swimming copepodid.

  12. Neue marine Cyclopoida Gnathostoma (Crustacea, Copepoda) von Puerto Rico. Amsterdam Expeditions to the West Indian Islands, Report 57

    NARCIS (Netherlands)

    Herbst, Hans-Volkmar

    1989-01-01

    In the flat littoral of the coast of Puerto Rico (West Indies) at the reef of Cayo Enrique a few Cyclopoida Gnathostoma were collected in colonies of the corallimorpharian Ricordea florida Duch & Mich., which belong to the subfamilies Pterinopsyllinae and Euryteinae. These are the following species:

  13. A new species of Mastigodiaptomus Light, 1939 from Mexico, with notes of species diversity of the genus (Copepoda, Calanoida, Diaptomidae

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    Martha Angélica Gutiérrez-Aguirre

    2016-11-01

    Full Text Available A new species of the genus Mastigodiaptomus Light, 1939, named Mastigodiaptomus cuneatus sp. n. was found in a freshwater system in the City of Mazatlán, in the northern region of Mexico. Morphologically, the females of this new species are distinguishable from those of its congeners by the following combination of features: the right distal corner of the genital double-somite and second urosomite have a wedge-shaped projection, the fourth urosomite has no dorsal projection and its integument is smooth. The males are distinct by the following features: the right caudal ramus has a wedge-shaped structure at the disto-ventral inner corner; the basis of the right fifth leg has one triangular and one rounded projection at the distal and proximal margins, respectively, plus one hyaline membrane on the caudal surface close to the inner margin; the aculeus length is almost the width of the right second exopod (Exp2; and the frontal and caudal surfaces of the right Exp2 are smooth. Furthermore, the analysis of the COI gene of M. cuneatus sp. n. has revealed that M. albuquerquensis (Herrick, 1895 is its nearest congener, with 18.64% of genetic distance. A key for the identification of the known species of the genus is provided.

  14. First record of Hemidiaptomus (Gigantodiaptomus superbus (Schmeil, 1895 in Italy, with notes on distribution and conservation status (Copepoda, Calanoida, Diaptomidae

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    Federico MARRONE

    2011-02-01

    Full Text Available Hemidiaptomus (Gigantodiaptomus superbus (Schmeil, 1895 was found in a temporary pool in the Pineta di Classe coastal pine-wood (Ravenna, northern Italy. This is the first official record of a species belonging to the subgenus Gigantodiaptomus of Italian fauna, and it widens the known distribution of this rare diaptomid to the Mediterranean basin. In order to supply data on this rare and poorly known species, original drawings for the Italian population have been provided, and some overlooked morphological features have been highlighted. In light of the growing evidence of the existence of a number of cryptic species in the Diaptomidae family, and considering the variability observed in the ornamentation of the fifth pair of female legs, the ribosomal DNA marker 16S was used to compare the specimens collected in Italy with those from the terra typica of the species. Molecular data confirmed the strict conspecificity of the two populations being studied. The environmental parameters relating to the new Italian site are described and compared with the few data currently available in the literature. A careful review of all the published data dealing with H. (G. superbus has been performed, and the paucity of recent records is stressed, together with the opportunity to support dedicated conservation measures for the protection of this species.

  15. Effects of Temperature and Salinity on the Survival and Egg Production of Gladioferens pectinatus Brady (Copepodas: Calanoida)

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    Hall, C. J.; Burns, C. W.

    2002-10-01

    The calanoid copepod Gladioferens pectinatus Brady occurs in Lake Waihola, New Zealand, a shallow, tidally-influenced lake. This lake experiences daily and seasonal fluctuations in salinity, and seasonal changes in temperature. To determine the potential contributions of salinity and temperature to observed seasonal population fluctuations, we tested the survival and egg production of G. pectinatus at two temperatures (10 °C and 20 °C) and in a range of ' salinities ' (20 to 2700 mg l -1 Cl). Adult survival was highest in 1000 mg l -1 Cl at 10 °C, when 50% still remained alive after 23 d. Increases in salinity and temperature decreased the survival time to less than 10 d. The salinities tolerated were well below the maximum of 2500 mg l -1 Cl recorded in the lake. There was no difference in adult survival between males and females. Eggs were produced in salinities of up to 600 mg l -1 Cl. Only in 20 mg l -1 Cl did an increase in temperature reduce clutch retention time, and increase the rate of egg production. The rate of increase in salinity did not affect copepod survival, but acclimation at an intermediate salinity increased survival at 10 °C. Our results suggest that high temperatures and salinities in summer may lower the fitness of this population of G. pectinatus.

  16. Five new species of lichomolgid copepods associated with ascidians from Korea, with proposal of two new genera (Crustacea, Copepoda, Lichomolgidae)

    Science.gov (United States)

    Moon, Seong Yong; Kim, Il-Hoi

    2011-09-01

    Five new species of the family Lichomolgidae associated with solitary ascidians are described from the east coast of Korea. Two new genera are proposed: Protomolgus n. gen. to incorpotate Protomolgus duplex n. sp. and P. singularis n. sp., and Dontimolgus n. gen. to incorporate Dontimolgus brevicaudatus n. sp. Protomolgus n. gen. characteristically has a four-segmented female maxilliped and a bipartite mandible. Dontimolgus n. gen. possesses a large, tooth-like process on the first maxillary segment and three spines on the third exopodal segment of leg 3. Other two new species described are Lichomolgus infirmus n. sp. and L. pectinatus n. sp.

  17. Laboratory evaluation of Mesocyclops annulatus (Wierzejski, 1892 (Copepoda: Cyclopidea as a predator of container-breeding mosquitoes in Argentina

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    María V Micieli

    2002-09-01

    Full Text Available In laboratory bioassays we tested the predatory capacity of the copepod Mesocyclops annulatus on Aedes aegypti and Culex pipiens larvae. A single adult female of M. annulatus caused 51.6% and 52.3% mortality of 50 first instar larvae of Ae. aegypti and Cx. pipiens respectively, in a 72 h test period. When alternative food was added to the containers, mortality rates declined to 16% and 10.3% for Ae. aegypti and Cx. pipiens respectively. When 50 first instar larvae of each of the two mosquito species tested were placed together with a single adult female of M. annulatus, mortality rates were 75.5% for Ae. aegypti larvae and 23.5% for Cx. pipiens larvae in a three day test period. Different density of adult females of M. annulatus ranged from 5 to 25 females produced mortality rates of Ae. aegypti first instar larvae from 50% to 100% respectively. When a single adult female of M. annulatus was exposed to an increasing number of first-instar Ae. aegypti larvae ranging from 10 to 100, 100% mortality was recorded from 1 to 25 larvae, then mortality declined to 30% with 100 larvae. The average larvae killed per 24 h period by a single copepod were 29.

  18. Survey of cyclopids (Crustacea, Copepoda in Brazil and preliminary screening of their potential as dengue vector predators

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    Luciana Urbano dos Santos

    1997-06-01

    Full Text Available INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. longisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were screened for copepods by collecting 1.5 l of water from each of then. The predatory potential of adults copepods was evaluated over 24 h, in the laboratory, for groups of 5 individuals preying upon 30 first instar Ae. albopictus larvae. RESULTS AND CONCLUSION: The following cyclopid species were found: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. The predatory potential of these copepods ranged from nil to 97.3%. A sample collected in the field containing only M. longisetus var. longisetus showed the best control efficiency with no significant difference from a three-year old laboratory culture (ML-01 of the same species evaluated for comparison. The sample with few M. albidus var. albidus was ranked in second place showing an average 25.9% efficiency. The use of copepods in trap tires as dengue vector controllers is discussed.

  19. Four new representatives of the genus Allocyclops Kiefer, 1932 from semi-consolidated subsoil aquifers in Benin (Copepoda, Cyclopoida, Cyclopidae

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    Frank Fiers

    2015-06-01

    Full Text Available Several species of cyclopoid copepods were collected from improved and unimproved hang-dug-wells in the Republic of Bénin over the years 2009–2014. Fifty five wells located in seven different districts were sampled: 15 wells in the district of Pobè (Department Plateau and 1 well in Kétou (Department Plateau, 4 wells in Porto-Novo District (Department Ouémé and, 15 wells in Lokossa District (Department Mono,18 wells in Parakou District (Department Borgou, 1 well in Abomey-Calavi District (Department Atlantique and 1 in Zogbodomè District (Department Zou. Among them, 4 new species of the genus Allocyclops Kiefer, 1932 were found and are described herein: Allocyclops spinifer sp. n., A. nudus sp. n., A. pilosus sp. n. and A. sakitii sp. n. They are compared with the three African species previously described. Allocyclops appears to be a sub-Saharan taxon specialized to thrive in the variable environment of subsoil aquifers in laterite deck beds. An identification key to the 7 different African Allocyclops species is provided.

  20. Lovenula (Neolovenula) alluaudi (Guerne and Richard, 1890) in the Canary Islands (Copepoda: Calanoida: Paradiaptominae). Stygofauna of the Canary Islands, 19

    NARCIS (Netherlands)

    Bowman, Thomas E.

    1990-01-01

    Lovenula (Neolovenula) alluaudi is widespread on Lanzarote, where it occurred at 22 of the 105 stations. On Fuerteventura it was found at only 2 of the 53 stations, both in the extreme northwest part of the island. It was also found in a reservoir on the south side of the small island of Alegranza.

  1. Redescription and taxonomic validity of Leptodiaptomus cuauhtemoci (Osorio- Tafall, 1941 (Copepoda, Calanoida, with notes on its known distribution

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    Marcelo SILVA-BRIANO

    2000-02-01

    Full Text Available Within the American freshwater calanoid copepods, Leptodiaptomus includes species whose taxonomical status is still unclear. One of them is L. cuauhtemoci (Osorio-Tafall, for decades considered to be a synonym of L. siciloides (Lilljeborg; another species involved in this problem is L. assiniboiensis (Anderson & Fabris described from Canada, which had been found to be closely related to L. cuauhtemoci. This species remained of uncertain taxonomy because the type material was lost decades ago. In order to disentangle this controversy, type specimens of L. assiniboiensis, topotypic specimens of L. cuauhtemoci from a National Park in central Mexico, and confirmed specimens of L. siciloides from different locations in Mexico and the United States were used to define the status of these species. Leptodiaptomus cuauhtemoci was fully redescribed using SEM. Based on the main characters used to differentiate species of Diaptomidae, L. assiniboiensis (= Diaptomus intermedius Anderson & Fabris turned out to be conspecific and a junior synonym of L. cuauhtemoci, which then becomes the valid name. The latter species shows taxonomically relevant differences with respect to L. siciloides. In the females the main differences is that the lateral spiniform processes on the genital somite are broader-based in L. cuauhtemoci, the genital field is different in both species. In L. cuauhtemoci the fifth leg endopods bear two large, broad, subterminal setae of about the same size, differently built than in L. siciloides. The male L. cuauhtemoci is slenderer, with wings of pediger 5 clearly more developed than those of L. siciloides. The armature of the modified right antennules and the structure of the fifth leg differ in both species. A large coxal spine is present on the right fifth leg of L. siciloides, whereas it is absent in L. cuauhtemoci. These differences were considered to be enough evidence for recognizing L. cuauhtemoci as a separate, valid species. Topotypic specimens of L. cuauhtemoci are designated as neotypes.

  2. Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida to potassium dichromate and sediment particle size

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    Cristiane M. V. Araújo-Castro

    2009-03-01

    Full Text Available For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil, sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any detrimental biological effects on benthic invertebrates. Neither survival nor fecundity was affected by grain size, suggesting that this species can be used with any kind of sediment from muddy to sandy. The sensitivity of T. biminiensis to K2Cr2O7 in acute tests was similar to that of other organisms. The LC50 (lethal concentration to 50% of the test organisms medium values for T. biminiensis were 7.51, 4.68 and 3.19 mg L-1 for Cr in 48, 72 and 96 h, respectively. These results suggest that T. biminiensis is a promising organism for use in solid-phase sediment toxicity assessments.Visando o uso futuro do copépodo marinho bentônico Tisbe biminiensis em bioensaios toxicológicos de sedimentos na fase sólida, o presente estudo investigou o efeito do sedimento lamoso do estuário de Maracaípe (Nordeste do Brasil. Foram considerados a granolometria e o tóxico de referência dicromato de potássio sobre a espécie. O sedimento lamoso de Maracaípe pode ser usado como controle, uma vez que não interfere no ciclo de vida do copépodo e possui níveis de contaminação de metais que não causariam efeitos biológicos em invertebrados bentônicos. Nem a sobrevivência ou fecundidade foi afetada pelo tamanho do grão, sugerindo que esta espécie pode ser usada com qualquer tipo de sedimento, de lama a areia. A sensibilidade de T. biminiensis ao K2Cr2O7 em testes agudos foi similar a de outros organismos. Os valores de CL50 (concentração letal a 50% dos organismos para T. biminiensis foram em média 7,51, 4,68 e 3,19 mg L-1 para o Cr em 48, 72 e 96h, respectivamente. Estes resultados sugerem que T. biminiensis é um organismo promissor para uso em avaliações de toxicidade com a fase sólida do sedimento.

  3. Sensitivity of the marine benthic copepod Tisbe biminiensis (copepoda, harpacticoida) to potassium dichromate and sediment particle size

    OpenAIRE

    Cristiane M. V. Araújo-Castro; Souza-Santos, Lília P.; Torreiro,Anny Gabrielle A .G.; Garcia, Karina S.

    2009-01-01

    For the future use of the marine benthic copepod Tisbe biminiensis in solid-phase sediment toxicological bioassays, the present study investigated the effect of muddy sediment from the Maracaípe estuary (northeastern Brazil), sediment particle size and the reference toxicant potassium dichromate on the species. Muddy sediment from Maracaípe can be used as control sediment, since it does not interfere in the copepod life-cycle and has metal contamination levels that are unlikely to produce any...

  4. [The family Pontellidae (Crustacea: Copepoda) in la Ventosa Bay, Oaxaca, México: systematies and basic ecology].

    Science.gov (United States)

    Alvarez Silva, Carlos; Miranda Arce, María Guadalupe; De Lara-Isassi, Graciela

    2003-01-01

    A study on ecological records of planktonic copepods from The Ventosa Bay, Oaxaca, Mexico is presented. Five species were identified: Labidocera acuta, L. lubbockii, Pontella agassizi, P. tenuiremis and Pontellina plumata. The most abundant species was L. acuta and their copepodite stages conforming the 95.7% of Pontellids, followed by L. lubbockii 4.09%; other species were less than one percent. The reproductive success of L. acuta is probably favored by its resistance to the changes in temperature and salinity, because of it is an eurytherme and euryhaline organism. Total density of this family was between 18 and 472 copepods/100 m3 in 1987 and 1988. Nevertheless in 1992 and 1993 the density was between 490 to 123,030 copepods/100 m3. This copepod density increment could be related local phenomenon (upwelling) at the beginning and end of the year.

  5. Two new species of Hemicyclops (Copepoda: Poecilostomatoida: Clausidiidae) associated with mud shrimps of the genus Callichirus from Brazil

    NARCIS (Netherlands)

    Kihara, Terue Cristina; Falavigna da Rocha, Carlos Eduardo

    1994-01-01

    Two new clausidiid copepods of the genus Hemicyclops (Poecilostomatoida: Clausidiidae) associated with mud shrimps are described from Brazil: Hemicyclops caissarum sp. n. associated with Callichirus major (Say, 1808) from a beach in Santos and Hemicyclops sebastiani sp. n., in burrows of Callichirus

  6. Three new species of benthonic Harpacticoida (Copepoda, Crustacea from São Sebastião Channel

    Directory of Open Access Journals (Sweden)

    Tagea Björnberg

    Full Text Available Three benthonic Harpacticoida (Crustacea new to science were collected in the São Sebastião Channel region (SE Coast of Brazil: Rhizotrix virginiae n.sp. (Rhizotrichidae, Galapalaophonte alvaroi n. sp. (Laophontidae and Laophontisochra terueae n.sp. (Nannopodidae. Though similar to described species from the NW Atlantic benthos, the Caribbean region and the Patagonian continental slope, they differ in details, such as number of leg segments and/or setae, ornaments, etc. and are here described for the first time.

  7. Harpacticoida (Crustacea, Copepoda of Mussel Beds and Macroalgae on the Rocky Substrates in the North-Western Black Sea

    Directory of Open Access Journals (Sweden)

    Portianko V. V.

    2017-10-01

    Full Text Available The role of harpacticoid copepods in total abundance, biomass and species diversity of meiobenthos on rocky substrates is described. Th e fauna of harpacticoid copepods consists of 19 species in algal beds, 23 species in mussel beds and 24 species in mixed aggregation of molluscs and macrophytes. In the macrophyte aggregation, the maximal abundance was registered in Cladophora vagabunda - 88 750 ind. × m-2, while minimal was on Laurensia paniculata - 8250 ind. × m-2. According to the frequency of occurrence, the habitat preferred by copepods was Ceramium elegans, but according to their percentage in total meiobenthos among macrophytes it was Ulva intestinalis, 56.6 %. The percentage of copepods in the pure mussel beds was higher comparing to mixed aggregation of molluscs and macrophytes.

  8. First record of the Calanoid Copepod Pseudodiaptomus serricaudatus (Scott, T. 1894), (Copepoda: Calanoida: Pseudodiaptomidae) in the equatorial Indian ocean.

    Digital Repository Service at National Institute of Oceanography (India)

    Rebello, V.; Narvekar, J.; Gadi, P.; Venenkar, A.; Gauns, M.; PrasannaKumar, S.

    for his valuable advice. We acknowledge the help from Shweta, Genevieve and Byju for data collection and analysis. EIOPS was funded by the Ministry of Earth Science (MoES), New Delhi. This is NIO contribution No.xxxx. References Achuthankutty, C.T., N...

  9. Distribution and hosts of Stellicola (Copepoda, Cyclopoida) associated with Linckia (Asteroidea) in the Indo-West Pacific

    NARCIS (Netherlands)

    Humes, Arthur G.

    1976-01-01

    Five lichomolgid copepods belonging to the genus Stellicola are reported from three species of the sea star genus Linckia in the Moluccas: Stellicola flexilis n. sp. from Linckia guildingi. L. laevigata, and L. multiflora, S. caeruleus (Stebbing, 1900) from L. laevigata, L. guildingi, and L.

  10. New records of the rare glacial relict Eurytemora lacustris (Poppe 1887 (Copepoda; Calanoida in atypical lake habitats of northern Germany

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    Peter KASPRZAK

    2011-02-01

    Full Text Available During monitoring investigations of lakes in Schleswig-Holstein (northern Germany in 2000 and 2008, the calanoid copepod Eurytemora lacustris (POPPE 1887 was found in three lakes of the Ratzeburger Lake complex: the Kleine Küchensee, the Große Küchensee and the Große Ratzeburger See. The species has a broad geographic distribution but has become rare and endangered by eutrophication and global change. The lakes are mesotrophic (Gr. Ratzeburger See and eutrophic (Kl. Küchensee, Gr. Küchensee with cool (1 mg O2 L-1. Food and physical conditions seem to be favourable enough to permit survival and reproduction of the species at least in spring. It remains unclear, however, whether the populations in the studied lakes are autochthonous. Eurytemora lacustris possibly invaded the lakes or was transported via a canal from the Schaalsee upstream, where a viable population exists.

  11. Genome- and transcriptome-assisted development of nuclear insertion/deletion markers for Calanus species (Copepoda: Calanoida) identification

    DEFF Research Database (Denmark)

    Smolina, I.; Kollias, S.; Poortvliet, M.

    2014-01-01

    Copepods of the genus Calanus are key zooplankton species in temperate to arctic marine ecosystems. Despite their ecological importance, species identification remains challenging. Furthermore, the recent report of hybrids among Calanus species highlights the need for diagnostic nuclear markers t...

  12. Seasonal occurrence and habitat of two pennellids (Copepoda, Siphonostomatoida) infecting marine ranched black scraper and Korean rockfish in Korea.

    Science.gov (United States)

    Venmathi Maran, B A; Oh, S Y; Choi, H J; Myoung, J G

    2014-06-01

    The seasonal occurrence and habitat of two parasitic copepods, Peniculus minuticaudae (Shiino, 1956) and Peniculus truncatus (Shiino, 1956) (Siphonostomatoida, Pennellidae) infecting the fins of black scraper Thamnaconus modestus and Korean rockfish Sebastes schlegelii, respectively were investigated. The fishes were collected from Tongyeong marine living resources research and conservation center, southern coast of Korea as five per month for two years from July 2011 to June 2013. In total, 391 copepods of P. minuticaudae were collected in two years, in contrast to P. truncatus. Prevalence was 85%, mean intensity was 3.25, and maximum intensity was 33. Season wise, the infestation was observed as the highest in autumn (September-November) season, and the lowest in winter (December- February). It was infested only on fins of black scrapers. Abundance of P. minuticaudae was found on the pectoral fin (43.5%), followed by anal (22.5%), second dorsal (20.5%) and caudal fins (13.5%). Statistically significant interactions were observed between season, infestation and infected regions (PKorea from the fins of wild threadsail filefish Stephanolepis cirrhifer from Busan, Jeju, Tongyeong and Yeosu fish markets. It can be a new record on its host and localities. A total of 51 P. truncatus were collected with the prevalence of 37.5%, mean intensity of 0.37 and maximum intensity of 6. Season wise, infestation was observed as the highest in summer (June-August), and the lowest in winter. Attachment site was the dorsal fin and not found from any other fins of rockfish. Statistically significant interaction was observed between season and infestation (P<0.05). This is the first report on the ecology of these two pennellids.

  13. Survey of cyclopids (Crustacea, Copepoda in Brazil and preliminary screening of their potential as dengue vector predators

    Directory of Open Access Journals (Sweden)

    Santos Luciana Urbano dos

    1997-01-01

    Full Text Available INTRODUCTION: Cyclopid copepods are known to be good mosquito controllers, specially as regards the larvae of the dengue vectors Aedes aegypti and Ae. albopictus. MATERIAL AND METHOD: The objective of the study was to survey the local copepod fauna and search for new strains of M. longisetus var. longisetus, comparing the potential of the samples found with the current strain ML-01 against Ae. albopictus larvae, under laboratory conditions. Eleven bodies of water in Campinas, SP, Brazil, were screened for copepods by collecting 1.5 l of water from each of then. The predatory potential of adults copepods was evaluated over 24 h, in the laboratory, for groups of 5 individuals preying upon 30 first instar Ae. albopictus larvae. RESULTS AND CONCLUSION: The following cyclopid species were found: Metacyclops mendocinus, Tropocyclops prasinus, Eucyclops sp, Eucyclops serrulatus, Eucyclops solitarius, Eucyclops ensifer, Macrocyclops albidus var. albidus and Mesocyclops longisetus var. longisetus. The predatory potential of these copepods ranged from nil to 97.3%. A sample collected in the field containing only M. longisetus var. longisetus showed the best control efficiency with no significant difference from a three-year old laboratory culture (ML-01 of the same species evaluated for comparison. The sample with few M. albidus var. albidus was ranked in second place showing an average 25.9% efficiency. The use of copepods in trap tires as dengue vector controllers is discussed.

  14. De novo assembly of a transcriptome for Calanus finmarchicus (Crustacea, Copepoda--the dominant zooplankter of the North Atlantic Ocean.

    Directory of Open Access Journals (Sweden)

    Petra H Lenz

    Full Text Available Assessing the impact of global warming on the food web of the North Atlantic will require difficult-to-obtain physiological data on a key copepod crustacean, Calanus finmarchicus. The de novo transcriptome presented here represents a new resource for acquiring such data. It was produced from multiplexed gene libraries using RNA collected from six developmental stages: embryo, early nauplius (NI-II, late nauplius (NV-VI, early copepodite (CI-II, late copepodite (CV and adult (CVI female. Over 400,000,000 paired-end reads (100 base-pairs long were sequenced on an Illumina instrument, and assembled into 206,041 contigs using Trinity software. Coverage was estimated to be at least 65%. A reference transcriptome comprising 96,090 unique components ("comps" was annotated using Blast2GO. 40% of the comps had significant blast hits. 11% of the comps were successfully annotated with gene ontology (GO terms. Expression of many comps was found to be near zero in one or more developmental stages suggesting that 35 to 48% of the transcriptome is "silent" at any given life stage. Transcripts involved in lipid biosynthesis pathways, critical for the C. finmarchicus life cycle, were identified and their expression pattern during development was examined. Relative expression of three transcripts suggests wax ester biosynthesis in late copepodites, but triacylglyceride biosynthesis in adult females. Two of these transcripts may be involved in the preparatory phase of diapause. A key environmental challenge for C. finmarchicus is the seasonal exposure to the dinoflagellate Alexandrium fundyense with high concentrations of saxitoxins, neurotoxins that block voltage-gated sodium channels. Multiple contigs encoding putative voltage-gated sodium channels were identified. They appeared to be the result of both alternate splicing and gene duplication. This is the first report of multiple NaV1 genes in a protostome. These data provide new insights into the transcriptome and physiology of this environmentally important zooplankter.

  15. Observations on feeding behaviour and survival rates in the estuarine calanoid copepods Acartia spinicauda and Heliodiaptomus cinctus (Crustacea: Copepoda: Calanoida)

    Digital Repository Service at National Institute of Oceanography (India)

    Srivastava, Y.; Fernandes, Brenda; Goswami, S.C.; Goswami, U.; Achuthankutty, C.T.

    Experiments were conducted on the calanoid copepods, Acartia spinicauda (Acartiidae) and Heliodiaptomus cinctus (Diaptomidae) in order to determine food preference and survival rates respectively. Adults of A. spinicauda were fed monocultures...

  16. A new species of Cletocamptus Schmankewitsch, 1875 (Crustacea, Copepoda, Harpacticoida from a high altitude saline lake in Central Mexico

    Directory of Open Access Journals (Sweden)

    Eduardo Suarez Morales

    2013-04-01

    Full Text Available During the analysis of littoral samples collected from a high-altitude saline crater lake in Central Mexico, several female and male specimens of harpacticoid copepods were recovered and taxonomically examined. They were found to represent an undescribed species of the canthocamptid genus Cletocamptus Schmankewitsch, 1875. The new species, C. gomezi n. sp. is described herein based on specimens of both sexes. It resembles C. stimpsoni Gómez, Fleeger, Rocha-Olivares and Foltz, 2004 from Louisiana but also C. trichotus Kiefer, 1929. The new species differs from C. stimpsoni and from other congeners by details of the maxillular armature, the setation of the endopodal segments of legs 2 and 3, and the armature of the third exopodal segment of legs 3 and 4. Also, the dorsal (VII and the outer (IV caudal setae are both relatively shorter than in C. stimpsoni. This is the second species of the genus known to be distributed in Mexico. The occurrence of the new species in a high-altitude saline lake, the isolation of the type locality, and its absence from adjacent freshwater lakes suggest that this species is endemic to this site.

  17. Infestation of Lernaea cyprinacea (Copepoda: Lernaeidae in two invasive fish species in Romania, Lepomis gibbosus and Pseudorasbora parva

    Directory of Open Access Journals (Sweden)

    Stavrescu-Bedivan M.M.

    2014-01-01

    Full Text Available In this study we analyzed comparatively the host-parasite associations between two fish host species invasive in Europe (Lepomis gibbosus and Pseudorasbora parva and one known generalist parasite species, the copepod Lernaea cyprinacea. We used a fragment of the hypervariable region D1-D2 of the 28S rRNA to confirm that the copepod specimens collected on both host species in our study are indeed conspecific. The prevalence of infection was significantly different between the two host species in all three aquatic ecosystems. Two populations of L. gibbosus exhibited a positive correlation coefficient between the standard body length and infection intensity, while a negative correlation coefficient was observed in one population of P. parva. This is one of the few studies providing parasitological parameters of infections of Lernaea cypriancea in Lepomis gibbosus and Pseudorasbora parva.

  18. A new species of Monstrillopsis (Crustacea, Copepoda, Monstrilloida from the lower Northwest Passage of the Canadian Arctic

    Directory of Open Access Journals (Sweden)

    Aurélie Delaforge

    2017-10-01

    Full Text Available A new species of monstrilloid copepod, Monstrillopsis planifrons sp. n., is described from an adult female that was collected beneath snow-covered sea ice during the 2014 Ice Covered Ecosystem – CAMbridge bay Process Study (ICE-CAMPS in Dease Strait of the Canadian Arctic Archipelago. Currently, up to six species of this order are known to occur in polar latitudes. The new species described herein shares similarities with Monstrillopsis dubia (Scott, 1904 but differs in its body proportions and cephalothorax ornamentation; the cephalothorax is covered by minute scattered papillae on dorsal and ventral surfaces; this species has a reduced fifth leg endopod, fifth leg exopod armed with three setae, antennule with fused segments 3–4, and the genital double-somite bears unique posterolateral processes. This is the second species of this genus recorded in the Arctic, after Monstrillopsis ferrarii (Suárez-Morales & Ivanenko, 2004, described from the White Sea, and is the first record of Monstrillopsis in Canadian waters. With the addition of this new species and the recognition of Monstrillopsis bernardensis comb. nov. as a member of this genus, the number of nominal species is now 15. Overall, this genus has a tendency to be distributed in temperate and cold waters, while only three species have been found in tropical and subtropical latitudes.

  19. Molecular characterisation of key components of the mucosal immune system in Atlantic salmon (Salmo salar L) and transcriptome analysis of responses against the salmon louse (Lepeophtheirus salmonis)

    OpenAIRE

    Tadiso, Tariku Markos

    2012-01-01

    Mucosal immunity in mammals is mediated mainly by secretory immunoglobulin A (SIgA), which is produced by IgA plasma cells commonly located in the lamina propria, and a transport system involving the polymeric Ig receptor (pIgR). In teleost fish, IgM plays some roles associated with mucosal defence. Very recent findings indicate that IgT, an antibody exclusive to teleosts, might have a special role in mucosal immune responses, and a possible pIgR counterpart has been identified...

  20. Gene expression in Atlantic salmon skin in response to infection with the parasitic copepod Lepeophtheirus salmonis, cortisol implant, and their combination

    Directory of Open Access Journals (Sweden)

    Krasnov Aleksei

    2012-04-01

    Full Text Available Abstract Background The salmon louse is an ectoparasitic copepod that causes major economic losses in the aquaculture industry of Atlantic salmon. This host displays a high level of susceptibility to lice which can be accounted for by several factors including stress. In addition, the parasite itself acts as a potent stressor of the host, and outcomes of infection can depend on biotic and abiotic factors that stimulate production of cortisol. Consequently, examination of responses to infection with this parasite, in addition to stress hormone regulation in Atlantic salmon, is vital for better understanding of the host pathogen interaction. Results Atlantic salmon post smolts were organised into four experimental groups: lice + cortisol, lice + placebo, no lice + cortisol, no lice + placebo. Infection levels were equal in both treatments upon termination of the experiment. Gene expression changes in skin were assessed with 21 k oligonucleotide microarray and qPCR at the chalimus stage 18 days post infection at 9°C. The transcriptomic effects of hormone treatment were significantly greater than lice-infection induced changes. Cortisol stimulated expression of genes involved in metabolism of steroids and amino acids, chaperones, responses to oxidative stress and eicosanoid metabolism and suppressed genes related to antigen presentation, B and T cells, antiviral and inflammatory responses. Cortisol and lice equally down-regulated a large panel of motor proteins that can be important for wound contraction. Cortisol also suppressed multiple genes involved in wound healing, parts of which were activated by the parasite. Down-regulation of collagens and other structural proteins was in parallel with the induction of proteinases that degrade extracellular matrix (MMP9 and MMP13. Cortisol reduced expression of genes encoding proteins involved in formation of various tissue structures, regulators of cell differentiation and growth factors. Conclusions These results suggest that cortisol-induced stress does not affect the level of infection of Atlantic salmon with the parasite, however, it may retard repair of skin. The cortisol induced changes are in close concordance with the existing concept of wound healing cascade.

  1. Study of the type 4B protein secretion system (Dot/Icm) and the effector protein SdhA in Piscirickettsia Salmonis

    OpenAIRE

    Cortés Sobarzo, Marcos Andrés

    2017-01-01

    Chilean Salmon Farming is an important industry nowadays in Chile with significanteconomics entry to the country. The troubles with the handling and maintenance of this industry to avoid product losses is a key factor of concern right now. Piscirickettsiosis disease has been a problem that persist over the time in this industry and several attempts had been made to try to solve the mortalities induced by this fish pathogen. According to Aquaculture and Fishery report from Sernapesca, the amou...

  2. NCBI nr-aa BLAST: CBRC-TTRU-01-0346 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TTRU-01-0346 ref|YP_271845.1| NADH dehydrogenase subunit 4 [Lepeophtheirus sal...monis] gb|AAT42064.1| NADH dehydrogenase subunit 4 [Lepeophtheirus salmonis] YP_271845.1 0.014 29% ...

  3. EST Table: AV402944 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available AV402944 heS30768 10/09/28 76 %/117 aa gb|ACO12033.1| 40S ribosomal protein S8 [Lepeo...phtheirus salmonis] gb|ACO12251.1| 40S ribosomal protein S8 [Lepeophtheirus salmonis] 10/08/28 67 %/122 aa

  4. NCBI nr-aa BLAST: CBRC-BTAU-01-1417 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-BTAU-01-1417 ref|YP_271845.1| NADH dehydrogenase subunit 4 [Lepeophtheirus sal...monis] gb|AAT42064.1| NADH dehydrogenase subunit 4 [Lepeophtheirus salmonis] YP_271845.1 0.025 33% ...

  5. NCBI nr-aa BLAST: CBRC-DNOV-01-2151 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DNOV-01-2151 ref|YP_271845.1| NADH dehydrogenase subunit 4 [Lepeophtheirus sal...monis] gb|AAT42064.1| NADH dehydrogenase subunit 4 [Lepeophtheirus salmonis] YP_271845.1 7e-04 26% ...

  6. EST Table: DC537811 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available iron-sulfur protein 3, mitochondrial precursor [Lepeophtheirus salmonis] gb|ADD38463.1| NADH dehydrogenase ...iron-sulfur protein 3, mitochondrial [Lepeophtheirus salmonis] 10/09/02 68 %/103 aa FBpp0195557|DsecGM14080-

  7. Ampliación del ámbito de Macrochiron sargassi G. O. Sars (Copepoda: Lichomolgidae) en el Atlántico Noroccldental

    OpenAIRE

    Suárez-Morales, Eduardo; Reid, Janet W

    2016-01-01

    Orden Poecilostomatoida incluye fundamentalmente copépodos asociados con diversos vertebrados e invertebrados marinos. y también formas típicamente plactonicas como Oncaea y Sapphirina. Macrochiron sargassi G. O. Sars, 1916, que es la especie que aquí se refiere, pertenece a la Familia Lichomolgidae, y fue originalmente descrita por Sars (1916) a partir de material. recolectado por el Príncipe Alberto de Monaco en el Mar de los Sargazos. Orden Poecilostomatoida incluye fundamentalmente cop...

  8. Preface: Recent Developments in Taxonomy and Biodiversity of Symbiotic Copepoda (Crustacea)-A Volume in Celebration of the Career of Prof. Il-Hoi Kim.

    Science.gov (United States)

    Huys, Rony

    2016-10-11

    Symbiosis is one of the most successful modes of life displayed by aquatic organisms, as measured by the number of times it evolved and how many symbiotic species are presently in existence. Among the Crustacea copepods utilize an extraordinary range of hosts, occurring on virtually every phylum of marine macroinvertebrates and, jointly with the monogeneans, are the most speciose group of metazoan ectoparasites of marine fishes (Rhode 2005). Several species have a major impact on global finfish and shellfish aquaculture, causing significant effects on farm production, economic viability and sustainability (Shinn et al. 2015). Parasitism by copepods on other metazoans has evolved independently numerous times in the evolutionary history of animal life on Earth and has led to an exceptional diversity in morphologies, physiologies, life-strategies and habitat preferences of its members. Reflecting the diversity of hosts, copepods show an amazing variety of adaptations which secure infection of and survival on the hosts. Since the first descriptions of parasitic copepods occurring on fish by Linnaeus (1758) and the first report of a copepod utilizing an invertebrate host by Say (1818) (Clausidium caudatum (Say, 1818)) the number of described symbiotic copepods has seen a steady increase over a 200-yr period, culminating in a total of 5,306 valid species recognized today. About 38% of all described copepod species utilize either vertebrate (2,450 spp.) or invertebrate hosts (2,856 spp.), however, many host groups have not been thoroughly examined, and for this reason even approximate estimates of true species numbers are futile. Plotting the proposal of new species by decade (Fig. 1) shows a sharp rise since 1950 with 67% of the species having been described in the preceding 65 years. This period of exceptionally rapid progress can be attributed to a number of highly prolific investigators such as Arthur Humes, Il-Hoi Kim, Ju-shey Ho and Jan Stock who, single-handedly or in collaboration with other authors, described 698, 356, 290 and 246 species, respectively. Historically, the number of described copepod species parasitizing fish typically outnumbered those known to be associated with invertebrates. Only during the mid-1970s the species curves of both categories converged and during the last 30 years the discovery of new species associated with invertebrate hosts appears to progress more rapidly. Despite a significant drop in the number of specialists working on symbiotic copepods the steady addition of new taxa shows that the dynamism of their taxonomy is clearly set to continue.

  9. The Life Cycle of the Parasitic Crustacean, Lernanthropus latis Yamaguti, 1954 (Copepoda: Lernanthropidae, on Marine-Cultured Fish, Lates calcarifer, from Setiu Wetland, Terengganu

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    Nur Qamarina Abdul Khalid

    2014-01-01

    Full Text Available Parasitic crustaceans of Lernanthropus latis were isolated from the host, the seabass, Lates calcarifer, obtained from a cage culture in Setiu Wetland, Terengganu. The adult females with egg were kept alive in vials containing 20 mL of filtered seawater and incubated at 30°C. The eggs were monitored every hour and the hatching periods were recorded. Three developmental stages were observed, namely, nauplii I, nauplii II, and infective copepodid. The infective copepodids were then transferred into a tank containing 60 litres of seawater with 150 fingerlings for infection purpose. One fish was sacrificed every 24 hr to inspect the next developmental stage. As a result, six more stages were obtained within 298 hrs starting from the infection day. The stages were known as fixed copepodid I, fixed copepodid II, fixed copepodid III, fixed copepodid IV, preadult, and adult. Parasitic L. latis takes a 483 hr period to complete a life cycle.

  10. Familia Pontellidae (Crustacea: Copepoda en la Bahía La Ventosa, Oaxaca, México: Sistemática y ecología

    Directory of Open Access Journals (Sweden)

    Carlos Álvarez Silva

    2003-09-01

    Full Text Available Se presenta un estudio sobre la sistemática y notas ecológicas de los copépodos pláncticos de la Bahía de La Ventosa, Oaxaca, México. Se identificaron cinco especies: Labidocera acuta, L. lubbockii, Pontella agassizi, P. tenuiremis y Pontellina plumata. La especie más abundante fue L. acuta y sus estados copepodito que conformaron el 95.7% del total de Pontellidos, seguidos por L. lubbockii 4.09%, otras especies constituyeron menos del 1%. El éxito reproductivo de L. acuta se vea favorecido por su resistencia a los cambios en temperatura y salinidad que la consignan como euriterma y euriahalina. Considerando la densidad total de esta familia se observó que durante 1987 y 1988 la densidad de estos copépodos osciló entre 18 y 472 copépodos/100 m 3 , pero entre 1992 y 1993 la densidad se incrementó de 490 a 123 030 copépodos/100 m³ . El aumento interanual en la densidad numérica de copépodos parece estar relacionado con fenómenos de escala local (surgencias presentes a principios y finales del añoA study on ecological records of planktonic copepods from The Ventosa Bay, Oaxaca, Mexico is presented. Five species were identified: Labidocera acuta, L. lubbockii, Pontella agassizi, P. tenuiremis and Pontellina plumata. The most abundant species was L. acuta and their copepodite stages conforming the 95.7% of Pontellids, followed by L. lubbockii 4.09%; other species were less than one percent. The reproductive success of L. acuta is probably favored by its resistance to the changes in temperature and salinity, because of it is an eurytherme and euryhaline organism. Total density of this family was between 18 and 472 copepods/100 m³ in 1987 and 1988. Nevertheless in 1992 and 1993 the density was between 490 to 123 030 copepods/100 m³ . This copepod density increment could be related local phenomenon (upwelling at the beginning and end of the year

  11. Effects of cold selective breeding on the body length, fatty acid content, and productivity of the tropical copepod Apocyclops royi (Cyclopoida, Copepoda)

    DEFF Research Database (Denmark)

    Pan, Yen-Ju; Souissi, Anissa; Sadovskaya, Irina

    2017-01-01

    strain) temperature for 10 months, corresponding to ~40 and 15 generations, respectively. After temperature acclimation, multigenerational observations were made to investigate the effects of cold selection on the copepods. Differences in female and nauplius lengths, nauplius production, and fatty acid...... and omega 6 and omega 3 polyunsaturated fatty acid contents were higher in the selective strain than in the control strain; however, the fatty acid content gradually decreased in subsequent generations. This paper reports the effects of temperature acclimation on the morphological and physiological traits...

  12. Exotic "Gill Lice" Species (Copepoda: Lernaeopodidae: Salmincola SPP.) Infect Rainbow Trout (Oncorhynchus mykiss) and Brook Trout (Salvelinus fontinalis) in the Southeastern United States.

    Science.gov (United States)

    Ruiz, Carlos F; Rash, Jacob M; Besler, Doug A; Roberts, Jackson R; Warren, Micah B; Arias, Cova R; Bullard, Stephen A

    2017-08-01

    Salmincola californiensis infected 25 of 31 (prevalence 0.8; intensity 2-35 [mean 6.6 ± standard deviation 7.7; n = 25]) rainbow trout, Oncorhynchus mykiss, from a private trout farm connected to the Watauga River, North Carolina. Salmincola edwardsii infected all of 9 (1.0; 2-43 [9.3 ± 13.0; 9]) brook trout, Salvelinus fontinalis, from Big Norton Prong, a tributary of the Little Tennessee River, North Carolina. Both lernaeopodids are well-known salmonid pathogens, but neither is native to, nor has been previously taxonomically confirmed from, the southeastern United States. Herein, we (1) use light and scanning electron microscopy to identify and provide supplemental morphological observations of these lernaeopodids, (2) furnish complementary molecular sequence data from the 28S rDNA (28S), and (3) document the pathological effects of gill infections. We identified and differentiated these lernaeopodids by the second antenna (exopod tip with large [S. californiensis] vs. slender [S. edwardsii] spines; endopod terminal segment with subequal ventral processes shorter than [S. californiensis] vs. longer than or equal to [S. edwardsii] dorsal hook), maxilliped palp (length typically ≤1/3 [S. californiensis] vs. 1/3-1/2 [S. edwardsii] subchela length exclusive of claw), and bulla (sub-circular and concave on manubrium's side [S. californiensis] vs. non-stellate [S. edwardsii]). Analysis of the 28S rDNA sequences confirmed our taxonomic assignments as demonstrated by 100% sequence similarity among the sympatric, morphologically-conspecific isolates. Histopathology revealed focal gill epithelial hyperplasia, obstruction of interlamellar water channels, lamellar fusion, and crypting of gill filaments. High intensity infections by either lernaeopodid are surveillance-worthy because they are potentially pathogenic to trout in the southeastern United States.

  13. Effect of water quality parameters on the distribution of Pleuromamma (Copepoda-Calanoida) species in the Indian Ocean: A statistical approach

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, V.K.; Saraswathy, M.; Nair, M.

    The region between 10 degrees N and 10 degrees S latitude was known to be congenial for distribution of Pleuromamma species. Diel and ontogenetic migrations were observed for Pleuromamma xiphias. Multivariate analyses such as factor analysis...

  14. A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae

    Directory of Open Access Journals (Sweden)

    Eduardo Suárez-Morales

    2017-04-01

    Full Text Available Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP, Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos. The new taxon, S. fernandoi sp. n., is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species, followed by the Mediterranean (seven species and the Northeastern Atlantic (six species; only four species are known from the Northwestern Tropical Atlantic (NWTA. The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos.

  15. A new anchialine Stephos Scott from the Yucatan Peninsula with notes on the biogeography and diversity of the genus (Copepoda, Calanoida, Stephidae).

    Science.gov (United States)

    Suárez-Morales, Eduardo; Gutiérrez-Aguirre, Martha A; Cervantes-Martínez, Adrián; Iliffe, Thomas M

    2017-01-01

    Surveys of the anchialine crustacean fauna of the Yucatan Peninsula (YP), Mexico, have revealed the occurrence of calanoid copepods. The genus Stephos Scott, 1892, belonging to the family Stephidae is among the most frequent and widely distributed groups in anchialine caves but has not been hitherto recorded from the YP. Recent collections from an anchialine cave in an island off the northern coast of the YP yielded many specimens of a new species of Stephos. The new taxon, S. fernandoisp. n., is described here based on male and female specimens. The new species is clearly distinguished from its congeners by the following characters: male left fifth leg with three terminal lamellae plus subdistal process, right leg with distal row of peg-like elements; female fifth leg with single long, acute apical process; genital double-somite with two rows each of 4 long spinules adjacent to operculum; legs 2-4 with articulated setae. The diversity of the genus shows regional differences; the Australia-Western Pacific region is the most diverse (eleven species), followed by the Mediterranean (seven species) and the Northeastern Atlantic (six species); only four species are known from the Northwestern Tropical Atlantic (NWTA). The morphology of the female fifth leg was examined to explore possible biogeographic trends in the genus; patterns suggest multiple colonization events in the highly diverse regions and a relatively recent radiation in the NWTA, characterized by anchialine forms. The introduction of stephid copepods in the region may be a relatively recent event derived from colonization of benthopelagic ancestral forms and subsequent invasion onto cave habitats. The new species appears to be linked to the strictly anchialine Miostephos.

  16. Transcriptome survey of the lipid metabolic pathways involved in energy production and ecdysteroid synthesis in the salmon louse Caligus rogercresseyi (Crustacea: Copepoda).

    Science.gov (United States)

    Gonçalves, Ana Teresa; Farlora, Rodolfo; Gallardo-Escárate, Cristian

    2014-10-01

    The goal of this study was to identify and analyze the lipid metabolic pathways involved in energy production and ecdysteroid synthesis in the ectoparasite copepod Caligus rogercresseyi. Massive transcriptome sequencing analysis was performed during the infectious copepodid larval stage, during the attached chalimus larval stage, and also in female and male adults. Thirty genes were selected for describing the pathways, and these were annotated for proteins or enzymes involved in lipid digestion, absorption, and transport; fatty acid degradation; the synthesis and degradation of ketone bodies; and steroid and ecdysteroid syntheses. Differential expression of these genes was analyzed by ontogenic stage and discussed considering each stage's feeding habits and energetic needs. Copepodids showed a low expression of fatty acid digestion genes, reflected by a non-feeding behavior, and the upregulation of genes involved in steroid biosynthesis, which was consistent with a pathway for cholesterol synthesis during ecdysis. The chalimus stage showed an upregulation of genes related to fatty acid digestion, absorption, and transport, as well as to fatty acid degradation and the synthesis of ketone bodies, therefore suggesting that lipids ingested from the mucus and skin of the host fish are metabolized as important sources of energy. Adult females also showed a pattern of high lipid metabolism for energy supply and mobilization in relation to reproduction and vitellogenesis. Adult females and males revealed different lipid metabolism patterns that reflected different energetic needs. This study reports for the first time the probable lipid metabolic pathways involved in the energy production and ecdysteroid synthesis of C. rogercresseyi. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Scanning electron microscopy of damage caused by Mesocyclops thermocyclopoides (Copepoda: Cyclopoidea on larvae of the Dengue fever vector Aedes aegypti (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Stefan Schaper

    2006-09-01

    Full Text Available Dengue fever is a mosquito-borne viral disease, whose main biological vector is Aedes aegypti. This mosquito colonizes tropical areas where the disease is endemic. The most obvious action against dengue is attacking its vector. Biological control appears to be an alternative approach, using natural enemies of the mosquitoes, such as predatory copepods. Thus, the morphological study of the damage caused by copepods is important to understand its predatory capacity. Twenty-five A. aegypti larvae were exposed to the copepod Mesocyclops thermocyclopoides and the damage caused by the copepods was evaluated using scanning electron microscopy. The larvae showed damage mainly at the anal segment, the siphon and the abdomen; only three attacks to the head were observed. The size of the siphon might be of importance in determining whether or not a copepod will attack a mosquito larva. Rev. Biol. Trop. 54 (3: 843-846. Epub 2006 Sept. 29.El dengue es una enfermedad viral transmitida por mosquitos, cuyo principal vector es Aedes aegypti. Este mosquito coloniza muchas áreas tropicales donde la enfermedad es endémica. La acción más obvia contra el dengue es el ataque a su vector. El control biológico parece una buena alternativa, empleando enemigos naturales de los mosquitos, como los copépodos. Por lo tanto, es importante el estudio morfológico del daño causado por los copépodos para comprender su capacidad depredadora. Veinticinco larvas de A. aegypti fueron expuestas a la actividad depredadora del copépodo Mesocyclops thermocyclopoides. Mediante microscopia electrónica de rastreo se evaluó el daño causado por los copépodos. Éstos atacaron principalmente el segmento anal, el sifón y el abdomen de las larvas; sólo vimos tres ataques a la cabeza. El tamaño del sifón podría ser de importancia para predecir si los copépodos pudiesen atacar larvas de determinado mosquito.

  18. The Life Cycle of the Parasitic Crustacean, Lernanthropus latis Yamaguti, 1954 (Copepoda: Lernanthropidae), on Marine-Cultured Fish, Lates calcarifer, from Setiu Wetland, Terengganu

    OpenAIRE

    Nur Qamarina Abdul Khalid; Faizah Shaharoum-Harrison

    2014-01-01

    Parasitic crustaceans of Lernanthropus latis were isolated from the host, the seabass, Lates calcarifer, obtained from a cage culture in Setiu Wetland, Terengganu. The adult females with egg were kept alive in vials containing 20 mL of filtered seawater and incubated at 30°C. The eggs were monitored every hour and the hatching periods were recorded. Three developmental stages were observed, namely, nauplii I, nauplii II, and infective copepodid. The infective copepodids were then transferred ...

  19. The effects of power station entrainment passage on three species of marine planktonic crustacean, Acartia tonsa (Copepoda), Crangon crangon (Decapoda) and Homarus gammarus (Decapoda).

    Science.gov (United States)

    Bamber, Roger N; Seaby, Richard M H

    2004-05-01

    Experiments have been undertaken exposing larval common shrimp (Crangon crangon) and lobster (Homarus gammarus) and adult copepods (Acartia tonsa) to the key stresses of entrainment within power-station cooling-water systems. The apparatus has enabled the testing of mechanical, thermal, chlorine and realistic pressure effects both alone and in combination, the range of stressors spanning the standard conditions found within a temperate coastal direct-cooled power station. Mechanical stresses affected only lobster larvae, pressure changes affected only the Acartia adults. Residual chlorine caused significant mortality of Acartia and shrimp larvae, but had no effect on lobster larvae even at 1 ppm. The temperature increment significantly affected all three species, with a synergistic effect on chlorine sensitivity in the shrimp larvae, but only temperatures higher than would be experienced in a normally-operating power station affected the copepods. The majority of individuals of each species would survive passage through a power-station system under normal conditions. It is notable that, within the species tested, generalizations from the responses of one species to those of another are not valid.

  20. A new species of the rare endoparasitic copepod Entobius (Copepoda: Entobiidae) from Mexico with a key to the species of the genus.

    Science.gov (United States)

    Suárez-Morales, Eduardo; Carrera-Parra, Luis F

    2012-09-01

    Abstract: In a study of the benthic polychaete fauna of the southern Gulf of Mexico and the Caribbean Sea, several specimens of the terebellid polychaete Scionides reticulata (Ehlers) were found to host endoparasitic copepods that represent an undescribed species of the rare cyclopoid genus Entobius Dogiel, 1948. The new species, E. scionides sp. n., can be distinguished from its congeners by a combination of characters including a genital region without constrictions, three-segmented antennules, a reduced antenna with a blunt terminal process, reduced ornamentation of endopods of legs 1-4 and its relatively small size (2.3-2.7 mm). It is the smallest species of the genus. Comments on immature females are also provided, but males of this species remain unknown. It has a high prevalence (53%) in populations of the terebellid S. reticulata in the southern Gulf of Mexico, but it is absent from the Caribbean. This is the first occurrence of this copepod genus in the Americas. The finding of the new species of Entobius in S. reticulata confirms the strict specificity of most members of the genus and expands the host range of this copepod genus. A key for the identification of the species of Entobius is provided.

  1. A new species of Asterocheres (Copepoda, Siphonostomatoida) with a redescription of A. complexus Stock, 1960 and A. sarsi Bandera & Conradi, 2009.

    Science.gov (United States)

    Bandera, Eugenia; Conradi, Mercedes

    2014-07-07

    The present paper reviews the material of three species of Asterocheres Boeck 1859 deposited in four different Zoological European museums as part of the ongoing taxonomical revision of this genus. Asterocheres sarsi Bandera & Conradi 2009, the species described by Sars in 1915 as Ascomyzon latum (Brady 1880) and lately recognized as a distinct species by Bandera and Conradi in 2009 is fully described in this paper from material collected by Sars in Norway in 1915 and deposited in The Natural History Museum of the University of Oslo. Asterocheres complexus Stock, 1960 which has been sometimes confused with A. sarsi is redescribed from material collected by Stock in France in 1959 and deposited in the Zoological Museum of the University of Amsterdam. Furthermore, a new species, previously misidentified as A. suberitis Gieisbrecht 1897, from the Norman`s collection of The Natural History Museum of London, is described as A. eugenioi, new species. These three species, A. complexus, A. eugenioi, and A. sarsi share the general appearance of body thanks to the pointed posterolateral angle of the epimeral area of somite bearing leg 3, sometimes slightly produced into backwardly directed processes, and somite bearing leg 4 largely concealed under somite bearing leg 3.

  2. Harpacticoida (Crustacea: Copepoda associated with cold-water coral substrates in the Porcupine Seabight (NE Atlantic: species composition, diversity and reflections on the origin of the fauna

    Directory of Open Access Journals (Sweden)

    Hendrik Gheerardyn

    2009-12-01

    Full Text Available The harpacticoid copepod fauna associated with the coral degradation zone of Lophelia pertusa (Linnaeus, 1758 reefs was investigated for the first time in the Porcupine Seabight (NE Atlantic. The species list of the coral degradation zone includes 157 species, 62 genera and 19 families, and the most species-rich families were Ectinosomatidae (36 species, Ameiridae (29 species and Argestidae (17 species. At least 80% of the species were considered new to science. Most of the 23 known species have been reported from NE Atlantic coastlines and from higher latitudes in northern Subpolar and Polar Seas. At the family level, the harpacticoid fauna in the Porcupine Seabight did not seem to differ markedly from other deep-sea areas, with essentially the same abundant families. However, the presence of typically epifaunal taxa indicates that the hard substrates of the coral degradation zone provide an exceptional habitat. Further, harpacticoid composition and diversity of sediment and coral fragments were compared with similar substrates in a tropical reef lagoon (Zanzibar, Tanzania. Both regions harboured different fauna and the difference between coral and sediment was more obvious in the tropical lagoon. Species richness and evenness of the two microhabitats in the tropical lagoon were lower than in the deep sea.

  3. Amsterdam Expeditions to the West Indian Islands, Report 42. Harpacticoid copepods from the West Indian Islands: Canuellidae and Longipediidae (Copepoda, Harpacticoida)

    NARCIS (Netherlands)

    Fiers, Frank

    1984-01-01

    This paper is the first of a series dealing with the systematics of harpacticoid copepods collected during the West Indian Expeditions of the University of Amsterdam. In the present paper a new species, Scottolana antillensis n. sp., is described. Furthermore, Ellucana secunda Coull, 1971, is

  4. Prediction of the protein components of a putative Calanus finmarchicus (Crustacea, Copepoda) circadian signaling system using a de novo assembled transcriptome.

    Science.gov (United States)

    Christie, Andrew E; Fontanilla, Tiana M; Nesbit, Katherine T; Lenz, Petra H

    2013-09-01

    Diel vertical migration and seasonal diapause are critical life history events for the copepod Calanus finmarchicus. While much is known about these behaviors phenomenologically, little is known about their molecular underpinnings. Recent studies in insects suggest that some circadian genes/proteins also contribute to the establishment of seasonal diapause. Thus, it is possible that in Calanus these distinct timing regimes share some genetic components. To begin to address this possibility, we used the well-established Drosophila melanogaster circadian system as a reference for mining clock transcripts from a 200,000+ sequence Calanus transcriptome; the proteins encoded by the identified transcripts were also deduced and characterized. Sequences encoding homologs of the Drosophila core clock proteins CLOCK, CYCLE, PERIOD and TIMELESS were identified, as was one encoding CRYPTOCHROME 2, a core clock protein in ancestral insect systems, but absent in Drosophila. Calanus transcripts encoding proteins known to modulate the Drosophila core clock were also identified and characterized, e.g. CLOCKWORK ORANGE, DOUBLETIME, SHAGGY and VRILLE. Alignment and structural analyses of the deduced Calanus proteins with their Drosophila counterparts revealed extensive sequence conservation, particularly in functional domains. Interestingly, reverse BLAST analyses of these sequences against all arthropod proteins typically revealed non-Drosophila isoforms to be most similar to the Calanus queries. This, in combination with the presence of both CRYPTOCHROME 1 (a clock input pathway protein) and CRYPTOCHROME 2 in Calanus, suggests that the organization of the copepod circadian system is an ancestral one, more similar to that of insects like Danaus plexippus than to that of Drosophila. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Decline of Pseudodiaptomus hessei (Copepoda, Calanoida) in two water bodies located in the Senegal River hydrosystem (West Africa): Hypotheses and perspectives

    Science.gov (United States)

    Mendoza-Vera, Juana Mireya; Kâ, Samba; Cuoc, Corinne; Bouvy, Marc; Pagano, Marc

    2008-09-01

    Pseudodiaptomus hessei is a key species in many water bodies in the Senegal River hydrosystem but it became rare or completely disappeared from two ecosystems (Lake Guiers and Dakar Bango Reservoir; Senegal, West Africa) after major hydrological changes caused by human action, mainly impoundments on the river in 1985, and the opening of a new estuary mouth in 2003. Kâ et al. [Kâ, S., Pagano, M., Ba, N., Bouvy, M., Leboulanger, C., Arfi, R., Thiaw, O.T., Ndour, E.H.M., Corbin, D., Defaye, D., Cuoc, C., Kouassi, E., 2006. Zooplankton distribution related to environmental factors and phytoplankton in a shallow tropical lake (Lake Guiers, Senegal, West Africa). International Review of Hydrobiology 91(5), 389-405] put forward several hypotheses to explain the reasons for this decline: salinity and chemical changes in the water, predation by a cyclopid predator Mesocyclops ogunnus and/or the inhibiting effects of cyanobacteria and/or diatoms (allelopathy). This study assessed these hypotheses by studying the distribution of P. hessei in 13 stations (including the Dakar Bango reservoir and Lake Guiers) in relation to physical, chemical and biological (phyto- and zooplanktons) factors at each station. We produced a distribution pattern for this species in the Senegal River hydrosystem. Rank correlations and principal component analysis showed that P. hessei was not correlated with conductivity but was positively correlated with pH and alkalinity, suggesting chemical effects. The clear association with two filamentous cyanobacteria ( Cylindrospermopsis raciborskii and Anabaena sp.) did not appear to support the hypothesis of cyanobacteria inhibition but blooming conditions were never encountered during the study. Negative correlation with diatoms (especially with Fragilaria sp.) suggested that aldehyde producing diatoms had a negative effect. Negative correlations with cyclopids such as Mesocyclops supported the hypothesis of cyclopid predation to explain the decline of P. hessei. This study proposes several lines of research for future studies to test these hypotheses.

  6. Colobomatus kimi sp. nov. (Copepoda: Philichthyidae) parasitic in the dwarf goatfish Upeneus parvus Poey, 1852 (Perciformes: Mullidae) in the South Atlantic Ocean.

    Science.gov (United States)

    Paschoal, Fabiano; Pereira, Aldenice N; Luque, José Luis

    2016-10-11

    A new species of copepod, Colobomatus kimi sp. nov., belonging to the cyclopoid family Philichthyidae Vogt, 1877, is proposed based on female specimens collected from the pores of the cephalic sensory system of the dwarf goatfish, Upeneus parvus Poey from the southeastern Brazilian coastal zone. The new species can be distinguished from its closest congeners by the unique combination of characters displayed by the female, including the forked caudal rami, the position of the midventral cephalic process shorter in relation to the lateral cephalic processes, and the presence of paired genital processes. The new species is the first member of Colobomatus Hesse, 1873 found to parasitize mullids of the genus Upeneus.

  7. Two new species of Nitocrella (Crustacea, Copepoda, Harpacticoida from groundwaters of northwestern Australia expand the geographic range of the genus in a global hotspot of subterranean biodiversity

    Directory of Open Access Journals (Sweden)

    Danny Tang

    2016-11-01

    Full Text Available In Australia, the Ameiridae is the most diverse harpacticoid family in groundwater, with 35 species hitherto reported. In this study, we describe two new species belonging to the “vasconica”-group of the ameirid genus Nitocrella based on specimens collected from groundwaters near mine sites in the Pilbara and Great Sandy Desert regions of northwestern Australia. Nitocrella knotti sp. n. can be distinguished from related taxa by having two setae on the antennal exopod, four armature elements on the distal endopodal segment of leg 2, four armature elements on the distal endopodal segment of leg 3, three armature elements on the distal endopodal segment of leg 4, and three setae on the basoendopodal lobe of leg 5. Nitocrella karanovici sp. n. differs from its congeners by having a short outer spine and long inner seta on the distal endopodal segment of leg 2, three armature elements on the distal endopodal segment of leg 3, and four setae on the basoendopodal lobe of leg 5 in the female. This study is of biogeographic interest in providing the first documentation of the genus Nitocrella from the Pilbara and Great Sandy Desert regions. Both new species of Nitocrella are recorded from restricted localities and appear to be short-range endemics, thus making them potentially vulnerable to environmental changes and threatening processes such as mining. The distribution range of N. karanovici sp. n. coincides with the centre of diversity of the Ethel Gorge aquifer stygobiont community, a globally significant hotspot which is listed as endangered.

  8. Familia Pontellidae (Crustacea: Copepoda) en la Bahía La Ventosa, Oaxaca, México: Sistemática y ecología

    OpenAIRE

    Carlos Álvarez Silva; María Guadalupe Miranda Arce; Graciela De Lara-Isassi

    2003-01-01

    Se presenta un estudio sobre la sistemática y notas ecológicas de los copépodos pláncticos de la Bahía de La Ventosa, Oaxaca, México. Se identificaron cinco especies: Labidocera acuta, L. lubbockii, Pontella agassizi, P. tenuiremis y Pontellina plumata. La especie más abundante fue L. acuta y sus estados copepodito que conformaron el 95.7% del total de Pontellidos, seguidos por L. lubbockii 4.09%, otras especies constituyeron menos del 1%. El éxito reproductivo de L. acuta se vea favorecido p...

  9. Familia Pontellidae (Crustacea: Copepoda) en la Bahía La Ventosa, Oaxaca, México: Sistemática y ecología

    OpenAIRE

    Álvarez Silva, Carlos; Miranda Arce, María Guadalupe; De Lara-Isassi, Graciela

    2014-01-01

    Se presenta un estudio sobre la sistemática y notas ecológicas de los copépodos pláncticos de la Bahía de La Ventosa, Oaxaca, México. Se identificaron cinco especies: Labidocera acuta, L. lubbockii, Pontella agassizi, P. tenuiremis y Pontellina plumata. La especie más abundante fue L. acuta y sus estados copepodito que conformaron el 95.7% del total de Pontellidos, seguidos por L. lubbockii 4.09%, otras especies constituyeron menos del 1%. El éxito reproductivo de L. acuta se vea favorecido p...

  10. Diversity and structure of microcrustacean assemblages (Cladocera and Copepoda and limnological variability in perennial and intermittent pools in a semi-arid region, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Nadson R. Simões

    2011-12-01

    Full Text Available Temporary wetlands undergo recurrent drought due to the scarcity of water, which disrupts the hydrological connectivity with adjacent aquatic systems. However, some environments retain water for longer periods, allowing greater persistence of the community. The current study evaluated differences in the microcrustacean assemblages and limnological variability between perennial and intermittent pools in a semi-arid region of Brazil. The abiotic features (water temperature, pH, total alkalinity, electrical conductivity and depth of intermittent pools were affected more than perennial pools due to loss of water volume. This may have contributed to a higher average richness and diversity index in some intermittent pools and differences in the structure of the assemblages. The lowest species richness and diversity were recorded where physical factors, such as a large quantity of suspended solids and variability in the electrical conductivity of the water and pH, make the environment unsuitable for these organisms. These results suggest that community development in intermittent pools is interrupted by the dry season; when the water returns, due to rainfall or rising groundwater, each pond undergoes a different process of colonization. In these circumstances, the biological importance of temporary aquatic environments is clear, since such pools provide shelters and have an important role in the maintenance of the regional diversity of aquatic environments.

  11. Potential zooplankton preys (Copepoda and Appendicularia for Engraulis anchoita in relation to early larval and spawning distributions in the Patagonian frontal system (SW Atlantic Ocean

    Directory of Open Access Journals (Sweden)

    Mariela L. Spinelli

    2011-11-01

    Full Text Available We investigated the spatial distribution of the abundance, biomass and size of zooplankton (nauplii, calanoids, cyclopoids and appendicularians in relation to the distribution of first-feeding larvae and eggs of Engraulis anchoita across the frontal system of Peninsula Valdés. Twelve samples of zooplankton and ichthyoplankton were taken with small Bongo (67 μm and Pairovet (200 μm nets during the spring of 2004 along two transects. The total abundance of zooplankton and the chlorophyll a concentration were higher in homogeneous waters, while total biomasses were higher in stratified waters. Temperature was negatively correlated with biological variables and was the main factor affecting the zooplankton distribution. In both transects, abundance peaks of first-feeding larvae were detected at coastal stations along with the smallest fraction of zooplankton ( < 500 μm, while the largest fraction was dominant at the external stations, coinciding with the highest egg abundance. The physical structure of this front generates different levels of food availability for first-feeding larvae. Calanoids (southern transect and cyclopoids (northern transect are predominant followed by nauplii and appendicularians. The biomass of zooplankton preys contributes to the carbon transfer to the upper trophic levels and is probably important for the survival and growth of anchovy larvae in this frontal system.

  12. New species of Pseudodiaptomus (Copepoda: Calanoida) from the salt pans of the Gulf of Kutch, India and a comment on its speciation

    Digital Repository Service at National Institute of Oceanography (India)

    Madhupratap, M.; Haridas, P.

    A new species of calanoid copepod Pseudodiaptomus pankajus (family Pseudodiaptomidae) is described from the north-west coast of India. This species inhabits high saline waters of salt pans. It appears to have evolved allopatrically during...

  13. Response of abyssal Copepoda Harpacticoida (Crustacea) and other meiobenthos to an artificial disturbance and its bearing on future mining for polymetallic nodules

    Science.gov (United States)

    Ahnert, Ahmed; Schriever, Gerd

    Long-term effects of an anthropogenic physical disturbance on the Harpacticoida taxocene at a deep-sea site were investigated during the course of the disturbance and recolonization (DISCOL) experiment in a manganese nodule area in the southeastern Pacific. Nineteen harpacticoid copepod families were found, contributing 9-12% to the metazoan meiofauna of the experimental area (Nematoda 72-80%). Twelve families occurred in sufficient numbers to be considered representatively sampled. Dominant are the Ameiridae (17%) followed by Ectinosomatidae, Argestidae, Tisbidae, Neobradyidae, Diosaccidae, Paranannopidae, Paramesochridae, Canthocamptidae, Cletodidae, Thalestridae and Huntemanniidae. These families are mainly distributed at random. Basic data on developmental stage composition and sex ratio of total Harpacticoida as well as vertical distribution of harpacticoid families in the sediment column are provided. Within the overall aim of the experiment, which was to assess the ecological risks of future deep-sea manganese nodule mining, we conducted multivariate community analyses based on the familial composition of the Harpacticoida assemblages immediately before and after experimental impact as well as seven years later. We were not able to detect a community response at the family level immediately after impact. An identification of the Tisbidae to species, however, revealed initial disturbance effects. After seven years we found significant differences in the assemblage composition of the directly disturbed portions of the experimental area and the secondarily disturbed areas in between, which to some extent had received blanketing from sediment plumes created during the experimental disturbance. Best discriminating families for long-term effects are the Ameiridae, Argestidae and Thalestridae. Their potential value as indicator taxa for monitoring disturbances in the deep sea is discussed, including some considerations on a cost-effective design of such monitoring programs that would include the meiofaunal Harpacticoida.

  14. Ergasilus turkayi n. sp. (Copepoda, Cyclopoida, Ergasilidae: a gill parasite of Serrasalmus hollandi Jégu, 2003 (Characiformes, Serrasalmidae from the Paragua River, Bolivia

    Directory of Open Access Journals (Sweden)

    Taísa M. Marques

    Full Text Available Abstract A new parasitic copepod species, Ergasilus turkayi n. sp., found on the gills of the Holland’s piranha, Serrasalmus hollandi Jégu, 2003, in the Paragua River, Bolivia, is described based on 10 adult females. The new species presents a triangular-shaped cephalothorax, spinules on interpodal plates and aesthetascs on antennule - two aesthetascs on the sixth, and one aesthetasc plus two setae on the fifth segment. Additionally, the second abdominal somite of E. turkayi n. sp. bears an anal pseudoperculum, a dorsal and elongate projection which is usually absent or vestigial in poecilostome families within the Cyclopoida but that was never reported in species of Ergasilidae.

  15. 'Snorkel' lice barrier technology reduced two co- occurring parasites, the salmon louse (Lepeophtheirus salmonis) and the amoebic gill disease causing agent (Neoparamoeba perurans), in commercial salmon sea-cages.

    Science.gov (United States)

    Wright, D W; Stien, L H; Dempster, T; Vågseth, T; Nola, V; Fosseidengen, J-E; Oppedal, F

    2017-05-01

    Diverse chemical-free parasite controls are gaining status in Atlantic salmon sea-cage farming. Yet, the intricacies of their use at commercial scale, including effects on co-occurring parasites, are seldom reported. A new salmon lice prevention method involves installing a deep net roof and 'snorkel' lice barrier in cages to shelter salmon from free-living infective larvae which concentrate at shallow depths, and allows salmon to jump and re- inflate their buoyancy-regulating swim bladder by swallowing air. We document use of snorkel cages (10m deep barrier) in commercial farms, where their effects on salmon lice levels, amoebic gill disease (AGD)-related gill scores, the cage environment, fish welfare and farm management practices were compared to standard cages. During an autumn-winter study involving only snorkel cages, high AGD-related gill scores were observed to decline when freshwater was pumped into snorkels, creating a freshwater surface layer for salmon to enter for self-treatment. In a spring-summer study incorporating snorkel and standard cages, snorkel cages were found to reduce new lice infestations by 84%. The deployment of snorkels and intermittent oxygen depletion detected within them in the spring-summer study did not alter fish welfare parameters. Overall, the results suggest snorkel technology has a place in the toolkit of commercial salmon sea-cage farmers co-managing salmon lice and amoebic gill disease outbreaks - two principal parasite issues facing the industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Addition of a selective breeding program for resistance to sea lice Lepeophtheirus salmonis (Kroyer 1838) to existing lines of Atlantic Salmon, Salmo salar L., at the USDA's National Cold Water Marine Aquaculture Center

    Science.gov (United States)

    Sea lice are likely the single most economically costly pathogen that has faced the salmon farming industry over the past 40 years. The most recent economic estimates put the annual cost of sea lice at just under $500 million USD in 2006. This is likely an underestimate of the current costs to indus...

  17. A mathematical model of the growth of sea lice, Lepeophtheirus salmonis, populations on farmed Atlantic salmon, Salmo salar L., in Scotland and its use in the assessment of treatment strategies.

    Science.gov (United States)

    Revie, C W; Robbins, C; Gettinby, G; Kelly, L; Treasurer, J W

    2005-10-01

    Sea lice are a persistent problem for farmed and wild salmonid populations. Control can be achieved through the use of veterinary medicines. A model was developed to describe the patterns of sea lice infection on salmon farms in Scotland and to predict the likely effect of various treatment strategies. This model takes into account development rates and mortality using compartments representing life history stages and external infection pressure. The national sea lice infection pattern was described using parameters representing stage survival, background infection levels and egg viability rates. The patterns observed across farms varied greatly and the model gave broad agreement to observed trends with different parameters being required in the model for sites using hydrogen peroxide and cypermethrin treatments. The parameter estimates suggest that the background infection pressure on sites where cypermethrin was administered was higher than for those using hydrogen peroxide. Both models had comparable magnitudes of sensitivity with survival from one stage to another being the most sensitive parameter, followed by feedback rates at which gravid females produce eggs, with background infection levels the least sensitive. The effect of different cypermethrin treatment strategies was assessed using the model. Increasing treatments in a production cycle gave more effective control. However, the model showed that timing of treatments is most important if sea lice are to be effectively controlled.

  18. Kroyeria brasiliense sp. nov. (Copepoda, Kroyeriidaea gill parasite of the shark, Galeorhinus vitaminicus de Buen, in Rio Grande do Sul State, Brazil Kroyeria brasiliense sp. nov. (Copepoda, Kroyeriidae um parasito de guelras do tubarão, Galeorhinus vitaminicus de Buen, no Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Vernon E. Thatcher

    2006-12-01

    Full Text Available Kroyeria brasiliense sp. nov. from the shark, Galeorhinus vitaminicus de Buen, 1950, from Rio Grande do Sul, State, Brazil, is described on the basis of 14 adult females. The new species is superficially similar to Kroyeria deetsi Dippenaar, Benz & Olivier, 2000, but differs from it in the following characters. The maxillipeds of the new species are large and project well beyond the lateral margins of the cephalothorax. Those of K. deetsi are much smaller. The third endopodal segments of K. deetsi are twice as long as the second endopodal segments and are provided with prominent marginal denticles. The second and third endopodal segments of the new species are rounded, of similar length and lack teeth.Kroyeria brasiliense sp. nov. proveniente de guelras de G. vitaminicus de Buen, 1950 do Rio Grande do Sul, é descrita baseada em 14 fêmeas adultas. A nova espécie aproxima-se de Kroyeria deetsi Dippenaar, Benz & Oliver, 2000, mas a nova espécie se distingue por apresentar os maxilípedes grandes e estendendo-se bem além das margens do cefalotorax. Os terceiros segmentos dos endopoditos de K. deetsi são duas vezes mais cumpridos que os segundos e têm dentículos marginais proeminentes. Os segundos e terceiros segmentos dos endopoditos da nova espécie são arredondados, de tamanhos parecidos e carecem de dentículos.

  19. Phytoplankton-zooplankton inter-relationships in tropical waters - Grazing and gut pigment dynamics

    Digital Repository Service at National Institute of Oceanography (India)

    Goes, J.I.; Caeiro, S.; Gomes, H.

    An examination of the feeding mechanisms in two taxonomically dissimilar classes of tropical planktonic harbivores Evadne tergestina (Cladocera) and Acrocalanus spp. (Copepoda) revealed a distinct rhythmicity of food intake. Brief bouths...

  20. Zooplankton composition and diversity in western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Nair, V.R.; Achuthankutty, C.T.; Madhupratap, M.

    higher standing stock. Copepoda formed the dominant group followed by Decapoda and Chaetognatha. Species composition of various groups and their distribution is discussed. A general inverse relationship between biomass and species diversity was the trend...

  1. Zooplankton biomass & composition in the Western Bay of Bengal during late SW monsoon; 15 August 1978 to 07 September 1978 (NODC Accession 0000941)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Copepoda formed the predominant group except in the southern region where a swarm of pelagic tunicates reduced their contribution to only 19% of the total...

  2. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea)

    DEFF Research Database (Denmark)

    Pérez-Losada, Marcos; Høeg, Jens Thorvald; Crandall, Keith A

    2009-01-01

    ,402), Histone H3 (328)] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup) and 12 Malacostraca and 10 Copepoda (outgroup). Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida...

  3. Zoogeography of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.S.S.

    The distribution pattern of zooplankton in the Indian Ocean is briefly reviewed on a within and between ocean patterns and is limited to species within a quite restricted sort of groups namely, Copepoda, Chaetognatha, Pteropoda and Euphausiacea...

  4. New record and redescription of Calanopia thompsoni A. Scott, 1909 (Copepoda, Calanoida, Pontellidae) from the Red Sea, with notes on the taxonomic status of C. parathompsoni Gaudy, 1969 and a key to species.

    Science.gov (United States)

    Al-Aidaroos, Ali M; Salama, Adnan J; El-Sherbiny, Mohsen M

    2016-01-01

    During a plankton sampling programme around Al-Wajh area, Saudi Arabian coast of the northern Red Sea, a copepod Calanopia thompsoni A. Scott, 1909 (Calanoida: Pontellidae) was reported for the first time in the Red Sea. Both sexes are fully redescribed and compared to previous descriptions as well as the closely related species, Calanopia parathompsoni. The zoogeographical distribution of the species confirms that it is of Indo-Pacific origin. A dichotomous key for the identification of males and females of the species of Calanopia is included.

  5. On the ecology of Cletocamptus gomezi Suárez-Morales, Barrera-Moreno & Ciros-Pérez 2013 (Crustacea, Copepoda, Harpacticoida micro-endemic to Lake Alchichica, Central Mexico

    Directory of Open Access Journals (Sweden)

    Javier Alcocer

    2014-11-01

    Full Text Available Cletocamptus gomezi Suárez-Morales, Barrera-Moreno & Ciros-Pérez (2013 is a recently described new species of meiobenthic Harpacticoida copepod, micro-endemic to Lake Alchichica, Puebla, Central Mexico. Cletocamptus gomezi lives in saline water (K25 =12.6 mS cm-1 dominated by sodium, magnesium, chloride, and bicarbonate ions and markedly alkaline (pH 9.0±0.1. Cletocamptus gomezi occurs in a depth range of surface to 10 m with preference to shallow (<3 m, well oxygenated (above saturation and warm (>20ºC waters; fine sandy sediments (2.3 ϕ, rich in organic matter (8.4% and carbonate concentrations (29%, and abundant aquatic vegetation coverage. In the littoral zone the average density and biomass of Cletocamptus gomezi reaches 4106±10,962 ind m-2 and 3.66±9.75 mg C m-2. Below 3 m, along the lake’s slope, the density reduces dramatically down to 265±593 ind m-2 and 0.23±0.51 mg C m-2 at 10 m. Cletocamptus gomezi is absent below 10 m down to 62 m, the maximum depth of the lake. Spatially, except L3 (whose density and biomass values are the lowest that differs (P<0.05 from L4 (whose density and biomass values are the highest, the littoral sampling stations are statistically similar in density and biomass (P>0.5. Temporally, there are no statistical differences (P>0.5 in density or biomass. The fact of finding Cletocamptus gomezi far away from the coast line (>100 km and at high altitude (2335 m asl is uncommon since most reports of Cletocamptus are from coastal brackish waters, and consequently, at sea level. Migrating waterbirds, as dispersal agents could be the explanation of Cletocamptus gomezi successfully inhabiting Lake Alchichica. Cletocamptus gomezi shares the same habitat with dense populations of tubificid oligochaetes, amphipods, leeches, chironomids, and nematodes. The disappearance of Cletocamptus gomezi habitat by the lake’s -natural and mostly anthropogenic- desiccation process, seriously threatens the survival of this and the other numerous micro-endemic species of Lake Alchichica.

  6. Shallow-water and not deep-sea as most plausible origin for cave-dwelling Paramisophria species (Copepoda: Calanoida: Arietellidae), with description of three new species from Mediterranean bathyal hyperbenthos and littoral caves

    NARCIS (Netherlands)

    Jaume, Damià; Cartes, Joan E.; Boxshall, Geoffrey A.

    2000-01-01

    Japan (Tanaka, 1967; Ohtsuka, 1985; Ohtsuka & Mitsuzumi, 1990; Ohtsuka et al., 1991), Australia (McKinnon & Kimmerer, 1985), and New Zealand (Othman & Greenwood, 1992). Records of species far from their ordinary ranges, such as those of Paramisophria cluthae T. Scott, 1897 from the Mediterranean

  7. New tantulocarid Polynyapodella ambrosei gen. et sp., (Basipodellidae) from the Northeast Water Polynya (Greenland) with emphasis on the phylogeny of its host genus Cervinia (Copepoda: Harpacticoida)

    OpenAIRE

    Huys, R.; Møbjerg, N.; Kristensen, R.M.

    1997-01-01

    Several life cycle stages of a new genus and species of Tantulocarida are described from the Arctic Northeast Water Polynya (NEW) on the East Greenland shelf. Polynyapodella ambrosei gen. et sp. nov. was found to infest a new species of the deepwater harpacticoid genus Cervinia (Cerviniidae). The tantulocarid is placed in the family Basipodellidae on account of the male trunk sac formation and appears to be most closely related to Nipponotantulus heteroxenus recorded from southern Japan. The ...

  8. Taxonomy, ecology, and geographical distribution of the species of the genus Thermocyclops Kiefer, 1927 (Copepoda, Cyclopoida in São Paulo State, Brazil, with description of a new species

    Directory of Open Access Journals (Sweden)

    W. M. Silva

    Full Text Available The taxonomy and ecology of the cyclopoid copepod genus Thermocyclops were studied. Samples were collected in 207 water bodies located in the 22 hydrographic basins of São Paulo State, Brazil, including large reservoirs, small and shallow lakes, and ponds and rivers. The genus Thermocyclops inhabits mainly water bodies within a limnetic region. Four species were found, of which one is new: Thermocyclops iguapensis, which occurred in the reservoirs of the Ribeira do Iguape and Paraíba do Sul basins. The description of the new species and the geographical distribution of all four species in São Paulo State are presented. Thermocyclops decipiens was the most frequent species, occurring in 71% of the water bodies within a limnetic region. This species is characteristic of eutrophic environments where it can occur in great abundance, whereas Thermocyclops minutus is characteristic in oligotrophic systems. Thermocyclops inversus and Thermocyclops iguapensis n. sp. were not common but can occur together with Thermocyclops decipiens.

  9. Local variations in size and activity among Calanus finmarchicus and Metridia longa (Copepoda, Calanoida) overwintering on the west coast of Norway. Journal of Plankton Research, 01 January 1994 to 31 December 2002 (NODC Accession 0000489)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Vertical net hauls were taken at thirteen stations between latitude 60 degrees 8 minutes N - 61 degrees 20 minutes N and longitude 3 degrees 4 minutes E - 7 degrees...

  10. Hydrobiological studies in the catchment of Vaal dam, South Africa part 3. Notes on the Cladocera and Copepoda of stones-in-current, marginal vegetation and stony backwater biotopes

    CSIR Research Space (South Africa)

    Chutter, FM

    1971-01-01

    Full Text Available greatest. The beginning of the Summer was taken from the first widespread and heavy summer rains, which washed away the algae and the animals associated with them. The above systems of classification of the streams and rivers and of the seasons has been...0r~i~ where the amount of vegetation sampled was estimated. The densities are given as numbers per 0.3 in of vegetation, but it should be borne in mind that the hand net was swept back and forth through the vegetation. Data presented in Part 1...

  11. An annotated list of fish parasites (Isopoda, Copepoda, Monogenea, Digenea, Cestoda, Nematoda) collected from Snappers and Bream (Lutjanidae, Nemipteridae, Caesionidae) in New Caledonia confirms high parasite biodiversity on coral reef fish

    Science.gov (United States)

    2012-01-01

    Background Coral reefs are areas of maximum biodiversity, but the parasites of coral reef fishes, and especially their species richness, are not well known. Over an 8-year period, parasites were collected from 24 species of Lutjanidae, Nemipteridae and Caesionidae off New Caledonia, South Pacific. Results Host-parasite and parasite-host lists are provided, with a total of 207 host-parasite combinations and 58 parasite species identified at the species level, with 27 new host records. Results are presented for isopods, copepods, monogeneans, digeneans, cestodes and nematodes. When results are restricted to well-sampled reef fish species (sample size > 30), the number of host-parasite combinations is 20–25 per fish species, and the number of parasites identified at the species level is 9–13 per fish species. Lutjanids include reef-associated fish and deeper sea fish from the outer slopes of the coral reef: fish from both milieus were compared. Surprisingly, parasite biodiversity was higher in deeper sea fish than in reef fish (host-parasite combinations: 12.50 vs 10.13, number of species per fish 3.75 vs 3.00); however, we identified four biases which diminish the validity of this comparison. Finally, these results and previously published results allow us to propose a generalization of parasite biodiversity for four major families of reef-associated fishes (Lutjanidae, Nemipteridae, Serranidae and Lethrinidae): well-sampled fish have a mean of 20 host-parasite combinations per fish species, and the number of parasites identified at the species level is 10 per fish species. Conclusions Since all precautions have been taken to minimize taxon numbers, it is safe to affirm than the number of fish parasites is at least ten times the number of fish species in coral reefs, for species of similar size or larger than the species in the four families studied; this is a major improvement to our estimate of biodiversity in coral reefs. Our results suggest that extinction of a coral reef fish species would eventually result in the coextinction of at least ten species of parasites. PMID:22947621

  12. Effects of host migration, diversity and aquaculture on sea lice threats to Pacific salmon populations.

    Science.gov (United States)

    Krkosek, Martin; Gottesfeld, Allen; Proctor, Bart; Rolston, Dave; Carr-Harris, Charmaine; Lewis, Mark A

    2007-12-22

    Animal migrations can affect disease dynamics. One consequence of migration common to marine fish and invertebrates is migratory allopatry-a period of spatial separation between adult and juvenile hosts, which is caused by host migration and which prevents parasite transmission from adult to juvenile hosts. We studied this characteristic for sea lice (Lepeophtheirus salmonis and Caligus clemensi) and pink salmon (Oncorhynchus gorbuscha) from one of the Canada's largest salmon stocks. Migratory allopatry protects juvenile salmon from L. salmonis for two to three months of early marine life (2-3% prevalence). In contrast, host diversity facilitates access for C. clemensi to juvenile salmon (8-20% prevalence) but infections appear ephemeral. Aquaculture can augment host abundance and diversity and increase parasite exposure of wild juvenile fish. An empirically parametrized model shows high sensitivity of salmon populations to increased L. salmonis exposure, predicting population collapse at one to five motile L. salmonis per juvenile pink salmon. These results characterize parasite threats of salmon aquaculture to wild salmon populations and show how host migration and diversity are important factors affecting parasite transmission in the oceans.

  13. Dicty_cDB: VSA222 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e) Lepeophtheirus salmonis Pacific fo... 78 2e-13 BT076915_1( BT076915 |pid:none) Caligus rogercresseyi clon...e crog-e... 74 4e-12 BT077060_1( BT077060 |pid:none) Caligus rogercresseyi clone

  14. Differential rejection of salmon lice by pink and chum salmon: disease consequences and expression of proinflammatory genes.

    Science.gov (United States)

    Jones, Simon R M; Fast, Mark D; Johnson, Stewart C; Groman, David B

    2007-05-09

    The consequences of high (735 copepodids fish-1) and low (243 copepodids fish-1) level exposures of size-matched juvenile pink and chum salmon to Lepeophtheirus salmonis copepodids were examined. At both levels of exposure the prevalence and abundance of L. salmonis was significantly higher on chum salmon. In addition, the weight of exposed chum salmon following the high exposure was significantly less than that of unexposed chum salmon. At both exposures, the haematocrit of exposed chum salmon was significantly less than that of unexposed chum. Neither weight nor haematocrit of pink salmon was affected by exposures at these levels. Despite the presence of microscopic inflammatory lesions associated with attachment of L. salmonis on the epithelium of gill and fin of both salmon species, there were no mortalities following either exposure. A transient cortisol response was observed in chum salmon 21 d after low exposure. An earlier and quantitatively higher expression of the proinflammatory genes interleukin-8 (IL-8), tumour necrosis factor alpha-1 (TNFalpha-1) and interleukin-1beta (IL-1beta) in fin and head kidney of pink salmon suggested a mechanism of more rapid louse rejection in this species. Together, these observations indicate a relatively enhanced innate resistance to L. salmonis in the juvenile pink salmon compared with the juvenile chum salmon.

  15. The Impact of Feedback Frequency on Learning and Task Performance: Challenging the "More Is Better" Assumption

    Science.gov (United States)

    Lam, Chak Fu; DeRue, D. Scott; Karam, Elizabeth P.; Hollenbeck, John R.

    2011-01-01

    Previous research on feedback frequency suggests that more frequent feedback improves learning and task performance (Salmoni, Schmidt, & Walter, 1984). Drawing from resource allocation theory (Kanfer & Ackerman, 1989), we challenge the "more is better" assumption and propose that frequent feedback can overwhelm an individual's cognitive resource…

  16. Dicty_cDB: VSF120 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 915 |pid:none) Caligus rogercresseyi clone crog-e... 75 2e-12 BT077060_1( BT077060 |pid:none) Caligus rogerc...78760 |pid:none) Lepeophtheirus salmonis Pacific fo... 78 2e-13 BT076915_1( BT076

  17. First records of parasitic copepods (Crustacea, Siphonostomatoida) from marine fishes in Korea.

    Science.gov (United States)

    Venmathi Maran, B A; Soh, H Y; Hwang, U W; Chang, C Y; Myoung, J G

    2015-06-01

    The knowledge of the biodiversity of parasitic copepods in South Korea is increasing. Interestingly we report here, some parasitic copepods considered as the first record of findings from Korea. Nine species of parasitic copepods (Siphonostomatoida) including six genera of three different families [Caligidae (7), Lernaeopodidae (1), Lernanthropidae (1)] were recovered from eight species of wild fishes in Korea: 1) Caligus hoplognathi Yamaguti & Yamasu, 1959 (♀, ♂) from the body surface of barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel); 2) Caligus lagocephali Pillai, 1961 (♀) from the gills of panther puffer Takifugu pardalis (Temminck & Schlegel); 3) Euryphorus brachypterus (Gerstaecker, 1853) (♀, ♂) from the opercular cavity of Atlantic bluefin tuna Thunnus thynnus (Linnaeus); 4) Euryphorus nordmanni Milne Edwards, 1840 (♀, ♂) from the opercular cavity of common dolphin fish Coryphaena hippurus Linnaeus; 5) Gloiopotes huttoni (Thomson) (♀, ♂) from the body surface of black marlin Istiompax indica (Cuvier); 6) Lepeophtheirus hapalogenyos Yamaguti & Yamasu, 1959 (♀) from the gill filaments of O. fasciatus; 7) Lepeophtheirus sekii Yamaguti, 1936 (♀, ♂) from the body surface of red seabream Pagrus major (Temminck & Schlegel); 8) Brachiella thynni Cuvier, 1830 (♀) from the body surface of longfin tuna or albacore Thunnus alalunga (Bonnaterre); 9) Lernanthropinus sphyraenae (Yamaguti & Yamasu, 1959) (♀) from the gill filaments of moon fish Mene maculata (Bloch & Schneider). Since the female was already reported in Korea, it is a new record for the male of C. hoplognathi. A checklist for the parasitic copepods of the family Caligidae, Lernaeopodidae and Lernanthropidae of Korea is provided.

  18. Food habits and diel feeding rhythm of introduced fish, Tilapia zillii ...

    African Journals Online (AJOL)

    Macrophytes, detritus, blue greens, diatoms, green algae, Ceratium, Euglena and Phacus constituted food of plant origin whereas chironomid larvae, Copepoda, Cladocera, Rotifera, Nematoda, fish eggs and fish scales constituted food of animal origin. Furthermore, animal foods such as Ephemeroptera and molluscs were ...

  19. New species of Paracalanidae along the west coast of India: Paracalanus arabiensis

    Digital Repository Service at National Institute of Oceanography (India)

    Kesarkar, K.S.; Anil, A.C.

    -709.] Bjornberg T.K.S. (1980) Revisão da distribuição dos gêneros Paracalanus, Clausocalanus e Ctenocalanus (Copepoda, Crustacea) ao largo do Brasil. Boletim do Instituto ocenografico. São Paulo 29, 65-68. Bowman T.E. (1971) The distribution of calanoid...

  20. Composition and abundance of the zooplankton community in the ...

    African Journals Online (AJOL)

    The taxonomic composition of the zooplankton community of the Bitter Lakes, Egypt, was examined in 2003–2004 in relation to the spatial and temporal distribution of environmental factors. Copepoda were dominant, forming 49% of the zooplankton, followed by Protista at 37%. During the autumn, zooplankton in Small ...

  1. Phylogenetic relationships and genetic diversity of Nemesis Risso ...

    African Journals Online (AJOL)

    Members of the order Siphonostomatoida (Copepoda) are generally poorly described from South African waters. Nemesi s is one of 12 genera in the family Eudactylinidae and includes about nine species. In this study, we investigated whether there is any population structure among Nemesis lamna individuals infecting the ...

  2. Browse Title Index

    African Journals Online (AJOL)

    Vol 15, No 3 (1980), The development of thermoregulation in Rhabdomys pumilio nambiensis, Abstract PDF. R.J. Couture. Vol 24, No 2 (1989), The developmental stages of Pseudodiaptomus hessei (Copepoda: Calanoida), Abstract PDF. H.L. Jerling, T.H. Wooldridge. Vol 5, No 1 (1970), The diagnosis and control of game ...

  3. Physico-chemical limnology and plankton dynamics of Mazvikadei ...

    African Journals Online (AJOL)

    Species richness was highest at the onset of the cool dry season, in response to high nutrient concentrations. Phytoplankton abundance and composition were significantly correlated with temperature, nitrates and total nitrogen. Nineteen zooplankton species were recorded, including Copepoda, Cladocera and Rotifera.

  4. Zooplankton composition and community structure in Lake Tiga ...

    African Journals Online (AJOL)

    A total of 54 species of zooplankton was recorded, comprising two species of Protozoa, 26 species of Rotifera, eight species of Copepoda, 11 species of Cladocera, four species of Ostracoda and three species of insect larvae. Species occurrence and abundance were both higher in the dry season than in the rainy season.

  5. Neuston composition in central Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.R.S.; Achuthankutty, C.T.; Haridas, P.; Nair, V.R.

    Composition of neuston in the Arabian Sea (lat. 16-19 degrees N., long. 60-72 degrees E) was studied. The standing stock ranged between 1.5 and 49.3 ml (100 m2)-1. Copepoda was generally the dominant group, forming on average 50.5% of the total...

  6. Aquatic Resources of Rocky Mountain Arsenal Adams County, Colorado

    Science.gov (United States)

    1989-09-01

    Pseudochydorus globosus, Simocephalus vetulus , and some daphnids and copepods are found in vegetated shallows. -45- DERBY • LADORA MARY 1200 1000 N 800U M B E R...x D. parvula X xID. rosea X x x Simocephalus vetulus x Ostracoda sp. XI Copepoda Copepod nauplii x x X Calanoida Calanoid copepodids X x XI

  7. The tantulocarid genus Arcticotantalus removed from Basipodellidae into Deoterthridae (Crustacea

    DEFF Research Database (Denmark)

    Knudsen, Steen Wilhelm; Kirkegaard, Maja; Olesen, JØrgen

    2009-01-01

    A new species of Tantulocarida was found off the coast of Disko Island, West Greenland. The new species, Arcticotantulus kristenseni sp. nov., is exclusively found on an as yet undescribed species of Brady a Boeck, 1873 (Copepoda, Harpacticoida) caught at depths of 200 m off the coast in muddy se...

  8. A new species of Copepoda Harpacticoida, Xylora calyptogenae spec. n., with a carnivorous life-style from a hydrothermally active submarine volcano in the New Ireland Fore-Arc system (Papua New Guinea) with notes on the systematics of the Donsiellinae Lang, 1948

    Science.gov (United States)

    Willen, Elke

    2006-12-01

    A new species of harpacticoid copepods, Xylora calyptogenae spec. n., from Edison Seamount, a hydrothermally active submarine volcano in the New Ireland Fore-Arc system (Papua New Guinea) is described. The new species belongs to the Donsiellinae Lang, 1944, a highly specialised taxon, the members of which have previously been encountered only in association with decaying wood and/or wood-boring isopods. A closer relationship of the Donsiellinae with the Pseudotachidiidae Lang, 1936, can be stated on the basis of characteristics concerning the setation and/or segmentation of A1, A2, Mxl, Mxp, the shape of the female P5, anal somite, sexual dimorphisms on P2 and P3 and missing caudal seta I. Within the Pseudotachidiidae, the Donsiellinae again can be well characterized, e.g. by the setation and segmentation of A2, Mxl, swimming-legs, the shape of P1, female P5, male P2, sexual dimorphism and male P5. The Donsiellinae share some apomorphies with the pseudotachidiid subtaxon Paranannopinae Por, 1986: setation/segmentation of Mx, P1, A1. X. calyptogenae spec. n. is more closely related to Xylora bathyalis Hicks 1988 living in the deep sea wood substrata in New Zealand waters. Some traits of the evolutionary history of the Donsiellinae become evident, probably starting from the more primitive deep sea taxa X .calyptogenae spec. n., which lives in the hydrothermal seafloor in the absence of decaying wood, and X. bathyalis, which is found in decaying wood but not necessarily associated with the wood-boring isopod Limnoria Leach, 1814, towards the more advanced genera such as Donsiella Stephensen, 1936, which invades shallow waters and, further, clings to Limnoria, forming a close and, for the copepod, probably obligatory association. The specialised mouthparts of X. calyptogenae spec. n. seem to facilitate the grabbing and fixing of larger and/or active food items. This is confirmed by the presence of a large prey organism, presumably a copepod, consumed either alive or dead, in the gut of one of the available specimens. This morphology of the mouthparts is also shared by the closely related X. bathyalis.

  9. Gammaridean amphipods in the Columbia River Estuary

    Energy Technology Data Exchange (ETDEWEB)

    Holton, R.L.; Higley, D.L.

    1976-01-01

    The distribution, abundance, and habitat preference of the amphipods Corophium salmonis, C. spinicorne, and Anisogammarus confervicolus were studied in the Columbia River estuary as part of baseline research during 1974 to 1976. A figure is presented showing densities of two species at selected stations in the Columbia River. Studies were also conducted on changes in faunal composition and substrate texture existing across an intertidal mudflat on the southwest shore of Youngs Bay. (HLW)

  10. Histochemical characterization of AGD lesions in ballan wrasse (Labrus bergylta)

    OpenAIRE

    Kvinnsland, Herman Høgenes

    2017-01-01

    With the increasing problem of sea lice (Lepeoptheirus salmonis) in production of Atlantic salmon (Salmo salar), the use of biological and non-drug treatments, such as cleaner fish, like ballan wrasse (Labrus bergylta) and lumpfish (Cyclopterus lumpus), have become methods of choice in Norwegian aquaculture. Recently, there has been outbreaks of amoebic gill disease (AGD) caused by the amoeba Neoparamoeba perurans in facilities producing ballan wrasse. This raised several issue...

  11. A stage-structured Bayesian hierarchical model for salmon lice populations at individual salmon farms – Estimated from multiple farm data sets

    OpenAIRE

    Aldrin, Magne Tommy; Huseby, Ragnar Bang; Stien, Audun; Grøntvedt, Randi Nygaard; Viljugrein, Hildegunn; Jansen, Peder A

    2017-01-01

    Salmon farming has become a prosperous international industry over the last decades. Along with growth in the production farmed salmon, however, an increasing threat by pathogens has emerged. Of special concern is the propagation and spread of the salmon louse, Lepeophtheirus salmonis. To gain insight into this parasite’s population dynamics in large scale salmon farming system, we present a fully mechanistic stage-structured population model for the salmon louse, also allowing for complexiti...

  12. Metazoan Parasite Infracommunities in Five Sciaenids from the Central Peruvian Coast

    Directory of Open Access Journals (Sweden)

    Oliva Marcelo E

    1998-01-01

    Full Text Available Parasitological analysis of 237 Menticirrhus ophicephalus, 124 Paralonchurus peruanus, 249 Sciaena deliciosa, 50 Sciaena fasciata and 308 Stellifer minor from Callao (Perú yielded 37 species of metazoan parasites (14 Monogenea, 11 Copepoda, 4 Nematoda, 3 Acanthocephala, 1 Digenea, 1 Aspidobothrea, 1 Eucestoda, 1 Isopoda and 1 Hirudinea. Only one species, the copepoda Bomolochus peruensis, was common to all five hosts. The majority of the components of the infracommunities analyzed are ectoparasites. The Brillouin index (H and evenness (J´ were applied to the fully sampled metazoan parasite infracommunities. High values of prevalence and mean abundance of infection are associated to the polyonchoinean monogeneans; the low values of J' reinforce the strong dominance of this group in the studied communities. The paucity of the endoparasite fauna may be a consequence of the unstable environment due to an upwelling system, aperiodically affected by the El Niño Southern Oscillation phenomena.

  13. Berbagai Cara Pengendalian Larva Nyamuk

    Directory of Open Access Journals (Sweden)

    Nungki Hapsari Suryaningtyas

    2017-02-01

    Full Text Available Tindakan pencegahan dengan memberantas sarang nyamuk dan membunuh larva serta nyamuk dewasa terus digalakkan. Stadium pradewasa atau larva dapat dikontrol secara biologi maupun kimiawi.1 Berikut adalah beberapa cara pengendalian larva nyamuk.Pengendalian secara biologi Beberapa organisme yang efektif untuk mengendalikan larva secara biologi diantaranya adalah Ikan (larvavivorous fish,Aplocheilus panchax (ikan kepala timah, Ctenops vittatus (ikan cupang,Oreochromis (Tilapia mossambicus (ikan nila dan Cyprinus carpio (ikan tombro, larva nyamuk dari genus Toxorhynchites, Capung (Dragonflies/Labellula . Kelompok Udang (Cyclopoid copepods Jenis Copepoda yang tersebar sebagai plankton dan bentos ini bersifat predator yang efektif untuk mengendalikan stadium pradewasa nyamuk instar satu dan instar dua. Pada suatu penelitian di Polynesia Perancis terbukti bahwa M. aspericornis pengaruhnya tidak konsisten terhadap larva Ae. aegypti yang ditemukan berada di tangki air, drum dan sumur yang tertutup. Keadaan tersebut tampaknya bergantung pada tersedianya mikrofauna di tempat perkembangbiakannya yang dibutuhkan untuk pertumbuhan Copepoda tersebut

  14. Seasonal succession of crustacean zooplankton in Wular Lake of the Kashmir Himalaya

    Directory of Open Access Journals (Sweden)

    Shah Javaid Ahmad

    2013-01-01

    Full Text Available The present study was undertaken on Wular Lake, a Ramsar Site in Kashmir Himalaya, to study the seasonal succession of crustacean zooplankton from September 2010 to August 2011. A total of 42 crustacean taxa belonging to Cladocera (23, Copepoda (16 and Ostracoda (3 were identified at five different sampling sites. Among the crustaceans, Cladocera was numerically the most dominant group at sites III, IV and V, followed by Copepoda at sites I and II. On an average basis total crustacean density ranged from 416 ind./l in winter to 1567.6 ind./l in summer. On the basis of Sorensen’s similarity index, study sites IV and V showed close similarity (88.13%.

  15. Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil

    OpenAIRE

    Chaves, Paulo de Tarso C.; Vendel, Ana Lúcia

    1998-01-01

    Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil, were studied from February 1996 to February 1997. It was observed that its diet was based on invertebrates, mainly Decapoda non-Brachyura and Polychaeta. In a smaller proportion there were plants, Copepoda, Gammaridea and Mollusca. The level of contribution of each food item changed according to the season and the individual size. Such plasticity in feeding behaviour was similar to that desc...

  16. Influence of varying manure concentrations on the productivity of ...

    African Journals Online (AJOL)

    Seven poultry manure concentrations of 0.05, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 gl-1 were filtered into duckweed (Lemnaceae) culture tanks for the culture of Moina (Cladocera) and Cyclops (Copepoda). The duckweeds were allowed to grow and completely cover the surface of the culture tank. The same concentration of ...

  17. Garrison Dam/Lake Sakakawea Master Plan with Integrated Programmatic Environmental Assessment, Missouri River, Montana: Update of Design Memorandum MGR-107D

    Science.gov (United States)

    2007-12-14

    earthworms) Hirudinea (leeches) Arthropoda Crustacea Anostraca (fairy shrimp) Conchostraca (clam shrimp) Cladocera (water fleas ) Copepoda...courtship, the terns will mate . Eggs are laid in a nest bowl that is a shallow scrape in the sand, soil, or pebbles. The eggs are laid at a rate of...2007 2-75 INSECTS Flea beetle species Altica nancyae S2/G? Range grasses Dakota skipper Hesperia dacotae S2/G2 Tall grass and mid-grass prairie

  18. Five ectoparasites from Turkish fish.

    Science.gov (United States)

    Oktener, Ahmet; Trilles, Jean Paul; Leonardos, Ioannis

    2007-01-01

    Five ectoparasites were collected during the period of 2002-2005 from fish of Mediterranean Sea, Aegean Sea and inland waters of Turkey: Four crustaceans [Ergasilus mosulensis and Pennella instructa (Copepoda), Ceratothoa steindachneri (Isopoda) and Argulus foliaceus (Branchiura)] and one Annelida (Piscicola geometra) were found. The species, E. mosulensis, P. instructa and C. steindachneri have been reported for first time in Turkish waters, and A. foliaceus and P. geometra for the time from the Cavuşçu Lake.

  19. Spatio-temporal variations of zooplankton community in the hypersaline lagoon of Bardawil, North Sinai, Egypt

    OpenAIRE

    Mageed, A.A.A.

    2006-01-01

    Bardawil Lagoon is a shallow oligotrophic hypersaline lake, located at the northern periphery of Sinai peninsula-Egypt, connected to SE Mediterranean Sea through two main openings known as Boughazes. Distribution of zooplankton in Bardawil Lagoon during 2004 was studied, not only in space and time but also with reference to species assemblages and environmental factors. Copepoda, Protozoa, and Mollusca were dominating the lagoon zooplankton community during the period of study with 58 identif...

  20. Groundwater ecology literature review

    OpenAIRE

    Maurice, L.

    2009-01-01

    Groundwater ecology is the study of ecosystems that occur in the subsurface within groundwater. Groundwater often contains a diverse range of organisms, and those that live in groundwater and generally do not live above the ground surface are called Stygobites. Stygobites species come from several different taxonomic groups of animals. Many animals found in groundwater are Crustaceans (Copepoda, Ostracoda, Amphipoda, Isopoda, Syncarida, Cladocera) but species of Oligocheata and...

  1. Winter Fish Populations in Probable Locations of Air Bubblers in the St. Marys River-Lake Superior Area

    Science.gov (United States)

    1980-09-01

    Clodocera 415 Copepoda 40 26 Isopoda 7 Asel lus 7 Ephemeroptera Ephemera 46 Hexagenia limboto 7 46 Trichoptera 13 Neureclipsis 7 Hydropsyche 7...Hyalella azteca 7 Lirceus 7 Ephemeroptera 7 Ephemeridee 7 Caenis 7 Ephemera 46 13 Hexacjenia limbatu 408 53 39 Hemiptera Corixidee 20 Megaloptera Si ciis...racoda 7 Hyalella azteca 13 Lirceus 39 Ephemeroptera Caenis 7 Ephemera 102 Hexagenia limbata 13 402 53 Coleoptera Ha lip lus 7 Trichoptera Phy locentropus

  2. Metabolic Theory of Ecology and diversity of continental zooplankton in Brazil - doi: 10.4025/actascibiolsci.v34i1.9087

    Directory of Open Access Journals (Sweden)

    José Alexandre Felizola Diniz-Filho

    2011-11-01

    Full Text Available Several ecological hypotheses try to explain geographical patterns in biodiversity. The Metabolic Theory of Ecology (MTE predicts that temperature is the main determinant of richness patterns for ectothermic organisms and that the relationship between richness (lnS and temperature (1/kT is a linear relationship with angular coefficient (b near -0.65. This study tested the MTE for continental zooplankton diversity in 63 lakes in Brazil. Copepoda, Cladocera and Rotifera, as well as the three groups combined, showed different patterns from that predicted by MTE, with b values equal to 0.871, 0.516, 0.720 and 0.901, respectively. Temperature explains 12.7% of the richness of Copepoda, 5.3% of Cladocera, 6.7% of Rotifera, and 11.4% of all zooplankton groups together. Several studies have shown that the MTE does not apply to many terrestrial groups, perhaps because the model does not consider variances generated by other factors such as environmental spatial range, body size and other variables. The present study confirms this point of view, expanding it to continental aquatic invertebrates as well. macroecology; biodiversity; Copepoda; Cladocera; Rotífera; temperature gradients

  3. Composição e variabilidade espaço-temporal da meiofauna de uma praia arenosa na região amazônica (Ajuruteua, Pará Composition and spatio-temporal variability of meiofauna community on a sandy beach in the Amazon region (Ajuruteua, Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Tatianne P. Gomes

    2009-06-01

    Full Text Available Este trabalho avalia a variabilidade espaço-temporal da meiofauna do médiolitoral na praia de Ajuruteua, Estado do Pará. As coletas foram realizadas a cada dois meses, entre abril de 2003 a fevereiro de 2004 durante as marés de sizígia, em diferentes zonas da praia. As amostras foram retiradas com um amostrador cilíndrico de 3,14 cm² e fixadas em formalina salina a 5%. Em laboratório, as amostras foram passadas em malha de 0,063 mm de abertura e os organismos retidos identificados em nível de grandes grupos taxonômicos, contados e fixados em álcool etílico a 70%. A meiofauna esteve representada por oito grupos: Turbellaria, Nematoda, Tardigrada, Polychaeta, Oligochaeta, Acari, adultos de Copepoda Harpacticoida e juvenis de Copepoda Harpacticoida. Nematoda foi o grupo dominante, representando 74% do total de indivíduos, seguido de Copepoda (19%. Pôde-se observar clara zonação horizontal da fauna, que se distribuiu em três faixas paralelas à linha de praia, com características significativamente distintas quanto à abundância, riqueza e densidade dos principais grupos taxonômicos. No médiolitoral médio foram observados valores significativamente mais elevados de riqueza e abundância, enquanto os valores mais baixos foram registrados no médiolitoral superior e inferior. A comunidade de meiofauna, ainda que não tenha variado significativamente entre períodos climáticos, foi mais rica e abundante nos meses secos. Os principais fatores responsáveis pelas variações espaço-temporais da meiofauna foram a ação das ondas e das marés e as variações na salinidade da água.The present study investigates the spatio-temporal changes in the meiofauna community along the intertidal zone of Ajuruteua Beach, State of Pará, Brazil. Samples were collected during spring tides at different levels of the beach face every two months from April 2003 to February 2004. The material was sampled using a cylindrical corer (3.14 cm² and

  4. Comparative genome analysis of two Streptococcus phocae subspecies provides novel insights into pathogenicity.

    Science.gov (United States)

    Bethke, J; Avendaño-Herrera, R

    2017-02-01

    Streptococcus phocae is a beta-hemolytic, Gram-positive bacterium that was first isolated in Norway from clinical specimens of harbor seal (Phoca vitulina) affected by pneumonia or respiratory infection, and in 2005, this bacterium was identified from disease outbreaks at an Atlantic salmon farm. A recent comparative polyphasic study reclassified Streptococcus phocae as subsp. phocae and subsp. salmonis, and there are currently two S. phocae NCBI sequencing projects for the type strains ATCC 51973T and C-4T. The present study compared these genome sequences to determine shared properties between the pathogenic mammalian and fish S. phocae subspecies. Both subspecies presented genomic islands, prophages, CRISPRs, and multiple gene activator and RofA regulator regions that could play key roles in the pathogenesis of streptococcal species. Likewise, proteins possibly influencing immune system evasion and virulence strategies were identified in both genomes, including Streptokinases, Streptolysin S, IgG endopeptidase, Fibronectin binding proteins, Daunorubicin, and Penicillin resistance proteins. Comparative differences in phage, non-phage, and genomic island sequences may form the genetic basis for the virulence, pathogenicity, and ability of S. phocae subsp. salmonis to infect and cause disease in Atlantic salmon, in contrast to S. phocae subsp. phocae. This comparative genomic study between two S. phocae subsp. provides novel insights into virulence factors and pathogenicity, offering important information that will facilitate the development of preventive and treatment measures against this pathogen. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Zooplankton assemblage of Oyun Reservoir, Offa, Nigeria

    Directory of Open Access Journals (Sweden)

    Moshood K Mustapha

    2009-12-01

    Full Text Available The influence of physico-chemical properties of Oyun Reservoir, Offa, Nigeria (a shallow tropical African reservoir on its zooplankton composition and abundance were investigated at three stations for two years between January 2002 and December 2003. Diversity is not high: only three groups of zooplankton were found: Rotifera with eight genera; and Cladocera and Copepoda with three genera each. Rotifera dominated numerically (71.02%, followed by Cladocera (16.45% and Copepoda (12.53%. The zooplankton was more prevalent during the rainy season, and there were variations in the composition and abundance along the reservoir continuum. Factors such as temperature, nutrients, food availability, shape and hydrodynamics of the reservoir, as well as reproductive strategies of the organisms, strongly influence the generic composition and population density of zooplankton. Prevention of ecological deterioration of the water body would greatly should result in a more productive water body, rich in zooplankton and with better fisheries. Rev. Biol. Trop. 57 (4: 1027-1047. Epub 2009 December 01.La influencia de las propiedades fisicoquímicas del Reservorio Oyun, Offa, Nigeria (un embalse tropical somero sobre la composición y abundancia del zooplancton fue investigada en tres estaciones entre enero de 2002 y diciembre de 2003. La diversidad no resultó muy alta con tres grupos de zooplancton: Rotifera con ocho géneros, y Cladocera y Copepoda con tres géneros cada uno. Rotifera dominó (71.02%, seguido de Cladocera (16.45% y Copepoda (12.53%. El zooplancton fue más común durante la temporada de lluvias, y hubo variaciones en su composición y abundancia a lo largo del embalse. Factores tales como la temperatura, los nutrientes, la disponibilidad de alimentos, la forma y la hidrodinámica del embalse, así como las estrategias reproductivas de los organismos, influyen fuertemente en la composición genérica y la densidad poblacional del zooplancton. La

  6. Spatial zonation of zooplankton in the northwestern Arabian Sea: A multivariate approach

    Digital Repository Service at National Institute of Oceanography (India)

    Jayalakshmy, K.V.

    ), each sample was sorted into 10 major taxa and heir densities were expressed as number per 100 m3. The taxa considered were: (1) Copepoda, (2) Chaethognatha, (3) Decapoda, (4) Amphipoda, (5) Euphasiacea, (6) Ostracoda, (7) fish eggs, (8) fish larvae... in majority of the stations resulted in very high biomass. Decapoda were mostly represented by Zoea and Alima larvae. Fish eggs were present mostly in Gulf of Oman region. But were not very frequent in the Arabian coast where as fish larvae were represented...

  7. [Parasitic metazoans of Stenella coeruleoalba (Cetacea: Delphinidae) stranded along the coast of Latium, 1985-1991].

    Science.gov (United States)

    Cerioni, S; Mariniello, L

    1996-12-01

    The striped dolphin represents the most common species of cetacean stranded along the Italian coasts. A parasitological survey on 17 specimens of Stenella coerulecaiba stranded along coasts of Latium from 1985 to 1991, has been carried out. The morphological study enabled the identification of the following parasites. The sites are reported in brackets. DIGENEA: Campula rochebruni (liver), Campula palliata (liver), Pholeter gastrophilus (pyloric stomach). CESTODA: Tetrabothrium forsteri (intestine), Strobilocephalus triangularis (intestine), Monorygma grimaldii, larvae (abdominal cavity, mesentery, testes), Phyliobothrium delphini, larvae (subcutaneous fat). NEMATODA: Skrjabinalius sp. (lungs). COPEPODA: Pennella sp. (skin). ISOPODA: Ceratothoa parallela (mouth, stomach). AMPHIPODA: Syncyamus aequus (blowhole).

  8. DAMPAK KONSENTRASI FE DAN PB TERHADAP MORFOLOGI ZOOPLANKTON DI TAMBAK SOCAH BANGKALAN

    Directory of Open Access Journals (Sweden)

    Apri Arisandi

    2013-04-01

    Full Text Available Zooplankton dalam mata rantai antara produsen primer dengan karnivora besar dan kecil dapat mempengaruhi kompleksitas rantai makanan dalam ekosistem perairan. Penelitian ini dilakukan untuk mengetahui dampak konsentrasi Fe dan Pb terhadap morfologi zooplankton  di Tambak Socah. Morfologi zooplankton diamati menggunakan mikroskop dengan metode sensus melalui 3 kali ulangan. Konsentrasi Fe dan Pb di ukur menggunakan spektrofotometer. Zooplankton yang terdapat di tambak socah adalah jenis Copepoda, Nitzchia dan Nauplius. Hasil penelitian menunjukkan bahwa konsentrasi Fe dan Pb berada pada kisaran yang normal sehingga tidak mempengaruhi morfologi plankton. Kata kunci: Fe, Pb, zooplankton

  9. Parasitism of dolfinfhishes, Coryphaena hippurus and Coryphaena equiselis, in the western Mediterranean (Balearic Islands and central-eastern Atlantic (Canary Islands

    Directory of Open Access Journals (Sweden)

    Enrique Carbonell

    1999-12-01

    Full Text Available A total of 648 dolphinfishes were examined for internal and external parasites in western Mediterranean (Balearic Islands and central-eastern Atlantic (Canary Islands waters in order to make a comparative study between the two areas. The specimens studied from the Mediterranean Sea was Coryphaena hippurus, with 62 large individuals captured from May to September and 497 juveniles captured from August to December. The specimens studied from the central-eastern Atlantic were 39 adult C. hippurus and 49 adult Coryphaena equiselis. Parasites were found in 70% of the fish examined, and represented a total of nine endoparasitic taxa: six digeneans (Class Trematoda, Subclass Digenea; Dinurus tornatus, Dinurus breviductus, Dinurus longisinus, Lecithocladium excisum, Bathycotyle branchialis and Hirudinella sp., two nematodes (Class Nematoda, Order Spirurida; Philometroides sp. and Metabronema magna and one acanthocephalan (Phyllum Acanthocephala; Rhadinorhynchus pristis. Seven crustacean copepod ectoparasites were identified: Caligus quadratus, Caligus productus, Caligus bonito, Caligus coryphaenae (Family Caligidae and Euryphorus nymphae (Family Euriphoridae were found in gill mucus masses or on the inner surface of the operculum, the lernaeopodid Neobrachiella coryphaenae (Family Lernaeopodidae was attached to gill filaments and the pennellid Pennella filosa (Family Pennellidae was anchored to fins and rays or, deeply, to muscular tissue and abdominal cavity. The relationships between feeding habits, parasite recruitment and parasite transmission were analysed, some ecological aspects of all the parasitic species are discussed, and some comments are made on parasite-host relationships.

  10. Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae at Guaratuba mangrove, Parana, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo de Tarso C. Chaves

    1998-08-01

    Full Text Available Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae at Guaratuba mangrove, Parana, Brazil, were studied from February 1996 to February 1997. It was observed that its diet was based on invertebrates, mainly Decapoda non-Brachyura and Polychaeta. In a smaller proportion there were plants, Copepoda, Gammaridea and Mollusca. The level of contribution of each food item changed according to the season and the individual size. Such plasticity in feeding behaviour was similar to that described to some fish populations from other estuaries, and could be an indicator of the high level of instability presented by this kind of ecosystem.A alimentação do cangulo ou canguá, Stellifer rastrifer, foi estudada no manguezal da Baía de Guaratuba entre fevereiro 1996 e fevereiro 1997. Constatou-se que a dieta está baseada em invertebrados, sobretudo Decapoda Brachyura e Polychaeta. Secundariamente, registram-se vegetais superiores, Copepoda, Gammaridea e Mollusca. O grau de participação dos itens varia com a estação e o tamanho dos indivíduos. Tal plasticidade no hábito alimentar, também conhecida em outras populações de peixes estuarinos, pode ser considerada como mais um indicador do grau de instabilidade encontrado nestes ambientes.

  11. Variaciones de abundancia y biomasa del zooplancton en un embalse tropical oligo-mesotrófico del norte de Venezuela

    Directory of Open Access Journals (Sweden)

    Sandra Merayo

    2010-06-01

    Full Text Available La abundancia del zooplancton en los embalses está determinada principalmente por la velocidad y el contenido del agua, pero se sabe relativamente poco sobre los embalses tropicales. Se estudió la distribución temporal y espacial de la abundancia y la biomasa del zooplancton en el eje longitudinal del embalse de Clavellinos, en el norte de Venezuela, entre octubre 2006 y septiembre 2007. El zooplancton fue recolectado en el estrato oxigenado con una red de plancton. Un total de 16 taxones fueron identificados: Copepoda, Cladocera, Rotifera, Ostracoda y Diptera. Thermocyclops decipiens (Copepoda, Cyclopoida dominó la comunidad, mientras que los rotíferos fueron los más diversos, con 10 especies. La abundancia del zooplancton varió de 31 a 101ind/l en E1, 36 a 84ind/l en E2, y, de 30 a 250ind/L en el E3. La biomasa varió de 97,4 a 1406.3μg/l en E1, 108,5 a 397.2μg/l en E2, y de 25,9 a 763.9μg/l en el E3. Esta comunidad de zooplancton pareciσ responder a las variaciones ambientales en el embalse, mαs que a las variaciones en la disponibilidad de recursos.

  12. Carotenoid metabolic profiling and transcriptome-genome mining reveal functional equivalence among blue-pigmented copepods and appendicularia

    KAUST Repository

    Mojib, Nazia

    2014-06-01

    The tropical oligotrophic oceanic areas are characterized by high water transparency and annual solar radiation. Under these conditions, a large number of phylogenetically diverse mesozooplankton species living in the surface waters (neuston) are found to be blue pigmented. In the present study, we focused on understanding the metabolic and genetic basis of the observed blue phenotype functional equivalence between the blue-pigmented organisms from the phylum Arthropoda, subclass Copepoda (Acartia fossae) and the phylum Chordata, class Appendicularia (Oikopleura dioica) in the Red Sea. Previous studies have shown that carotenoid–protein complexes are responsible for blue coloration in crustaceans. Therefore, we performed carotenoid metabolic profiling using both targeted and nontargeted (high-resolution mass spectrometry) approaches in four different blue-pigmented genera of copepods and one blue-pigmented species of appendicularia. Astaxanthin was found to be the principal carotenoid in all the species. The pathway analysis showed that all the species can synthesize astaxanthin from β-carotene, ingested from dietary sources, via 3-hydroxyechinenone, canthaxanthin, zeaxanthin, adonirubin or adonixanthin. Further, using de novo assembled transcriptome of blue A. fossae (subclass Copepoda), we identified highly expressed homologous β-carotene hydroxylase enzymes and putative carotenoid-binding proteins responsible for astaxanthin formation and the blue phenotype. In blue O. dioica (class Appendicularia), corresponding putative genes were identified from the reference genome. Collectively, our data provide molecular evidences for the bioconversion and accumulation of blue astaxanthin–protein complexes underpinning the observed ecological functional equivalence and adaptive convergence among neustonic mesozooplankton.

  13. The impact of water table drawdown and drying on subterranean aquatic fauna in in-vitro experiments.

    Directory of Open Access Journals (Sweden)

    Christine Stumpp

    Full Text Available The abstraction of groundwater is a global phenomenon that directly threatens groundwater ecosystems. Despite the global significance of this issue, the impact of groundwater abstraction and the lowering of groundwater tables on biota is poorly known. The aim of this study is to determine the impacts of groundwater drawdown in unconfined aquifers on the distribution of fauna close to the water table, and the tolerance of groundwater fauna to sediment drying once water levels have declined. A series of column experiments were conducted to investigate the depth distribution of different stygofauna (Syncarida and Copepoda under saturated conditions and after fast and slow water table declines. Further, the survival of stygofauna under conditions of reduced sediment water content was tested. The distribution and response of stygofauna to water drawdown was taxon specific, but with the common response of some fauna being stranded by water level decline. So too, the survival of stygofauna under different levels of sediment saturation was variable. Syncarida were better able to tolerate drying conditions than the Copepoda, but mortality of all groups increased with decreasing sediment water content. The results of this work provide new understanding of the response of fauna to water table drawdown. Such improved understanding is necessary for sustainable use of groundwater, and allows for targeted strategies to better manage groundwater abstraction and maintain groundwater biodiversity.

  14. Zooplankton community of Parnaíba River, Northeastern Brazil

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    Ludmilla Cavalcanti Antunes Lucena

    2015-03-01

    Full Text Available Aim:The objective of the present work is to present a list of species of zooplankton (Rotifera, Cladocera and Copepoda from the Parnaíba River. Additionally, we provide comments on their distribution along the river, and between dry and wet seasons.MethodsZooplankton was collected with a plankton net (60 µm mesh and concentrated into a volume of 80 mL for further analysis, during the dry (October 2010 and wet (April 2011 seasons. Sampling was restricted to the marginal areas at depths between 80 and 150 cm.ResultsA total of 132 species was recorded among the three zooplankton groups studied. During the dry season a total of 82 species was registered and 102 species was registered for the wet season. Rotifera contributed with 66.7% of the species, followed by Cladocera (26.5% and Copepoda (6.8%.ConclusionsThe richness of species observed was high compared to other large rivers in Brazil. In the context of current policies for water management and river diversions in northeastern Brazil, the present study highlights the importance of this river system for biodiversity conservation.

  15. The impact of water table drawdown and drying on subterranean aquatic fauna in in-vitro experiments.

    Science.gov (United States)

    Stumpp, Christine; Hose, Grant C

    2013-01-01

    The abstraction of groundwater is a global phenomenon that directly threatens groundwater ecosystems. Despite the global significance of this issue, the impact of groundwater abstraction and the lowering of groundwater tables on biota is poorly known. The aim of this study is to determine the impacts of groundwater drawdown in unconfined aquifers on the distribution of fauna close to the water table, and the tolerance of groundwater fauna to sediment drying once water levels have declined. A series of column experiments were conducted to investigate the depth distribution of different stygofauna (Syncarida and Copepoda) under saturated conditions and after fast and slow water table declines. Further, the survival of stygofauna under conditions of reduced sediment water content was tested. The distribution and response of stygofauna to water drawdown was taxon specific, but with the common response of some fauna being stranded by water level decline. So too, the survival of stygofauna under different levels of sediment saturation was variable. Syncarida were better able to tolerate drying conditions than the Copepoda, but mortality of all groups increased with decreasing sediment water content. The results of this work provide new understanding of the response of fauna to water table drawdown. Such improved understanding is necessary for sustainable use of groundwater, and allows for targeted strategies to better manage groundwater abstraction and maintain groundwater biodiversity.

  16. Concordance patterns in zooplankton assemblages in the UHE - Luís Eduardo Magalhães reservoir in the Mid-Tocantins river, Tocantins State, Brazil - doi: 10.4025/actascibiolsci.v33i2.7336 Concordance patterns in zooplankton assemblages in the UHE - Luís Eduardo Magalhães reservoir in the Mid-Tocantins river, Tocantins State, Brazil - doi: 10.4025/actascibiolsci.v33i2.7336

    Directory of Open Access Journals (Sweden)

    Deusiano Florêncio dos Reis

    2011-05-01

    Full Text Available The goal of this study was to evaluate the concordance amongst three zooplankton groups (Rotifera, Cladocera, and Copepoda and between the zooplankton groups and the environmental variables in the Luis Eduardo Magalhães reservoir, in the Mid-Tocantins River, Tocantins State, Brazil. Concordance patterns were found in relation to environmental variables, cladocerans, and rotifers, although values were relatively low. These results indicate that one should be cautious about the use of indicative taxonomic groups to detect environmental changes, where divergent results annul extrapolation possibilities and indicate the existence of distinct environmental factors controlling different groups.The goal of this study was to evaluate the concordance amongst three zooplankton groups (Rotifera, Cladocera, and Copepoda and between the zooplankton groups and the environmental variables in the Luis Eduardo Magalhães reservoir, in the Mid-Tocantins River, Tocantins State, Brazil. Concordance patterns were found in relation to environmental variables, cladocerans, and rotifers, although values were relatively low. These results indicate that one should be cautious about the use of indicative taxonomic groups to detect environmental changes, where divergent results annul extrapolation possibilities and indicate the existence of distinct environmental factors controlling different groups.

  17. Potential retention effect at fish farms boosts zooplankton abundance

    Science.gov (United States)

    Fernandez-Jover, D.; Toledo-Guedes, K.; Valero-Rodríguez, J. M.; Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2016-11-01

    Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10-20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues.

  18. Horizontal and vertical distribution of mesozooplankton species richness and composition down to 2,300 m in the southwest Atlantic Ocean

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    Sérgio L.C. Bonecker

    2014-10-01

    Full Text Available We describe the species richness, distribution and composition of mesozooplankton over the continental shelf and slope, and in the water masses in the Campos Basin, southwest Atlantic Ocean. We analyzed the mesozooplankton from two oceanographic cruises (rainy and dry seasons, 2009 with samples taken in five different water masses from the surface to 2,300 m depth. In the Subsurface Water (SS, in both sampling periods, more species were recorded over the slope (rainy: 100; dry: 128 than the continental shelf (rainy: 97; dry: 104. Over the slope, species richness decreased with increasing depth: the highest values were observed in the South Atlantic Central Water (SACW, and the lowest values in the North Atlantic Deep Water (NADW, in both sampling periods. We recorded 262 species in 10 groups (Hydrozoa, Siphonophora, Ctenophora, Branchiopoda, Copepoda, Euphausiacea, Decapoda, Chaetognatha, Appendicularia e Thaliacea, with 13 new occurrences for the southwest Atlantic. Copepoda was the group with the highest species richness, containing 138 species. In both periods, the samples from SS, SACW and Antarctic Intermediate Water (AAIW/Upper Circumpolar Deep Water (UCDW were clustered in different faunistic zones, based on species composition. This study confirmed that zooplankton richness in the southwest Atlantic Ocean is underestimated, and suggests that additional efforts must be directed toward a better understanding of this fairly unknown region.

  19. Diel activity of two amphipods in the Columbia River estuary

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.S.; Holton, R.L.

    1976-01-01

    A study was conducted in the fall of 1975 to observe the vertical activity pattern of Corophium Salmonis and Anisogammarus confervicolus over a 24 hr period at the mouth of Youngs Bay. Figures are presented to show densities of the amphipods for all samples over the 3 sample depths. Few Corophium and very few Anisogammarus were captured in the surface and mid-water regions during daylight. However, at sunset densities notably increased. Bottom samples revealed a pattern of density similar to that in upper waters. The basic activity pattern appeared to be diel. Anisogammarus were most abundant in the epibenthic region during a night-time ebb flow, reflecting the larger effect of water flow on this non-burrowing form. Corophium was found more evenly distributed from the surface to the bottom. (HLW)

  20. Counter-insurgents of the blue revolution? Parasites and diseases affecting aquaculture and science.

    Science.gov (United States)

    Blaylock, Reginald B; Bullard, Stephen A

    2014-12-01

    Aquaculture is the fastest-growing segment of food production and is expected to supply a growing portion of animal protein for consumption by humans. Because industrial aquaculture developed only recently compared to industrial agriculture, its development occurred within the context of a growing environmental awareness and acknowledgment of environmental issues associated with industrial farming. As such, parasites and diseases have become central criticisms of commercial aquaculture. This focus on parasites and diseases, however, has created a nexus of opportunities for research that has facilitated considerable scientific advances in the fields of parasitology and aquaculture. This paper reviews Myxobolus cerebralis , Lepeophtheirus salmonis , white spot syndrome virus, and assorted flatworms as select marquee aquaculture pathogens, summarizes the status of the diseases caused by each and their impacts on aquaculture, and highlights some of the significant contributions these pathogens have made to the science of parasitology and aquaculture.

  1. Disease management mitigates risk of pathogen transmission from maricultured salmonids

    DEFF Research Database (Denmark)

    Jones, Simon R. M.; Bruno, David W.; Madsen, Lone

    2015-01-01

    Open marine net pens facilitate virus and sea lice transfer, occasionally leading to infections and outbreaks of disease in farmed salmon. A review of 3 salmon pathogens (infectious salmon anaemia virus [ISAV], salmon alphavirus [SAV] and the salmon louse Lepeophtheirus salmonis) shows...... that increased risk of exposure to neighbouring farms is inversely related to distance from and directly related to biomass at the source of infection. Epidemiological techniques integrating data from oceanography, diagnostics and pathogen shedding rates and viability contribute to improved understanding...... of pathogen transmission pathways among farms and permit the designation of areas of risk associated with sources of infection. Occupation of an area of risk may increase the likelihood of exposure, infection and disease among susceptible fish. Disease mitigation in mariculture occurs at 2 scales: area...

  2. Three new records of copepods (Siphonostomatoida) parasitic on marine fishes of Iraq, including the relegation of two species of Lernanthropinus to Lernanthropinus temminckii (von Nordmann, 1864).

    Science.gov (United States)

    Venmathi Maran, B A; Moon, Seong Yong; Adday, Thamir Katea; Khamees, Najim Rijab; Myoung, Jung-Goo

    2014-03-01

    Three parasitic copepods (Siphonostomatoida) belonging to three different genera were recovered from marine fishes of Iraq, and are listed here as new records. The sea lice Caligus epinepheli Yamaguti, 1936 (Caligidae) was collected from the Japanese threadfin bream, Nemipterus japonicus (Bloch). It had been frequently reported from teleost fishes around the world. The second record, comprising male and female, was another caligid, rarely caught from fishes - Hermilius longicornis Bassett-Smith, 1898, collected from the giant catfish, Netuma thalassina (Rüppell). This paper features the first description of the male of the latter species. The third record was the lernanthropid, Lernanthropinus temminckii (von Nordmann, 1864) (Lernanthropidae), redescribed based on the specimens collected from the greater lizard fish, Saurida tumbil (Bloch) (Synodontidae). In order to clarify its taxonomic status, our specimen was compared with the holotype of L. gibbosus (Pillai, 1964) from the collections of Zoological Survey of India, Kolkata, and the syntypes of L. sauridae Do in Ho and Do, 1985 and L. temminckii from the collections of the Smithsonian Institution, Washington D.C. We found similarities in the morphology of the body, mouthparts, and legs 1-4 in three above-mentioned species. The prominent feature, the setation pattern of legs 1 and 2 was similar in all the female specimens examined. In the light of this, we formally relegate L. gibbosus and L. sauridae to synonymy with L. temminckii. Another important similarity is that Lernanthropinus gibbosus, L. sauridae, and L. temminckii have exclusively been parasitic on lizardfishes (Synodontidae). The attachment site of all three copepods reported form Iraq were the gill filaments.

  3. Multiple gene analyses of caligid copepods indicate that the reduction of a thoracic appendage in Pseudocaligus represents convergent evolution.

    Science.gov (United States)

    Freeman, Mark A; Anshary, Hilal; Ogawa, Kazuo

    2013-11-28

    The Caligidae is a family of parasitic copepods containing over 30 recognised genera. They are commercially important parasites as they cause disease in numerous finfish aquaculture facilities globally. Morphological features are used to distinguish between the genera and Pseudocaligus has traditionally been differentiated from Caligus solely by the presence of a much reduced form of the fourth thoracic leg. Currently there are numerous DNA sequences available for Caligus spp. but only the type species, Pseudocaligus brevipedis, has molecular data available, so systematic studies using molecular phylogenetic analyses have been limited. Three gene regions, SSU rDNA, 16S and CO1, for Pseudocaligus fugu from puffer fish from Japan and Pseudocaligus uniartus from rabbit fish from Indonesia are sequenced and molecular phylogenetic analyses performed in order to infer phylogenetic relationships between Pseudocaligus and other caligid copepods. The analysis revealed that there was no discrete grouping of Pseudocaligus spp. and that they had a polyphyletic distribution within Caligus taxa. Pseudocaligus fugu grouped with Caligus elongatus and contained a unique synapomorphy in the SSU rDNA region only seen in members of that clade. Pseudocaligus uniartus formed a well-supported group, in the SSU rDNA analyses, with a Caligus sp. that also infects rabbit fish, but was unresolved in the other analyses. Pseudocaligus brevipedis consistently and robustly grouped with Caligus curtus and C. centrodonti in all analyses. The majority of Lepeophtheirus spp. form a monophyletic sister group to the Caligus clade; however, L. natalensis is unresolved in all analyses and does not form part of the main Lepeophtheirus clade. These findings do not support the morphological-based distinction between Pseudocaligus and Caligus, suggesting that the reduced fourth leg is a feature that has evolved on multiple occasions throughout caligid evolution. Congruent molecular phylogenetic data support

  4. Zooplankton Composition and Abundance as Indicators of Eutrophication in Two Small Man-made Lakes.

    Science.gov (United States)

    Ismail, Azma Hanim; Adnan, Anis Amalina Mohd

    2016-11-01

    The distribution and abundance of zooplankton species of Harapan and Aman Lakes were investigated in relation to physical parameters and chlorophyll- a content. Both lakes were characterised by the occurrence of algal bloom problem. The composition of zooplankton was collected at monthly intervals from November 2013 to February 2014. The total number of taxa in Harapan and Aman Lakes were 23 and 27, respectively. Rotifera was the highest abundance group represent 64% of the total species recorded followed by Copepoda (29%) and Cladocera (7%). Three dominant zooplankton that been recorded in both the lakes are Brachionus forficula , Brachionus nilsoni, and Trichocerca sp. High abundance of these species indicates that the lakes are eutrophic water bodies. Overall, zooplankton species distribution and abundance in the study sites are influenced by various environmental factors such as water transparency and chlorophyll- a content.

  5. The effects of environmental parameters on zooplankton assemblages in tropical coastal estuary, South-west, Nigeria

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    Waidi O. Abdul

    2016-09-01

    Full Text Available The present study was carried out to examine the distribution and assemblage structure of zooplankton in relation to environmental parameters of tropical coastal estuarine ecosystem impounding Bight of Benin, Nigeria. The estuarine water samples were collected between January and December, 2014 from three sampling zones (Brushpark, Open water and Wetland then were fixed in 4% formalin. A total of twenty-eight (28 species belonging to four (4 groups were recorded in this study. These groups were rotifera, copepoda, cladocerans and ostracodas, and were all widely distributed in the three investigated zones. Higher richness, dominance and abundance indices were recorded in Zone I when compared to both Zones II and III. Cluster analysis showed five distinct species communities. The canonical correspondence analysis (CCA showed a distinct smattering positive and negative correlation on the distribution of zooplankton indicating that the relative abundance of any species was dependent on specific environmental variables.

  6. Sublittoral meiobenthic assemblages from disturbed and non-disturbed sediments in the Balearics

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    S. Deudero

    2000-09-01

    Full Text Available Qualitative and quantitative differences in species composition of meiobenthic communities illustrate the differences among various taxonomic assemblages in the Balearic Islands (Western Mediterranean analysed by means of multivariate analysis. Average densities ranged between 1000 and 4000 ind?10cm-2, and are in the same range as previously reported from other shallow Mediterranean areas. The dominant meiofaunal taxa were Nematoda (range 40 to 75%, Turbellaria (5-47% and Copepoda (2-14%, while other meiofaunal groups (Tardigrada and Rotifera were only represented by approximately 5% of the total abundance. The dominant nematode families were Desmodoridae, Chromadoridae and Xyalidae. The meiofaunal communities showed little variation among locations. Moreover, small-scale heterogeneity does not seem to affect nematode distribution as shown by the high similarity between replicates in the multivariate analysis.

  7. Microcrustacea (Crustacea: Branchiopoda of Deepor Beel, Assam, India: richness, abundance and ecology

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    B.K. Sharma

    2009-08-01

    Full Text Available Plankton samples collected from two sampling stations of Deepor Beel, an important floodplain lake of Assam and a Ramsar site of India, revealed 51 species of Microcrustacea and showed qualitative dominance of Cladocera (45 species. Microcrustacea comprised a significant quantitative component (45.6 � plus or minus 5.8 and 50.8 � plus or minus 4.5 % of zooplankton and exhibited bimodal and trimodal annual patterns with peaks during winter. Cladocera > Copepoda are important quantitative groups. ANOVA registered significant variation in species richness and abundance of Microcrustacea over time and between stations. Richness and abundance were inversely correlated with water temperature and rainfall, and positively correlated with specific conductivity and dissolved oxygen. Multiple regression registered significantly higher cumulative effects of ten abiotic factors on these two parameters. Our results are characterized by higher species diversity, higher evenness and lower dominance of Microcrustacea and show lack of distinct quantitative importance of individual species.

  8. Pemanfaatan Plankton sebagai Sumber Makanan Ikan Bandeng di Waduk Ir. H. Juanda, Jawa Barat

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    Deden Ibnu Aqil

    2016-03-01

    Full Text Available Introducing of Milkfish (Chanos chanos was aimed to utilize natural food from plankton that were abundant in Ir. H. Juanda Reservoir, West Java. This research aimed to know plankton utilization by Milkfish in Ir. H. Juanda Reservoir, West Java. The research was conducted from February to July 2010 at 4 stations of sampling which representing the reservoir condition. The fishes collected based on the catch of fishermen. The sample was analyzed in physiology laboratory of Center Research for Limnology. The result of this research showed that the main food were plankton 43%, detritus 46%, and complement food were vegetation 11%. The domination food from the phytoplankton were Bacillariophyceae and zooplankton were Copepoda.

  9. Variaciones de abundancia y biomasa del zooplancton en un embalse tropical oligo-mesotrófico del norte de Venezuela

    Directory of Open Access Journals (Sweden)

    Sandra Merayo

    2010-06-01

    Full Text Available La abundancia del zooplancton en los embalses está determinada principalmente por la velocidad y el contenido del agua, pero se sabe relativamente poco sobre los embalses tropicales. Se estudió la distribución temporal y espacial de la abundancia y la biomasa del zooplancton en el eje longitudinal del embalse de Clavellinos, en el norte de Venezuela, entre octubre 2006 y septiembre 2007. El zooplancton fue recolectado en el estrato oxigenado con una red de plancton. Un total de 16 taxones fueron identificados: Copepoda, Cladocera, Rotifera, Ostracoda y Diptera. Thermocyclops decipiens (Copepoda, Cyclopoida dominó la comunidad, mientras que los rotíferos fueron los más diversos, con 10 especies. La abundancia del zooplancton varió de 31 a 101ind/l en E1, 36 a 84ind/l en E2, y, de 30 a 250ind/L en el E3. La biomasa varió de 97,4 a 1406.3μg/l en E1, 108,5 a 397.2μg/l en E2, y de 25,9 a 763.9μg/l en el E3. Esta comunidad de zooplancton pareciσ responder a las variaciones ambientales en el embalse, mαs que a las variaciones en la disponibilidad de recursos.Variations of zooplankton abundance and biomass in a tropical oligo-mesotrophic reservoir in Northern Venezuela. Zooplankton abundance in reservoirs is mainly determined by the speed and content of the water, but relatively little is known regarding tropical reservoirs. We studied the seasonal and spatial distribution of zooplankton abundance and biomass along the longitudinal axis of Clavellinos reservoir, northern Venezuela, from October 2006 to September 2007. Zooplankton was collected from the oxygenated layer using a plankton net. A total of 16 taxa were identified: Copepoda, Cladocera, Rotifera, Ostracoda and Diptera. Thermocyclops decipiens (Copepoda, Cyclopoida dominated the community, while rotifers were the most diverse, with 10 species. Zooplankton abundance varied from 31 to 101ind/L in E1, 36 to 84ind/L in E2, and, from 30 to 250ind/L in E3. Biomass varied from 97.4 to

  10. [Parasitic Crustacea of fishes from the north-east Atlantic Ocean].

    Science.gov (United States)

    Gaevskaja, A V

    1991-01-01

    Fish from the north-east Atlantic, including neighbouring aquens are host of 3 species of Branchiura, 163 Copepoda, 37 Isopoda, 2 Amphipoda, and 1 of parasitic Cirripedia. Chondrichthyes have more species of parasitic crustaceans than Osteichthyes. Many specific parasites of Osteichthyes and the facultative parasites of fish include species of crustaceans to fish of both classes. 165 species of parasitic crustaceans are found in benthic and near-benthic fish, and 55 in pelagic fish. The greatest variety of species parasitic crustaceans is found in fishes in the North Sea (139); it is much smaller in the Baltic Sea (15). Endemic species constitute 15% of the total number of parasitic crustacean. The irregular distribution of parasitic crustaceans is among others connected with the biology and ecology of both hosts and their parasites.

  11. Zoogeography of Chilean inland water crustaceans

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    Patricio De los Ríos-Escalante

    2013-11-01

    Full Text Available The Chilean inland water crustaceans are characterized by a combination of endemic and cosmopolitan species: some occur throughout the territory of continental Chile, while others are restricted to specific latitudinal regions. This study examined the zoogeographical patterns exhibited by Chilean inland water crustaceans. We considered six regions: Northern Chile (18°-27°S, North-Central Chile (27°-30°S, Central Chile (30°-38°S, Northern Patagonia (38°-41°S, Central Patagonia (41°-51°S, and Southern Patagonia (51°-55°S, and these were identified based on literature records of inland water crustaceans. The classification analysis generated dendrograms for the following groups considered in this categories: all inland water crustaceans (Branchiopoda, Copepoda and Malacostraca, the zooplanktonic crustaceans (Branchiopoda and Copepoda, the Malacostraca alone, and each group separately. Analysis of total data and of the zooplankton group taxa alone revealed the existence of a main grouping consisting of the three Patagonian zones plus Central Chile, that is distinct from that of Northern Chile and North-Central Chile. Similarly, analysis of the malacostracan data revealed the existence of two main groups, one comprising the three Patagonian zones plus Central Chile, contrasted with a second group of Northern and North-Central Chile combined. Our results are in agreement with other panbiogeographical studies of South American crustaceans and insects. Possible factors responsible for generating this pattern are the dispersal and colonization potential of zooplanktonic crustaceans and the marked endemism of the malacostracans.

  12. Diversity of the parasite fauna of cyprinid (Cyprinidae) and percid (Percidae) fishes in the Vistula Lagoon, Poland.

    Science.gov (United States)

    Rolbiecki, Leszek

    2003-01-01

    A total of 2398 fish specimens (1091 Percidae and 1307 Cyprinidae) belonging to 16 species (3 Percidae and 13 Cyprinidae), caught in the Polish part of the Vistula Lagoon were examined within December 1994-March 1997. The parasites found were identified as belonging to 63 taxa (61 species as well as Diplostomum spp. flukes and glochidia Unionidae gen. sp. which could not be identified to species) of the Microsporea (1), Protozoa (1), Myxozoa (2), Monogenea (10), Digenea (15), Cestoda (11), Nematoda (11), Acanthocephala (5), Hirudinea (1), Mollusca (1), Copepoda (4), and Branchiura (1). The percids and cyprinids were found to support 37 and 40 parasitic taxa, respectively, the taxon-richest parasite fauna occurring in zander, Sander lucioperca (26 taxa), followed by carp bream, Abramis brama (24), European perch, Perca fluviatilis (24), roach, Rutilus rutilus (19), ruffe, Gymnocephalus cernuus (15), and Prussian carp, Carassius gibelio (11). The remaining fish species hosted less than 10 parasitic species each. Metacercariae of the genus Diplostomumn, found in about 37% of the fish examined, and Tylodelphys clavata, recorded in about 24% of the fish, proved the commonest parasites. The study showed the Vistula Lagoon cyprinid and percid parasite fauna to be dominated by freshwater species, frequencies of their occurrence in the brackishwater lagoon being lower than those in freshwater reservoirs. Frequencies of the 6 marine parasitic species found in the lagoon were, too, lower than those in the sea. It is suggested that some of the parasites (Ancyrocephalus paradoxus, Diplozoon paradoxum of the Monogenea, Diplostomum spp., Tylodelphys clavata of the Digenea, and Achtheres percarum of the Copepoda) prefer brackishwater habitats.

  13. Işıklı Gölü ve Kaynaklarının (Çivril-Denizli Crustacea Faunası.

    Directory of Open Access Journals (Sweden)

    Cem Aygen

    2015-12-01

    Full Text Available Bu çalışmada, Işıklı Gölü Crustacea faunasının taksonomik açıdan incelenmesi hedeflenmiştir. Bu amaçla Şubat 1998-Ocak 1999 ayları arasında, gölde ve göle akan kaynak bölgesinde belirlenen 6 istasyondan aylık periyotlarla biyolojik örnekler ve su örnekleri alınmıştır. Araştırma sonunda Işıklı Gölü ve Kaynağı’nda bulunan Crustacea faunasının başlıca Cladocera (16 tür, Copepoda (12 tür, Ostracoda (1 tür, Amphipoda (2 tür, Isopoda (1 tür, Mysidacea (1 tür ve Decapoda (1 tür gruplarından oluştuğu saptanmıştır. Tespit edilen türlerden Cladocera grubundan Diaphanosoma brachyurum, Diaphanosoma mongolianum, Ceriodaphnia pulchella, Simocephalus vetulus, Macrothrix laticornis, Alona rectangula, Alona guttata, Graptoleberis testudinaria, Leydigia leydigi, Biapertura affinis, Chydorus sphaericus, Pleuroxus aduncus ve Disparalona rostrata; Copepoda grubundan Macrocyclops albidus, Eucyclops serrulatus, Eucyclops speratus, Eucyclops macruroides, Metacyclops gracilis, Mesocyclops leuckarti, Cyclops vicinus, Cyclops abyssorum, Cyclops strenuus, Megacyclops viridis, Acanthocyclops robustus, Canthocamptus staphylinus; Ostracoda grubundan Psychrodromus olivaceus; Amphipoda grubundan Gammarus balcanicus, Gammarus obnixus; Isopoda grubundan Asellus aquaticus türleri Işıklı Gölü’nden ilk kez bildirilmektedir

  14. A comparison of the zooplankton community in the Bay of Bengal and South China Sea during April–May, 2010

    Science.gov (United States)

    Li, Kaizhi; Yin, Jianqiang; Huang, Liangmin; Tan, Yehui; Lin, Qiang

    2017-12-01

    This study compares the structure of the zooplankton community in the Bay of Bengal (BoB) and South China Sea (SCS) during the period of spring inter-monsoon, 2010. A total of 215 species of zooplankton were identified, of which 187 species were present in the BoB and 119 in the SCS. Of the taxonomic groups recorded, Copepoda was the most diverse group in all samples followed by pelagic Tunicata, Siphonophorae and Chaetognatha. Flaccisagitta enflata, Cosmocalanus darwinii, Euchaeta larva, Macrura larva and Candacia truncata were predominant both in the BoB and SCS. Moreover, the distribution of some dominant species differed regionally, such as Cypridina dentata, Pleuromamma robusta and Mesosagitta decipiens only in the BoB, and Pleuromamma gracilis, Neocalanus gracilis and Eudoxoides spiralis in the SCS. The average zooplankton abundance was 33.37 ± 7.19 ind. m-3 in the BoB and 35.08 ± 2.07 ind. m-3 in the SCS. Copepoda was one of the most abundant groups in the BoB and SCS. Based on multivariate analysis, it was possible to distinguish the zooplankton in the BoB and SCS communities at the similarity level of approximately 55%, and the dissimilarity was mainly due to C. dentata, P. robusta, M. decipiens, C. darwinii, N. gracilis and P. gracilis. The relationships between zooplankton and temperature, salinity and chlorophyll a were not statistically significant. Zooplankton community structure in the BoB and SCS was observed to be generally similar in terms of species composition and abundance, but the differences observed may be the result of species-specific geographical distribution and local hydrographic conditions.

  15. Carotenoid metabolic profiling and transcriptome-genome mining reveal functional equivalence among blue-pigmented copepods and appendicularia.

    Science.gov (United States)

    Mojib, Nazia; Amad, Maan; Thimma, Manjula; Aldanondo, Naroa; Kumaran, Mande; Irigoien, Xabier

    2014-06-01

    The tropical oligotrophic oceanic areas are characterized by high water transparency and annual solar radiation. Under these conditions, a large number of phylogenetically diverse mesozooplankton species living in the surface waters (neuston) are found to be blue pigmented. In the present study, we focused on understanding the metabolic and genetic basis of the observed blue phenotype functional equivalence between the blue-pigmented organisms from the phylum Arthropoda, subclass Copepoda (Acartia fossae) and the phylum Chordata, class Appendicularia (Oikopleura dioica) in the Red Sea. Previous studies have shown that carotenoid-protein complexes are responsible for blue coloration in crustaceans. Therefore, we performed carotenoid metabolic profiling using both targeted and nontargeted (high-resolution mass spectrometry) approaches in four different blue-pigmented genera of copepods and one blue-pigmented species of appendicularia. Astaxanthin was found to be the principal carotenoid in all the species. The pathway analysis showed that all the species can synthesize astaxanthin from β-carotene, ingested from dietary sources, via 3-hydroxyechinenone, canthaxanthin, zeaxanthin, adonirubin or adonixanthin. Further, using de novo assembled transcriptome of blue A. fossae (subclass Copepoda), we identified highly expressed homologous β-carotene hydroxylase enzymes and putative carotenoid-binding proteins responsible for astaxanthin formation and the blue phenotype. In blue O. dioica (class Appendicularia), corresponding putative genes were identified from the reference genome. Collectively, our data provide molecular evidences for the bioconversion and accumulation of blue astaxanthin-protein complexes underpinning the observed ecological functional equivalence and adaptive convergence among neustonic mesozooplankton. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  16. Oceanographic mechanisms that possibly explain dominance of neritic-tropical zooplankton species assemblages around the Islas Marías Archipelago, Mexico

    Directory of Open Access Journals (Sweden)

    Jaime Gómez-Gutiérrez

    2014-11-01

    Full Text Available The nearshore zooplankton species assemblage, identified per taxonomic groups (20 and per species for 12 selected groups, was analyzed from samples collected during November 2010 at four volcanic islands of the Islas Marías Archipelago (IMA, located 90-120 km offshore Nayarit, Mexico. From chlorophyll-a concentration and zooplankton biovolume perspective mesotrophic conditions prevailed in comparison with the Gulf of California during November. Crustaceans numerically dominated the zooplankton assemblage (92.3% [Copepoda (79.2%, Decapoda larvae (4.7%, Cladocera (3.7%, Mysidacea (2.7%, and Euphausiacea (2.0%]. The other 15 taxonomic groups (7.7% combined accounted each one less than 1.5% of the relative abundance. Species richness of selected taxa (~56%> included 259 taxa (121 identified to species, 117 to genus, and 21 not identified. Tropical species from neritic affinity clearly dominated zooplankton assemblage around IMA. Five tropical Copepoda species [Calanopia minor (Dana, Clausocalanus jobei Frost & Fleminger, Acrocalanus gibber Giesbrecht, Canthocalanus pauper (Giesbrecht, and Centropages furcatus (Dana], a cladoceran Pseudevadne tergestina (Claus, and a Mysidacea species (Mysidium reckettsi Harrison & Bowman dominated the zooplankton assemblage (accounting about 55% of total abundance of the identified species. Except C. furcatus, all these species are not abundant at oceanic regions of the central and northern Gulf of California. The similarity of multiple neritic and tropical species in the zooplankton assemblage from IMA and Cape Corrientes suggests strong coastal-insular plankton connectivity. Episodic current plumes associated with anomalous intense rivers discharge during rainy years, eddies generated by coastal upwelling event that move offshore, and northward regional oceanic circulation are the most likely mesoscale oceanographic processes that cause costal tropical zooplankton drift enhancing coastal-Archipelago species

  17. Population dynamics of a dominant species (Pseudocalanus, Acartia and Temora) in the Gulf of Gdansk (southern Baltic Sea)

    Science.gov (United States)

    Dzierzbicka-Glowacka, L.; Janecki, M.; Lemieszek, A.; Jakacki, J.; Nowicki, A.

    2012-04-01

    1 - C3 and C4 - C5 and finally the adult stage - C6. The Baltic zooplankton is composed of microzooplankton, mezozooplankton and macroplankton with characteristic ichtyoplankton forms. The structure of mezozooplankton in the Gdansk Gulf mainly consisted of four taxa: copepoda, cladocera, rotatoria and meroplankton. The most important species in the Gdansk Gulf are copepoda: Acartia spp. (i.e. A. bifilosa, A. longiremis and A. tonsa), Temora longicornis, Pseudocalanus minutus elongatus and Centropages hamatus and cladocera: Bosmina coregoni maritime and Podon polyphemoides. Copepoda dominate numerically, while in the warm season Cladocera are subdominants. The study describes numerical simulations of the seasonal dynamics of Acartia spp., Temora longicornis and Pseudocalanus minutus elongatus in the southern Baltic Sea using a three-dimensional version of the coupled ecosystem-copepod model. In the case of the Baltic Sea, food concentration and temperature are the main factors controlling copepod development, and salinity is a masking factor. The surface water salinity of the southern Baltic is constant at 7-8 PSU. It is included in the present study. The simulated population dynamics were compared with observations at the Gulf of Gdansk. This work is supported by the Polish State Committee of Scientific Research [grant number: NN306 353239 and No. N N305 111636]. The partial support for this study was also provided by the project Satellite Monitoring of the Baltic Sea Environment - SatBaltyk founded by European Union through European Regional Development Fund contract no. POIG 01.01.02-22-011/09. Calculations were done at the Academic Computer Center in Gdansk.

  18. Modelling the impact of temperature-induced life history plasticity and mate limitation on the epidemic potential of a marine ectoparasite.

    Directory of Open Access Journals (Sweden)

    Maya L Groner

    Full Text Available Temperature is hypothesized to contribute to increased pathogenicity and virulence of many marine diseases. The sea louse (Lepeophtheirus salmonis is an ectoparasite of salmonids that exhibits strong life-history plasticity in response to temperature; however, the effect of temperature on the epidemiology of this parasite has not been rigorously examined. We used matrix population modelling to examine the influence of temperature on demographic parameters of sea lice parasitizing farmed salmon. Demographically-stochastic population projection matrices were created using parameters from the existing literature on vital rates of sea lice at different fixed temperatures and yearly temperature profiles. In addition, we quantified the effectiveness of a single stage-specific control applied at different times during a year with seasonal temperature changes. We found that the epidemic potential of sea lice increased with temperature due to a decrease in generation time and an increase in the net reproductive rate. In addition, mate limitation constrained population growth more at low temperatures than at high temperatures. Our model predicts that control measures targeting preadults and chalimus are most effective regardless of the temperature. The predictions from this model suggest that temperature can dramatically change vital rates of sea lice and can increase population growth. The results of this study suggest that sea surface temperatures should be considered when choosing salmon farm sites and designing management plans to control sea louse infestations. More broadly, this study demonstrates the utility of matrix population modelling for epidemiological studies.

  19. Cessation of a salmon decline with control of parasites

    KAUST Repository

    Peacock, Stephanie J.

    2013-04-01

    The resilience of coastal social-ecological systems may depend on adaptive responses to aquaculture disease outbreaks that can threaten wild and farm fish. A nine-year study of parasitic sea lice (Lepeophtheirus salmonis) and pink salmon (Oncorhynchus gorbuscha) from Pacific Canada indicates that adaptive changes in parasite management on salmon farms have yielded positive conservation outcomes. After four years of sea lice epizootics and wild salmon population decline, parasiticide application on salmon farms was adapted to the timing of wild salmon migrations. Winter treatment of farm fish with parasiticides, prior to the out-migration of wild juvenile salmon, has reduced epizootics of wild salmon without significantly increasing the annual number of treatments. Levels of parasites on wild juvenile salmon significantly influence the growth rate of affected salmon populations, suggesting that these changes in management have had positive outcomes for wild salmon populations. These adaptive changes have not occurred through formal adaptive management, but rather, through multi-stakeholder processes arising from a contentious scientific and public debate. Despite the apparent success of parasite control on salmon farms in the study region, there remain concerns about the long-term sustainability of this approach because of the unknown ecological effects of parasticides and the potential for parasite resistance to chemical treatments. © 2013 by the Ecological Society of America.

  20. Paranucleospora theridion (Microsporidia) infection dynamics in farmed Atlantic salmon Salmo salar put to sea in spring and autumn.

    Science.gov (United States)

    Sveen, S; Øverland, H; Karlsbakk, E; Nylund, A

    2012-10-10

    The microsporidian Paranucleospora theridion (syn. Desmozoon lepeophtheirii) is a parasite of Atlantic salmon Salmo salar and also a hyperparasite of the salmon louse Lepeophtheirus salmonis. The parasite develops 2 types of spores in salmon, cytoplasmic spores in phagocytes and intranuclear spores in epidermal cells. The former type of development is assumed to be propagative (autoinfection), while the epidermal spores transfer the parasite to lice. Development in lice is extensive, with the formation of xenoma-like hypertrophic cells filled with microsporidian spores. We show that salmon are infected in the absence of lice, likely through waterborne spores that initiate infections in the gills. During summer and autumn the parasite propagates in the kidney, as evidenced by peaking normalised expression of P. theridion rRNA. Lice become infected during autumn, and develop extensive infections during winter. Lice mortality in winter and spring is likely responsible for a reservoir of spores in the water. Salmon transferred to sea in November (low temperature) did not show involvement of the kidney in parasite propagation and lice on such fish did not become infected. Apparently, low temperatures inhibit normal P. theridion development in salmon.

  1. Parasites in cultured and feral fish.

    Science.gov (United States)

    Scholz, T

    1999-08-01

    Parasites, causing little apparent damage in feral fish populations, may become causative agents of diseases of great importance in farmed fish, leading to pathological changes, decrease of fitness or reduction of the market value of fish. Despite considerable progress in fish parasitology in the last decades, major gaps still exist in the knowledge of taxonomy, biology, epizootiology and control of fish parasites, including such 'evergreens' as the ciliate Ichthyophthirius multifiliis, a causative agent of white spot disease, or proliferative kidney disease (PKD), one of the most economically damaging diseases in the rainbow trout industry which causative agent remain enigmatic. Besides long-recognized parasites, other potentially severe pathogens have appeared quite recently such as amphizoic amoebae, causative agents of amoebic gill disease (AGD), the monogenean Gyrodactylus salaris which has destroyed salmon populations in Norway, or sea lice, in particular Lepeophtheirus salmonis that endanger marine salmonids in some areas. Recent spreading of some parasites throughout the world (e.g. the cestode Bothriocephalus acheilognathi) has been facilitated through insufficient veterinary control during import of fish. Control of many important parasitic diseases is still far from being satisfactory and further research is needed. Use of chemotherapy has limitations and new effective, but environmentally safe drugs should be developed. A very promising area of future research seems to be studies on immunity in parasitic infections, use of molecular technology in diagnostics and development of new vaccines against the most pathogenic parasites.

  2. Evolution of virulence under intensive farming: salmon lice increase skin lesions and reduce host growth in salmon farms.

    Science.gov (United States)

    Ugelvik, M S; Skorping, A; Moberg, O; Mennerat, A

    2017-06-01

    Parasites rely on resources from a host and are selected to achieve an optimal combination of transmission and virulence. Human-induced changes in parasite ecology, such as intensive farming of hosts, might not only favour increased parasite abundances, but also alter the selection acting on parasites and lead to life-history evolution. The trade-off between transmission and virulence could be affected by intensive farming practices such as high host density and the use of antiparasitic drugs, which might lead to increased virulence in some host-parasite systems. To test this, we therefore infected Atlantic salmon (Salmo salar) smolts with salmon lice (Lepeophtheirus salmonis) sampled either from wild or farmed hosts in a laboratory experiment. We compared growth and skin damage (i.e. proxies for virulence) of hosts infected with either wild or farmed lice and found that, compared to lice sampled from wild hosts in unfarmed areas, those originating from farmed fish were more harmful; they inflicted more skin damage to their hosts and reduced relative host weight gain to a greater extent. We advocate that more evolutionary studies should be carried out using farmed animals as study species, given the current increase in intensive food production practices that might be compared to a global experiment in parasite evolution. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  3. Animal cell cultures in microsporidial research: their general roles and their specific use for fish microsporidia.

    Science.gov (United States)

    Monaghan, S Richelle; Kent, Michael L; Watral, Virginia G; Kaufman, R John; Lee, Lucy E J; Bols, Niels C

    2009-01-01

    The use of animal cell cultures as tools for studying the microsporidia of insects and mammals is briefly reviewed, along with an in depth review of the literature on using fish cell cultures to study the microsporidia of fish. Fish cell cultures have been used less often but have had some success. Very short-term primary cultures have been used to show how microsporidia spores can modulate the activities of phagocytes. The most successful microsporidia/fish cell culture system has been relatively long-term primary cultures of salmonid leukocytes for culturing Nucleospora salmonis. Surprisingly, this system can also support the development of Enterocytozoon bienusi, which is of mammalian origin. Some modest success has been achieved in growing Pseudoloma neurophilia on several different fish cell lines. The eel cell line, EP-1, appears to be the only published example of any fish cell line being permanently infected with microsporidia, in this case Heterosporis anguillarum. These cell culture approaches promise to be valuable in understanding and treating microsporidia infections in fish, which are increasingly of economic importance.

  4. Salmon lice – impact on wild salmonids and salmon aquaculture

    Science.gov (United States)

    Torrissen, O; Jones, S; Asche, F; Guttormsen, A; Skilbrei, O T; Nilsen, F; Horsberg, T E; Jackson, D

    2013-01-01

    Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonids, although the extent of the impact is a matter of debate. Estimates from Ireland and Norway indicate an odds ratio of 1.1:1-1.2:1 for sea lice treated Atlantic salmon smolt to survive sea migration compared to untreated smolts. This is considered to have a moderate population regulatory effect. The development of resistance against drugs most commonly used to treat salmon lice is a serious concern for both wild and farmed fish. Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish. The newly sequenced salmon louse genome will be an important tool in this work. The use of cleaner fish has emerged as a robust method for controlling salmon lice, and aquaculture production of wrasse is important towards this aim. Salmon lice have large economic consequences for the salmon industry, both as direct costs for the prevention and treatment, but also indirectly through negative public opinion. PMID:23311858

  5. Studies on the antibody response and side effects after intramuscular and intraperitoneal injection of Atlantic lumpfish (Cyclopterus lumpus L.) with different oil-based vaccines.

    Science.gov (United States)

    Erkinharju, T; Lundberg, M R; Isdal, E; Hordvik, I; Dalmo, R A; Seternes, T

    2017-12-01

    Atlantic lumpfish (Cyclopterus lumpus L.) is used as a biological delousing agent for sea lice (Lepeophtheirus salmonis K.) infestations in Norwegian aquaculture. Here, we present a study on the antibody response and vaccine side effects after intramuscular and intraperitoneal injection of lumpfish with two vaccines. Both vaccines contained bacterial antigens from atypical Aeromonas salmonicida A-layer types V and VI, Vibrio anguillarum serotype O1 and Moritella viscosa sp., but one vaccine contained a vegetable oil-based adjuvant, while the other contained a mineral oil-based adjuvant. Intramuscular injection of the mineral oil-based vaccine caused a high acute mortality of fish within 48 hr after immunization. Intraperitoneal injection of the mineral oil-based vaccine resulted in a lower severity of intra-abdominal side effects than the vegetable oil-based vaccine. Intramuscular injection of the mineral oil-based vaccine resulted in a significantly higher antibody response against A. salmonicida when compared to controls and the vegetable oil-based vaccine group. The antibody response was poor against V. anguillarum and M. viscosa for all groups. Our results indicate that intramuscular injection of oil-based vaccines might be feasible for providing immunological protection for Atlantic lumpfish against bacterial diseases, especially atypical A. salmonicida, but more work is required to identity optimal adjuvants. © 2017 John Wiley & Sons Ltd.

  6. Using Agent-Based Modelling to Predict the Role of Wild Refugia in the Evolution of Resistance of Sea Lice to Chemotherapeutants.

    Directory of Open Access Journals (Sweden)

    Gregor F McEwan

    Full Text Available A major challenge for Atlantic salmon farming in the northern hemisphere is infestation by the sea louse parasite Lepeophtheirus salmonis. The most frequent method of controlling these sea louse infestations is through the use of chemical treatments. However, most major salmon farming areas have observed resistance to common chemotherapeutants. In terrestrial environments, many strategies employed to manage the evolution of resistance involve the use of refugia, where a portion of the population is left untreated to maintain susceptibility. While refugia have not been deliberately used in Atlantic salmon farming, wild salmon populations that migrate close to salmon farms may act as natural refugia. In this paper we describe an agent-based model that explores the influence of different sizes of wild salmon populations on resistance evolution in sea lice on a salmon farm. Using the model, we demonstrate that wild salmon populations can act as refugia that limit the evolution of resistance in the sea louse populations. Additionally, we demonstrate that an increase in the size of the population of wild salmon results in an increased effect in slowing the evolution of resistance. We explore the effect of a population fitness cost associated with resistance, finding that in some cases it substantially reduces the speed of evolution to chemical treatments.

  7. A survey of wild marine fish identifies a potential origin of an outbreak of viral haemorrhagic septicaemia in wrasse, Labridae, used as cleaner fish on marine Atlantic salmon, Salmo salar L., farms.

    Science.gov (United States)

    Wallace, I S; Donald, K; Munro, L A; Murray, W; Pert, C C; Stagg, H; Hall, M; Bain, N

    2015-06-01

    Viral haemorrhagic septicaemia virus (VHSV) was isolated from five species of wrasse (Labridae) used as biological controls for parasitic sea lice predominantly, Lepeophtheirus salmonis (Krøyer, 1837), on marine Atlantic salmon, Salmo salar L., farms in Shetland. As part of the epidemiological investigation, 1400 wild marine fish were caught and screened in pools of 10 for VHSV using virus isolation. Eleven pools (8%) were confirmed VHSV positive from: grey gurnard, Eutrigla gurnardus L.; Atlantic herring, Clupea harengus L.; Norway pout, Trisopterus esmarkii (Nilsson); plaice, Pleuronectes platessa L.; sprat, Sprattus sprattus L. and whiting, Merlangius merlangus L. The isolation of VHSV from grey gurnard is the first documented report in this species. Nucleic acid sequencing of the partial nucleocapsid (N) and glycoprotein (G) genes was carried out for viral characterization. Sequence analysis confirmed that all wild isolates were genotype III the same as the wrasse and there was a close genetic similarity between the isolates from wild fish and wrasse on the farms. Infection from these local wild marine fish is the most likely source of VHSV isolated from wrasse on the fish farms. © 2014 Crown Copyright. Journal of Fish Diseases © 2014 John Wiley & Sons Ltd.

  8. Modeling parasite dynamics on farmed salmon for precautionary conservation management of wild salmon.

    Directory of Open Access Journals (Sweden)

    Luke A Rogers

    Full Text Available Conservation management of wild fish may include fish health management in sympatric populations of domesticated fish in aquaculture. We developed a mathematical model for the population dynamics of parasitic sea lice (Lepeophtheirus salmonis on domesticated populations of Atlantic salmon (Salmo salar in the Broughton Archipelago region of British Columbia. The model was fit to a seven-year dataset of monthly sea louse counts on farms in the area to estimate population growth rates in relation to abiotic factors (temperature and salinity, local host density (measured as cohort surface area, and the use of a parasiticide, emamectin benzoate, on farms. We then used the model to evaluate management scenarios in relation to policy guidelines that seek to keep motile louse abundance below an average three per farmed salmon during the March-June juvenile wild Pacific salmon (Oncorhynchus spp. migration. Abiotic factors mediated the duration of effectiveness of parasiticide treatments, and results suggest treatment of farmed salmon conducted in January or early February minimized average louse abundance per farmed salmon during the juvenile wild salmon migration. Adapting the management of parasites on farmed salmon according to migrations of wild salmon may therefore provide a precautionary approach to conserving wild salmon populations in salmon farming regions.

  9. Effect of ectoparasite infestation density and life history stages on the swimming performance of Atlantic salmon Salmo salar

    Directory of Open Access Journals (Sweden)

    Samantha Bui

    2016-06-01

    Full Text Available To overcome sustainability obstacles and improve operations, the Atlantic salmon farming industry is testing novel approaches to production. Redistributing farm sites to offshore locations is one such solution; however, tolerance to high-current velocity sites must be considered, particularly if fish health status is compromised by parasites. We tested the effect of parasite density and life-history stage on the swimming performance of Atlantic salmon Salmo salar using a swim flume. Salmon with 3 different salmon lice Lepeophtheirus salmonis densities (0, 0.02 � 0.01 and 0.11 � 0.01 lice cm-2 [mean � SE] were tested across the 4 major life-history stages of lice (copepodid, chalimus, pre-adult and adult for critical swimming performance (Ucrit. Salmon Ucrit declined slightly by a mean of 0.04 to 0.10 body lengths s-1 with high parasite densities compared to uninfested and low densities, across the lice stages, while progression through the parasite life-history stages had little effect on swimming performance. Our results suggest that increasing infestation density of salmon lice incurs negative fitness consequences for farmed Atlantic salmon held in high-current velocity sites, with little difference in costs associated with attachment by different life-history stages of the lice.

  10. Morphology and pathology of the ectoparasitic copepod, Nicothoë astaci ('lobster louse') in the European lobster, Homarus gammarus.

    Science.gov (United States)

    Wootton, Emma C; Pope, Edward C; Vogan, Claire L; Roberts, Emily C; Davies, Charlotte E; Rowley, Andrew F

    2011-09-01

    Ectoparasitic copepods have been reported in a wide range of aquatic animals, including crustacean shellfish. However, with the exception of the salmon louse, Lepeophtheirus salmonis, our knowledge of such parasites in commercial species is rudimentary. The current study examines the morphology and pathology of the parasitic copepod, Nicothoë astaci (the 'lobster louse') in its host, the European lobster, Homarus gammarus. Lobsters were sampled from waters surrounding Lundy Island (Bristol Channel, UK) and all individuals collected were found to harbour female adult N. astaci in their gills, with a mean of 47·3 parasites/lobster. The majority of N. astaci were found in the basal region of pleurobranch gills. The parasite was found to attach to gill filaments via its oral sucker, maxillae and maxillipeds, and to feed on host haemolymph (blood) through a funnel-like feeding channel. It caused varying degrees of damage to the host gill, including occlusion of gill filaments and disruption to the vascular system in the central axis. Although there was evidence of extensive host response (haemocytic infiltration) to the parasite, it was displaced from the parasite attachment site and thus was observed in the central gill axis below. The region of gill filament immediately underlying the parasite feeding channel was devoid of such activity suggesting that the parasite interferes with the cellular defence and haemostatic mechanisms of the lobster in order to maintain invasion of the host.

  11. Considerations in developing an integrated pest management programme for control of sea lice on farmed salmon in Pacific Canada.

    Science.gov (United States)

    Brooks, K M

    2009-01-01

    In the development of integrated pest management (IPM) plans for the control of sea lice there are some components that are common to many areas. However, effective plans must be tailored to regionally varying environmental and biological factors affecting the severity of sea lice infections. This paper describes factors that would be involved in the development of an IPM plan for sea lice in the Broughton Archipelago, British Columbia. Temperature, salinity and currents affect the production, dispersion and competence of larvae of sea lice, Lepeophtheirus salmonis (Krøyer), as they develop to the infective copepodid stage. This information can be coupled with oceanographic conditions in the Broughton Archipelago and emerging computer models to define zones of infection where infections of new hosts are most likely. Salinity and temperature depend, in part, on river discharge in estuarine systems. River discharge depends on precipitation, snow pack and ambient temperatures, which can be monitored to help forecast the intensity of sea lice infections associated with both farmed and wild hosts. One of the goals of IPM planning is to reduce reliance on pesticides to avoid development of resistance in targeted parasites and to minimize environmental residues. Recommendations for developing an IPM plan specific to the Broughton Archipelago are provided along with a discussion of the additional information needed to refine IPM plans in this and other areas.

  12. Monitoring of Downstream Salmon and Steelhead at Federal Hydroelectric Facilities, 1992 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hawkes, Lynnette A.; Martinson, Rick D.; Absolon, Randall F. (Northwest and Alaska Fisheries Science Center, Environmental and Technical Services Division, Portland, OR)

    1993-05-01

    The seaward migration of salmonid smolts was monitored by the National marine Fisheries Service (NMFS) at two sites on the Columbia River in 1992. The NMFS Smolt Monitoring Project is part of a larger Smolt Monitoring Program to index Columbia Basin juvenile salmonied stocks. It is coordinated by the Fish Passage Center (FPC) for the Columbia Basin Fish and Wildlife Agencies and Tribes. Its purpose is to facilitate fish passage through reservoirs and at dams by providing FPC with timely smolt migration data used for flow and spill management. Data is also used for travel time, migration timing and relative run size magnitude analysis. This program is carried out under the auspices of the Northwest Power Planning Council Fish and Wildlife Program and is funded by the Bonneville Power Administration (BPA). Sampling sites were John Day and Bonneville Dams under the 1992 Smolt Monitoring Program. All pertinent fish capture, condition, brand recovery, and flow data, were reported daily to FPC. These data were incorporated into the FPC`s Fish Passage Data System (FPDS).

  13. Lice pressure from salmon farms on wild sea trout (Salmo trutta in a Norwegian fjord

    Directory of Open Access Journals (Sweden)

    Pablo Arechavala-Lopez

    2015-11-01

    Full Text Available Salmon lice Lepeophtheirus salmonis are external parasites on salmonids in the marine environment. However, during recent years, salmon lice abundance has increased due to the presence of salmon farming. Scientific studies shows that salmon farming increases the abundance of lice in the marine habitat and that salmon lice in the most intensively farmed areas have negatively affected wild fish populations. The present study assesses the spatiotemporal distribution of salmon lice infestations on wild sea trout population in the Romsdalsfjord region (Norway, and the potential relationship with fish-farming activity and environmental parameters in this area. Salmon lice at farms varied among localities or farming areas, although infestation levels were under the safety established thresholds (max: 0.5 adult females per fish in most of the cases. However, salmon farms with these levels might produce and release millions of copepods, potentially infecting wild salmonids. In accordance, low lice loads were recorded on wild sea trout captured in areas with low farming activity, while higher mean loads were recorded in areas with higher farming activity. A clear seasonal pattern and a positive correlation between lice on sea trout and sea water temperature were observed throughout the study period. The estimated production of copepods at farms and the mobile lice counted on wild sea trout one month later were correlated, suggesting the potential use of lice monitoring on sea trout as a proxy indicator of salmon lice infestation risks.

  14. Modeling Parasite Dynamics on Farmed Salmon for Precautionary Conservation Management of Wild Salmon

    Science.gov (United States)

    Rogers, Luke A.; Peacock, Stephanie J.; McKenzie, Peter; DeDominicis, Sharon; Jones, Simon R. M.; Chandler, Peter; Foreman, Michael G. G.; Revie, Crawford W.; Krkošek, Martin

    2013-01-01

    Conservation management of wild fish may include fish health management in sympatric populations of domesticated fish in aquaculture. We developed a mathematical model for the population dynamics of parasitic sea lice (Lepeophtheirus salmonis) on domesticated populations of Atlantic salmon (Salmo salar) in the Broughton Archipelago region of British Columbia. The model was fit to a seven-year dataset of monthly sea louse counts on farms in the area to estimate population growth rates in relation to abiotic factors (temperature and salinity), local host density (measured as cohort surface area), and the use of a parasiticide, emamectin benzoate, on farms. We then used the model to evaluate management scenarios in relation to policy guidelines that seek to keep motile louse abundance below an average three per farmed salmon during the March–June juvenile wild Pacific salmon (Oncorhynchus spp.) migration. Abiotic factors mediated the duration of effectiveness of parasiticide treatments, and results suggest treatment of farmed salmon conducted in January or early February minimized average louse abundance per farmed salmon during the juvenile wild salmon migration. Adapting the management of parasites on farmed salmon according to migrations of wild salmon may therefore provide a precautionary approach to conserving wild salmon populations in salmon farming regions. PMID:23577082

  15. Parasites of Bloater Coregonus hoyi (Salmonidae) from Lake Michigan, U.S.A

    Science.gov (United States)

    Madenjian, Charles P.; Muzzall, Patrick M.

    2013-01-01

    In total, 158 bloaters Coregonus hoyi collected in September and October 2011 from 4 Lake Michigan, U.S.A., ports were examined for parasites. The ports included Waukegan (WK), Illinois; Port Washington (PW) and Sturgeon Bay (SB), Wisconsin; and Saugatuck (SG), Michigan. Parasites found in bloaters by port were cestodes Cyathocephalus truncatus (WK, PW, and SB) and Eubothrium salvelini (WK, PW, SB, and SG); the nematode Cystidicola farionis (WK, PW, SB, and SG); acanthocephalans Acanthocephalus dirus (WK and PW), Echinorhynchus salmonis (WK, PW, and SB), and Neoechinorhynchus tumidus (SB); and the copepod Salmincola corpulentus (WK and PW). Gravid individuals of all parasite species were found except for E. salvelini and A. dirus. Cystidicola farionis had the highest prevalence at each port, and the highest mean intensity and mean abundance at PW. The numbers of C. farionis at PW were significantly higher than those at WK and SB. Echinorhynchus salvelini had the highest mean intensities and mean abundances at WK, SB, and SG. The values for parasite species richness in bloaters were similar among ports. The total numbers of parasites were similar between WK and PW, but they were higher at these ports than at SB. The parasite faunas of bloaters were characterized by autogenic helminth species.

  16. Sucessão de invertebrados durante o processo de decomposição de duas plantas aquáticas (Eichhornia azurea e Polygonum ferrugineum = Succession of invertebrates during the decomposition process of two aquatic plants (Eichhornia azurea and Polygonum ferrugineum

    Directory of Open Access Journals (Sweden)

    Roger Paulo Mormul

    2006-04-01

    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 aanálise 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 predominânciade 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 andPolygonum 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.azureaand 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 macroinvertebratesshowed 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 plant.

  17. Lake Roosevelt Fisheries Evaluation Program, Part B; Limnology, Primary Production, and Zooplankton in Lake Roosevelt, Washington, 1998 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Shields, John; Spotts, Jim; Underwood, Keith

    2002-11-01

    of 1.5 m (5 ft) when compared with a 4.6 m (15 ft) depth, and during the shorter incubation periods (two and four weeks). Mean zooplankton densities were greatest for Copepoda (88 %), then Daphnia spp. (10%) and other Cladocera (2.1%), while the zooplankton biomass assessment indicated Daphnia spp. had the greatest biomass (53.6%), then Copepoda (44.0%) and other Cladocera (2.5%). Mean overall zooplankton densities were the lowest observed since 1991. The cause was unclear, but may have been an artifact of human error. It seems unlikely that hydro-operations played a significant part in the reduction of zooplankton in light of the relatively friendly water year of 1998.

  18. Abundância natural do isótopo estável de carbono (13C de alguns itens alimentares e sua contribuição no crescimento de juvenis de pintado, Pseudoplatystoma corruscans (Agassiz, 1829 (Osteichthyes, Carbon stable isotope (13C natural abundance of some foods and its contribution to the pintado juvenile growth, Pseudoplatystoma corruscans (Agassiz, 1829 (Osteichthyes, Pimelodidae

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    Carlos Ducatti

    2002-05-01

    Full Text Available O presente estudo foi realizado com o objetivo de determinar a abundância natural do isótopo estável de carbono (13C de alguns componentes alimentares e determinar sua contribuição no crescimento de juvenis de pintado, em condições laboratoriais. Foram utilizados 150 peixes com peso vivo médio de 1,39 g, que permaneceram em dois tanques-rede com volume útil unitário de 125L, durante 60 dias. A cada 10 dias foram coletadas amostras de água para análise de fitoplâncton e zooplâncton. Cladocera foi o item dominante na análise de conteúdo estomacal, seguido de Chironomidae e Copepoda. Foi coletada amostra de peixes ao início e final do experimento para determinação do sinal isotópico. Foram obtidos valores médios de -20,94; -15,36 e -18,81 δ 13C‰ para o fitoplâncton, Cladocera e Chironomidae, respectivamente. Cladocera foi a principal fonte de carbono e contribuiu com uma média de 89,24% do carbono na alimentação dessa espécie, enquanto que Chironomidae contribuiu com 10,76%. O δ 13C demonstrou ser efetivo como marcador de carbono (C ao longo da cadeia alimentar, uma vez que o consumidor reflete isotopicamente sua dieta.The aim of this study is to determine the natural abundance of carbon stable isotope (13C of some food components and determine its contribution to the pintado juvenile growth, in laboratory conditions. 150 fishes were used with average weight of 1.39 g, and stocked in two net ponds with 125L each, during 60 days. Every 10 days a water sample was collected to analyse phytoplakton and zooplankton. Clacocera was dominant in the analysis of the stomach contents, following Chironomidae and Copepoda. A fish sample was collected in the beginning, and at the end of the experiment to analyses the isotopic signal. An average value of -20.94; -15.36 and -18.81 δ 13C‰ was obtained for phytoplankton, Cladocera and Chironomidae, respectively. Cladocera was the main carbon source and contribution with carbon

  19. Estrutura da Comunidade de Invertebrados Bentônicos do Rio Piranhas-Assu, Rio Grande do Norte, Nordeste do Brasil

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    Jansen Fernandes Medeiros

    2008-12-01

    Full Text Available Esse trabalho teve como objetivo conhecer os invertebrados bentônicos, bem como caracterizar os grupos tróficos funcionais existentes no rio Piranhas-Assu, município de Alto do Rodrigues, Rio Grande do Norte. As coletas foram realizadas nos meses de maio (chuva, julho e setembro (seca de 2002, em trechos diferentes do rio. Foi medida a velocidade da correnteza, a largura, profundidade do rio e temperatura da água. Foram coletados 3525 indivíduos de Insecta e outras classes (Malacostraca, Gastropoda, Bivalvia, Arachnida, Ostracoda e Copepoda. A maior abundância da classe Insecta ocorreu no mês de setembro (seca. A vazão apresentou correlação com a abundância com na Classe Insecta, já a velocidade superficial da água para outras classes. Entre os Insecta observou-se uma maior abundância de predadores, seguida dos coletores, já para as outras classes os raspadores foram mais abundantes.Structure of benthic invertebrate’s community with focus in the aquatic insects of the Piranhas-Assu river, State of Rio Grande do Norte, Northeast, BrazilAbstract. The aim of this work was to verify the benthonic invertebrates, and to identify the functional trophic groups that exist in the Piranhas-Assu, in Alto do Rodrigues municipality, Rio Grande do Norte State. The samples were carried taken on May (rain season, July and September (dry season from 2002, in different sites in the river. The measurements of water speed, wide, temperature and river deep where made. It was collected 3525 individuals of Insecta and other classes (Malacostraca, Gastropoda, Bivalvia, Arachnida, Ostracoda and Copepoda. Insecta showed a higher abundance in September (dry season. The river discharge showed significant correlation with Insecta classe abundance, and the superficial water speed had correlation with other classes. The insects showed a highest abundance of predators, followed by collectors, in the other classes, the scrappers were the most abundant.

  20. 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

    Directory of Open Access Journals (Sweden)

    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

  1. Community ecology of the metazoan parasites of freshwater fishes of Kerala.

    Science.gov (United States)

    Beevi, M Razia; Radhakrishnan, S

    2012-10-01

    The prevalence and mean intensity of metazoan parasite infection, the community characteristics (richness index, dominance index, evenness index and Shannon index of diversity) and the qualitative similarity of the metazoan parasite fauna among the species and families of the fishes were determined of 13 fish species of freshwater fishes of Kerala belonging to seven families. The metazoan parasite fauna of this geographical area is very diverse; it consisted of 33 species of parasites belonging to seven major taxa: ten species of Monogenea, nine Digenea, two Cestoda, six Nematoda, three Acanthocephala, two Copepoda and one Isopoda. Prevalence of infection ranged from 32.9% (Puntius vittatus) to 87.1% (Mystus oculatus) and mean intensity from 3.8 (Puntius vittatus) to 27.6 (Aplocheilus lineatus). The infra- and component communities of parasites were somewhat characteristic. The dominance pattern of the major taxa was in the order Digenea > Nematoda > Monogenea = Acanthocephala > Cestoda = Copepoda > Isopoda. Macropodus cupanus harboured the richest fauna and Puntius vittatus had the least rich fauna. The parasite fauna of A. lineatus was the most heterogeneous and that of M. cavasius, the most homogeneous. The diversity of the parasite fauna was the greatest in M. cavasius and the least in A. lineatus. The parasite faunas of A. lineatus and M. cupanus and of M. cavasius and M. oculatus were similar. However, in spite of the taxonomic nearness and the similarity of the habits and habitats of the four species of cyprinids (P. amphibius, P. filamentosus, P. sarana and P. vittatus), their parasite fauna were qualitatively very dissimilar-of the seven species of parasites encountered in them only one was shared by the four host species. The cyprinid, Rasbora daniconius, had its own characteristic component community of parasites consisting of six species none of which was shared by the other four cyprinids. The richest parasite fauna was that of the family

  2. Microbial community variation and functions to excess sludge reduction in a novel gravel contact oxidation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lin Shanshan; Jin, Y.; Fu, L. [School of Urban and Environmental Science, Northeast Normal University, Changchun (China); Quan, C. [Jilin University, College of medicine, Changchun (China); Yang, Y.S., E-mail: yangy6@cf.ac.uk [Cardiff University, School of Earth and Ocean Sciences, Cardiff CF10 3YE (United Kingdom)

    2009-06-15

    both in GCOR (15 no. per 20 ml) and in ASR (15 no. per 20 ml); the next abundant group was attachment plants 10 no. per 20 ml in GCOR and 4 no. per 20 ml in ASR, respectively. Rotifers and copepoda belonging to metazoan were only present in GCOR (8 no. per 20 ml for both rotifers and copepoda). The microbial diversity and population difference both in the GCOR carriers and ASR sludge indicated that the diverse microbes, a large amount of biomass forming longer microbial food chains attached on the carriers may be the main functions for the excess sludge reduction in GCOR.

  3. Zooplankton fluctuations in Jurumirim Reservoir (São Paulo, Brazil: a three-year study

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    LP. Sartori

    Full Text Available During three consecutive years, monthly samples of zooplankton were taken in the lacustrine (dam zone of Jurumirim (São Paulo, Brazil. The seasonal effect on basic limnological features (thermal regime, oxygen distribution, phytoplankton biomass, etc. was also examined. The influence of the seasonality on the fluctuation of the zooplankton composition and abundance was not clearly detected (low degree of recurrent patterns. Rotifers (32 taxa were the most abundant organisms during almost the entire study period with some seasonal alternations in the maximum abundance peaks of the main taxa (Conochilus unicornis, Keratella americana, K. cochlearis and Hexarthra spp., except for Polyarthra (mainly P. vulgaris. Only occasionally copepods were numerically dominant. Higher copepod abundance was positively associated to periods of increase in the water retention time. Among the Copepoda (10 taxa the calanoids (mainly Notodiaptomus iheringi were more abundant, especially in warmer periods. Conversely, cyclopoids had higher abundance in autumn and winter. The species Thermocyclops minutus and T. decipiens co-occurred, but the first attained higher abundance. Some evidence of co-existence strategies between both species are considered. Cladocera (17 taxa was never numerically dominant and the main taxa (Bosmina spp., Ceriodaphnia spp. and Diaphanosoma spp. occurred almost the whole study period and did not present a seasonal pattern of fluctuation. Diaphanosoma (mainly D. birgei attained the highest abundance among cladocerans. Most organisms were always found at the surface, but they also occupy the whole water column, even in periods of stratified conditions and low oxygen concentration in the bottom layers. Among the main zooplanktonic taxa, only Hexarthra avoids deep layers. An exceptionally high concentration of Copepoda nauplii on the surface was influenced by low transparency, high concentration of phytoplankton at this layer and low oxygen

  4. Variação nictemeral da composição bioquímica e biomassa do zooplâncton em tanques de cultivo de plâncton - DOI: 10.4025/actascibiolsci.v28i2.1014 Diurnal variation of zooplankton biochemical composition and biomass in plankton production tanks - DOI: 10.4025/actascibiolsci.v28i2.1014

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    Ricardo Motta Pinto-Coelho

    2006-03-01

    Full Text Available O valor nutricional do zooplâncton (teor de lipídios e fósforo foi analisado em tanques externos de cultivo de plâncton, sendo monitorados os efeitos da variação diurna e fertilização. O teor de lipídios foi significantemente mais elevado no tanque que sofreu fertilização na semana da coleta, com valor médio de 14% PS. Em geral, elevadas concentrações de lipídios foram observadas quando a biomassa de Moina sp. (Cladocera e de náuplios de Thermocyclops sp. (Copepoda também foram altas, estando relacionadas com a filtração do zooplâncton. Os valores tenderam a ser maiores durante os períodos diurno e vespertino. O teor de fósforo no zooplâncton variou entre 0,15% e 0,91% PS, com diferenças significativas entre os tanques. A qualidade nutricional do zooplâncton foi influenciada pelo regime de fertilização dos tanques, o qual também determinou a composição das espécies presentes.The nutritional value of zooplankton (lipid and phosphorus contents was analyzed in outdoor, plankton-culture tanks, to monitor the effects of diurnal variation and fertilization. Total lipid contents were significantly higher (average values of about 14% DW for the treatment fertilized during the sampling week. A significantly highher total lipid concentrations generally coincided with high biomass of Moina sp. (Cladocera and Thermocyclops sp. nauplii (Copepoda, which is probably related to zooplankton filtration rates. The values tended to be higher during the afternoon and the night. Phosphorus contents in the zooplanktonic population varied from 0.15 to 0.91% DW, with significant differences among the tanks. The zooplankton nutritional quality was greatly influenced by fertilization, which also determined the species composition in the tanks.

  5. Phytophilous Fauna of a Small and Artificial Urban Lake

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    Krajina Ivanka Orkić

    2017-06-01

    Full Text Available Phytophilous community on Myriophyllum spicatum was studied in a small artificial urban lake in the city of Osijek (eastern Croatia, during the spring and summer season in 2010. In the eutrophic conditions, macrophyte stands were well developed and in the formed periphyton representatives of the following invertebrate taxa were found: Hydrozoa, Nematoda, Gastropoda, Cladocera, Copepoda, Insecta larvae - including families Chironomidae and Coleoptera. They displayed differences in temporal abundance patterns. Two separate phases in macrophyte colonization with differences in invertebrate composition and abundance were recorded. Insect larvae, particularly Chironomidae, were most abundant in the first phase, through the spring period, and Hydra oligactis (brown hydra was most abundant in the second phase, i.e. summer period. Concurrently, microcrustacean abundance declined towards the end of the summer. Results of the analyses indicated that water temperature and perihyton biomass were the variables exerting the main influence on the invertebrate assemblage, while interestingly, macrophyte size and biomass were negatively correlated with most of the fauna abundance. On the other hand, brown hydra was negatively correlated with all other invertebrate taxa, except gastropods. Larger surface of submersed macrophytes is the main parameter supporting the increase of invertebrate abundance due to providing protection from predators and growth for periphyton, an important food source for these phytophilous organisms. Macrophyte length was positively correlated with Hydra abundance, while Chironomids were more influenced by periphyton biomass. These organisms can indicate water quality conditions and a potential increase in primary and secondary production.

  6. 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.

  7. Two new stygobiotic copepod species from the Tibesti area (Northern Chad) and a re-description of Pilocamptus schroederi (van Douwe, 1915).

    Science.gov (United States)

    Brancelj, Anton

    2015-08-04

    Between 4th and 18th March 2014, an international group of biologists carried out a hydrobiological expedition to the Ounianga-Tibesti area of northern Chad (Africa). The Tibesti is a desert volcanic area, intersected by the beds of ancient rivers which were active in the Tertiary. In deep canyons there are small water bodies (gueltas/aguelmans), fed by rain and spring water. They are rich in zooplankton, benthos, and even fish, but their groundwater fauna has previously been unknown. Groundwater samples collected in the vicinity of one guelta contained Syncarida, Isopoda, and Copepoda. Among the latter, two new species were recognised, Haplocyclops (H.) henrii sp. nov. and Parastenocaris joi sp. nov., together with a third species, Pilocamptus schroederi (van Douwe, 1915), previously known only from the littoral zone and wet mosses of Lake Victoria. The Tibesti area is thus the third known location of P. schroederi. All these species have a Gondwanaland distribution and are probably relicts of the Tertiary fauna, formerly widespread in the Sahara. Together with descriptions of two new species, a detailed re-description of P. schroederi is presented, along with remarks on their ecology.

  8. [Community Dynamics of Phytoplankton and Related Affecting Factors in a Eutrophicated Small Pond].

    Science.gov (United States)

    Yang, Wen; Zhu, Jin-yong; Zhang, Ke-xin; Wan, Li; Lu, Kai-hong

    2015-04-01

    The high-density sampling of eutrophic water can help to reveal the general rules of phytoplankton community succession and the relationship with environmental factors. The species and abundance of plankton and the physical-chemical factors were tracked for 30 weeks from March to October in a eutrophicated small pond. The relationships between the phytoplankton community dynamic change and the physical-chemical factors as well as the zooplankton in the water body community were studied by the multivariate statistical analysis with PRIMER. A total of 54 phytoplankton and 55 zooplankton species were identified, and the abundances of plankton varied from 0.28 x 10(8) - 6.11 x 10(8) cells x L(-1) for phytoplankton and 26-2.5 x 10(5) ind x L(-1) for zooplankton. The dominant species of phytoplankton were Cyanophyta and Chlorophyta, and an obvious succession process was showed with the seasonal change, which could be roughly divided into three stages: Chlorophyta-Cryptophyta type, Chlorophyta-Cyanophyta type and Cyanophyta type. BIO-ENV showed that pH, water temperature, transparency, total phosphorus and the abundances of Rotifera and Copepoda were the most critical influencing factors on the community dynamics of phytoplankton, and compared to zooplankton, the physical-chemical factors might have a greater influence.

  9. Norwegian deep-water coral reefs: cultivation and molecular analysis of planktonic microbial communities.

    Science.gov (United States)

    Jensen, Sigmund; Lynch, Michael D J; Ray, Jessica L; Neufeld, Josh D; Hovland, Martin

    2015-10-01

    Deep-sea coral reefs do not receive sunlight and depend on plankton. Little is known about the plankton composition at such reefs, even though they constitute habitats for many invertebrates and fish. We investigated plankton communities from three reefs at 260-350 m depth at hydrocarbon fields off the mid-Norwegian coast using a combination of cultivation and small subunit (SSU) rRNA gene and transcript sequencing. Eight months incubations of a reef water sample with minimal medium, supplemented with carbon dioxide and gaseous alkanes at in situ-like conditions, enabled isolation of mostly Alphaproteobacteria (Sulfitobacter, Loktanella), Gammaproteobacteria (Colwellia) and Flavobacteria (Polaribacter). The relative abundance of isolates in the original sample ranged from ∼ 0.01% to 0.80%. Comparisons of bacterial SSU sequences from filtered plankton of reef and non-reef control samples indicated high abundance and metabolic activity of primarily Alphaproteobacteria (SAR11 Ia), Gammaproteobacteria (ARCTIC96BD-19), but also of Deltaproteobacteria (Nitrospina, SAR324). Eukaryote SSU sequences indicated metabolically active microalgae and animals, including codfish, at the reef sites. The plankton community composition varied between reefs and differed between DNA and RNA assessments. Over 5000 operational taxonomic units were detected, some indicators of reef sites (e.g. Flavobacteria, Cercozoa, Demospongiae) and some more active at reef sites (e.g. Gammaproteobacteria, Ciliophora, Copepoda). © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  10. Diet and trophic ecomorphology of the silverside, Odontesthes bonariensis, of the Salto Caxias reservoir, rio Iguaçu, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Fernanda Aparecida da Silva Cassemiro

    Full Text Available This study aims to analyze the diet and trophic ecomorphology of Odontesthes bonariensis, relating these features with species' abundance in the natural environment and in the Salto Caxias reservoir (at Iguaçu river after the reservoir's formation. The samples were carried out before (from March 1997 to February 1998- pre and after (from October 1998 to February 2001 - post 1 and 2 the damming. The stomach contents of 218 individuals were analyzed by occurrence and volumetric methods. O. bonariensis' diet is based on insects, scales, plants and detritus. Microcrustaceans (Cladocera and Copepoda were the main items, allowing the characterization of the species as zooplanktivore. The species has a superior position and protractible mouth, with small teeth, creating a serrated pattern, uniformly lined side by side. There are many gill rakers, that are long and close together (typical of filtering fishes; the stomach is ill defined and the intestine is short. There was a gradual increase of O. bonariensis' abundance during the period of field study, mainly after the second year of damming. This fact seems to be closely related with the high abundance and availability of zooplankton in the dammed environment, and also with the ability of the species to exploit this resource.

  11. 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.

  12. Associative dependence among plankton and macrophytes as pollution markers at tropical lentic environ, Gujarat, India

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    Hiren B Soni

    2014-05-01

    Full Text Available The present research was undertaken at three sampling stations of Gomti catchment, Central Gujarat, India, to study dominance, interaction, and interdependence among biotic components (phytoplankton, zooplankton and aquatic macrophytes. The phytoplankton population was represented by 39 genera and 48 species belongs to family Bacillariophyceae (21 species, followed by Cyanophyceae (7, Cholorophyceae (18, and Euglenophyceae (2. In total, seven classes of zooplankton were represented by 36 genera and 39 species. Zooplankton dominance was reflected by class Ciliophora (16 species, followed by Zooflagellata, Rhizopoda and Rotifera (6 each, and Cladocera (3,and least by Copepoda and Ostracoda (1 species each. Of 16 species of aquatic macrophytes, 3 (18.75% were abundant, 4 (25% common, and 9 (56.25% were rare. The indices (Palmer, Nygaard’s, and Macrophyte index were determined to delineate the interdependent relationship among studied biotic components. Strong association was observed between Chlorophyceae and Bacillariophyceae, Ostracods and Ciliophorans, and Cladocerans and Bacillariophyceans. The detailed results of indices and interdependent associations among biotic components are discussed. The information provided herewith makes an insight for better understanding of the environmental aspects to be addressed effectively for the better protection, conservation, and management of Gomti reservoir, Gujarat, India. DOI: http://dx.doi.org/10.3126/ije.v3i2.10528 International Journal of the Environment Vol.3(2 2014: 175-191

  13. Effects of 4-nonylphenol on the biota in a littoral pond ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Liber, K.; Schmude, K.; O`Halloran, S.; Corry, T.; Gangl, J. [Univ. of Wisconsin, Superior, WI (United States); Stay, F. [Environmental Protection Agency, Duluth, MN (United States). Environmental Research Lab.

    1994-12-31

    National water quality criteria for 4-nonylphenol, a surfactant precursor and metabolite, are currently being developed by the US EPA. Preliminary data from laboratory tests indicate that the criterion maximum concentration may be as low as 3--10 {mu}g/L; field data on biological effects are rare. The study presented here was designed to assess the effects of 4-nonylphenol on a natural aquatic community using a set of 18 littoral enclosures (average volume 33 m{sup 3}). The common occurrence of 4-nonylphenol in municipal and industrial discharges dictated the use of a ``chronic`` exposure scenario for this study. Test concentrations ranged from 3 to 300 {mu}g/L, with applications every 48 hours for a 20 day period. This ensured a 21-day ``chronic`` exposure period and allowed sediment concentration of 4-nonylphenol to steadily increase. Survival of juvenile bluegill sunfish was reduced at 300 {mu}g/L, but not at 100, {mu}g/L; no effects on growth were noted over the 68-day assessment period. Abundance of Cladocera and Copepoda were also reduced at 300 {mu}g/L, with recovery observed within 2--4 weeks after the last nonylphenol application. Benthic macroinvertebrates, including Chironomidae, Oligochaeta, and Mollusca, were affected at 100--300 {mu}g/L, with impacts persisting for several months. The slow recovery of benthic macroinvertebrates was partially attributed to their prolonged exposure to sediment associated nonylphenol residues.

  14. Evaluation of model predictions of the ecological effects of 4-nonylphenol -- before and after model refinement

    Energy Technology Data Exchange (ETDEWEB)

    Hanratty, M.P.; Liber, K. [Univ. of Wisconsin, Superior, WI (United States)

    1994-12-31

    The Littoral Ecosystem Risk Assessment Model (LERAM) is a bioenergetic ecosystem effects model. It links single species toxicity data to a bioenergetic model of the trophic structure of an ecosystem in order to simulate community and ecosystem level effects of chemical stressors. LERAM was used in 1992 to simulate the ecological effects of diflubenzuron. When compared to the results from a littoral enclosure study, the model exaggerated the cascading of effects through the trophic levels of the littoral ecosystem. It was hypothesized that this could be corrected by making minor changes in the representation of the littoral food web. Two refinements of the model were therefore performed: (1) the plankton and macroinvertebrate model populations [eg., predatory Copepoda, herbivorous Insecta, green phytoplankton, etc.] were changed to better represent the habitat and feeding preferences of the endemic taxa; and (2) the method for modeling the microbial degradation of detritus (and the resulting nutrient remineralization) was changed from simulating bacterial populations to simulating bacterial function. Model predictions of the ecological effects of 4-nonylphenol were made before and after these refinements. Both sets of predictions were then compared to the results from a littoral enclosure study of the ecological effects of 4-nonylphenol. The changes in the LERAM predictions were then used to determine the success of the refinements, to guide. future research, and to further define LERAM`s domain of application.

  15. Short-term and seasonal variability of mesozooplankton at two coastal stations (Gdynia, Sopot in the shallow water zone of the Gulf of Gdańsk

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    Anna Józefczuk

    2003-06-01

    Full Text Available The idea of the study was to describe short-term and seasonal variationsin the composition and abundance of zooplankton in the coastal area of theGulf of Gdansk at two shore stations and the influence of selectedenvironmental factors (temperature, salinity, wind velocity on it. The studieswere based on material collected in the shallow waters of the Gulf of Gdanskfrom stations located by the Marine Promenade (Bulwar Nadmorski in Gdynia andthe pier in Sopot. Samples were collected in 2001 mainly at weekly intervalsusing an open-type plankton net. Environmental parameters were measured at thesame time. The zooplankton at the Gdynia and Sopot stations consisted of30 taxa; Rotatoria, Copepoda and meroplankton were dominants.There was a much higher percentage of Rotatoria and a lower percentage of meroplankton at Sopot than at Gdynia. Considerable differences were apparent in the numbers ofparticular groups of zooplankton at these stations in the same periods.Simpson's biodiversity index, here based on the zooplankton of the shallowwaters off Gdynia and Sopot, was relatively high most of the time.Diversity of mesozooplankton was greatest in July and October. There was a significantcorrelation between the abundance of mesozooplankton and environmental factorsin the case of cladoceran and polychaete larvae. Frequent studies at stationslocated close to each other illustrate the highly dynamic range of variationsoccurring in the coastal area: the concentrations of particular organismsfluctuated very considerably from one week to another, even by a factor ofseveral dozen. Nevertheless, the statistically mean numbers of zooplankton atboth stations are comparable.

  16. The early development of the onychopod cladoceran Bythotrephes longimanus (Crustacea, Branchiopoda)

    Science.gov (United States)

    2014-01-01

    Introduction Within arthropods, several crustacean groups are unique in their early development due to their stereotyped cell division patterns and cell lineages. However, it is still unclear whether these cell division patterns are homologous between the various crustacean groups and whether they could indicate the ground pattern of Tetraconata (Crustacea and Hexapoda). In this study we describe the early development of the raptorial water flea Bythotrephes longimanus as a representative of the Cladocera within branchiopods. Results In B. longimanus the early cell lineage and the cell division pattern are stereotyped up to the fifth cell division cycle. As a morphological marker a nurse cell remnant (ncr) identifies the cell lineage of the smallest and division delayed blastomere up to the 16-cell stage. This marker might be indicative of the germ line. By combining histology, confocal laser scanning microscopy, and 4D microscopy, we reconstruct the early cell lineage and cell division pattern and follow transient formations of cell morphological structures in their temporal and spatial behavior up to gastrulation. Conclusions Correspondences to the early cleavage pattern of other Cladocera suggest that the described pattern can be assumed to be ancestral for either the entire Cladocera or for the majority of the Cladocera comprising Anomopoda, Ctenopoda and Onychopoda. The comparison to the cell division patterns of other crustacean groups such as Malacostraca, Ostracoda, and Copepoda reveals similarities that allow for a discussion of a common pattern for the crustacean groups and a ground pattern for the Tetraconata. PMID:24507018

  17. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea

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    Crandall Keith A

    2009-04-01

    Full Text Available Abstract Background The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta. Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305, 28S rRNA (2,402, Histone H3 (328] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup and 12 Malacostraca and 10 Copepoda (outgroup. Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica. Conclusion Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite.

  18. Remarkable convergent evolution in specialized parasitic Thecostraca (Crustacea)

    Science.gov (United States)

    Pérez-Losada, Marcos; Høeg, Jens T; Crandall, Keith A

    2009-01-01

    Background The Thecostraca are arguably the most morphologically and biologically variable group within the Crustacea, including both suspension feeders (Cirripedia: Thoracica and Acrothoracica) and parasitic forms (Cirripedia: Rhizocephala, Ascothoracida and Facetotecta). Similarities between the metamorphosis found in the Facetotecta and Rhizocephala suggests a common evolutionary origin, but until now no comprehensive study has looked at the basic evolution of these thecostracan groups. Results To this end, we collected DNA sequences from three nuclear genes [18S rRNA (2,305), 28S rRNA (2,402), Histone H3 (328)] and 41 larval characters in seven facetotectans, five ascothoracidans, three acrothoracicans, 25 rhizocephalans and 39 thoracicans (ingroup) and 12 Malacostraca and 10 Copepoda (outgroup). Maximum parsimony, maximum likelihood and Bayesian analyses showed the Facetotecta, Ascothoracida and Cirripedia each as monophyletic. The better resolved and highly supported DNA maximum likelihood and morphological-DNA Bayesian analysis trees depicted the main phylogenetic relationships within the Thecostraca as (Facetotecta, (Ascothoracida, (Acrothoracica, (Rhizocephala, Thoracica)))). Conclusion Our analyses indicate a convergent evolution of the very similar and highly reduced slug-shaped stages found during metamorphosis of both the Rhizocephala and the Facetotecta. This provides a remarkable case of convergent evolution and implies that the advanced endoparasitic mode of life known from the Rhizocephala and strongly indicated for the Facetotecta had no common origin. Future analyses are needed to determine whether the most recent common ancestor of the Thecostraca was free-living or some primitive form of ectoparasite. PMID:19374762

  19. Seasonal variability of meiofauna, especially harpacticoid copepods, in Posidonia oceanica macrophytodetritus accumulations

    Science.gov (United States)

    Mascart, Thibaud; Lepoint, Gilles; Deschoemaeker, Silke; Binard, Marc; Remy, François; De Troch, Marleen

    2015-01-01

    The overall aim of this study was (1) to assess the diversity and density of meiofauna taxa, especially harpacticoid copepod species, present within accumulated seagrass macrophytodetritus on unvegetated sand patches and (2) to elucidate the community structure of detritus-associated harpacticoid copepods in relation to natural temporal variability of physico-chemical characteristics of accumulations. This was investigated in a Posidonia oceanica (L.) Delile seagrass ecosystem in the northwest Mediterranean Sea (Bay of Calvi, Corsica, 42°35‧N, 8°43‧E) using a triplicate macrophytodetritus core field sampling in two contrasting sites over the four seasons of 2011. Meiofauna higher taxa consisted of 50% Copepoda, of which 87% belonged to the Harpacticoida order. Nematoda was the second most abundant taxa. The copepod community displayed a wide variety of morphologically similar and ecologically different species (i.e. mesopsammic, phytal, phytal-swimmers, planktonic and parasitic). The harpacticoid copepod community followed a strong seasonal pattern with highest abundances and species diversity in May-August, revealing a link with the leaf litter epiphyte primary production cycle. Aside from the important role in sheltering, housing and feeding potential of macrophytodetritus, a harpacticoid community BEST analysis demonstrated a positive correlation with habitat complexity and a negative correlation with water movements and P. oceanica leaf litter accumulation.

  20. PREIMAGINAL STAGES OF COENAGRION PUELLA L. 1758 (ODONATA

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    L. Sh. Amhaeva

    2013-01-01

    Full Text Available Abstract. Aim. Ages and stages of dragonfly larvae Coenagrion puella L., 1758 with a wide area of distribution throughout Russia were determined in the laboratory. Morphological and morphometric characteristics of larvae instars are described.Location. Zoological laboratory of Kabardino-Balkarian State University (Russia.Methods. Common methods of entomological research were used. In experimental conditions, the development stage (F of 260 ex. of Coenagrion puella were studied. Eggs of Coenagrion puella were taken from natural reservoirs and incubated at 22–24 °C. Larvae were fed once a day by Cladocera, Copepoda, Ostracoda, Chironomidae, Oligochaeta.Results and conclusions. Larvae of Coenagrion puella L., 1758 are hatched from eggs after 24–26 days at the temperature 22–24 °C. Time diapason between exuviations is increased with age of larvae: 1–5 stages exuviate by 3–4 days, 6–7 stages by 5–6 days, 8–9 by 6–18 days, 10th by 9–12 days. Morphometric parameters of the larvae are changed with each molting. Main morphological changes indicate a stages of development and are due with change of mask (including its distal margin, lateral lobe, external lamellae (gill plates, antennae and tarsi. The results can be used in ecological monitoring, micropopulation studies. These data can help to determine the variability of dragonflies in mountain ecosystems.

  1. Olfaction in a viscous environment: the "color" of sexual smells in Temora longicornis

    Science.gov (United States)

    Hinow, Peter; Strickler, J. Rudi; Yen, Jeannette

    2017-06-01

    We investigate chemical aspects of mating in the marine copepod Temora longicornis (Copepoda, Calanoidea). Our emphasis is the female pheromone signaling in form of well-defined trails for males to follow, observed in Doall et al. (Phil Trans R Soc Lond B 353:681-689, 1998). The viscous environment and the properties of the odorants play important roles as the spread of the pheromone trail limits the time during which it is useful for tracing. A key observation from our earlier work is the ability of a searching male to detect the direction of the female and to correct its swimming direction if necessary. We propose a simple mathematical model for the spread of a pheromone from a moving source and carry out numerical simulations of two possible detection mechanisms. We find that a searching agent that is capable to detect a ratio outperforms a searcher that depends on the gradient of a single compound. This suggests that copepod sex pheromones consist of blends of chemical compounds, and that a ratio detection mechanism similar to that in airborne insects is at work.

  2. Zooplankton variability in the subtropical estuarine system of Paranaguá Bay, Brazil, in 2012 and 2013

    Science.gov (United States)

    Salvador, Bianca; Bersano, José Guilherme F.

    2017-12-01

    Spatial and temporal dynamics of zooplankton assemblages were studied in the Paranaguá Estuarine System (southern Brazil), including data from the summer (rainy) and winter (dry) periods of 2012 and 2013. Zooplankton and environmental data were collected at 37 stations along the estuary and examined by multivariate methods. The results indicated significantly distinct assemblages; differences in abundance were the major source of variability, mainly over the temporal scale. The highest abundances were observed during rainy periods, especially in 2012, when the mean density reached 16378 ind.m-3. Winter assemblages showed lower densities but higher species diversity, due to the more extensive intrusion of coastal waters. Of the 14 taxonomic groups recorded, Copepoda was the most abundant and diverse (92% of total abundance and 22 species identified). The coastal copepods Acartia lilljeborgi (44%) and Oithona hebes (26%) were the most important species in both abundance and frequency, followed by the estuarine Pseudodiaptomus acutus and the neritic Temora turbinata. The results indicated strong influences of environmental parameters on the community structure, especially in response to seasonal variations. The spatial distribution of species was probably determined mainly by their preferences and tolerances for specific salinity conditions. On the other hand, the abundances were strongly related to higher water temperature and precipitation rates, which can drive nutrient inputs and consequently food supply in the system, due to intense continental drainage.

  3. Diversity and distribution of heterotrophic dinoflagellates from the coastal waters of Port Blair, South Andaman.

    Science.gov (United States)

    Sai Elangovan, S; Padmavati, G

    2017-11-06

    The interaction between the environment and heterotrophic dinoflagellates inhabiting coastal waters of South Andaman was studied based on year round collections made during September 2012-August 2013 in the bay, eastern, and western region of South Andaman. The distribution pattern of microzooplankton in South Andaman showed high abundance in eutrophic waters (bay region) and gradually decreased towards the off shore region. Microzooplankton community comprised of six different taxa, viz. tintinnids, heterotrophic dinoflagellates, non-loricate ciliates, Foraminifera, Rotifera, and Copepoda (nauplii). Tintinnids were the major component of the microzooplankton (43.8 ± 7%) followed by heterotrophic dinoflagellates (34 ± 12%) and copepod nauplii (18.8 ± 4.0%). This study focused on heterotrophic dinoflagellates which ranked next to tintinnids in overall abundance and contributed 38-42% in the bay, 22-37% in the eastern, and 15-29% in the western region to the microzooplankton community. Dinoflagellates showed a positive correlation with salinity and a negative correlation with dissolved oxygen and chlorophyll a (r = - 0.3). Abundance of heterotrophic dinoflagellates in this area may be due to their diverse and advantageous mode of nutrition. A total of 35 species belonging to 8 genera of heterotrophic dinoflagellates were recorded during the study period. Heterotrophic dinoflagellates showed a great potential to thrive in low oxygenated and low productive area (p population was found in the bay region (avg. H' = 3.46).

  4. Food of forage fishes in western Lake Erie, 1975-76

    Science.gov (United States)

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

  5. Mesozooplankton assemblages in two bays in the Beagle Channel (Argentina during January, 2001

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    Melisa Daiana Fernández-Severini

    2005-12-01

    Full Text Available This paper describes the composition and abundance of mesozooplankton of Bahía Ushuaia and Bahía Golondrina. These small bays are located in the northern Beagle Channel. Sampling was carried out from January 20 to 23, 2001 and samples were collected from the upper layer at nine stations. This study is the first research on mesozooplankton in this part of the Beagle Channel. Due to their dominance in the mesozooplankton community, we compared our Copepoda data with those reported by other authors from Antarctic coastal environments. By applying cluster analysis, we found two station groups in both bays: one in slightly polluted zones and the other in undisturbed external zones. Four assemblages in Bahía Ushuaia and two in Bahía Golondrina were determined by using non-metric multidimensional scaling (MDS and cluster analysis. Mesozooplanktonic assemblages showed a certain resemblance in zones with and without anthropogenic influence. Most of the copepod species in our samples are typical of the sub-Antarctic region. Oithona similis (=O. helgolandica sensu Ramírez, 1966, Oncaea curvata, and Ctenocalanus citer show either similar or higher abundances at Antarctic coastal sites, including the upper layer in oceanic areas, in comparison with sub-Antarctic coastal localities. This suggests that, in agreement with other findings, the Polar Front is probably not a major geographic boundary for the distribution of these species.

  6. Microcrustacean diversity in the Gemenc-Béda-Karapancsa Floodplains (Danube-Drava National Park, Hungary: rare and alien species

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    Ágoston-Szabó, E.

    2015-11-01

    Full Text Available The composition of microcrustacean fauna was investigated in different water bodies of Gemenc-Béda-Karapancsa Floodplains with special regard to the distribution of alien and rare taxa. Between 2002 and 2013 101 taxa (57 Cladocera, 27 Copepoda, 17 Ostracoda, were recorded from the water bodies with differing degrees of connectivity to the main river (eu-, para-, plesio- and paleopotamon. 18 species are reported for the first time from the area of Danube-Drava National Park and among them Daphnia ambigua, Pleuroxus denticulatus and Eurytemora velox are allochtonous species in Hungary. E. velox and P. denticulatus have persistent populations in the area, but their contribution to floodplain biodiversity is still not significant. Daphnia ambigua has only local and temporal populations and its presence is confined to the disconnected side of the floodplain. The abundance of thirty species was very low and their distribution pattern in the floodplain is different. The microcrustacean diversity of the plesiopotamal side arms is remarkable, particularly in the Nyéki-Holt-Danube.

  7. Abundance, food habits, and breeding season of exotic T ilapia zillii and native O reochromis niloticus L. fish species in Lake Zwai , Ethiopia

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    Padanillay C. Prabu

    2008-05-01

    Full Text Available Relative abundance, diet and breeding season overlap in the reproduction of exotic Tilapia zillii and native Oreochromis niloticus in Lake Zwai were studied from samples collected over 12 months. Younger fish of both species collected were also evaluated for food composition.Food items from stomachs of both species were collected and analysed using the frequency of occurrence method. In terms of number, T. zillii dominated O. niloticus at the sampling sites. In both species, macrophytes, detritus, blue green algae, diatoms, green algae, Ceratium, Euglena,and Phacus constituted foods of plant origin, whereas chironomid larvae, Copepoda, Cladocera,Rotifera, Nematoda, fish eggs, and fish scales constituted foods of animal origin. Foods of the latter type such as Ephemeroptera and mollusks were also noted in the diet of adult T. zillii.Despite the extensive overlap in food habits of the two species, however, the food items were found in the diet of the species with different average percentage frequencies of occurrence. The level of gonad maturation and gonadosomatic index (GSI values showed that in Lake Zwai breeding was year-round for both T. zillii and O. niloticus, with a peak during April-September and February-August respectively, indicating extended breeding season overlap in reproduction. The two species were always found together in the catches from the sampling sites, which indicated some niche overlap between them.

  8. Biodiversity and community structure of zooplankton in the Sub-basin of Rio Poxim, Sergipe, Brazil

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    Eliane Maria de Souza Nogueira

    2011-08-01

    Full Text Available The zooplankton of aquatic environments is composed mostly of protozoans, rotifers, cladocerans and copepods, which play an important role in the food chain, transferring mass and energy from primary producers to higher trophic levels. This work was prepared with the objective of contributing to the knowledge of zooplankton biodiversity that occurs in the Sub-basin of Rio Poxim. Water samples were taken at monthly intervals at four sampling stations located along the sub-basin in the period August 2009 to July 2010. To obtain the zooplankton community, 100 L of water were filtered on nylon net with an aperture of 50 mm. Were identified 72 taxa distributed in the following taxonomic categories Rotifera, Protozoa, Porifera, Nematoda, Anellida, Cladocera, Copepoda, Ostracoda, Isopoda and Insecta. In terms of species richness, the phylum Rotifera followed by the Protoctista were the most relevant with forty and fifteen taxa, respectively. The most representative taxa in numerical terms were Arcella vulgaris, Notholca sp. Rotary sp. and nematodes. Regarding the community diversity index, the community was characterized as low diversity, but the taxa were distributed evenly in all monitoring points.

  9. Synoptic patterns of meiofaunal and macrofaunal abundances and specific composition in littoral sediments

    Science.gov (United States)

    Armonies, Werner; Hellwig-Armonies, Monika

    1987-03-01

    During recent years, many investigations on small zoobenthos have been performed at the island of Sylt. As these studies were carried out sporadically over many years and as different extraction methods were used, comparisons of the results have been hampered. Therefore, in August/September 1986, 24 sites were sampled and evaluated using one quantitative method throughout. Sites range from mud to exposed sand and from the sublittoral to the supralittoral. Macrofauna and the taxa Plathelminthes, Polychaeta, and Oligochaeta are determined to species level. Macrofaunal (>0.5 mm) abundance is highest in mud and continuously decreases with increasing exposure to wave action. Meiofaunal (taxa only intermittently. Related to surface area, no correlation between macro-and meiofaunal abundance is apparent. Plathelminthes and Copepoda reach highest abundance per surface area in sand but their per volume density is higher in mud and muddy sand. Related to sediment volume instead of surface area, the meiofaunal abundance pattern is very similar to the macrofaunal pattern. The faunal composition changes gradually along the tidal gradient without general faunal boundaries. On an averange, the faunal similarity of neighbouring sites is highest in Oligochaeta and lowest in Plathelminthes. Presumably, Oligochaeta tolerate wider ranges of environmental factors. This may explain the low number of oligochaete species. On the other hand, Plathelminthes seem to adapt to relatively narrow ranges of factors and their species richness is highest. Because of macrofaunameiofauna interaction it is suggested that the meiofaunal assemblage will be least stable in mud and muddy sand, and most stable in exposed sand.

  10. Seasonal trophic activity of the aquatic morphotype of Atelognathus patagonicus (Anura, Neobatrachia and prey availability in the littoral benthos of a permanent pond in Argentinean Patagonia

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    María Elena Cuello

    2009-12-01

    Full Text Available The diet of the aquatic morphotype of Atelognathus patagonicus was studied in frogs collected from the Laguna Verde pond (Laguna Blanca National Park, Neuquén, Argentina. The content of 35 gastrointestinal tracts of post-metamorphic specimens from November 2003 to April 2006 was related to the composition of the benthos in their microhabitat. Number, size, occurrence and relative importance of preys, diversity of the diet, trophic niche breadth and electivitywere estimated for each season of the year. The diet consisted of aquatic arthropods. The composition of both the benthos and the food (number and occurrence of organisms in the diet were dominated by the amphipod Hyalella sp. The relative importance (IRI of Hyalella sp. in the diet was over 99% in summer and autumn, and 100% in winter and spring. Diptera and Copepoda in summer, and Dytiscidae and Ostracoda in autumn, had seasonal IRI values ≤ 0.2%. Trophic niche breadth was very low in summer and autumn, and null (= 0 in winter and spring. The mean number of preys per individual was highest in spring (19 preys/frog and lowest in winter (4 preys/frog. Frogs continued with their trophic activity in winter, even when the surface of the pond was frozen. There is a correspondence between the frogs’ main food item and its presence in the benthos.

  11. Feeding ecology of the beach silverside Atherinella blackburni (Atherinopsidae in a tropical sandy beach, Southeastern Brazil

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    Júlio Guazzelli Gonzalez

    Full Text Available Abstract The feeding ecology of the beach silverside (Atherinella blackburni in the surf zone of a tropical sand beach, located in the southeastern Brazil, was accessed through the gut content analysis of 198 fish. Factors such as fish's size, season and day period were analysed to understand how these variables affect the diet composition of the species. Results show that A. blackburni is a coastal neritic fish with a broad feeding niche. Most recurrent prey were zooplanktonic crustaceans, insects and benthic molluscs, in which Copepoda crustaceans were the dominant dietary item in occurrence and abundance. A. blackburni appears to have a slight ontogenetic shift in its diet, changing from benthic molluscs to crustaceans and insects along its life cycle. The diel activity also reveals to be an important factor to the A. blackburni feeding ecology. The predominant occurrence of small fish during the morning, along with the main preys for this size class, suggests that small individuals use shallower waters as feeding grounds during the morning and, during the night, they move to deeper waters for protection against predators.

  12. First record of association of copepods with highly venomous box jellyfish Chironex, with description of new species of Paramacrochiron (Cyclopoida: Macrochironidae).

    Science.gov (United States)

    Ohtsuka, Susumu; Metillo, Ephrime; Boxshall, Geoffrey A

    2015-04-01

    Paramacrochiron chironecicola n. sp. (Copepoda: Cyclopoida: Macrochironidae) is described from the highly venomous box jellyfish Chironex sp. collected from Malampaya Sound, Palawan Island, The Philippines. This is the first record of copepods associated with cubozoan medusae, although other cnidarian groups such scyphozoans, hydrozoans, and anthozoans are common hosts for symbiotic copepods. The infection sites were on the subumbrella, pedalium, and rhopalium, but also rarely on the adradial furrow. The new species is distinguished from other congeners by a combination of the following features: (1) the fifth pedigerous somite dorsally covering the anterior part of the female genital double-somite; (2) the fine structures of the antenna (relative lengths of segments) and maxilliped (positions of terminal elements) of the female; (3) the relatively long outer spines on the exopodal segments of legs 1-4; (4) the relatively long and thick female leg 5 bearing a long protopodal seta which reaches to the distal margin of the exopod; (5) the relatively short caudal ramus in the female; and (6) the plump prosome and short urosome in the male. Since members of the genus typically parasitize scyphozoans, especially rhizostomes, the association of this parasitic copepod on cubozoans may reflect the relatively close phylogenetic relationship between cubozoans and scyphozoans.

  13. Zooplankton diversity of a sub-tropical reservoir of Mizoram, Northeast India

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    Sharma, B.K.

    2013-06-01

    Full Text Available This study on zooplankton diversity from the state of Mizoram of northeast India, based on plankton samples collected from Khawiva reservoir during November 2005-October 2007, recorded a total of 46 species. Zooplankton indicated monthly richness ranging between 19-36 and 25-34 species; registered 52.8-88.9 and 60.0-89.3% community similarities (vide Sørensen’s index; and comprised between 31.2±12.7 and 46.7±11.3% of net plankton abundance during two years, respectively. Copepoda and Rotifera, together, influenced zooplankton abundance. Rhizopoda and Cladocera showed limited importance while Nematoda and Ciliata recorded poor densities. Mesocyclops spp. > Keratella tropica are important taxa. Our results are characterized by moderate species diversity, high evenness and low dominance except in some months. Richness, abundance and species diversity followed no definite patterns of monthly variations. Individual abiotic parameters exerted limited influence on zooplankton richness and abundance, and on abundance of its constituent groups. The canonical correspondence analysis with fifteen abiotic parameters explained high cumulative variance (84.8% of zooplankton assemblages along axis 1 and 2 with importance of water temperature, rainfall, free carbon dioxide, conductivity and phosphate. Sladecek’s Q B/T quotient and Shannon’s diversity index reflected mesotrophic nature of Khawiva reservoir.

  14. Genetic diversity patterns of microeukaryotic plankton communities in Shenhu Bay, southeast China

    Science.gov (United States)

    Zhang, Wenjing; Pan, Yongbo; Yu, Lingyu; Liu, Lemian

    2017-06-01

    Microeukaryotic plankton is an abundant and diverse component of marine environments and plays an important role in microbial food webs. However, few studies have been conducted on the genetic diversity of microeukaryotes in the subtropical bays of China. In the present study, we investigated the microeukaryotic plankton in the Shenhu Bay by using denaturing gradient gel electrophoresis (DGGE) and sequencing of prominent bands. Our results indicated that Copepoda and Dinophyceae were the most diverse groups, and that the microeukaryotic communities varied significantly between summer and autumn, with the autumn communities exhibited a higher diversity than summer communities. Furthermore, the community composition and diversity from both surface and bottom waters showed more significant differences in summer than in autumn. Environmental parameters also displayed obvious seasonal patterns. Redundancy analysis (RDA) showed that temperature was the most significant environmental factor shaping the seasonal patterns of the microplanktonic members in the Shenhu Bay. Community-level molecular techniques such as DGGE appear as useful tools to detect the presence of red tide causing species and to guide the management of coastal water mariculture.

  15. Hyporheic fauna from interstitial of the Someş River basin (Transylvania, northwestern Romania

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    Claudia Pavelescu

    2009-01-01

    Full Text Available Biodiversity in hyporheic habitats (interstitial water habitats in river bank sediments has been studied on Someşul Cald (Warm Someş and Someşul Rece (Cold Someş River (north-western Romania, Transylvania, from March to October 2004. pH and electrical conductivity were measured monthly at each site, and animals were collected with the Karaman-Chappuis method and by filtering water through a hand-net. The relative abundance of the best-represented hyporheic invertebrates (oligochaetes and insect larvae was higher in Someşul Cald interstitial habitats than in Someşul Rece. The focus was directed to the role of water mites (Acari, Hydrachnidia, cyclopoid copepods (Crustacea, Copepoda, Cyclopoida and oligochaetes (Annelida, Oligochaeta in hyporheic communities. Nine water mites and five cyclopoid species were identified in five sampling sites of the two rivers. Their higher diversity was recorded in two stations on the Someşul Cald River. The cyclopoid copepod Diacyclops disjunctus (Thallwitz, 1927 is a new record for Romania. As for oligochaetes, 17 species were identified and their higher diversity was recorded on Someşul Rece River. Canonical Correspondence Analysis (CCA shows that presence of some water mites and cyclopoid species can be associated with measured physicochemical parameters (pH, electrical conductivity. Principal Component Analysis (PCA shows similarities between stations and the dominant taxa in some samples.

  16. Impact of environmental factors on maintaining water quality of Bakreswar reservoir, India

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    Moitreyee Banerjee

    2015-09-01

    Full Text Available Reservoirs and dams are engineered systems designed to serve purposes like supply of drinking water as well as other commercial and industrial use. A thorough assessment of water quality for these systems is thus necessary. The present study is carried out at Bakreswar reservoir, in Birbhum district, which was created by the dam, built on Bakreswar River. The major purpose of the reservoir is the supply of drinking water to the surrounding villages and Bakreswar Thermal Power Station. Water samples were collected fortnightly from three different stations of the reservoir. Physical and chemical factors like dissolved oxygen, atmospheric temperature, pH, conductivity, salinity, solar radiation, water temperature, alkalinity, hardness, chloride, productivity etc. were analysed using standard procedure. Abundance data is calculated for four major groups of zooplanktons (Cladocera, Copepoda, Ostracoda, and Rotifera with the software PAST 2.1. Multivariate statistical analysis like PCA, hierarchical cluster and CCA are performed in order to predict the temporal variation in the water quality factors using SPSS 20. Distinct seasonal variation was found for environmental factors and zooplankton groups. Bakreswar reservoir has good assemblage of zooplankton and distinct temporal variation of environmental factors and its association with zooplankton predicts water quality condition. These results could help in formulating proper strategies for advanced water quality management and conservation of reservoir ecosystem. Key elements for growth and sustenance of the system can then be evaluated and this knowledge can be further applied for management purposes.

  17. Diel and seasonal changes in the macrozooplankton community of a tropical estuary in Northeastern Brazil

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    Tâmara de Almeida e Silva

    2003-09-01

    Full Text Available Studies were carried out to assess the macrozooplankton small-scale temporal and spatial variability at three stations in three hours intervals, during 24 hours in July 1996 (rainy season and December 1996 (dry season. A plankton net 300µm mesh size was hauled at surface during three minutes. Water samples for salinity, temperature, dissolved oxygen and pH were taken simultaneously with the zooplankton samples. Sixty-five macrozooplankton taxa were registered. Copepoda constituted the most common taxon and comprised 58% of the total zooplankton counts. Brachyuran zoeae, cirripedian larvae, Larvacea (Oikopleura dioica Fol, 1872, and Gastropoda veligers were abundant at some tidal cycles, mainly during the night. Species diversity average was 2.0 bits.ind-1. The mean density ranged from 23 ind.m-3 to 5,201 ind.m-3. The rainy season presented greater numerical abundance. A regular temporal zooplankton cycle was not observed. Instead, there was a large stochastic variation between samples.

  18. Determining Microeukaryotic Plankton Community around Xiamen Island, Southeast China, Using Illumina MiSeq and PCR-DGGE Techniques.

    Science.gov (United States)

    Yu, Lingyu; Zhang, Wenjing; Liu, Lemian; Yang, Jun

    2015-01-01

    Microeukaryotic plankton are important components of aquatic environments and play key roles in marine microbial food webs; however, little is known about their genetic diversity in subtropical offshore areas. Here we examined the community composition and genetic diversity of the microeukaryotic plankton in Xiamen offshore water by PCR-DGGE (polymerase chain reaction-denaturing gradient gel electrophoresis), clone-based sequencing and Illumina based sequencing. The Illumina MiSeq sequencing revealed a much (approximately two orders of magnitude) higher species richness of the microeukaryotic community than DGGE, but there were no significant difference in species richness and diversity among the northern, eastern, southern or western stations based on both methods. In this study, Copepoda, Ciliophora, Chlorophyta, Dinophyceae, Cryptophyta and Bacillariophyta (diatoms) were the dominant groups even though diatoms were not detected by DGGE. Our Illumina based results indicated that two northern communities (sites N2 and N3) were significantly different from others in having more protozoa and fewer diatoms. Redundancy analysis (RDA) showed that both temperature and salinity were the significant environmental factors influencing dominant species communities, whereas the full microeukaryotic community appeared to be affected by a complex of environmental factors. Our results suggested that extensive sampling combined with more deep sequencing are needed to obtain the complete diversity of the microeukaryotic community, and different diversity patterns for both abundant and rare taxa may be important in evaluating the marine ecosystem health.

  19. A 12-year study of the seasonal and interannual dynamics of mesozooplankton in the Laptev Sea: Significance of salinity regime and life cycle patterns

    Science.gov (United States)

    Abramova, E.; Tuschling, K.

    2005-09-01

    Over a 12-year period (1989-2000) the spatial and temporal distribution of zooplankton in the Laptev Sea (Arctic Siberia) has been investigated. A total number of 111 taxa from 10 phyla were found. Sixteen species are reported from this region for the first time. The distribution and abundance of zooplankton on the Laptev Sea shelf is dependent on the main direction of river water spread, which varies between years. While the western and northeastern Laptev Sea shelf is dominated by a marine-neritic fauna, the central part is inhabited by a transitional brackish-marine assemblage. A brackish-neritic community characterizes the eastern and southeastern regions, where lowest salinities usually prevail. Closer to estuaries the summer zooplankton consists of both freshwater and brackish-water species, whereas in winter brackish-water species are dominant. Average zooplankton abundance varies seasonally and interannually, particularly in the southeastern Laptev Sea. The amplitude of these variations mainly depends on the state of the populations of the most common Copepoda species, the intensity of their reproduction, and their success in overwintering. Two seasonal abundance maxima were found, at the end of winter and at the end of summer. During the period of highest reproduction in summer the abundance may be 50 times greater than during overwintering. The average population abundance can vary by the factor of 2 in summer and in winter from year to year.

  20. Zoo-heleoplankton structure in three artificial ponds of North-eastern Argentina

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    S. M Frutos

    2008-09-01

    Full Text Available The aim of the present study was to compare the abundance and species richness of zoo-heleoplankton bigger than 53 µm in an annual cycle under similar climate conditions in three artificial ponds, in order to observe the changes during an annual cycle. Samples were taken monthly from June 1993 to July 1994 in Corrientes, Argentina. The first pond (A was covered an 80% by Eichhornia crassipes (Mart., the second one (B with bloom of Microcystis aeruginosa (Kurtzing and the last one (C with organic matter deposited in the bottom. The water was more acidic at pond A, and the water at pond B contained more dissolved oxygen concentration than the water at the other two ponds. The zoo-heleoplankton densities varied between 20-1728 ind.l-1 at pond A, 42-4082 ind.l-1 at pond B and 148-2447 ind.l-1 at pond C. The maximum zoo-heleoplankton abundance was found in the pond with cyanobacteria bloom during Autumn 1994 and the minimum abundance was found in the one with a predominance of E. crassipes. The rank of species richness was pond A > pond B > pond C. Rotifera was the most abundant group in pond A whereas the larval stages of Copepoda were abundant in the other two ponds. Anuraeopsis navicula Rousselt 1910 was the dominant population in the pond with macrophytes prevalence. Brachionus calyciflorus Pallas 1776 and larval stage of Copepoda had variable proportions in the pond with cyanobacteria bloom. Thermocyclops decipiens (Kiefer 1929 was present during the annual cycle only in the pond with organic matter deposited in the bottom. The succession of taxa was observed in the pond with coverage of aquatic macrophytes and with cyanobacteria bloom. Differences in species richness and low similarity in zoo-heleoplankton between ponds were determined by differences in the quality of the water in relation to the presence of macrophytes, cyanobacteria, organic matter deposited in the bottom and fish predation. Multiple regression analysis (stepwise revealed

  1. Biological baseline data Youngs Bay, Oregon, 1974

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Higley, D.L.; Holton, R.L.

    1975-04-01

    This report presents biological baseline information gathered during the research project, Physical, Chemical and Biological Studies on Youngs Bay.'' Youngs Bay is a shallow embayment located on the south shore of the Columbia River, near Astoria, Oregon. Research on Youngs Bay was motivated by the proposed construction by Alumax Pacific Aluminum Corporation of an aluminum reduction plant at Warrenton, Oregon. The research was designed to provide biological baseline information on Youngs Bay in anticipation of potential harmful effects from plant effluents. The information collected concerns the kinds of animals found in the Youngs Bay area, and their distribution and seasonal patterns of abundance. In addition, information was collected on the feeding habits of selected fish species, and on the life history and behavioral characteristics of the most abundant benthic amphipod, Corophium salmonis. Sampling was conducted at approximately three-week intervals, using commonly accepted methods of animal collection. Relatively few stations were sampled for fish, because of the need to standardize conditions of capture. Data on fish capture are reported in terms of catch-per-unit effort by a particular sampling gear at a specific station. Methods used in sampling invertebrates were generally more quantitative, and allowed sampling at a greater variety of places, as well as a valid basis for the computation of densities. Checklists of invertebrate species and fish species were developed from these samples, and are referred to throughout the report. The invertebrate checklist is more specific taxonomically than are tables reporting invertebrate densities. This is because the methods employed in identification were more precise than those used in counts. 9 refs., 27 figs., 25 tabs.

  2. Distribution and persistence of the anti sea-lice drug teflubenzuron in wild fauna and sediments around a salmon farm, following a standard treatment.

    Science.gov (United States)

    Samuelsen, Ole B; Lunestad, Bjørn T; Hannisdal, Rita; Bannister, Raymond; Olsen, Siri; Tjensvoll, Tore; Farestveit, Eva; Ervik, Arne

    2015-03-01

    The salmon louse (Lepeoptheirus salmonis) is a challenge in the farming of Atlantic salmon (Salmo salar). To treat an infestation, different insecticides are used like the orally administered chitin synthetase inhibitor teflubenzuron. The concentrations and distribution of teflubenzuron were measured in water, organic particles, marine sediment and biota caught in the vicinity of a fish farm following a standard medication. Low concentrations were found in water samples whereas the organic waste from the farm, collected by sediment traps had concentrations higher than the medicated feed. Most of the organic waste was distributed to the bottom close to the farm but organic particles containing teflubenzuron were collected 1100 m from the farm. The sediment under the farm consisted of 5 to 10% organic material and therefore the concentration of teflubenzuron was much lower than in the organic waste. Teflubenzuron was persistent in the sediment with a stipulated halflife of 170 days. Sediment consuming polychaetes had high but decreasing concentrations of teflubenzuron throughout the experimental period, reflecting the decrease of teflubenzuron in the sediment. During medication most wild fauna contained teflubenzuron residues and where polychaetes and saith had highest concentrations. Eight months later only polychaetes and some crustaceans contained drug residues. What dosages that induce mortality in various crustaceans following short or long-term exposure is not known but the results indicate that the concentrations in defined individuals of king crab, shrimp, squat lobster and Norway lobster were high enough shortly after medication to induce mortality if moulting was imminent. Considering food safety, saith and the brown meat of crustaceans contained at first sampling concentrations of teflubenzuron higher than the MRL-value set for Atlantic salmon. The concentrations were, however, moderate and the amount of saith fillet or brown meat of crustaceans to be

  3. Studies on Some Productive and Reproductive Performance in Female Rainbow Trout (Oncorhynchus Mykiss and Brown Trout (Salmo Trutta Fario at Four Years of Age, From Fiad-Telcişor Salmonids Complex, Bistriţa-Năsăud County

    Directory of Open Access Journals (Sweden)

    Daniel Cocan

    2010-10-01

    Full Text Available Consumer preferences regarding the various species of fish or aquatic organisms are highly variable. The criteria by which they orient are represented by: the price, organoleptic characteristics, healing and nutritional properties of meat. Today it is known that a high consumption of fish meat has a beneficial role in human health. Moreover, statistics indicates a high level of life expectancy in countries with tradition in terms of fish consumption, e.g. NorthEuropean and Asian countries. Statistics shows a high consumption of ocean fish and different species of salmonid family. The culture and intensive fish farming represents an alternative to the requirements of the fish market. The salmonids farmers focus their efforts to obtain high yields of high quality, in conditions of maximum economic efficiency. In Romania, the predominant specie encountered in salmonis farms is rainbow trout (Oncorhynchus mykiss. It is successfully reared because of its plasticity and resistance to changes in environmental conditions and disease, and efficient feed-conversion. For restocking mountain water with biological material, some trout farms operate successfully brown trout (Salmo trutta fario, a less effective specie for meat production, due to slow growth and development and low resistance to changing environmental factors. Profitability of fish production depends on the propagation processes, fish growth and developments, and supplying optimal environmental conditions for enhancement of the biological potential. The artificial reproduction of salmonids, involves several technological operations for achieving outstanding results on fisheries production. Of these operations, critical is the selection and improvement of breeding.

  4. Shared gene structures and clusters of mutually exclusive spliced exons within the metazoan muscle myosin heavy chain genes.

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    Martin Kollmar

    Full Text Available Multicellular animals possess two to three different types of muscle tissues. Striated muscles have considerable ultrastructural similarity and contain a core set of proteins including the muscle myosin heavy chain (Mhc protein. The ATPase activity of this myosin motor protein largely dictates muscle performance at the molecular level. Two different solutions to adjusting myosin properties to different muscle subtypes have been identified so far: Vertebrates and nematodes contain many independent differentially expressed Mhc genes while arthropods have single Mhc genes with clusters of mutually exclusive spliced exons (MXEs. The availability of hundreds of metazoan genomes now allowed us to study whether the ancient bilateria already contained MXEs, how MXE complexity subsequently evolved, and whether additional scenarios to control contractile properties in different muscles could be proposed, By reconstructing the Mhc genes from 116 metazoans we showed that all intron positions within the motor domain coding regions are conserved in all bilateria analysed. The last common ancestor of the bilateria already contained a cluster of MXEs coding for part of the loop-2 actin-binding sequence. Subsequently the protostomes and later the arthropods gained many further clusters while MXEs got completely lost independently in several branches (vertebrates and nematodes and species (for example the annelid Helobdella robusta and the salmon louse Lepeophtheirus salmonis. Several bilateria have been found to encode multiple Mhc genes that might all or in part contain clusters of MXEs. Notable examples are a cluster of six tandemly arrayed Mhc genes, of which two contain MXEs, in the owl limpet Lottia gigantea and four Mhc genes with three encoding MXEs in the predatory mite Metaseiulus occidentalis. Our analysis showed that similar solutions to provide different myosin isoforms (multiple genes or clusters of MXEs or both have independently been developed

  5. Análise comparativa da alimentação de peixes (Teleostei entre ambientes de marisma e de manguezal num estuário do sul do Brasil (Baía de Guaratuba, Paraná Study on feeding habits in estuarine fish (Teleostei comparatively between salt marshes and mangroves in southern Brazil (Guaratuba Bay

    Directory of Open Access Journals (Sweden)

    Paulo de T. Chaves

    2008-03-01

    Full Text Available Estudou-se a composição da dieta de peixes em dois tipos de ambiente de áreas rasas estuarinas - marisma e manguezal, objetivando avaliar se essas formações vegetais desencadeiam na ictiofauna respostas diferentes quanto à alimentação. As seis espécies avaliadas, as mais abundantes nessas áreas, mostraram-se predominantemente planctívoras, porém com particularidades quanto ao tipo de vegetação ocupada. Na marisma, Atherinella brasiliensis (Quoy & Gaimard, 1825 apresentou a dieta com maior número de itens e menor similaridade em relação às demais espécies. No manguezal tal isolamento coube a Anchoa januaria (Steindachner, 1879, espécie com maior participação de Decapoda Brachyura e Decapoda não-Brachyura, e única que nesse ambiente incluiu Gammaridae na dieta. Anchoviella lepidentostole (Fowler, 1911 identificou-se com Anchoa lyolepis (Evermann & Marsh, 1900 na marisma e com Opisthonema oglinum (Le Sueur, 1818 e Harengula clupeola (Cuvier, 1829 no manguezal. Uma situação comum a marisma e manguezal registrou-se entre O. oglinum e H. clupeola, espécies com dietas praticamente restritas a Diatomacea e Copepoda. Evidenciou-se o quanto as espécies são capazes de variar sua dieta com o ambiente, provavelmente em resposta à disponibilidade local. Mais que isso, porém, constatou-se que, seja na marisma, seja no manguezal, mesmo havendo mudança nos hábitos tróficos das espécies, cada uma delas mantém um padrão de diferenças em relação às demais que compõem a assembléia, fato que possivelmente assegura a abundância e coexistência entre elas nas áreas estuarinas rasas.Diet of fish inhabiting shallow waters close to salt marshes and mangroves was analyzed in order to evaluate how different the influence of these environments on fish feeding habits is. The six studied species, the most abundant in these areas, are mainly planctyvores, however they showed particularities in each area. In salt marshes Atherinella

  6. Sampling and quantifying invertebrates from drinking water distribution mains.

    Science.gov (United States)

    van Lieverloo, J Hein M; Bosboom, Dick W; Bakker, Geo L; Brouwer, Anke J; Voogt, Remko; De Roos, Josje E M

    2004-03-01

    Water utilities in the Netherlands aim at controlling the multiplication of (micro-) organisms by distributing biologically stable water through biologically stable materials. Disinfectant residuals are absent or very low. To be able to assess invertebrate abundance, methods for sampling and quantifying these animals from distribution mains were optimised and evaluated. The presented method for collecting invertebrates consists of unidirectionally flushing a mains section with a flow rate of 1 ms(-1) and filtering the flushed water in two separate flows with 500 microm and 100 microm mesh plankton gauze filters. Removal efficiency from mains was evaluated in nine experiments by collecting the invertebrates removed from the mains section by intensive cleaning immediately subsequent to sampling. Of 12 taxa distinguished, all except case-building Chironomidae larvae (2%) and Oligochaeta (30%) were removed well (51-75%). Retention of invertebrates in 100 microm filters was evaluated by filtering 39 filtrates using 30 microm filters. Except for flexible and small invertebrates such as Turbellaria (13%), Nematoda (11%) and Copepoda larvae (24%), most taxa were well retained in the 100 microm filters (53-100%). During sample processing, the method for taking sub-samples with a 10 ml pipette from the suspension of samples with high sediment concentrations was found to perform well in 75% of the samples. During a 2-year national survey in the Netherlands and consecutive investigations, the method appeared to be very suitable to assess the abundance of most invertebrate taxa in drinking water distribution systems and to be practicable for relatively inexperienced sampling and lab technicians. Although the numbers of small, less abundant or sessile taxa were not accurately assessed using the method, these taxa probably should not be the primary focus of monitoring by water utilities, as consumer complaints are not likely to be caused by these invertebrates. The accuracy of

  7. Spatial variations in zooplankton diversity in waters contaminated with composite effluents

    Directory of Open Access Journals (Sweden)

    Asitava CHATTERJEE

    2007-08-01

    Full Text Available Zooplankton species are cosmopolitan in their clean freshwater habitat and are also found in industrial and municipal wastewaters. The present study records for the first time the aspects of zooplankton diversity in relation to physico-chemical environment of five selected sites of the East Calcutta wetlands, a Ramsar site of Kolkata city, India, heavily contaminated by industrial and municipal wastewaters. The study revealed the occurrence of 22 species of zooplankton, among these 3 species of Cladocera, 2 species of Copepoda, 15 species of Rotifera, and 2 species of Ostracoda were recorded. The copepod Mesocyclops leuckarti was found in all the five sites, rotifers Asplanchna brightwelli, Brachionus angularis, B. calyciflorus and Cladocera Ceriodaphnia cornuta were found in four sites; Moina micrura and Diaphanosoma sarsi were found at three sites. Site wise variation in dominance, diversity, evenness and richness were calculated. Site 1, a fish-pond that stabilized composite wastewater, showed the maximum species richness having 17 species, while Site 2, SWF wastewater carrying canal, showed only 4 species. The calculated Jack 1 values of Sites 1 to 5 were 21.78, 3.77, 18.63, 12.5 and 16.95 respectively. Shannon-Wiener species diversity index (H/ values were almost similar for all the three relatively less polluted sites viz, Site 1 (1.959, Site 4 (2.010, Site 5 (2.047. However, at highly polluted sites viz., 2 and 3, H/ value of 1.336 and 0.984 respectively, were calculated. Simpson’s Dominance index (Dsimp value was highest at Site 3 (0.618 indicating maximum dominance, whereas at Site 5 dominance was lowest (0.1680 and diversity was highest. We discuss the role of zooplankton in the amelioration of wastewater.

  8. Feeding ecology of the early life-history stages of two dominant gobiid species in the headwaters of a warm-temperate estuary

    Science.gov (United States)

    Wasserman, Ryan J.

    2012-08-01

    The diet and population structure of larval and early juvenile Glossogobius callidus and Redigobius dewaali (Gobiidae) were examined from the headwater region of the permanently open Great Fish Estuary along the south-east coast of southern Africa. Stomach contents of five selected size classes were sorted and identified to the lowest possible taxonomic level for each goby species. Using % Index of Relative Importance values, ontogenic shifts and dietary breadth were determined for each species as was dietary overlap between species. Numerically, both gobiid species showed similar temporal and spatial trends. Seasonal differences in catches were evident, although no numerical differences across sampled sites were found. A large degree of dietary overlap was found between the two species. The zooplanktonic diet showed a greater degree of ontogenic shift in R. dewaali than G. callidus, although similar trends were found for both. In both goby species, Calanoid sp. (Copepoda) generally decreased in importance across size classes, being the most important in the smallest size class whilst Corophium sp. (Amphipoda) increased in importance across size classes, being the least important at the smallest size classes. For both G. callidus and R. dewaali, Insecta contributed significantly to at least one of the five size classes. The larger size classes showed the least dietary overlap and the highest niche breadth. In addition, as is the case in many gobiids worldwide, the larger size classes of both sampled gobiid species consumed a broader prey size range. In conclusion, dietary overlap was largely similar between the young gobiids, suggesting that either food resources are not limiting, or niche separation is attributed to differences in foraging strategies. Ontogenic dietary shifts were however present for both gobiids with regard to prey items and prey size, suggesting a greater degree of foraging niche separation in adults of the species.

  9. Latitudinal environmental gradients and diel variability influence abundance and community structure of Chaetognatha in Red Sea coral reefs

    KAUST Repository

    Al-aidaroos, Ali M.

    2016-08-15

    The Red Sea has been recognized as a unique region to study the effects of ecohydrographic gradients at a basin-wide scale. Its gradient of temperature and salinity relates to the Indian Ocean monsoon and associated wind-driven transport of fertile and plankton-rich water in winter from the Gulf of Aden into the Red Sea. Subsequent evaporation and thermohaline circulation increase the salinity and decrease water temperatures toward the North. Compared with other ocean systems, however, relatively little is known about the zooplankton biodiversity of the Red Sea and how this relates to Red Sea latitudinal gradients. Among the most abundant zooplankton taxa are Chaetognatha, which play an important role as secondary consumers in most marine food webs. Since Chaetognatha are sensitive to changes in temperature and salinity, we surmised latitudinal changes in their biodiversity, community structure and diel variability along the coast of Saudi Arabia. Samples were collected at nine coral reefs spanning approximately 1500km, from the Gulf of Aqaba in the northern Red Sea to the Farasan Archipelago in the southern Red Sea. Thirteen Chaetognatha species belonging to two families (Sagittidae and Krohnittidae) were identified. Latitudinal environmental changes and availability of prey (i.e. Copepoda, Crustacea) altered Chaetognatha density and distribution. The cosmopolitan epiplanktonic Flaccisagitta enflata (38.1%) dominated the Chaetognatha community, and its abundance gradually decreased from South to North. Notable were two mesopelagic species (Decipisagitta decipiens and Caecosagitta macrocephala) in the near-reef surface mixed layers at some sites. This was related to wind-induced upwelling of deep water into the coral reefs providing evidence of trophic oceanic subsidies. Most Sagittidae occurred in higher abundances at night, whereas Krohnittidae were more present during the day. Chaetognatha with developing (stage II) or mature ovaries (stage III) were more active

  10. Cenotes – Lakes of the Yucatan Peninsula (Mexico

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    Szeroczyńska Krystyna

    2015-06-01

    Full Text Available Cenote lakes are natural sinkholes or depressions resulting from the collapse of limestone bedrock exposing the groundwater underneath. Thousands of such lakes are particularly encountered on the Yucatan Peninsula (Mexico. These lakes were of great significance for the Maya culture as important religious places and primary source of drink­ing water. They permitted the survival of Mayan communities through dry periods known as “Maya drought”. Most of the cenote lakes are large open water pools measuring tens of meters in diameter. The majority of cenotes are smaller sheliered sites. Their waiers are usually very clear and oligotrophic, originating from rain waier filtering slowly through the ground. The auihors visited and coliected zooplankion samples from eight cenotes in November 2013, namely: Ik-Kil, Samula, Zaci, X-Kekn, Actum Ha, Cristal, Sian Ka’an, and Chan Chemuxil (transect Merida-Tulum- Cancun. The analysed lakes differ considerably in morphological terms, varying from very deep to shallow. Some of them are under human impact (tourists. The water samples were anaiysed for zooplankton content, but the phyto­plankton frequently occurring was also taken into account. The obtained results are largely varied, indicated big eco­logical verity among cenotes which depended on lake age, localization and morphometry. As showed our study Cladocera zooplankion was very rare and only present at several sites. Beiween the fauna community Copepoda and Ostracoda species were the most abundant. Phytoplankton were present in all studied lakes and it sees that played the central role in those ecosystems.

  11. Ocean acidification alters zooplankton communities and increases top-down pressure of a cubozoan predator.

    Science.gov (United States)

    Hammill, Edd; Johnson, Ellery; Atwood, Trisha B; Harianto, Januar; Hinchliffe, Charles; Calosi, Piero; Byrne, Maria

    2018-01-01

    The composition of local ecological communities is determined by the members of the regional community that are able to survive the abiotic and biotic conditions of a local ecosystem. Anthropogenic activities since the industrial revolution have increased atmospheric CO 2 concentrations, which have in turn decreased ocean pH and altered carbonate ion concentrations: so called ocean acidification (OA). Single-species experiments have shown how OA can dramatically affect zooplankton development, physiology and skeletal mineralization status, potentially reducing their defensive function and altering their predatory and antipredatory behaviors. This means that increased OA may indirectly alter the biotic conditions by modifying trophic interactions. We investigated how OA affects the impact of a cubozoan predator on their zooplankton prey, predominantly Copepoda, Pleocyemata, Dendrobranchiata, and Amphipoda. Experimental conditions were set at either current (pCO 2 370 μatm) or end-of-the-century OA (pCO 2 1,100 μatm) scenarios, crossed in an orthogonal experimental design with the presence/absence of the cubozoan predator Carybdea rastoni. The combined effects of exposure to OA and predation by C. rastoni caused greater shifts in community structure, and greater reductions in the abundance of key taxa than would be predicted from combining the effect of each stressor in isolation. Specifically, we show that in the combined presence of OA and a cubozoan predator, populations of the most abundant member of the zooplankton community (calanoid copepods) were reduced 27% more than it would be predicted based on the effects of these stressors in isolation, suggesting that OA increases the susceptibility of plankton to predation. Our results indicate that the ecological consequences of OA may be greater than predicted from single-species experiments, and highlight the need to understand future marine global change from a community perspective. © 2017 John Wiley & Sons

  12. DNA barcoding of Arctic Ocean holozooplankton for species identification and recognition

    Science.gov (United States)

    Bucklin, Ann; Hopcroft, Russell R.; Kosobokova, Ksenia N.; Nigro, Lisa M.; Ortman, Brian D.; Jennings, Robert M.; Sweetman, Christopher J.

    2010-01-01

    Zooplankton species diversity and distribution are important measures of environmental change in the Arctic Ocean, and may serve as 'rapid-responders' of climate-induced changes in this fragile ecosystem. The scarcity of taxonomists hampers detailed and up-to-date monitoring of these patterns for the rarer and more problematic species. DNA barcodes (short DNA sequences for species recognition and discovery) provide an alternative approach to accurate identification of known species, and can speed routine analysis of zooplankton samples. During 2004-2008, zooplankton samples were collected during cruises to the central Arctic Ocean and Chukchi Sea. A ˜700 base-pair region of the mitochondrial cytochrome oxidase I (mtCOI) gene was amplified and sequenced for 82 identified specimens of 41 species, including cnidarians (six hydrozoans, one scyphozoan), arthropod crustaceans (five amphipods, 24 copepods, one decapod, and one euphausiid); two chaetognaths; and one nemertean. Phylogenetic analysis used the Neighbor-Joining algorithm with Kimura-2-Parameter (K-2-P) distances, with 1000-fold bootstrapping. K-2-P genetic distances between individuals of the same species ranged from 0.0 to 0.2; genetic distances between species ranged widely from 0.1 to 0.7. The mtCOI gene tree showed monophyly (at 100% bootstrap value) for each of the 26 species for which more than one individual was analyzed. Of seven genera for which more than one species was analyzed, four were shown to be monophyletic; three genera were not resolved. At higher taxonomic levels, only the crustacean order Copepoda was resolved, with bootstrap value of 83%. The mtCOI barcodes accurately discriminated and identified known species of 10 taxonomic groups of Arctic Ocean holozooplankton. A comprehensive DNA barcode database for the estimated 300 described species of Arctic holozooplankton will allow rapid assessment of species diversity and distribution in this climate-vulnerable ocean ecosystem.

  13. Ocean-lagoon water and plankton exchanges in a semi-closed pearl farming atoll lagoon (Ahe, Tuamotu archipelago, French Polynesia)

    Science.gov (United States)

    Pagano, M.; Rodier, M.; Guillaumot, C.; Thomas, Y.; Henry, K.; Andréfouët, S.

    2017-05-01

    In atoll lagoons, plankton richness is highly dependent on water exchange with the ocean through the atoll rim. However, the dynamics of the physical and biological fluxes at the lagoon-ocean interface remain poorly characterized. Here, we studied the combined effects of lagoon-ocean water exchanges and local environmental conditions on the phyto- and zooplankton abundance and community structure across the atoll lagoon rim of Ahe (Tuamotu Archipelago, French Polynesia). Plankton and environmental variables were monitored in May 2013 (i) at several stations inside and outside the lagoon and (ii) during time-series corresponding to ebb-flood tidal cycles in the two types of channels connecting the lagoon to the ocean: at the passage (300 m long and about 11 m deep) and in hoa (i.e reef-flat less than 50 cm depth). Our results highlight tidally-driven selective plankton exchanges between the lagoon and external ocean. Phytoplankton (chlorophyll-a) and zooplankton biomass were respectively 4 times and 7 times higher in the lagoon than at stations outside the atoll lagoon. Copepoda was the dominant zooplankton group at the oceanic station (>75% abundance) whereas meroplankton (with bivalve larvae most common) was dominant at the lagoon stations (54%), in the passage (55-82%) and in hoa (>80%). These differences between sites suggest a loss of bivalve larvae through export to the ocean and retention and/or increased production of copepods in the lagoon. The daily export of bivalve larvae represents a low percentage of the lagoon stock, in agreement with previously published larval dispersal numerical models. The retention of copepods could constitute a significant input of nutrients and organic matter (through excretion, feces release, decomposition, and remineralization) into the lagoon.

  14. Evolution of Respiratory Proteins across the Pancrustacea.

    Science.gov (United States)

    Burmester, Thorsten

    2015-11-01

    Respiratory proteins enhance the capacity of the blood for oxygen transport and support intracellular storage and delivery of oxygen. Hemocyanin and hemoglobin are the respiratory proteins that occur in the Pancrustacea. The copper-containing hemocyanins evolved from phenoloxidases in the stem lineage of arthropods. For a long time, hemocyanins had only been known from the malacostracan crustaceans but recent studies identified hemocyanin also in Remipedia, Ostracoda, and Branchiura. Hemoglobins are common in the Branchiopoda but have also been sporadically found in other crustacean classes (Malacostraca, Copepoda, Thecostraca). Respiratory proteins had long been considered unnecessary in the hexapods because of the tracheal system. Only chironomids, some backswimmers, and the horse botfly, which all live under hypoxic conditions, were known exceptions and possess hemoglobins. However, recent data suggest that hemocyanins occur in most ametabolous and hemimetabolous insects. Phylogenetic analysis showed the hemocyanins of insects and Remipedia to be similar, suggesting a close relationship of these taxa. Hemocyanin has been lost in dragonflies, mayflies, and Eumetabola (Hemiptera + Holometabola). In cockroaches and grasshoppers, hemocyanin expression is restricted to the developing embryo while in adults oxygen is supplied solely by the tracheal system. This pattern suggests that hemocyanin was the oxygen-transport protein in the hemolymph of the last common ancestor of the pancrustaceans. The loss was probably associated with miniaturization, a period of restricted availability of oxygen, a change in life-style, or morphological changes. Once lost, hemocyanin was not regained. Some pancrustaceans also possess cellular globin genes with uncertain functions, which are expressed at low levels. When a respiratory protein was again required, hemoglobins evolved several times independently from cellular globins. © The Author 2015. Published by Oxford University Press

  15. Ecological impacts of fluridone and copper sulphate in catfish aquaculture ponds.

    Science.gov (United States)

    Jacob, Annie P; Culver, David A; Lanno, Roman P; Voigt, Astrid

    2016-05-01

    Fluridone and copper sulphate are often used for controlling macrophytes and algae in aquaculture ponds. The present study examined the ecological effects of these chemicals on macrophyte, phytoplankton, and zooplankton biomass; plankton community structure; water quality parameters; and fish survival and yield in catfish culture ponds using a randomized complete block design. The estimated half-life of fluridone in the individual ponds ranged from 1.6 d to 10.8 d. Free copper ion activity in ponds treated with copper sulphate was dynamic, ranging from pCu of 7.7 to 8.9 after each application and decreasing to approximately 12 (1 × 10(-12)  M) within 1 wk after each application, approaching observed values in control ponds (pCu = 12.3-13.4). No difference in macrophyte biomass was observed among treatments. Fluridone and copper treatments elicited different responses within the phytoplankton community. Copper treatments reduced Cyanophyta biomass but increased biomass of more tolerant taxa among the Chlorophyta and Chrysophyta. Fluridone treatments reduced total phytoplankton biomass including Cyanophyta and increased the sensitivity of Chlorophyta and Chrysophyta to copper. Copper also affected zooplankton community composition as a result of direct toxic effects on sensitive zooplankton taxa (e.g., Cladocera), whereas Copepoda biomass in copper-treated ponds exceeded that in controls. Catfish survival and yield were not significantly different among treatments. The results of the present study suggest that fluridone and copper interact at realistic application rates, increasing the ability to control algae compared with treatments where they are applied alone. © 2015 SETAC.

  16. The deep-sea zooplankton of the North, Central, and South Atlantic: Biomass, abundance, diversity

    Science.gov (United States)

    Vereshchaka, Alexander; Abyzova, Galina; Lunina, Anastasia; Musaeva, Eteri

    2017-03-01

    Ocean-scale surveys of vertical distribution of the zooplankton from the surface to the bathypelagic zone along transects are quite rare in the North Atlantic and absent in the Equatorial and South Atlantic. We present the first deep-sea quantitative survey of the zooplankton in the Equatorial and South Atlantic, analyze the interaction between environment (depth, water masses, surface productivity) and zooplankton abundance and biomass, and assess the biodiversity and role of copepods in various deep strata. Samples were taken at 20 sites along a submeridional transect between 40°N and 30°S at four discrete depth strata: epi- meso-, upper- and lower- bathypelagic. A closing Bogorov-Rass plankton net (1 m2 opening, 500 μm mesh size, towed at a speed of 1 m s-1) was used and three major plankton groups were defined: non-gelatinous mesozooplankton (mainly copepods and chaetognaths; 1-30 mm length), gelatinous mesozooplankton (mainly siphonophorans, medudae and salps; individual or zooid; 1-30 mm length) and macroplankton (mainly shrimps; over 30 mm length). Over 300 plankton taxa were identified, among which 243 belonged to Copepoda. Two-dimensional distribution (latitude versus depth zone) of major group biomass, total copepod abundance, and abundance of dominant species is presented as well as distribution of biodiversity parameters (number of species, Shannon and 'dominance' indices). Biomass and abundance of all major groups were depth-dependent. The number of taxa (N) was depended on surface productivity, diversity of the communities was strongly linked to depth, whilst 'evenness' was independant upon both variables. Each of depth strata was inhabited by distinct copepod assemblages, which significantly differed from each other. The paper is concluded with brief descriptions of the deep Atlantic plankton communities from studied strata.

  17. Microbial colonization of copepod body surfaces and chitin degradation in the sea

    Science.gov (United States)

    Kirchner, M.

    1995-03-01

    Next to cellulose, chitin (composed of N-acetyl-D-glucosamine sugar units) is the most frequently occurring biopolymer in nature. Among the most common sources of chitin in the marine environment are copepods and the casings of their fecal pellets. During the mineralization of chitin by microorganisms, which occurs chiefly by means of exoenzymes, nitrogen and carbon are returned to the nutrient cycle. In this study, the microbial colonization of the moults (exuviae), carcasses and fecal pellets of Tisbe holothuriae Humes (Copepoda: Harpacticoida) was examined in the laboratory. Results obtained with DAPI staining indicated that a succession of microorganisms from rodshaped bacteria and cocci to starlike aggregates took place, followed by the yeastlike fungus Aureobasidium pullulans (de Bary) Arnaud. No differences were noted between moults from various developmental stages, from nauplius to adult. The ventral sides and extremities of exuviae and carcasses were more rapidly colonized than other parts of the bodies. The casings of fecal pellets were frequently surrounded by bacteria with fimbriae or slime threads. In situ studies of chitin degradation (practical grade chitin from crustacean shells) with the mesh bag technique showed that about 90% of the original substance was lost after 3 months exposure in seawater at temperatures between 10 and 18°C. Chitinase activity was measured in the water at two stations near Helgoland, an island in the North Sea. A higher exoenzymatic activity was found in the rocky intertidal zone, compared to the Station Cable Buoy located between the main and Düne island. These values correspond to the higher bacteria numbers (cfu ml-1) found in the rocky intertidal: 10 to 100× greater than those found at the Cable Buoy Station.

  18. Meiofauna communities from the Straits of Magellan and the Beagle Channel

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    G. C. Chen

    1999-12-01

    Full Text Available Meiofauna from 20 stations (ranging between 8 and 550 m in the Magellan Straits and the Beagle Channel revealed 28 small sized taxa of higher categories including the temporary meiofauna. Nematoda, Copepoda Harpacticoidea and Polychaeta occurred in all samples; Turbellaria, Bivalvia, Kinorhyncha and Ostracoda were regularly present. Nematodes represented between 68% and 94% of the meiofauna at each station, followed by the copepods (2.3% to 14.5% and polychaetes (1.1% to 11.5%. Maximal total density, 9700 individuals 10 cm-2, was found in the surroundings of Picton Island, while the mean abundance per station was 3374 individuals 10 cm-2. The vertical pattern within the sediment showed that 87% of meiofauna components concentrated in the upper 0-5 cm sediment layers and 13% in the lower ( > 5cm layers. More than 95% of copepods, as well as the temporary meiofauna occurred in the top 5 cm layers. The proportion of nematodes and copepods shows opposite trends in the vertical distribution. Multivariate analysis using the total density and the 10 `true´ meiofauna taxa densities discriminates between communities in the Straits of Magellan and the Beagle Channel area. Meiofaunal density was much higher in the Beagle Channel, but the diversity was lower than that in the Straits of Magellan. The Southern Magellan meiofauna communities are compared with those found at the Antarctic Peninsula and in the Weddell Sea (high Antarctic. It is considered that hydrodynamic features (tidal currents with strong winds, geographical characteristics, together with sediment composition are the key parameters structuring the meiofauna community in the Straits of Magellan and in the Beagle Channel.

  19. Alimentación de la anchoveta (Engraulis ringens en el norte de Chile (18°25'-25°40'S en diciembre de 2010

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    Marianela Medina

    2015-03-01

    Full Text Available Se analiza la dieta de Engraulis ringens para determinar posibles diferencias en su comportamiento alimentario por longitud y gradiente latitudinal. Las muestras se obtuvieron entre 18°25'S y 24°40'S durante el crucero de evaluación hidroacústica del reclutamiento de E. ringens, realizado entre el 1 y 20 de diciembre de 2010. El análisis comprendió la determinación de la dieta contenida en un total de 294 estómagos, provenientes de 18 estaciones de muestreo y distribuidos en tres clases de longitud (pre-reclutas, reclutas y adultos. La dieta se describió mediante los métodos numéricos de frecuencia de ocurrencia e índice de importancia relativa, además de la similitud dietaria por longitud y latitud, y especialización trófica. E. ringens registró un amplio espectro trófico, tanto de presas fitoplanctónicas como zooplanctónicas, con una alta predominancia de fitoplancton por sobre zooplancton en 2,5 órdenes de magnitud, por rango de longitud y latitud. Los componentes de mayor importancia relativa en la dieta fueron las diatomeas de los géneros Rhizosolenia y Chaetoceros, y Copepoda dentro del zooplancton. El análisis de la similitud trófica intraespecífica mostró una alta sobreposición entre los grupos de longitud, conformando una "unidad trófica". Mientras que el análisis latitudinal reveló una alta sobreposición trófica con tendencia a formar dos "unidades tróficas", pero sin seguir un patrón definido. Los resultados, confirman el carácter de depredador generalista y oportunista de E. ringens en la zona norte de Chile durante el periodo analizado.

  20. Hirfanlı Baraj Gölü (Kırşehir, Türkiye'nde yaşayan kadife balığı (Tinca tinca (Linnaeus, 1758'nın beslenme özellikleri.

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    Özlem Ablak Gürbüz

    2015-12-01

    Full Text Available Hirfanlı Baraj Gölü’nden avlanan ve 0-VI yaş grupları arasında dağılım gösteren 249 adet Kadife balığı (Tinca tinca’nın beslenme biyolojisi incelenmiştir. Tinca tinca’nın besin tercihinin tespit edilebilmesi için Geometrik Önem İndeksi (GII metodu kullanılmıştır. Ayrıca balığın besin tercihindeki aylık, mevsimlik ve yıllık değişim de incelenmiştir. Balıkların sindirim kanalında zooplanktonik (Copepoda, Rotifera, Cladocera, Ostracoda, Ephippium ve bentik (Chironomus, Oligochaeta, Gastropoda, Corethra, Gammarus organizmalar ile bunlara ait ekstremite parçaları, fitoplanktonik organizmalar (Bacillariophyta, Cyanophyta, Chlorophyta, Pyrrophyta, Euglenophyta, çamur, detritus ve balık yumurtası tespit edilmiştir. Bu çalışmada alglerin en çok tercih edilen besin tipi olduğu, bunu zooplanktonik ve bentik organizmaların takip ettiği belirlenmiştir. Tinca tinca’nın sindirim kanalında 44’ü bitkisel 16’sı hayvansal olmak üzere toplam 60 besin çeşidi saptanmıştır. Beslenmenin en fazla olduğu mevsimler sırasıyla yaz, sonbahar, kış ve ilkbahar olarak saptanmıştır. Sindirim kanalı dolu birey sayısı yaz ve sonbahar aylarında daha fazla bulunmuştur

  1. Mining pollution and the diet of the purple-striped Gudgeon Mogurnda Mogurnda Richardson (Eleotridae) in the Finniss River, Northern Territory, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Jeffree, R.A.; Williams, N.J.

    1980-01-01

    During the dry season of 1974, collections of the purple-striped Gudgeon Mogurnda Mogurnda were taken from the Finniss River of the Northern Territory; during the wet season, this river receives acidic and metallic pollutants from the formerly mined area of Rum Jungle. The fish consumed a great variety of foods, with high abundances of dytiscidae, chironomidae, ceratopogonidae, trichoptera, odonata, copepoda, decapoda, and pisces. For no food was there a significant regression against habitat descriptors in both of the zones; this emphasizes that pollution effects are more complex than simply depressing or raising the abundances of the dietary species. Five foods were more abundant in the diets of the polluted zone, and three in those of the unpolluted zone. The dietary abundances of two foods, both crustacean, increased in the polluted zone, compared to the unpolluted zone, through the dry season. Two categories of foods: (1) those obtaining oxygen directly from the atmosphere or via a film or bubble of air; and (2) the converse set (aquatic respirers), were contrasted for their usefulness in distinguishing between the zones, by both hierarchical agglomerative and discriminant function analyses. One collection from the polluted zone was reclassified as unpolluted on the basis of its grouping behaviour. The relevance for pollution studies of dietary analysis of euryphagous fish, rather than sampling aquatic fauna directly, is discussed in terms of food substitution, switching, strategies for abundance and recovery by the fauna, and possible effects of the pollutants on the fish as an intervening collector. Downstream patterns of abundance of the invertebrate fauna in this study are broadly similar to those of other studies in which such chemically diverse metals as Pb, Zn, and Cu are the pollutants, but there are differences for some faunal components.

  2. Water and Soil Analyses of Balongis Fish Cage and Oster (Talaba Farms in Concepcion River, Kabasalan, Zamboanga Sibugay Province, Philippines

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    Victoria L. Lim

    2017-02-01

    Full Text Available The decline of the talaba (saccosrea malabonensis production in Barangay Concepcion, Kabasalan, Zamboanga Sibugay motivated the fisher folks to determine the cause of the phenomenon through the Social Action Ministry (SAM – Diocese of Ipil, Ipil, Zamboanga Sibugay,Philippines who arranged for the conduct of the study. The research was hypothesized to be caused by climate change. Data collection began on January 28 until February 8, 2012 on site. Twelve (12 sampling sites were installed in Concepcion River barangay Balongis, Buayan Zamboanga Sibugay where the barangay’s fish cage and oyster (Talaba farms are Global Positioning System (GPS gadget was used for the identification/markings of sampling stations (07⁰ 46.00 N and 122⁰47.116E to 07⁰45.778 N and 122⁰47.151 E Water and soil/sediment samples were taken and analyzed once a week for three consecutive weeks – January 28 to February 18, 2012. Physical water parameters were taken in situ (pH, Temperature, salinity and TSS. Water temperature raging 24⁰C-31.5⁰C, water pH 7.0-8.24, water salinity 18 -27.6 ppt. Total Suspended Solids (TSS ranged 0.104 g/L to 0.672 g/L – classified turbid water for all sampling sites. Sediment analysis: for mercury containment – qualitative analysis is negative, Soil Classification using the Textual triangle – soil classified as Loamy Sand (Sites 7-10 and Sandy Loam for all other sites. Meiofauna component using the Nematoma, turbellaria, Ciliophora, Ostracoda, Gastrotricha, Tardigrada, Sarcomastigaphora, Sincarida, Copepoda and some other unidentified fauna. Sedimentation rate averaged from 1410-6469 g/m2 per week. The high sediment rate could have caused the decline in oyster production but not by mercury contamination as suspected.

  3. Combined, short-term exposure to reduced seawater pH and elevated temperature induces community shifts in an intertidal meiobenthic assemblage.

    Science.gov (United States)

    Mevenkamp, Lisa; Ong, Ee Zin; Van Colen, Carl; Vanreusel, Ann; Guilini, Katja

    2018-02-01

    In future global change scenarios the surface ocean will experience continuous acidification and rising temperatures. While effects of both stressors on marine, benthic communities are fairly well studied, consequences of the interaction of both factors remain largely unknown. We performed a short-term microcosm experiment exposing a soft-bottom community from an intertidal flat in the Westerscheldt estuary to two levels of seawater pH (ambient pH T  = 7.9, reduced pH T  = 7.5) and temperature (10 °C ambient and 13 °C elevated temperature) in a crossed design. After 8 weeks, meiobenthic community structure and nematode staining ratios, as a proxy for mortality, were compared between treatments and structural changes were related to the prevailing abiotic conditions in the respective treatments (pore water pH T , sediment grain size, total organic matter content, total organic carbon and nitrogen content, phytopigment concentrations and carbonate concentration). Pore water pH T profiles were significantly altered by pH and temperature manipulations and the combination of elevated temperature and reduced pH intensified the already more acidic porewater below the oxic zone. Meiofauna community composition was significantly affected by the combination of reduced pH and elevated temperature resulting in increased densities of predatory Platyhelminthes, reduced densities of Copepoda and Nauplii and complete absence of Gastrotricha compared to the experimental control. Furthermore, nematode staining ratio was elevated when seawater pH was reduced pointing towards reduced degradation rates of dead nematode bodies. The observed synergistic interactions of pH and temperature on meiobenthic communities and abiotic sediment characteristics underline the importance of multistressor experiments when addressing impacts of global change on the marine environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. [Spatial and temporal variation in diet composition of invertivore fishes in a tropical stream, Venezuela].

    Science.gov (United States)

    Ortaz, Mario; Martín, Ricardo; López-Ordaz, Adriana

    2011-09-01

    Invertivores fishes are an important component of neotropical streams and they represent a link between aquatic invertebrates and piscivorous species. This study evaluated the breadth diet and interspecific food overlap of nine invertivores fish species during three consecutive hydrological phases: falling (December/07, January/08, February/08 and March/08), low (April/08) and rising waters (June/08), in two sections of a Venezuelan neotropical stream, which were located at different elevation, high watershed (HW) and low watershed (LW). The fishes were collected with a beach seine (5mm mesh) between 8:00 and 11:00 hours. The diet of each species was evaluated using an index of relative importance (IRI), which includes as variables the number, weight and occurrence frequency of food items consumed. The Levin' index (B ) and Morisita (IM) were used to estimate the breadth diet and interspecific food overlap, respectively. All estimations were made using the numeric proportion of preys. Nine fish species were captured, eight Characiformes, of which three were captured in HW (Knodus deuteronoides, Creagrutus bolivari and C. melasma) and five in LW (Thoracocharax stellatus, Moenkhausia lepidura, Cheirodon pulcher, Ctenobrycon spilurus and Aphyocharax alburnus), and one Cyprinodontiformes (Poecilia reticulata), which was also found in HW. In HW aquatic insects were the main resource consumed by fishes while plant material and terrestrial arthropods were secondary resources. In LW the fishes ingested all of these items in addition to zooplankton (Copepoda, Cladocera and larval stages of Decapoda). However, there was a temporal replacement with a predominance of zooplankton in falling and low water. In general, the breadth diet decreased during the falling water in both sections and increased in rising water. However, the average breadth diet was higher in HW. The interspecific food overlap was high in HW while low values were more frequent in LW and its temporal

  5. The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions.

    Directory of Open Access Journals (Sweden)

    Michael J Raupach

    Full Text Available During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD, unique BINs were identified for 198 (96.6% of the analyzed species. Six species were characterized by two BINs (2.9%, and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%. Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%. Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761, underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequences.

  6. Canyon effect and seasonal variability of deep-sea organisms in the NW Mediterranean: Synchronous, year-long captures of ;swimmers; from near-bottom sediment traps in a submarine canyon and its adjacent open slope

    Science.gov (United States)

    Romano, C.; Flexas, M. M.; Segura, M.; Román, S.; Bahamon, N.; Gili, J. M.; Sanchez-Vidal, A.; Martin, D.

    2017-11-01

    Numerous organisms, including both passive sinkers and active migrators, are captured in sediment traps together with sediments. By capturing these "swimmers", the traps become an extraordinarily tool to obtain relevant information on the biodiversity and dynamics of deep-sea organisms. Here we analyze near-bottom swimmers larger than 500 μm and their fluxes collected from eight near-bottom sediment traps installed on instrumented moorings deployed nearby Blanes Canyon (BC). Our data, obtained from November 2008 to October 2009 with a sampling rate of 15 days, constitutes the first year-long, continuous time series of the whole swimmers' community collected at different traps and bottom depths (from 300 m to 1800 m) inside a submarine canyon and on its adjacent open slope (OS). The traps captured 2155 specimens belonging to 70 taxa, with Crustacea (mainly Copepoda) and Annelida Polychaeta accounting for more than 90% of the total abundance. Almost half of the identified taxa (33) were only present in BC traps, where mean annual swimmer fluxes per trap were almost one order of magnitude higher than in the OS ones. Temporal variability in swimmer fluxes was more evident in BC than in OS. Fluxes dropped in winter (in coincidence with the stormy period in the region) and remained low until the following spring. In spring, there was a switch in taxa composition, including an increase of planktonic organisms. Additionally, we report drastic effects of extreme events, such as major storms, on deep-sea fauna. The impact of such extreme events along submarine canyon systems calls to rethink the influence of climate-driven phenomena on deep-sea ecosystems and, consequently, on their living resources.

  7. Effects of the toxic dinoflagellate Karlodinium sp. (cultured at different N/P ratios on micro and mesozooplankton

    Directory of Open Access Journals (Sweden)

    Dolors Vaqué

    2006-03-01

    Full Text Available An experimental study was carried out to investigate whether two potential predators such as Oxyrrhis marina (phagotrophic dinoflagellate and Acartia margalefi (Copepoda: Calanoida had different responses when feeding on toxic (Karlodinium sp.-strain CSIC1- or non-toxic (Gymnodinium sp1 dinoflagellates with a similar shape and size. Both prey were cultured at different N/P ratios (balanced N/P = 15, and P-limited N/P > 15 to test whether P-limitation conditions could lead to depressed grazing rates or have other effects on the predators. Both predators ingested the non-toxic Gymnodinium sp1, and low or non-ingestion rates were observed when incubated with Karlodinium sp. The dinoflagellate O. marina did not graze at all on Karlodinium sp. at N/P > 15 and very little at NP = 15, as its net growth rates were always negative when feeding on Karlodinium sp. cultured under P-limitation conditions. A. margalefi had lower ingestion rates when feeding on Karlodinium sp. grown at N/P = 15 than when feeding on Gymnodinium sp1, and did not graze on P-limited Karlodinium sp. Nevertheless, feeding on Karlodinium sp. grown under N/P =15 or N/P > 15 did not have any paralyzing or lethal effect on A. margalefi after 24 h. Finally, a direct effect on the viability of A. margalefi eggs was detected when healthy eggs were incubated for 5 days in the presence of Karlodinium sp. grown under N/P =15 or N/P > 15, producing a decrease in viability of 20% and 60% respectively.

  8. Hydrogen peroxide treatment in Atlantic salmon induces stress and detoxification response in a daily manner.

    Science.gov (United States)

    Vera, L M; Migaud, H

    2016-01-01

    Daily variation in the absorption, metabolism and excretion of toxic substances will ultimately determine the actual concentration to which the cells and tissues are exposed. In aquaculture, Atlantic salmon (Salmo salar) can be frequently exposed to hydrogen peroxide (H2O2) to treat topical skin and gill infections, particularly in relation to parasitic infections (e.g. sea lice Lepeophtheirus salmonis and amoebic gill disease caused by Neoparamoeba perurans). It is well accepted that the time of administration influences pharmacodynamics and pharmacokinetics of drugs which in turn affects their efficacy and toxicity. Consequently, a better understanding of drug side effects as a function of time of day exposure would help to improve treatment efficacy and fish welfare. To this end, salmon were exposed to H2O2 (1500 mg/L) for 20 min at six different times of the day during a 24-h cycle and we investigated the time-dependent effects of exposure on physiological stress (glucose, lactate and cortisol) and antioxidant enzyme expression (gpx1, cat, Mn-sod and hsp70) in liver and gills. In addition, at each sampling point, 8 control fish were also sampled. Our results revealed that the time of administration of H2O2 caused significant differences in the induction of both physiological and oxidative stress responses. Glucose and lactate were higher in the treated fish during daytime whereas cortisol levels appeared to be systematically increased (>1000 ng/mL) after H2O2 treatment irrespective of exposure time, although differences with control levels were higher during the day. In liver, gene expression of antioxidant enzymes displayed daily rhythmicity in both treated and control groups and showed higher mRNA expression levels in salmon treated with H2O2 at ZT6 (6 h after lights onset). In gills, rhythmic expression was only found for gpx1 in the control fish and for hsp70 and Mn-sod in the treated groups. However, in the treated salmon, higher gene expression levels of

  9. Immunization against parasitic diseases of fish.

    Science.gov (United States)

    Woo, P T

    1997-01-01

    sonicated/killed cercariae or metacercariae have fewer metacercariae in the eyes and survives longer. Lepeophtheirus salmonis and Caligus elongatus are parasitic copepods (sea lice), and they are important parasites of Atlantic salmon in cage cultures. A vaccine against fish lice is plausible, and the efficacy of about 20 candidate antigens in protecting fish is being tested.

  10. Distribution and persistence of the anti sea-lice drug teflubenzuron in wild fauna and sediments around a salmon farm, following a standard treatment

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Ole B. [Institute of Marine Research, P.O. Box 1870 Nordnes, N-5817 Bergen (Norway); Lunestad, Bjørn T.; Hannisdal, Rita [National Institute of Nutrition and Seafood Research, P.O. Box 2029 Nordnes, N-5817 Bergen (Norway); Bannister, Raymond; Olsen, Siri [Institute of Marine Research, P.O. Box 1870 Nordnes, N-5817 Bergen (Norway); Tjensvoll, Tore [National Institute of Nutrition and Seafood Research, P.O. Box 2029 Nordnes, N-5817 Bergen (Norway); Farestveit, Eva; Ervik, Arne [Institute of Marine Research, P.O. Box 1870 Nordnes, N-5817 Bergen (Norway)

    2015-03-01

    The salmon louse (Lepeoptheirus salmonis) is a challenge in the farming of Atlantic salmon (Salmo salar). To treat an infestation, different insecticides are used like the orally administered chitin synthetase inhibitor teflubenzuron. The concentrations and distribution of teflubenzuron were measured in water, organic particles, marine sediment and biota caught in the vicinity of a fish farm following a standard medication. Low concentrations were found in water samples whereas the organic waste from the farm, collected by sediment traps had concentrations higher than the medicated feed. Most of the organic waste was distributed to the bottom close to the farm but organic particles containing teflubenzuron were collected 1100 m from the farm. The sediment under the farm consisted of 5 to 10% organic material and therefore the concentration of teflubenzuron was much lower than in the organic waste. Teflubenzuron was persistent in the sediment with a stipulated halflife of 170 days. Sediment consuming polychaetes had high but decreasing concentrations of teflubenzuron throughout the experimental period, reflecting the decrease of teflubenzuron in the sediment. During medication most wild fauna contained teflubenzuron residues and where polychaetes and saith had highest concentrations. Eight months later only polychaetes and some crustaceans contained drug residues. What dosages that induce mortality in various crustaceans following short or long-term exposure is not known but the results indicate that the concentrations in defined individuals of king crab, shrimp, squat lobster and Norway lobster were high enough shortly after medication to induce mortality if moulting was imminent. Considering food safety, saith and the brown meat of crustaceans contained at first sampling concentrations of teflubenzuron higher than the MRL-value set for Atlantic salmon. The concentrations were, however, moderate and the amount of saith fillet or brown meat of crustaceans to be

  11. A critical life stage of the Atlantic salmon Salmo salar: behaviour and survival during the smolt and initial post-smolt migration.

    Science.gov (United States)

    Thorstad, E B; Whoriskey, F; Uglem, I; Moore, A; Rikardsen, A H; Finstad, B

    2012-07-01

    The anadromous life cycle of Atlantic salmon Salmo salar involves long migrations to novel environments and challenging physiological transformations when moving between salt-free and salt-rich waters. In this article, (1) environmental factors affecting the migration behaviour and survival of smolts and post-smolts during the river, estuarine and early marine phases, (2) how behavioural patterns are linked to survival and (3) how anthropogenic factors affect migration and survival are synthesized and reviewed based on published literature. The timing of the smolt migration is important in determining marine survival. The timing varies among rivers, most likely as a consequence of local adaptations, to ensure sea entry during optimal periods. Smolts and post-smolts swim actively and fast during migration, but in areas with strong currents, their own movements may be overridden by current-induced transport. Progression rates during the early marine migration vary between 0.4 and 3.0 body lengths s(-1) relative to the ground. Reported mortality is 0.3-7.0% (median 2.3) km(-1) during downriver migration, 0.6-36% (median 6.0) km(-1) in estuaries and 0.3-3.4% (median 1.4) km(-1) in coastal areas. Estuaries and river mouths are the sites of the highest mortalities, with predation being a common cause. The mortality rates varied more among studies in estuaries than in rivers and marine areas, which probably reflects the huge variation among estuaries in their characteristics. Behaviour and survival during migration may also be affected by pollution, fish farming, sea lice Lepeophtheirus salmonis, hydropower development and other anthropogenic activities that may be directly lethal, delay migration or have indirect effects by inhibiting migration. Total mortality reported during early marine migration (up to 5-230 km from the river mouths) in the studies available to date varies between 8 and 71%. Hence, the early marine migration is a life stage with high mortalities, due

  12. Comparison of laboratory single species and field population-level effects of the pyrethroid insecticide lambda-cyhalothrin on freshwater invertebrates.

    Science.gov (United States)

    Schroer, A F W; Belgers, J D M; Brock, T C M; Matser, A M; Maund, S J; Van den Brink, P J

    2004-04-01

    The toxicity of the pyrethroid insecticide lambda-cyhalothrin to freshwater invertebrates has been investigated using data from short-term laboratory toxicity tests and in situ bioassays and population-level effects in field microcosms. In laboratory tests, patterns of toxicity were consistent with previous data on pyrethroids. The midge Chaoborus obscuripes was most sensitive (48- and 96-h EC50 = 2.8 ng/L). Other insect larvae (Hemiptera, Ephemeroptera) and macrocrustacea (Amphipoda, Isopoda) were also relatively sensitive, with 48- and 96-h EC50 values between 10 and 100 ng/L. Generally, microcrustacea (Cladocera, Copepoda) and larvae of certain insect groups (Odonata and Chironomidae) were less sensitive, with 48-h EC50 values higher than 100 ng/L. Mollusca and Plathelminthes were insensitive and were unaffected at concentrations at and above the water solubility (5 microg/L). Generally, the EC50 values based on initial population responses in field enclosures were similar to values derived from laboratory tests with the same taxa. Also, the corresponding fifth and tenth percentile hazard concentrations (HC5 and HC10) were similar (laboratory HC5 = 2.7 ng/L and field HC5 = 4.1 ng/L; laboratory and field HC10 = 5.1 ng/L), at least when based on the same sensitive taxonomic groups (insects and crustaceans) and when a similar concentration range was taken into account. In the three field enclosure experiments and at a treatment level of 10 ng/L, consistent effects were observed for only one population (Chaoborus obscuripes), with recovery taking place within 3 to 6 weeks. The laboratory HC5 (2.7 ng/L) and HC10 (5.1 ng/L) based on acute EC50 values of all aquatic arthropod taxa were both lower than this 10 ng/L, a concentration that might represent the "regulatory acceptable concentration." The HC5 and HC10 values in this study in The Netherlands (based on static laboratory tests with freshwater arthropods) were very similar to those derived from a previous study in

  13. Observing copepods through a genomic lens.

    Science.gov (United States)

    Bron, James E; Frisch, Dagmar; Goetze, Erica; Johnson, Stewart C; Lee, Carol Eunmi; Wyngaard, Grace A

    2011-09-20

    Copepods outnumber every other multicellular animal group. They are critical components of the world's freshwater and marine ecosystems, sensitive indicators of local and global climate change, key ecosystem service providers, parasites and predators of economically important aquatic animals and potential vectors of waterborne disease. Copepods sustain the world fisheries that nourish and support human populations. Although genomic tools have transformed many areas of biological and biomedical research, their power to elucidate aspects of the biology, behavior and ecology of copepods has only recently begun to be exploited. The extraordinary biological and ecological diversity of the subclass Copepoda provides both unique advantages for addressing key problems in aquatic systems and formidable challenges for developing a focused genomics strategy. This article provides an overview of genomic studies of copepods and discusses strategies for using genomics tools to address key questions at levels extending from individuals to ecosystems. Genomics can, for instance, help to decipher patterns of genome evolution such as those that occur during transitions from free living to symbiotic and parasitic lifestyles and can assist in the identification of genetic mechanisms and accompanying physiological changes associated with adaptation to new or physiologically challenging environments. The adaptive significance of the diversity in genome size and unique mechanisms of genome reorganization during development could similarly be explored. Genome-wide and EST studies of parasitic copepods of salmon and large EST studies of selected free-living copepods have demonstrated the potential utility of modern genomics approaches for the study of copepods and have generated resources such as EST libraries, shotgun genome sequences, BAC libraries, genome maps and inbred lines that will be invaluable in assisting further efforts to provide genomics tools for copepods. Genomics research

  14. Modern and fossilized biological communities from sediments of Bolshoy Harbei lake (Bolshezemelskaya tundra, Russia) and their response to climate change

    Science.gov (United States)

    Tumanov, Oleg; Nazarova, Larisa; Fefilova, Elena; Baturina, Maria; Loskutova, Olga; Frolova, Larisa; Palagushkina, Olga

    2013-04-01

    High-altitude regions are subjected to the threats of global warming. During the last decade the depth of seasonal melting of permafrost in Northern Russia, significantly increased. Investigation of lake sediments from polar regions has an extreme importance for understanding of the modern environmental processes and their influence on northern ecosystems and biological diversity of these regions. Invertebrate communities are used for diagnostic of lake ecosystems because they have a great sensitivity to climatic changes (Andronnikova, 1996; Lazareva, 2008; O'Brien et al., 2005). The data can be used as well as a basis for inference models for reconstruction of the paleoclimatic conditions. Chironomid-based, Cladocera-based and diatom models have successfully been developed (Nazarova et al., 2008, 2011; Self et al., 2011) and can be used for precise paleotemperature reconstructions (Kienast et al., 2011). In summer 2012, we investigated complex of Kharbei lakes, located in the interfluve of Korotaiha and Bolshaya Rogovaya rivers in the east side of Bolshezemelskaya tundra, Russia (67°33'22″ N, 62°53'23″ E). Six different lakes were investigated using modern hydrobiological and palaeoecological methods. In total 9 cores were obtained, cut, dated and further investigated using sedimenthological, geochemical, and paleobiological methods. The standard hydrobiological methods have shown that the modern zooplankton communities did not change significantly during the last 40 years. Taxonomic composition and structure of planktonic communities didn't change, except for appearance of crustaceans Polyarthra euryptera and Daphnia cucullata. In planktonic communities of Bolshoy Harbei lake we revealed 39 species and forms of Rotifera, 19 - Cladocera and 11 - Copepoda. In zoobenthic communities we registered 24 taxonomical groups characteristic for large tundra lakes of the North East of Russia. Chironomids and Oligochaeta are dominant groups of invertebrates. 103 taxa of

  15. A “Rosetta Stone” for metazoan zooplankton: DNA barcode analysis of species diversity of the Sargasso Sea (Northwest Atlantic Ocean)

    Science.gov (United States)

    Bucklin, Ann; Ortman, Brian D.; Jennings, Robert M.; Nigro, Lisa M.; Sweetman, Christopher J.; Copley, Nancy J.; Sutton, Tracey; Wiebe, Peter H.

    2010-12-01

    Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ˜650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of "gold standard" DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean

  16. A Synoptic Assessment of the Amazon River-Ocean Continuum during Boreal Autumn: From Physics to Plankton Communities and Carbon Flux

    Directory of Open Access Journals (Sweden)

    Moacyr Araujo

    2017-07-01

    Full Text Available The Amazon generates the world's largest offshore river plume, which covers extensive areas of the tropical Atlantic. The data and samples in this study were obtained during the oceanographic cruise Camadas Finas III in October 2012 along the Amazon River-Ocean Continuum (AROC. The cruise occurred during boreal autumn, when the river plume reaches its maximum eastward extent. In this study, we examine the links between physics, biogeochemistry and plankton community structure along the AROC. Hydrographic results showed very different conditions, ranging from shallow well-mixed coastal waters to offshore areas, where low salinity Amazonian waters mix with open ocean waters. Nutrients, mainly NO3− and SiO2−, were highly depleted in coastal regions, and the magnitude of primary production was greater than that of respiration (negative apparent oxygen utilization. In terms of phytoplankton groups, diatoms dominated the region from the river mouth to the edge of the area affected by the North Brazil Current (NBC retroflection (with chlorophyll a concentrations ranging from 0.02 to 0.94 mg m−3. The North Equatorial Counter Current (NECC region, east of retroflection, is fully oligotrophic and the most representative groups are Cyanobacteria and dinoflagellates. Additionally, in this region, blooms of cyanophyte species were associated with diatoms and Mesozooplankton (copepods. A total of 178 zooplankton taxa were observed in this area, with Copepoda being the most diverse and abundant group. Two different zooplankton communities were identified: a low-diversity, high-abundance coastal community and a high-diversity, low-abundance oceanic community offshore. The CO2 fugacity (fCO2sw, calculated from total alkalinity (1,450 < TA < 2,394 μmol kg−1 and dissolved inorganic carbon (1,303 < DIC < 2,062 μmol kg−1 measurements, confirms that the Amazon River plume is a sink of atmospheric CO2 in areas with salinities <35 psu, whereas, in regions

  17. Comparação da dieta de duas espécies de Triportheus (Characidae, Triportheinae, em trechos do reservatório de Manso e lagoas do rio Cuiabá, Estado do Mato Grosso - DOI: 10.4025/actascibiolsci.v25i2.2023 Diet Comparison of two species of Triportheus in Manso Reservoir and lagoons of Cuiabá River, Mato Grosso do Sul - DOI: 10.4025/actascibiolsci.v25i2.2023

    Directory of Open Access Journals (Sweden)

    André Beal Galina

    2003-04-01

    Full Text Available O presente estudo teve por objetivo conhecer aspectos da alimentação de duas espécies de Triportheus, no reservatório de Manso e lagoas do rio Cuiabá, Estado do Mato Grosso. As coletas foram realizadas mensalmente (março/00 a fevereiro/01 e os conteúdos estomacais analisados pelos métodos de Ocorrência (O% e Volumétrico (V%. Os dados foram sintetizados graficamente no Índice de Costello. T. nematurus explorou insetos terrestres (Hymenoptera e Coleoptera e insetos aquáticos (larvas de Diptera no reservatório, durante todo o período de estudos. Nas lagoas, a dieta foi baseada principalmente em algas e insetos terrestres no período de cheia, sendo mais diversificada na seca. No reservatório, T. paranensis consumiu preferencialmente invertebrados aquáticos (Cladocera e Copepoda enquanto que, nas lagoas, explorou insetos terrestres no período de seca e insetos aquáticos na cheia. A sobreposição alimentar (Índice de Schoener intra e interespecífica apresentou valores baixos (The aim of this paper is to determine the diet of two species of Triportheus (T. paranensis e T. nematurus, in Manso Reservoir and lagoons of Cuiabá River, MT. Samples were monthly taken from March 2000 to February 2001. Stomach contents were analyzed by the occurrence and volumetric methods, and data were graphically grouped by Costello Index. The diet of T. nematurus was composed of terrestrial (Hymenoptera and Coleoptera and aquatic insects (larvae of Diptera in the reservoir. In lagoons it consumed algae and terrestrial insects during the flood period, and the diet was more diversified during the dry season. In the reservoir, T. paranensis consumed specially aquatic invertebrates, while in lagoons its diet was composed of terrestrial insects in dry season and aquatic insects in flood period. Schoener Index presented low values (< 0,6, showing partial segregation in both species diet

  18. Water quality and potamoplankton evaluation of the Nile River in Upper Egypt

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed El-Otify

    2015-06-01

    Full Text Available Aim: The composition, abundance, community structure of potamoplankton and major physical and chemical variables of the Nile water in Upper Egypt were investigated to assess its status in different seasons during 2007.MethodsWater samples were collected seasonally during 2007 from six investigated sites from variable depths at levels of 0, 2.5 and 5 m. The area of this investigation is defined as the southern 120 Km of the main stream of the Nile in Upper Egypt (24° 04’ – 25° 00’ latitudes and 32° 51’ – 32° 54’ longitudes, downstream of Aswan Old Dam.ResultsAltogether, 121 potamoplankton species, of which 85 related to phytoplankton and 36 appertaining to zooplankton were recorded. Most numerous phytoplankton were Chlorophyceae (42 species followed by Bacillariophyceae (30 species. Cyanobacteria and Dinophyceae were less numerous with only 11 and 2 species, respectively. Zooplankton species were mainly belonging to three systematic groups namely; Rotifera (24 species, Copepoda (3 species and Cladocera (9 species. Besides, other rare zooplankton including Platyhelminthes, Nemata and Ciliophora were sparsely encountered. The main hydrological conditions characterizing the investigated area include water level fluctuations (˂82 - ˃85 m above sea level, relatively high current velocity (0.8 - 1.3 m sec–1 and disposal of wastewater. Plankton populations were variably but rather weakly dependent on the major nutrients due to their excessive availability in accessible form for uptake by the producers. For phytoplankton, the community structure was categorized in relation to temperature, pH, SO42– and Mg2+. For zooplankton, the community structure was categorized in relation to conductivity as well as Mg2+. Sampling intervals were inadequate to demonstrate the existing successional pattern of the Nile potamoplankton community. Alterations in the phytoplankton community structure accompanied changes in water temperature represented

  19. Variación espacial y temporal en la composición de la dieta de peces invertívoros en un río neotropical, Venezuela

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    Mario Ortaz

    2011-09-01

    Full Text Available La ictiofauna invertívora es un componente importante en los ríos neotropicales y representa un enlace entre los invertebrados acuáticos y los piscívoros. En el presente trabajo se evaluó la amplitud y sobreposición interespecífica de dieta de nueve especies de peces invertívoros durante tres fases hidrológicas consecutivas: descenso (diciembre/07, enero/08, febrero/08, marzo/08, aguas bajas (abril/08 y ascenso de aguas (junio/08 en dos secciones de un río venezolano ubicadas a distinta altitud (subcuenca alta, SA y subcuenca baja, SB. Los peces se recolectaron con una red de cerco (0.5cm entrenudos entre las 8:00 y 11:00 horas. La dieta de cada especie se evaluó usando un índice de importancia relativa (IIR que incluyó el número, peso y frecuencia de ocurrencia de los items consumidos. Para estimar la amplitud y sobreposición interespecífica de dieta se emplearon los índices de Levín (Bi y Morisita (IM, respectivamente. Todas las estimaciones se realizaron con la frecuencia numérica de las presas consumidas. Se capturaron nueve especies, ocho Characiformes, tres en SA (Knodus deuteronoides, Creagrutus bolivari y C. melasma y cinco en SB (Thoracocharax stellatus, Moenkhausia lepidura, Cheirodon pulcher, Ctenobrycon spilurus y Aphyocharax alburnus y un Cyprinodontiformes (Poecilia reticulata, capturada en SA. En SA el principal recurso consumido fueron insectos acuáticos mientras que el material vegetal y los artrópodos terrestres fueron recursos secundarios. En SB, las especies consumieron estos items además de zooplancton (Copepoda, Cladocera y estadios larvales de crustáceos Decapoda, pero hubo una sustitución temporal con un predominio de zooplancton en descenso y aguas bajas. En general, la amplitud de la dieta disminuyó en descenso de aguas en ambas secciones e incrementó en ascenso de aguas. Sin embargo, la amplitud promedio fue mayor en SA. La sobreposición interespecífica de dieta fue alta en SA mientras que

  20. Fate and effects of the insecticide Dursban 4E in indoor Elodea-dominated and macrophyte-free freshwater model ecosystems: I. Fate and primary effects of the active ingredient chlorpyrifos.

    Science.gov (United States)

    Brock, T C; Crum, S J; van Wijngaarden, R; Budde, B J; Tijink, J; Zuppelli, A; Leeuwangh, P

    1992-07-01

    The fate of the insecticide Dursban 4E (active ingredient chlorpyrifos) and its effect on crustaceans and insects was studied in indoor experimental freshwater ecosystems that intended to mimick drainage ditches. A single dose (simulating aerial drift) was applied to achieve nominal chlorpyrifos concentrations of 5 or 35 micrograms/L. Two experiments were performed, one in which all model ecosystems were dominated by the macrophyte Elodea nuttallii, and one using systems devoid of macrophytes. In macrophyte-dominated systems, Elodea vegetation adsorbed a large proportion of the dose applied and hampered the mixing of the insecticide in the water (at least up till day 8). Only a small proportion became incorporated in the sediment. In open water systems the insecticide was rapidly mixed in the water, and the sediment played a very significant role as sink for chlorpyrifos. In both Elodea-dominated and open water systems 50% of the dose applied had disappeared on day 8 post-treatment. The rate of disappearance of chlorpyrifos was relatively rapid in water and macrophytes, and relatively slow in the sediment. Of the arthropods in the zooplankton Cladocera were more susceptible than Copepoda. Significant effects (p less than or equal to 0.05) on Cladocera occurred relatively late in Elodea-dominated systems (in week 4 post-application) in contrast to open water systems (week 1), which is in accordance with the observed differences in the fate of chlorpyrifos. Daphnia pulex, D. longispina and Simocephalus vetulus recovered in the model ecosystems when chlorpyrifos concentrations were lower than 0.1-0.2 micrograms/L, which is in agreement with results of laboratory protocol tests performed with these cladocerans. Among the macroscopic Arthropoda the apparent order of susceptibility was amphipods greater than insects greater than isopods. The isopod Asellus aquaticus was more sensitive to the application of the insecticide than the closely related species Proasellus

  1. Longitudinal processes in Salto Grande reservoir (Americana, SP, Brazil and its influence in the formation of compartment system

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    L. H. ZANATA

    Full Text Available Studies on the longitudinal processes in reservoirs, involving physical, chemical and biological processes have been thoroughly appraised, suggesting the existence of a longitudinal organization controlled by the entrance and circulation of water which inserts modifications in the structuring of the system. To evaluate this effect, the Salto Grande reservoir (Americana, SP was analyzed in 11 sampling stations in its longitudinal axis, in the rainy and dry seasons of 1997 considering the physical chemical and biological variables. Analyzing the results in agreement with the declining concentration degree of the river--barrage direction, a more significant correlation was verified in the dry period for total phosphorus (r² = 0.86, dissolved total phosphate (r² = 0.83, nitrite (r² = 0.93, inorganic phosphate (r² = 0.89, ammonium (r² = 0.84 and suspended material (r² = 0.85. In the rainy period, only nitrite (r² = 0.90 and conductivity (r² = 0.89 presented correlation with the distance of the dam, which demonstrates the effects of precipitation and the operational mechanism of the dam, as well as the distinction among the physical (sedimentation, chemical (oxidation and biological (decomposition processes in spatial heterogeneity of the system. These factors were decisive in the organization of these communities, with higher occurrence of rotifers and copepods in relation to cladocerans, the first ones being more abundant in the entrance of the Atibaia river, decreasing towards the dam direction, while copepods presented an inverse pattern. A distribution pattern similar to Copepoda was also verified for the Cladocera, evidencing a tendency to increase the density of organisms in the stations distant to the entrance of the Atibaia river, not being registered, however, a distribution gradient in the longitudinal axis, as observed for rotifers and copepods. In relation to the trophic degree a longitudinal gradient was also verified from

  2. Longitudinal processes in Salto Grande reservoir (Americana, SP, Brazil and its influence in the formation of compartment system

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    ZANATA L. H.

    2002-01-01

    Full Text Available Studies on the longitudinal processes in reservoirs, involving physical, chemical and biological processes have been thoroughly appraised, suggesting the existence of a longitudinal organization controlled by the entrance and circulation of water which inserts modifications in the structuring of the system. To evaluate this effect, the Salto Grande reservoir (Americana, SP was analyzed in 11 sampling stations in its longitudinal axis, in the rainy and dry seasons of 1997 considering the physical chemical and biological variables. Analyzing the results in agreement with the declining concentration degree of the river--barrage direction, a more significant correlation was verified in the dry period for total phosphorus (r² = 0.86, dissolved total phosphate (r² = 0.83, nitrite (r² = 0.93, inorganic phosphate (r² = 0.89, ammonium (r² = 0.84 and suspended material (r² = 0.85. In the rainy period, only nitrite (r² = 0.90 and conductivity (r² = 0.89 presented correlation with the distance of the dam, which demonstrates the effects of precipitation and the operational mechanism of the dam, as well as the distinction among the physical (sedimentation, chemical (oxidation and biological (decomposition processes in spatial heterogeneity of the system. These factors were decisive in the organization of these communities, with higher occurrence of rotifers and copepods in relation to cladocerans, the first ones being more abundant in the entrance of the Atibaia river, decreasing towards the dam direction, while copepods presented an inverse pattern. A distribution pattern similar to Copepoda was also verified for the Cladocera, evidencing a tendency to increase the density of organisms in the stations distant to the entrance of the Atibaia river, not being registered, however, a distribution gradient in the longitudinal axis, as observed for rotifers and copepods. In relation to the trophic degree a longitudinal gradient was also verified from

  3. Observing copepods through a genomic lens

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    Johnson Stewart C

    2011-09-01

    Full Text Available Abstract Background Copepods outnumber every other multicellular animal group. They are critical components of the world's freshwater and marine ecosystems, sensitive indicators of local and global climate change, key ecosystem service providers, parasites and predators of economically important aquatic animals and potential vectors of waterborne disease. Copepods sustain the world fisheries that nourish and support human populations. Although genomic tools have transformed many areas of biological and biomedical research, their power to elucidate aspects of the biology, behavior and ecology of copepods has only recently begun to be exploited. Discussion The extraordinary biological and ecological diversity of the subclass Copepoda provides both unique advantages for addressing key problems in aquatic systems and formidable challenges for developing a focused genomics strategy. This article provides an overview of genomic studies of copepods and discusses strategies for using genomics tools to address key questions at levels extending from individuals to ecosystems. Genomics can, for instance, help to decipher patterns of genome evolution such as those that occur during transitions from free living to symbiotic and parasitic lifestyles and can assist in the identification of genetic mechanisms and accompanying physiological changes associated with adaptation to new or physiologically challenging environments. The adaptive significance of the diversity in genome size and unique mechanisms of genome reorganization during development could similarly be explored. Genome-wide and EST studies of parasitic copepods of salmon and large EST studies of selected free-living copepods have demonstrated the potential utility of modern genomics approaches for the study of copepods and have generated resources such as EST libraries, shotgun genome sequences, BAC libraries, genome maps and inbred lines that will be invaluable in assisting further efforts to

  4. Variación espacial y temporal en la composición de la dieta de peces invertívoros en un río neotropical, Venezuela

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    Mario Ortaz

    2011-09-01

    Full Text Available La ictiofauna invertívora es un componente importante en los ríos neotropicales y representa un enlace entre los invertebrados acuáticos y los piscívoros. En el presente trabajo se evaluó la amplitud y sobreposición interespecífica de dieta de nueve especies de peces invertívoros durante tres fases hidrológicas consecutivas: descenso (diciembre/07, enero/08, febrero/08, marzo/08, aguas bajas (abril/08 y ascenso de aguas (junio/08 en dos secciones de un río venezolano ubicadas a distinta altitud (subcuenca alta, SA y subcuenca baja, SB. Los peces se recolectaron con una red de cerco (0.5cm entrenudos entre las 8:00 y 11:00 horas. La dieta de cada especie se evaluó usando un índice de importancia relativa (IIR que incluyó el número, peso y frecuencia de ocurrencia de los items consumidos. Para estimar la amplitud y sobreposición interespecífica de dieta se emplearon los índices de Levín (Bi y Morisita (IM, respectivamente. Todas las estimaciones se realizaron con la frecuencia numérica de las presas consumidas. Se capturaron nueve especies, ocho Characiformes, tres en SA (Knodus deuteronoides, Creagrutus bolivari y C. melasma y cinco en SB (Thoracocharax stellatus, Moenkhausia lepidura, Cheirodon pulcher, Ctenobrycon spilurus y Aphyocharax alburnus y un Cyprinodontiformes (Poecilia reticulata, capturada en SA. En SA el principal recurso consumido fueron insectos acuáticos mientras que el material vegetal y los artrópodos terrestres fueron recursos secundarios. En SB, las especies consumieron estos items además de zooplancton (Copepoda, Cladocera y estadios larvales de crustáceos Decapoda, pero hubo una sustitución temporal con un predominio de zooplancton en descenso y aguas bajas. En general, la amplitud de la dieta disminuyó en descenso de aguas en ambas secciones e incrementó en ascenso de aguas. Sin embargo, la amplitud promedio fue mayor en SA. La sobreposición interespecífica de dieta fue alta en SA mientras que

  5. Selectividad del zooplancton y solapamiento trófico entre tallas del pez Menidia humboldtiana (Atheriniformes: Atherinopsidae en el embalse Danxhó, México

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    Regina Sánchez Merino

    2009-06-01

    Full Text Available El charal Menidia humboldtiana es considerado como una de las especies de gran importancia en la industria pesquera de algunos estados de México. Es necesario conocer el efecto que esta especie ejerce sobre su alimento para saber si seleccionan las presas de mayor talla, si hay competencia por el alimento entre especies nativas e introducidas, y para comprender el comportamiento del zooplancton ante peces zooplanctófagos. Se determinó si M. humboldtiana selecciona su alimento, sobre qué géneros lo hace, y si existe traslape en la dieta entre las diferentes tallas. Los peces se recolectaron por medio de un chinchorro de 88 mm de abertura de malla, en seis estaciones de muestreo durante un año, en el embalse Danxhó, y una muestra de zooplancton fue recolectada por filtrado con una red de 125 µm. El análisis de los contenidos estomacales se realizó en peces agrupados en intervalos de longitud estándar para cada época del año, por medio del método volumétrico. Para evaluar el traslape trófico entre los diferentes intervalos de longitud, se utilizó el índice de Morisita modificado por Horn. El zooplancton estuvo representado por doce géneros: Mastigodiaptomus y Cyclops (Copepoda; Bosmina, Diaphanosoma, Daphnia, Ceriodaphnia, Moina, Alonopsis y Camptocercus (Cladocera; Asplanchna, Conochillus y Filinia (Rotifera. Durante la primavera, los charales de 3-8.9 cm presentaron un marcado traslape, para el verano fueron los grandes (7-10.9 cm, en otoño el traslape fue en todas las tallas, y en invierno solo las tallas intermedias (5-8.9 cm lo presentaron.Selectivity of zooplankton and trophic overlap between size Menidia humboldtiana fish (Atheriniformes: Atherinopsidae in the reservoir Danxhó, Mexico. The Menidia humboldtiana silverside is considered one of the most important species in fisheries in some states of Mexico. Knowing the choice that this species exercises over its food gives us an understanding of the behavior of

  6. Kelimpahan dan Keanekaragaman Plankton di Perairan Selat Bali (Plankton Abundance and Diversity in the Bali Strait

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    Ruly Isfatul Khasanah

    2013-12-01

    Full Text Available Fitoplankton mempunyai peran sangat penting dalam suatu perairan, selain berada pada dasar rantai makanan sedangkan zooplankton merupakan herbivor pemangsanya. Penelitian mengenai kelimpahan dan keanekaragaman plankton di perairan Selat Bali dilakukan pada musim peralihan II (Nopember 2012 dan musim barat (Pebruari 2013. Penelitian bertujuan untuk mengamati perbedaan kelimpahan dan keanekaragaman plankton pada dua musim angin muson. Sampel air diambil dengan menggunakan water sampler sedangkan sampel plankton diambil secara horisontal dan vertikal  pada kedalaman 1 m dan 20 m dengan jaring plankton Kitahara bermata jaring 20 µm. Hasil pengukuran nutrien pada musim peralihan II memiliki kadar fosfat, nitrat, bahan organik, silikat dan klorofil-a lebih tinggi dibandingkan pada musim barat. Informasi tersebut memperkuat indikasi adanya perpindahan massa air dari lapisan yang lebih dalam ke lapisan yang lebih dangkal. Nutrien fosfat dan nitrat diperlukan untuk mempertahankan fungsi membran sel dan silikia dibutuhkan untuk pembentukan dinding sel terutama pada diatom. Hasil penelitian juga menunjukkan bahwa kelas diatom (Bacillariophyceae mencapai 95,9 % dari total jenis dan kelimpahan fitoplankton seluruh stasiun penelitian, sisanya berasal dari genus Dinophyceae. Kelimpahan fitoplankton tertinggi terjadi pada musim peralihan II dengan Rhizosolenia stolterfothii sebesar 51.405 sel.L-1 (80,1%, sedangkan pada musim barat copepoda ditemukan melimpah sebesar 8.178 ind.L-1 (88,3 %. Hasil ini mengindikasikan bahwa dengan kelimpahan plankton yang ditemukan perairan Selat Bali dinilai cukup potensial untuk mendukung kehidupan biota laut pelagis. Kata kunci: plankton, selat Bali, rhizosolenia stolterfothii, muson   Abstract Phytoplankton has important role as primary producer in the sea and act as base of food chain while zooplankton act as herbivore prey on them. Research on abundance and diversity of plankton at Bali Strait was performed during

  7. Feeding of a pelagic chaetognath, Sagitta friderici Ritter-Záhony off Ubatuba region (São Paulo, Brazil

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    Luz Amelia Vega-Pérez

    1992-01-01

    Full Text Available The diet of Sagitta friderici off Ubatuba region, São Paulo State, was studied in March, 1989. Specimens were collected with a closing-net during three days at six hours' intervals (00:00; 06:00; 12:00; 18:00 h, at a fixed station of 38 m depth. The population was composed basically by young stages (O-II. A total of 3175 specimens were examined but only 760 contained preys in their guts. Copepods were the main constituent of food eaten (79.86%. There was a preference for the genera Paracalanus, Oncaea, Corycaeus and for crustacean nauplii. Other zooplanktonic groups such as Annelida, Urochordatha, and Mollusca were also found in the gut. Cannibalistic behavior occurred in 2.66% of the samples. In S. friderici the food was selected by size and was a direct function of the predator size. Younger stages (O-I selected small prey, whereas older stages (II preferred larger preys. Specimens collected above the thermocline exhibited higher feeding intensity (FCR during the night periods.Espécimens de Sagitta friderici foram coletados numa estação fixa de 38 m de profundidade, ao largo de Ubatuba, Estado de São Paulo, em março de 1989. Arrastos verticais, acima e abaixo da termoclina, foram feitos com rede de fechamento (50 cm de diâmetro de boca e malha de 0.200 mm durante três dias consecutivos e em intervalos de seis horas. O estudo de 3175 indivíduos, nos estágios de O-IV, revelou que 2415 apresentaram o trato digestivo vazio e 760 com algum tipo de alimento. Destes últimos, 283 continham material amorfo e os 473 restantes de 1 a 3 presas. Das 488 presas identificadas, 99,74% estavam localizadas na região posterior do trato digestivo e 0,26% na região anterior. A dieta de S. friderici esteve constituída de Crustácea, Annelida, Urochordata, Chaetognatha e Mollusca. Dentre os Crustácea, os Copepoda foram os mais abundantes, predominando os Calanoida e Cyclopoida. O estágio 0 de S. friderici teve preferência pelos náuplios de crust

  8. Composition, abundance and distribution of macrozooplankton in Culebra Bay, Gulf of Papagayo, Pacific coast of Costa Rica and its value as bioindicator of pollution

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    Melinda Bednarski

    2004-12-01

    Full Text Available The abundance, distribution and composition of the macrozooplankton of Culebra Bay, Costa Rica (10º 38’ N - 85º 40’ W were studied at four stations throughout the dry (February - May and rainy (September - November seasons of 2000. The samples were collected at two-week intervals using a 500µm mesh net with a 0.5 m diameter opening. Copepods (23-31% and ostracods (20-34% were predominant throughout the year, followed by cladocerans (2.5-14%, zoea (6.6-9.5%, and siphonophores (2.5-7.2%. High densities of zooplankton were obtained in February and March with peak abundance on March 18. The lowest densities were observed on September 3 and November 5. Significant differences in abundances at each station were observed for the groups Acartia tonsa (Copepoda, Ctenophora, Medusae, Ostracoda, Zoea, and Amphipoda. Comparison of the dry and rainy seasons revealed significantly higher zooplankton abundance in the dry season and copepod domination of all stations; during the rainy season ostracods dominated the off-shore areas. Zooplankton abundance and distribution are influenced by upwelling, which occurs during the dry season in Culebra BayLa abundancia, distribución y composición del macrozooplancton fue estudiada en bahía Culebra Costa Rica (10º 38’ N and 85º 40’ W en cuatro estaciones durante la época seca (Febrero-Mayo y lluviosa (Setiembre - Noviembre del año 2000. Las muestras fueron colectadas en intervalos de dos semanas usando una red de 500µm de poro y 0.50-m de diámetro. Copépodos (23-31% y ostrácodos (20-34% fueron predominantes através del año, seguidos por los cladóceros (2.5-14%, zoea (6.6-9.5%, y sifonóforos (2.5-7.2%. Altas densidades de zooplancton fueron obtenidas en Febrero y Marzo, con un pico el 18 de Marzo. Las más bajas densidades fueron observadas el 3 de Septiembre y 5 de Noviembre. Se observaron diferencias significativas en las abundancias en cada estación para los copépodos de la especie Acartia

  9. Composición, estructura y flujo energético del meiobentos frente a Chile central Composition, structure and energy flux of the meiobenthos off central Chile

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    JAVIER SELLANES

    2003-09-01

    Full Text Available Se estudió la estructura de la meiofauna metazoaria (a nivel de grandes grupos taxonómicos y su rol en el flujo de energía en el subsistema bentónico frente a Concepción (~3630' S. Las muestras se recolectaron en mayo y noviembre de 1997 y mayo de 1998 en cinco sitios correspondientes a: interior de la Bahía de Concepción (28 m, boca de la bahía (35 m, plataforma interior (64 m, plataforma intermedia (88 m y plataforma externa (120 m. El periodo de estudio coincidió con el evento El Niño 1997-1998 (EN. El meiobentos resultó ser poco diverso a nivel de grandes grupos, pero con abundancias y biomasas moderadas a altas, en comparación con los valores promedio reportados en la literatura para el sublitoral fangoso. Nematoda fue el grupo dominante, con más de un 95 % (10³­10(4 ind 10 cm­2 de la densidad total, seguidos por Copepoda y Polychaeta. Las mayores abundancias y biomasas totales se encontraron siempre en la boca de la bahía, seguida de su parte interior y de la plataforma interior, mientras que los menores valores se ubicaron en la plataforma intermedia y externa. Frente a Concepción el meiobentos juega un importante rol en el flujo de energía a través del subsistema bentónico. Se estimó que estos organismos podrían estar remineralizando y/o convirtiendo a biomasa hasta un 36 y 45 % del carbono orgánico que llega desde la columna de agua a los sedimentos en el centro y en la boca de la bahía, respectivamente.The general objective of this study was to determine the structure of metazoan meiofauna (at a high taxonomic level and to estimate its role in the energy flux of the benthic sub-system off Concepción, Chile (~3630' S. Samples were collected in May and November 1997 and May 1998 at five sites located at the: inner Bay of Concepción (28 m, bay-mouth (35 m, inner-shelf (64 m, mid-shelf (88 m and outer-shelf (120 m. The study period coincided with the El Niño 1997-1998 (EN event. The diversity of the meiobenthos

  10. Effects of liming and development of Curimbatá (Prochilodus lineatus larvae on the abundance of zooplankton in fish ponds Efeitos da calagem e desenvolvimento do Curimbatá (Prochilodus lineatus na abundância do zooplâncton em viveiros de piscicultura

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    Thécia Alfenas Silva Valente Paes

    2011-12-01

    Full Text Available AIM: We aimed to evaluate the influence of the correction of the water alkalinity in the fish ponds on the density of zooplankton under a period they were stocked with larvae of Prochilodus lineatus, a neotropical fish called "Curimbatá". METHODS: We used a factorial design completely randomized. In one plot (2 ponds there was no correction of the alkalinity of the water (20 mg CaCO3.L-1 and in two others, this variable was adjusted weekly to values around 30 and 60 mg CaCO3.L-1 ¹, with two replicates each. Zooplankton was sampled weekly and the experiment lasted 63 days. RESULTS: Significant differences in the density of the zooplankton over time (F = 6.78, p OBJETIVO: Nosso objetivo foi avaliar a influencia da correção da alcalinidade da água em viveiros de piscicultura na densidade do zooplâncton em período em que foram estocados com larvas de Prochilodus lineatus, um peixe neotropical denominado "Curimbatá". MÉTODOS: Foi utilizado um delineamento experimental fatorial, inteiramente causualizado. Em um tratamento (2 viveiros, não houve correção da alcalinidade da água, e em outros dois viveiros, a alcalinidade foi ajustada semanalmente para valores em torno de 30 e 60 mg CaCO3.L-1, com duas réplicas cada. Os organismos zooplanctônicos foram coletados semanalmente durante 63 dias. RESULTADOS: Diferenças significativas foram observadas na densidade do zooplâncton ao longo do tempo (F = 6,78, p < 0,05 e um decréscimo acentuado na densidade do zooplâncton foi observado da primeira para a segunda semana, e pequenos aumentos sucessivos na densidade da quarta semana até o final do experimento. Ao considerar todo o período experimental, a alcalinidade corrigida para 60 mg CaCO3.L-1 resultou em maiores densidades de zooplâncton. Ocorreram grandes mudanças na composição zooplanctônica. Rotifera foram dominantes no início do experimento e Cladocera e Copepoda nas últimas semanas, possivelmente devido a uma interação da

  11. The temporal dynamics of zooplankton communities of different types of water bodies within Ichniansky National Park

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    Z. V. Burian

    2017-05-01

    Full Text Available In recent decades, the influence of anthropogenic impact on aquatic ecosystems has increased. This has led to a restructuring of aquatic ecosystems and affected the structural and functional organization of groups of aquatic organisms, causing qualitative and quantitative changes. Particular attention is drawn to the different types of water bodies of protected areas like IchnyanskyNational Park, which is located in Ichnyansky district of Chernihiv region. This park is a newly created one, so the reduction in intensity of anthropogenic pressure can be traced within its waters. Zooplankton plays an important role in the functioning of trophic networks because it transfers energy from producers and primary consumers to young fish and planktonophagous fish. Therefore, three main groups of zooplankton were chosen as the object of study: rotifers (class Eurotatoria, cladocerans (class Branchiopoda, order Cladocera, different age stages of copepods (class Copepoda, and also ostracods (Class Ostracoda. The zooplankton used as research material was collected in the daytime in spring (April, summer (late July – early August and autumn (late September – early October in the years 2015–2016 from ten experimental stations. During this period 81 species of zooplankton were recorded within heterogeneous reservoirs of IchnianskyNational Park. Monogonont rotifers (subclass Monogononta included 35 species (43% of all species and bdelloid rotifers (subclass Bdelloidea, cladocerns, comprised 28 species (35%, and copepods included 18 species (22%. The faunal range of zooplankton over different years and seasons was characterized by the predominance of the rotator complex in spring, rotator-cladocerans and cladocerans in summer, and of the cladocerans complex in autumn. This was due to the formation during spring and summer of favourable conditions in the waters for filter feeders, which consist generally of rotifers and cladocerans. In autumn the water

  12. Estructura trófica de la asociación de peces intermareales de la costa rocosa del norte de Chile

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    C. Viviana Berrios

    2004-03-01

    , preying mainly on chlorophitic algae, Copepoda and Gastropoda. The carnivorous fishes Cheilodactylus variegatus, Helcogrammoides chilensis, Labrisomus philippii and the omnivorous Oplegnatus insignis showed euriphagic tendencies (>2.0 bits, however, the major trophic overlap (>0.90 was observed among herbivorous and omnivorous fishes. Finally, the increase of fish species towards lower latitudes and the increase of herbivory and omnivory levels in the rocky intertidal shore were analyzed

  13. Characterization of biocenosis in the storage-reservoirs of liquid radioactive wastes of 'Mayak' PA

    Energy Technology Data Exchange (ETDEWEB)

    Pryakhin, E.; Tryapitsina, G.; Andreyev, S.; Akleyev, A. [Urals Research Center for Radiation Medicine - URCRM (Russian Federation); Mokrov, Y.; Ivanov, I. [Mayak PA (Russian Federation)

    2014-07-01

    A number of storage-reservoirs of liquid radioactive wastes of 'Mayak' Production Association ('Mayak' PA) with different levels of radioactive contamination: reservoir R-17 ('Staroye Boloto'), reservoir R-9 (Lake Karachay), reservoirs of the Techa Cascade R-3 (Koksharov pond), R-4 (Metlinsky pond), R-10 and R-11 is located in Chelyabinsk Oblast (Russia). The operation of these reservoirs began in 1949-1964. Full-scale hydro-biological studies of these reservoirs were started in 2007. The research into the status of biocenosis of these storage reservoirs of liquid radioactive wastes of 'Mayak' PA was performed in 2007 - 2011. The status of biocenosis was evaluated in accordance with the status of following communities: bacterio-plankton, phytoplankton, zooplankton, zoo-benthos, macrophytes and ichthyofauna. The status of ecosystems was determined by radioactive and chemical contamination of water bodies. The results of hydro-biological investigations showed that no changes in the status of biota in reservoir R-11 were revealed as compared to the biological parameters of the water bodies of this geographical zone. In terms of biological parameters the status of the ecosystem of the reservoir R-11 is characterized by a sufficient biological diversity, and can be considered acceptable. The ecosystem of the reservoir R-10 maintains its functional integrity, although there were registered negative effects in the zoo-benthos community associated with the decrease in the parameters of the development of pelophylic mollusks that live at the bottom of the water body throughout the entire life cycle. In reservoir R-4 the parameters of the development of phytoplankton did not differ from those in Reservoirs R-11 and R-10; however, a significant reduction in the quantity of Cladocera and Copepoda was registered in the zooplankton community, while in the zoo-benthos there were no small mollusks that live aground throughout the entire life

  14. An Overview of Ecological Processes in the Rio de la Plata Estuary

    Science.gov (United States)

    Acha, M.; Mianzan, H.

    2005-05-01

    The Rio de la Plata, one of the most important estuarine environments in South America, is characterized by a salt-wedge regime. Large extension and shallow water depth make the estuary highly susceptible to atmospheric forcing. The estuary is a highly productive area, which sustain important artisanal and coastal fisheries in Uruguay and Argentina, mainly based on the whitemouth croaker, Micropogonias furnieri. The main goal of this paper is to summarize recent knowledge on this system, integrating physical, chemical and biological studies. This estuary is characterized by strong vertical salinity stratification, with marine waters (saltier and denser) penetrating deeper into the estuary along the bottom, while fresh waters advance ocean-ward on the surface, forming a salt wedge. The upstream reach of the salt wedge defines a bottom salinity fronts, whose location is controlled by the topography, a submerged shoal called Barra del Indio and at the opposite area, the convergence between the estuarine and marine waters define a surface salinity front. The convergence of water masses and the strong picnoclines at the head of the salt wedge produce the accumulation and retention of plankton, including the eggs of those fishes that concentrate here to spawn (e.g. Micropogonias furnieri and Brevoortia aurea) and even debris. High turbidity constrains here photosynthetic production and food chains are probably detritus based, supporting high densities of Acartia tonsa (Copepoda) and Neomysis americana (Mysid), both omnivorous species that complete its entire life-cycle within the estuary. In agreement, heterotophic microzooplankton is abundant. Moreover, high deposition of suspended matter support dense beds of the deposit feeding clams Mactra isabelleana. As soon as the water become less turbid, an extremely high chlorophyll signal is observed. The largest portion of the salt wedge regime (more than 200 km) is characterized by dense plankton aggregations below the

  15. The spider family Micropholcommatidae (Arachnida: Araneae: Araneoidea: a relimitation and revision at the generic level

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    Michael Rix

    2010-02-01

    .; the 20 previously described species of Textricella are thus transferred into Eterosonycha or other newly described genera. The Textricellini includes 10 genera from Australasia and Chile: Eterosonycha has four species, including the type E. alpina Butler (=Textricella parva Hickman syn. n., E. complexa (Forster, E. aquilina sp. n. and E. ocellata sp. n.; Epigastrina gen. n. has three species, including the type E. fulva (Hickman, E. loongana sp. n. and E. typhlops sp. n.; Guiniella gen. n. is monotypic, with G. tropica (Forster; Raveniella gen. n. has three species, including the type R. luteola (Hickman, R. hickmani (Forster and R. peckorum sp. n.; Rayforstia gen. n. has 12 species, including the type R. vulgaris (Forster, the two new species R. lordhowensis sp. n. and R. raveni sp. n., and the nine additional species R. antipoda (Forster, R. insula (Forster, R. mcfarlanei (Forster, R. plebeia (Forster, R. propinqua (Forster, R. salmoni (Forster, R. scuta (Forster, R. signata (Forster and R. wisei (Forster; Normplatnicka gen. n. has three species, including the type N. lamingtonensis (Forster, N. chilensis sp. n. and N. barrettae sp. n.; Eperiella gen. n. has two species, including the type E. alsophila sp. n., and E. hastings sp. n.; Algidiella gen. n. is monotypic, with A. aucklandica (Forster; Taliniella gen. n. has two species, including the type T. nigra (Forster, and T. vinki sp. n.; and Tinytrella gen. n. is monotypic, with T. pusilla (Forster. The micropholcommatine tribe Patelliellini trib. n. includes only one monotypic genus, Patelliella gen. n., represented by the enigmatic species Patelliella adusta sp. n. from Lord Howe Island. The subfamily Taphiassinae subfam. n. includes two genera of distinctive, heavily punctate Micropholcommatidae from Australasia: Taphiassa Simon has six species, including the type T. impressa Simon, T. punctata (Forster, T. castanea sp. n., T. globosa sp. n., T. magna sp. n. and T. robertsi sp. n.; the genus Parapua Forster

  16. Influence of net-cage fish farming on zooplankton biomass in the Itá reservoir, SC, Brazil Influência da piscicultura em tanque-rede sobre a biomassa do zooplâncton no reservatório de Itá, SC, Brasil

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    Bruna Roque Loureiro

    2011-12-01

    Full Text Available OBJECTIVES: This study aimed to verify the influence of net-cage fish farming on zooplankton biomass in the Itá reservoir (Uruguay River, Brazil. METHODS: Samples were collected monthly from October/2009 to May/2010 at the surface and at the bottom in two sampling stations, the net-cage area and in a control area using a Van Dorn bottle and a plankton net (68 µm. RESULTS: The Cladocera and Copepoda biomass was estimated by dry weight using a micro-analytical balance, and the Rotifera biomass by Biovolume. Total zooplankton biomass varied between 6.47 and 131.56 mgDW.m-3 Calanoida copepod presented the highest value of biomass (127.56 mgDW.m-3 and rotifers, despite having an important contribution to total density, showed a maximum biomass of 2.01 mgDW.m-3. Zooplankton biomass at the net-cage area surface was higher when compared with the control area during the months of October to January. However, the zooplankton biomass was similar at the bottom of the two areas throughout the studied period. From February until May, zooplankton biomass decreased in both sampling stations, a fact probably associated with the flushing of the reservoir, followed by an increase in water transparency and a decrease in chlorophyll-a concentration in the following months (February to May. CONCLUSIONS: The influence of fish farming on zooplankton biomass was detected at the surface of the net-cage area only from October to January. From February to May this influence was not found, probably by the influence of the flushing of the reservoir.OBJETIVO: Este estudo teve o objetivo de verificar a influencia da piscicultura em tanque-rede sobre a biomassa da comunidade zooplanctônica no reservatório de Itá (Rio Uruguai, Brasil. METODOLOGIA: Foram realizadas coletas mensais de outubro/2009 a maio/2010 na superfície e no fundo em dois pontos amostrais, ponto tanque-rede e em uma área controle, com o auxílio da garrafa Van Dorn e rede de plâncton (68 µm. RESULTADOS

  17. Distribuição geográfica da fauna e flora da Baía de Guanabara Geographic distribution of the flora and the fauna of the Guanabara Bay

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    Lejeune P. H. de Oliveira

    1947-09-01

    regime is Ceratiumplancton. POLYHALINE WATER REGIMB — Water almost sea water, but directly influenced by continental lands, with rock salts dissolved and in suspension. Salinity: 33 to 32/1.000. This waters endure the actions of the popular nicknamed «water of the hill» (as the waters of mesohaline and oligohaline regimes, becoming suddenly reddish during several hours. That pheno¬menon returns several times in the year and come with great mortality of fishes. In these waters, according to Dr. J. G. FARIA there are species of Protozoa : Peridinea, the Glenoidinium trochoideum St., followed by its satellites which he thinks that they are able to secret toxical substances which can slaughter some species of fishes. In these «waters of the hill» was found a species of Copepoda the Charlesia darwini. In August 1946 the west shore of the Guanabara was plenty of killed fishes occupying a area of 8 feet large by 3 nautical miles of lenght. The enclosure for catching fishes in the rivers mouthes presents in these periods mass dead fishes. The phenomenon of «waters of the hill» appears with the first rains after a period of long dryness. MESOHALINE WATER REGIME — Fig. 4 shows the the diagramm scheme. Salt or brackish water from 30 to 17/1.000 salinity, sometimes until 10/1.000. Turbid waters with mud in suspension, chestnut, claveyous waters; shore dirty black mud without waving bursting; the waters are warmer and shorner than those of the polihaline regime. Mangrove shore with the mangrove trees : Rhizophora mangle L., Avicennia sp., Laguncularia sp., and the »cotton tree of sea» Hibiscus sp. Fauna: the great land crab «guaimú» Cardisoma guanhumi Latr., ashore in dry firm land. There is the real land crab Ucides cordatus (L. in wetting mud and in neigh¬ bourhood of the burrows of the fiddler-crabs of genus Uca. On stones and in the roots of the Rhizophora inhabits the brightly colored mangrove-tree-crab («aratu» Portuguese nickname Goniopsis cruentata

  18. Plancto e hidrobiologia sanitária de tanques tropicais com dáfnias e rotíferos

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    Lejeune P. H. de Oliveira

    1967-01-01

    phases is merely to satisfy an easy explanation thus the first phase that of exudation of concrete. We consider the 2nd. phase formation of bacterian and cyanophycean thin pellicel. 3rd. phase - dilution by rains, and fertilisation by birds; the 4th phase - plankton flora and fauna established. The biological material arrived with the air, the rains, and also with contaminations by dusts; with big portion of sand, of earth, and leaves of trees resulted of the SW wind actions in the storming days (See - Est. I, fig. 3, G. - the mangrove trees of the Pinheiro Island. Many birds set down and rest upon the pillar structure, its faeces which are good fertilizers fall into the ponds. Some birds were commonly pigeons, black ravens, swallows, sparrows and other sea mews, moor hens, and a few sea birds of comparatively rare occurence. We get only some examples of tropical dust contaminated helioplankton, of which incipient observations were been done sparcely. See the systematic list of the species of plankters. Phytoplankters - Cyanophyta algae as a basic part for food of zooplankters, represented chiefly by rotiferse, water-fleas Moinodaphnia and other Crustacea: Ostracoda Copepoda and Insecta: Chironomidae and Culicidae larvae. The polysaprobic of septic irruptions have not been done only by heating in summer, and, a good reason of that, for example: when the fifth pond was in polysaprobic phase as the same time an alike septic phase do not happened into the 3rd. pond, therefore, both were in the same conditions of temperature, but with unlike contaminations. Among the most important aquatic organisms used as indicatiors of pollution - and microorganisms of real importance in the field of sanitary science, by authorities of renown, for instance: PALMER, PRESCOTT, INGRAM, LIEBMANN, we choose following microalgae: a The cosmopolite algae Scenedesmus quadricuada, a common indicator in mesosaprobio waters, which lives between pH 7,0 and it is assimilative of NO[3 subscripted] and