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Sample records for bdelloidea rotifera syndermata

  1. EST based phylogenomics of Syndermata questions monophyly of Eurotatoria

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    Bucher Gregor

    2008-12-01

    Full Text Available Abstract Background The metazoan taxon Syndermata comprising Rotifera (in the classical sense of Monogononta+Bdelloidea+Seisonidea and Acanthocephala has raised several hypotheses connected to the phylogeny of these animal groups and the included subtaxa. While the monophyletic origin of Syndermata and Acanthocephala is well established based on morphological and molecular data, the phylogenetic position of Syndermata within Spiralia, the monophyletic origin of Monogononta, Bdelloidea, and Seisonidea and the acanthocephalan sister group are still a matter of debate. The comparison of the alternative hypotheses suggests that testing the phylogenetic validity of Eurotatoria (Monogononta+Bdelloidea is the key to unravel the phylogenetic relations within Syndermata. The syndermatan phylogeny in turn is a prerequisite for reconstructing the evolution of the acanthocephalan endoparasitism. Results Here we present our results from a phylogenomic approach studying i the phylogenetic position of Syndermata within Spiralia, ii the monophyletic origin of monogononts and bdelloids and iii the phylogenetic relations of the latter two taxa to acanthocephalans. For this analysis we have generated EST libraries of Pomphorhynchus laevis, Echinorhynchus truttae (Acanthocephala and Brachionus plicatilis (Monogononta. By extending these data with database entries of B. plicatilis, Philodina roseola (Bdelloidea and 25 additional metazoan species, we conducted phylogenetic reconstructions based on 79 ribosomal proteins using maximum likelihood and bayesian approaches. Our findings suggest that the phylogenetic position of Syndermata within Spiralia is close to Platyhelminthes, that Eurotatoria are not monophyletic and that bdelloids are more closely related to acanthocephalans than monogononts. Conclusion Mapping morphological character evolution onto molecular phylogeny suggests the (partial or complete reduction of the corona and the emergence of a retractable

  2. TAXAS DE FILTRAÇÃO E INGESTÃO DE UMA MICROALGA POR Philodina roseola (Rotifera: Bdelloidea

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    Raquel Aparecida Moreira

    2016-04-01

    Full Text Available RESUMORotíferos possuem um importante papel nos ciclos biogeoquímicos e na produtividade orgânica dos ecossistemas de água doce em decorrência de suas elevadas taxas metabólicas. Informações sobre a filtração, seu principal processo de aquisição de energia, são relevantes e ainda escassos para a região tropical. Os rotíferos da Subclasse Bdelloidea alimentam-se por filtração ou raspagem consumindo pequenos itens alimentares, como bactérias, algas, leveduras ou matéria orgânica particulada. Sabemos pouco sobre o papel que desempenham na dinâmica trófica dos habitats que ocupam e por isso o objetivo deste estudo foi quantificar em laboratório as taxas de filtração e ingestão do rotífero Philodina roseola, alimentado com Raphidocelis subcapitata. O delineamento experimental consistiu na exposição de 10 rotíferos adultos por tratamento, em cinco concentrações que variaram entre 104 e 107 cels mL-1, mantidos sob temperatura de 25 ± 1 °C. Os experimentos tiveram a duração de 1 hora e as concentrações iniciais e finais da suspensão algal foram quantificadas por contagem numérica das células em câmara de Neubauer. Não foram encontradas diferenças significativas entre as concentrações iniciais e finais de células nos controles indicando não ter ocorrido crescimento algal. As taxas de filtração de P. roseola variaram entre 0,09 e 0,25 mL ind-1 h-1. Tendo em vista que a filtração é o principal processo de aquisição de energia de Philodina roseola, assim como dos demais rotíferos, e que está relacionada a questões importantes da dinâmica trófica dos ecossistemas aquáticos, informações adicionais são desejáveis mas necessitam, no entanto, ser ampliadas para outros tipos de alimento e para diferentes combinações de condições experimentais.Rates of Filtration and Ingestion of a Microalga by Philodina roseola (Rotifera: BdelloideaABSTRACTRotifers play an important role in biogeochemical cycles

  3. How does the 'ancient' asexual Philodina roseola (Rotifera : Bdelloidea) handle potential UVB-induced mutations?

    NARCIS (Netherlands)

    Fischer, Claus; Ahlrichs, Wilko H.; Buma, Anita G. J.; van de Poll, Willem H.; Bininda-Emonds, Olaf R. P.

    2013-01-01

    Like other obligate asexuals, bdelloid rotifers are expected to suffer from degradation of their genomes through processes including the accumulation of deleterious mutations. However, sequence-based analyses in this regard remain inconclusive. Instead of looking for historical footprints of mutatio

  4. Life cycle traits of Philodina roseola Ehrenberg, 1830 (Rotifera, Bdelloidea), a model organism for bioassays.

    Science.gov (United States)

    Moreira, Raquel A; Mansano, Adrislaine S; Rocha, Odete

    2016-01-01

    This paper describes experimental results on the life cycle of the rotifer Philodina roseola cultured in the laboratory. Detailed information on life-cycle parameters of a certain species provides a deep understanding and contributes to a better knowledge of the role of the species in the community, besides providing data that are basic to other ecological investigations such as secondary production estimates and knowledge for applications such as its utilization as test-organism in ecotoxicological studies. The average duration of embryonic development of P. roseola was 23.88 h, the age at maturity of primipara was 3.5 days and the maximum lifespan was 23 days. The average size of the rotifer neonate was 198.77 µm, the mean size of primipara was 395.56 µm and for adults 429.96 µm. The average fecundity was 1.22 eggs per female per day and the mean number of eggs produced per female during the entire life was 22.33. The deceleration of somatic growth from the start of the reproductive stage represents a trade-off between growth and reproduction that is often seen in micrometazoans. The life history of P. roseola follows the strategy of other bdelloid species characterized by a rapid pre-reproductive development and canalization of most assimilated energy to reproduction after reaching maturity. The differences observed in total fecundity and longevity between our P. roseola cultures and those from previous studies were probably due to differences of intrinsic adaptation of this species ecotypes to the conditions of their natural environments. PMID:27168371

  5. Effect of the lecanidae rotifera on the floc size in an activated sludge system; Efecto de rotiferos lecanidos en el tamano de los floculos de un sistema de fangos activos

    Energy Technology Data Exchange (ETDEWEB)

    Puigagut, J.; Salvado, H.; Tarrats, X.; Garcia, J.

    2008-07-01

    An activated sludge pilot plant was monitored for 5 months in order to determine the effect of the lecanidae rotifera on both the floc size and the nitrogen removal. Results show that rotifera abundances above 400 individuals/ml{sup -}1 produce a reduction of ca. 50% of the floc average surface. This floc area reduction had, in turn, a great significance on the nitrogen removal efficiency, either in terms of ammonia or nitrates. (Author) 20 refs.

  6. New records of rotifers (Rotifera: Eurotatoria from Deepor Beel - a Ramsar site of India with an update on its rich rotifer diversity.

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    B.K. Sharma

    2015-03-01

    Full Text Available Plankton samples collected from Deepor Beel (a Ramsar site, during July 2011 to June 2013, revealed 155 species of Rotifera, belonging to 35 genera and 20 families.  Of these, 16 species belonging to eight genera and seven families are new records to the rotifer fauna of this wetland of northeast India.  Our observations raise the total richness of the phylum known till date from this important floodplain lake (beel of the Brahmaputra river basin to 171 species and thus highlight its biodiversity value as one of the globally rich Rotifera habitats.  The updated list is interesting for following meta-analyses of rotifer occurrence in this only well sampled freshwater ecosystem of the Indian sub-region. 

  7. Rotifer assemblages (Rotifera: Eurotatoria of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India

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    Bhushan Kumar Sharma

    2014-12-01

    Full Text Available Our plankton and semi-plankton collections from twelve floodplain lakes (beels of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families; these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of  genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region.  Eleven species are new to the study area and we provide an updated list (144 species for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12 species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide Sørensen’s index, more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters.

  8. Catalogue of type specimens of invertebrates in the collection of the Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil: I. Acanthocephala, Nematoda, and Rotifera Catálogo dos espécimes-tipo de invertebrados da coleção do Instituto Nacional de Pesquisas da Amazônia, Manaus, Brasil: I. Acanthocephala, Nematoda e Rotifera

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    Célio Magalhães

    2006-09-01

    Full Text Available The catalogue of type specimens of the phyla Acanthocephala, Nematoda and Rotifera deposited in the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Brazil, is presented and updated to July, 2005. A total of three holotypes and six lots of paratypes of three species of Acanthocephala; nine holotypes and 16 lots of paratypes of nine species of Nematoda; and 12 holotypes, six lectotypes, nine lots of paratypes and five lots of paralectotypes of 23 species and subspecies of Rotifera are listed. Specific and subspecific names are listed alphabetically within family, followed by bibliographic citation, original genus name, status of type, collection number, locality data (host and site of infection for parasitic species, and remarks where appropriate. A list of references containing the papers in which the taxa were first described is furnished.É apresentado o catálogo dos espécimes-tipo dos filos Acanthocephala, Nematoda e Rotifera depositados na Coleção de Invertebrados do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Brasil, atualizado até julho de 2005. É relacionado um total de três holótipos e seis lotes de parátipos de três espécies de Acanthocephala; nove holótipos e 16 lotes de parátipos de nove espécies de Nematoda; e 12 holótipos, seis lectótipos, nove lotes de parátipos e cinco lotes de paralectótipos de 23 espécies e subespécies de Rotifera. São listados alfabeticamente em cada família os nomes das espécies e subespécies, seguidos da citação bibliográfica, nome original do gênero, categoria do tipo, número de registro na coleção, dados de localidade (hospedeiro e sítio de infecção no caso de espécies parasitas e comentários quando pertinentes. São relacionados, na lista de referências, os artigos nos quais a descrição original dos táxons foi publicada.

  9. Cladocers, Copepods and Rotifers in rice-fish culture handled with metsulfuron-methyl and azimsulfuron herbicides and carbofuran insecticide Cladocera, Copepoda e Rotifera em rizipiscicultura tratada com os herbicidas metsulfuron-metílico e azimsulfuron e o inseticida carbofuran

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    Jaqueline Ineu Golombieski

    2008-11-01

    Full Text Available This study determined the effects of metsulfuron-methyl, azimsulfuron and carbofuran in communities: Cladocers, Copepods and Rotifers that are present in irrigated rice farming with the rice-fish system. The field experiment was conducted in the 2004/05 growing season with eight treatments. The fish species were: Cyprinus carpio, Ctenopharyngodon idella and Aristichthys nobilis, introduced seven days after treatments were applied. Water samples were collected 17 days before and 1st, 3rd, 10th, 18th, 31th, 51th, and 75th days after the agrochemicals were applied for identification and evaluation of the zooplankton. The results indicated that the herbicides did not affect the zooplankton community studied and carbofuran insecticide application provoked negative effects in Cladocers. Copepods and Rotifers were slightly affected by carbofuran.O presente estudo determinou o efeito de metsulfuron-metílico, azimsulfuron e carbofuran nas comunidades: Cladocera, Copepoda e Rotifera presentes em lavouras de arroz irrigado com o sistema de rizipiscicultura. O experimento foi conduzido durante a safra agrícola 2004/05 com oito tratamentos. As espécies de peixes utilizadas foram: Cyprinus carpio, Ctenopharyngodon idella e Aristichthys nobilis, introduzidas sete dias após a aplicação dos tratamentos. Amostras de água foram coletadas 17 dias antes e no(s 1°, 3°, 10°, 18°, 31°, 51° e 75° dias após a aplicação dos tratamentos para a identificação e a avaliação de zooplâncton. Os resultados indicam que os herbicidas estudados não afetaram a comunidade zooplanctônica e a aplicação do inseticida carbofuran provocou efeitos negativos em Cladocera. Copepoda e Rotifera foram pouco afetados pelo carbofuran.

  10. Persistência na água e influência de herbicidas utilizados na lavoura arrozeira sobre a comunidade zooplanctônica de Cladocera, Copepoda e Rotifera Water persistence and influence of herbicides utilized in rice paddy about zooplankton community of Cladocers Copepods and Rotifers

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    Geovane Boschmann Reimche

    2008-02-01

    Full Text Available Em lavoura de arroz irrigado, é utilizada uma grande quantidade de agroquímicos que, dependendo da sua persistência a campo e toxicidade, podem contaminar corpos d’água e afetar organismos vivos. Com o objetivo de determinar o efeito de concentrações de campo dos herbicidas Clomazone, Quinclorac, Metsulfuron-methyl e Propanil na comunidade zooplanctônica (Cladocera, Copepoda e Rotifera, conduziu-se um experimento em viveiros de aqüicultura, de março a maio de 2005, na estação do outono. Nos dias 1°, 2°, 3°, 7°, 10°, 18°, 31° e 51° após a aplicação dos herbicidas, foram coletadas amostras de água para se determinarem parâmetros físico-químicos da água, concentração dos herbicidas e comunidade zooplanctônica. Os parâmetros médios da qualidade da água foram: oxigênio dissolvido (3,5mg L-1, temperatura (20,1°C, pH (6,0, dureza total (18mg L-1 de CaCO3 e alcalinidade total (9mg L-1 de CaCO3. A ordem decrescente de persistência dos herbicidas na água foi Clomazone = Quinclorac > Propanil > Metsulfuron-methyl, com média de 31, 31, 10 e 7 dias, respectivamente. Os resultados indicaram que os herbicidas provocaram poucas alterações na densidade de organismos dos grupos Rotifera e Copepoda (Adulto e Nauplio. A densidade do grupo Cladocera permaneceu baixa para todo o período experimental.In the rice paddy field it is used a large amount of agrochemical that, depending on their field persistence and toxicity, can contaminate water bodies and may affect living organism. With the objective of determining the effect of field concentrations of Clomazone, Quinclorac, Metsulfuron-methyl and Propanil herbicides on zooplankton community (Cladocers, Copepods and Rotifers, it was carried an experiment in aquaculture ponds, during March to May 2005, in autumn season. In the 1st, 2nd, 3rd, 7th, 10th, 18th, 31th and 51th days after the herbicides application, water samples were collected to evaluate the physical chemical water

  11. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera

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    Kubanek Julia

    2009-09-01

    Full Text Available Abstract Background Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s. We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. Results A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units, even at synonymous positions, suggests that the repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Conclusion Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

  12. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, H.; Ferrari, C.; Roque, C.V.; Nascimento, M.R. [Brazilian Nuclear Energy Commission/Pocos de Caldas Laboratory (Brazil); Wisniewski, M.J. [Alfenas Federal University/Limnology Laboratory (Brazil); Rodgher, S. [Universidade Estadual Paulista Julio de Mesquita Filho/Science and Technology Laboratory (Brazil)

    2014-07-01

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m{sup -3}), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  13. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    International Nuclear Information System (INIS)

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m-3), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  14. Gnathostomulida--an enigmatic metazoan phylum from both morphological and molecular perspectives.

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    Littlewood, D T; Telford, M J; Clough, K A; Rohde, K

    1998-02-01

    On the basis of few and contentious morphological characters Gnathostomulids have been thought to be the sister-group of either the Platyhelminthes or the Syndermata (Rotifera + Acanthocephala). We provide a full 18S rDNA sequence for a species of Gnathostomula and attempt to resolve its position among the Metazoa, on the basis of molecular evidence. Sixty sequences, representing 30 nominal phyla and including new entoproct and gastrotrich sequences, were used to reconstruct phylogenies using maximum-parsimony, neighbor-joining, and minimum evolution models. We were unable to support either of the morphological hypotheses outright and, moreover, our data supported more strongly a third possible relationship with the gnathostomulids as a member of the Nematoda + Chaetognatha clade. Superficially, as active benthic, vermiform creatures with sclerotized cuticular jaws, they fit a predicted ancestral form of the Nematoda + Chaetognatha clade and, as such, would arguably be members of the Ecdysozoa. The molecular data at least call for a reevaluation of the morphological data and a denser sampling of the lesser phyla. Data from morphology and molecules act synergistically in estimating phylogeny; morphology alone provided limited phylogenetic signal and alternative phylogenetic hypotheses, whereas the molecular solution suggested an alternative topology which, when interpreted in the light of comparative anatomy, may suggest previously unconsidered possibilities. PMID:9479696

  15. The diversity of Indian Brachionidae (Rotifera: Eurotatoria: Monogononta and their distribution

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    B.K. Sharma

    2014-11-01

    Full Text Available We evaluate diversity status of the Brachionidae of India and present an annotated checklist of 46 species excluding dubious and unconfirmed reports. These merit biodiversity value as ~27% of the global diversity of the taxon and ~81% of its Oriental species. We observed two Australasian elements, two Oriental endemics, one Indian endemic, one paleotropical and one cosmo (sub tropical species. The cold-water Keratella serrulata and Notholca squamula are new records from eastern Himalayas. Maximum brachionid diversity (32 species from Assam state of northeast India (NEI is followed by the reports of 27 and 26 species from Tamil Nadu and West Bengal, respectively; 25 species each from Tripura and Maharashtra; and 24 species from Jammu & Kashmir. Brachionus, the most diverse brachionid genus, is widely distributed in India with low richness in hill states of NEI and coastal waters in particular. The Indian brachionid taxonomy is confounded with unconfirmed reports, misidentifications, invalid taxa, and inconsistent treatment of morphological variants, while analysis of cryptic diversity in Brachionus calyciflorus, B. caudatus, B. forficula, B. plicatilis, B. quadridentatus, B. urceolaris, Keratella cochlearis and K. quadrata species-groups awaits attention.

  16. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    International Nuclear Information System (INIS)

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green® analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  17. Joint inhibition of TOR and JNK pathways interacts to extend the lifespan of Brachionus manjavacas (Rotifera).

    Science.gov (United States)

    Snell, Terry W; Johnston, Rachel K; Rabeneck, Brett; Zipperer, Cody; Teat, Stephanie

    2014-04-01

    The TOR kinase pathway is central in modulating aging in a variety of animal models. The target of rapamycin (TOR) integrates a complex network of signals from growth conditions, nutrient availability, energy status, and physiological stresses and matches an organism's growth rate to the resource environment. Important remaining problems are the identification of the pathways that interact with TOR and their characterization as additive or synergistic. One of the most versatile stress sensors in metazoans is the Jun-N-terminal kinase (JNK) signaling pathway. JNK is an evolutionarily conserved stress-activated protein kinase that is induced by a range of stressors, including UV irradiation, reactive oxygen species, DNA damage, heat, and bacterial antigens. JNK is thought to interact with the TOR pathway, but its effects on TOR are poorly understood. We used the rotifer Brachionus manjavacas as a model animal to probe the regulation of TOR and JNK pathways and explore their interaction. The effect of various chemical inhibitors was examined in life table and stressor challenge experiments. A survey of 12 inhibitors revealed two, rapamycin and JNK inhibitor, that significantly extended lifespan of B. manjavacas. At 1 μM concentration, exposure to rapamycin or JNK inhibitor extended mean rotifer lifespan by 35% and maximum lifespan by 37%. Exposure to both rapamycin and JNK inhibitor simultaneously extended mean rotifer lifespan by 65% more than either alone. Exposure to a combination of rapamycin and JNK inhibitors conveyed greater protection to starvation, UV and osmotic stress than either inhibitor alone. RNAi knockdown of TOR and JNK gene expression was investigated for its ability to extend rotifer lifespan. RNAi knockdown of the TOR gene resulted in 29% extension of the mean lifespan compared to control and knockdown of the JNK gene resulted in 51% mean lifespan extension. In addition to the lifespan, we quantified mitochondria activity using the fluorescent marker MitoTracker and lysosome activity using LysoTracker. Treatment of rotifers with JNK inhibitor enhanced mitochondria activity nearly 3-fold, whereas rapamycin treatment had no significant effect. Treatment of rotifers with rapamycin or JNK inhibitor reduced lysosome activity in 1, 3 and 8 day old animals, but treatment with both inhibitors did not produce any additive effect. We conclude that inhibition of TOR and JNK pathways significantly extends the lifespan of B. manjavacas. These pathways interact so that inhibition of both simultaneously acts additively to extend rotifer lifespan more than the inhibition of either alone.

  18. Moderately lower temperatures greatly extend the lifespan of Brachionus manjavacas (Rotifera): Thermodynamics or gene regulation?

    Science.gov (United States)

    Johnston, Rachel K; Snell, Terry W

    2016-06-01

    Environmental temperature greatly affects lifespan in a wide variety of animals, but the exact mechanisms underlying this effect are still largely unknown. A moderate temperature decrease from 22°C to 16°C extends the lifespan of the monogonont rotifer Brachionus manjavacas by up to 163%. Thermodynamic effects on metabolism contribute to this increase in longevity, but are not the only cause. When rotifers are exposed to 16°C for four days and then transfered to 22°C, they survive until day 13 at nearly identical rates as rotifers maintained at 16°C continuously. This persistence of the higher survival for nine days after transfer to 22°C suggests that low temperature exposure alters the expression of genes that affect the rate of aging. The relative persistence of the gene regulation effect suggests that it may play an even larger role in slowing aging than the thermodynamic effects. The life extending effects of these short-term low temperature treatments are largest when the exposure happens early in the life cycle, demonstrating the importance of early development. There is no advantage to lowering the temperature below 16°C to 11° or 5°C. Rotifers exposed to 16°C also displayed increased resistance to heat, starvation, oxidative and osmotic stress. Reproductive rates at 16°C were lower than those at 22°C, but because they reproduce longer, there is no significant change in the lifetime fecundity of females. To investigate which genes contribute to these effects, the expression of specific temperature sensing genes was knocked down using RNAi. Of 12 genes tested, RNAi knockdown of four eliminated the survival enhancing effects of the four-day cold treatment: TRP7, forkhead box C, Y-box factor, and ribosomal protein S6. This demonstrates that active gene regulation is an important factor in temperature mediated life extension, and that these particular genes play an integral role in these pathways. As a thermoresponsive sensor, TRP7 may be responsible for triggering the signaling cascade contributing to temperature mediated life extension. The TRP genes may also provide especially promising candidates for targeted gene manipulations or pharmacological interventions capable of mimicking the effects of low temperature exposure. These results support recent theories of aging that claim rate of aging is determined by an actively regulated genetic mechanism rather than an accumulation of molecular damage.

  19. Cholinergic neuromuscular junctions in Brachionus calyciflorus and Lecane quadridentata (Rotifera:Monogononta)

    Institute of Scientific and Technical Information of China (English)

    Ignacio Alejandro Prez-Legaspi; Alma Lilin Guerrero-Barrera; Ivn Jos Galvn-Mendoza; Jos Luis Quintanar; Roberto Rico-Martnez

    2014-01-01

    Objective:To identify the presence of joint muscular and cholinergic systems in two freshwater rotifer species, Brachionus calyciflorus and Lecane quadridentata. Methods: The muscle actin fibers were stained with phalloidin-linked fluorescent dye, and acetylcholine was detected with Amplex Red Acetylcholine/Acetylcholinesterase Assay Kit, and then confocal scanning laser microscopy was used. Results:The musculature of Brachionus calyciflorus showed a pattern similar to other species of the same genus, while that of Lecane quadridentata was different from other rotifer genera described previously. The cholinergic system was determined by co-localization of both muscles and acetylcholine labels in the whole rotifer, suggesting the presence of neuromuscular junctions. Conclusions: The distribution pattern of muscular and acetylcholine systems showed considerable differences between the two species that might be related to different adaptations to particular ecological niches. The confirmation of a cholinergic system in rotifers contributes to the development of potential neuro-pharmacological and toxicological studies using rotifers as model organism.

  20. Bioconcentration and localization of lead in the freshwater rotifer Brachionus calyciflorus Pallas 1677 (Rotifera: Monogononta)

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado-Flores, Jesus, E-mail: jalvaflo@hotmail.com [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rico-Martinez, Roberto, E-mail: rrico@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Quimica, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Ventura-Juarez, Javier, E-mail: jventur@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Morfologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Silva-Briano, Marcelo, E-mail: msilva@correo.uaa.mx [Universidad Autonoma de Aguascalientes, Centro de Ciencias Basicas, Departamento de Biologia, Avenida Universidad 940, Aguascalientes, Ags., CP 20131 (Mexico); Rubio-Franchini, Isidoro, E-mail: rubio_reyes@hotmail.com [Instituto de Servicios de Salud del Estado de Aguascalientes, Laboratorio Estatal de Salud Publica, Av. Siglo XXI 105, Ciudad Satelite Morelos, C.P. 20270, Aguascalientes, Ags. (Mexico)

    2012-03-15

    We studied how lead is bioconcentrated and distributed in the rotifer Brachionus calyciflorus using metal histochemistry to locate lead granules, Leadmium Green{sup Registered-Sign} analysis to establish the route of uptake, atomic absorption to determined the bioconcentration factor (BCF), and detected the presence of microelements in the cuticle by X-ray microanalysis with scanning electron microscopy. Our results indicate: (a) the digestive system is the main route of lead uptake in the rotifer B. calyciflorus, (b) after 24-h lead is deposited in granules in the mastax and vitellarium, (c) our energy-dispersive X-ray microanalysis indicates decalcification taking place in the cuticle of the rotifer after a 24-h lead exposure, and (d) we determined a BCF = 115 for lead after a 24 h exposure. However, the route of mobilization and storage of intracellular lead are still not fully understood in B. calyciflorus.

  1. Moderately lower temperatures greatly extend the lifespan of Brachionus manjavacas (Rotifera): Thermodynamics or gene regulation?

    Science.gov (United States)

    Johnston, Rachel K; Snell, Terry W

    2016-06-01

    Environmental temperature greatly affects lifespan in a wide variety of animals, but the exact mechanisms underlying this effect are still largely unknown. A moderate temperature decrease from 22°C to 16°C extends the lifespan of the monogonont rotifer Brachionus manjavacas by up to 163%. Thermodynamic effects on metabolism contribute to this increase in longevity, but are not the only cause. When rotifers are exposed to 16°C for four days and then transfered to 22°C, they survive until day 13 at nearly identical rates as rotifers maintained at 16°C continuously. This persistence of the higher survival for nine days after transfer to 22°C suggests that low temperature exposure alters the expression of genes that affect the rate of aging. The relative persistence of the gene regulation effect suggests that it may play an even larger role in slowing aging than the thermodynamic effects. The life extending effects of these short-term low temperature treatments are largest when the exposure happens early in the life cycle, demonstrating the importance of early development. There is no advantage to lowering the temperature below 16°C to 11° or 5°C. Rotifers exposed to 16°C also displayed increased resistance to heat, starvation, oxidative and osmotic stress. Reproductive rates at 16°C were lower than those at 22°C, but because they reproduce longer, there is no significant change in the lifetime fecundity of females. To investigate which genes contribute to these effects, the expression of specific temperature sensing genes was knocked down using RNAi. Of 12 genes tested, RNAi knockdown of four eliminated the survival enhancing effects of the four-day cold treatment: TRP7, forkhead box C, Y-box factor, and ribosomal protein S6. This demonstrates that active gene regulation is an important factor in temperature mediated life extension, and that these particular genes play an integral role in these pathways. As a thermoresponsive sensor, TRP7 may be responsible for triggering the signaling cascade contributing to temperature mediated life extension. The TRP genes may also provide especially promising candidates for targeted gene manipulations or pharmacological interventions capable of mimicking the effects of low temperature exposure. These results support recent theories of aging that claim rate of aging is determined by an actively regulated genetic mechanism rather than an accumulation of molecular damage. PMID:26939542

  2. A functional difference between native and horizontally acquired genes in bdelloid rotifers.

    Science.gov (United States)

    Barbosa, Elton G G; Crisp, Alastair; Broadbent, Sarah E; Carrillo, Martina; Boschetti, Chiara; Tunnacliffe, Alan

    2016-09-15

    The form of RNA processing known as SL trans-splicing involves the transfer of a short conserved sequence, the spliced leader (SL), from a noncoding SL RNA to the 5' ends of mRNA molecules. SL trans-splicing occurs in several animal taxa, including bdelloid rotifers (Rotifera, Bdelloidea). One striking feature of these aquatic microinvertebrates is the large proportion of foreign genes, i.e. those acquired by horizontal gene transfer from other organisms, in their genomes. However, whether such foreign genes behave similarly to native genes has not been tested in bdelloids or any other animal. We therefore used a combination of experimental and computational methods to examine whether transcripts of foreign genes in bdelloids were SL trans-spliced, like their native counterparts. We found that many foreign transcripts contain SLs, use similar splice acceptor sequences to native genes, and are able to undergo alternative trans-splicing. However, a significantly lower proportion of foreign mRNAs contains SL sequences than native transcripts. This demonstrates a novel functional difference between foreign and native genes in bdelloids and suggests that SL trans-splicing is not essential for the expression of foreign genes, but is acquired during their domestication. PMID:27312952

  3. Synergistic toxicity of Macondo crude oil and dispersant Corexit 9500A® to the Brachionus plicatilis species complex (Rotifera)

    International Nuclear Information System (INIS)

    Using the marine rotifer Brachionus plicatilis acute toxicity tests, we estimated the toxicity of Corexit 9500A®, propylene glycol, and Macondo oil. Ratios of 1:10, 1:50 and 1:130 for Corexit 9500A®:Macondo oil mixture represent: maximum exposure concentrations, recommended ratios for deploying Corexit (1:10–1:50), 1:130 the actual dispersant:oil ratio used in the Deep Water Horizon spill. Corexit 9500A® and oil are similar in their toxicity. However, when Corexit 9500A® and oil are mixed, toxicity to B. manjavacas increases up to 52-fold. Extrapolating these results to the oil released by the Macondo well, suggests underestimation of increased toxicity from Corexit application. We found small differences in sensitivity among species of the B. plicatilis species complex, likely reflecting phylogenetic similarity. Just 2.6% of the water-accommodated fraction of oil inhibited rotifer cyst hatching by 50%, an ecologically significant result because rotifer cyst in sediments are critical resources for the recolonization of populations each Spring. - Highlights: ► We determined LC50's of Corexit 9500A®, propylene glycol, and oil to B. plicatilis. ► Corexit 9500A® and oil are equivalent in toxicity. ► When Corexit 9500A® and oil are mixed, toxicity increases 52-fold to B. plicatilis. ► Results suggest underestimation of increased toxicity due to Corexit application. ► Sensitivity differences are small among species of the B. plicatilis species complex. - Using Brachionus plicatilis acute toxicity tests we estimated Corexit 9500A® and oil toxicity. When these compounds are mixed a 52-fold increase in toxicity was observed.

  4. Brachionidae (Rotifera: Monogononta de la albufera El Paraíso y el reporte de Brachionus ibericusen el Perú

    Directory of Open Access Journals (Sweden)

    Emily Toscano

    2013-12-01

    Full Text Available En este trabajo se reportan las especies de Brachionidae reconocidos en las muestras recogidas en octubre de 2010 en la albufera Laguna El Paraiso, Huacho (11°13' −11° 10'S, 77° 35' −77°40'W. Cinco especies fueron determinadas: Keratella tropica, Brachionus quadridentatus, B. urceolaris, B. angularis y B. ibericusCiros-Pérez 2001. Este último es un nuevo reporte para el Perú y amplía su distribución a nivel mundial.

  5. Effect of algal food (Chlorella vulgaris concentration and inoculation density on the competition among three planktonic Brachionidae (Rotifera: Monogononta Efecto de la concentración de algas (Chlorella vulgaris y la densidad de inoculación sobre la competencia entre tres Brachionidae (Rotifera: Monogononta planctónicos

    Directory of Open Access Journals (Sweden)

    S.S.S. Sarma

    2008-08-01

    Full Text Available Competitive outcomes among three rotifer species (Anuraeopsis fissa, Brachionus havanaensis and B. angularis were quantified with different inoculation densities of two competing species at a time (0, 25, 50, 75 and 100% and using different algal (Chlorella vulgaris densities (0.2 x 10(6, 0.4 x 10(6 and 0.8 x 10(6 cells ml-1. In control cultures, when each species was grown alone, the population growth of rotifers increased with increasing food availability in the medium, but in mixed cultures, decreased with increasing proportion of the competing species. At low food level, compared to B. havanaensis, B. angularis had stronger negative impact on A. fissa. However, with increasing algal density, both species of Brachionus had similar but reduced impact on A. fissa. Population growth of B. havanaensis was more adversely affected by A. fissa than B. angularis at low and intermediate concentrations. At high food level, the impact of either A. fissa or B. angularis on the growth of B. havanaensis was similar. When grown alone, for a given food density, A. fissa was more numerically (4 to 6 times abundant than the other two species. The rate of population increase (r of rotifers increased with increasing food levels. Depending on the rotifer species and the test conditions, the r varied from -0.001 to 0.34 d-1. Results showed that the competitive outcome in the tested rotifers depended on the initial inoculation density of the competing species, the offered food concentration as well as the interaction of these two factors.Se evaluaron los resultados de la competencia entre tres especies de rotíferos (Anuraeopsis fissa, Brachionus havanaensis y B. angularis usando dos especies a la vez con diferentes densidades de inóculo (0, 25, 50, 75 y 100% y diferentes niveles de alga (Chlorella vulgaris; 0.2 x 10(6, 0.4 x 10(6 y 0.8 x 10(6 células ml-1. En cultivos monoespecíficos, utilizados como control, el crecimiento poblacional de rotíferos aumentó con el aumento de disponibilidad del alimento en el medio, pero en los cultivos mixtos, disminuyeron con el aumento de la proporción de la especie competidora. En el nivel bajo de alimento, B. havanaensis tuvo un mayor impacto negativo sobre A. fissa en comparación con B. angularis. Sin embargo, al aumentar la densidad del alga, ambas especies de Brachionus tuvieron un impacto reducido, pero similar. Por otro lado, el crecimiento poblacional de B. havanaensis fue afectado más por A. fissa que por B. angularis en las concentraciones bajas e intermedias de alimento. Con altas concentraciones del alga, el impacto de A. fissa o B. angularis sobre el crecimiento de B. havanaensis fue semejante. Cuando fue cultivado solo, para una densidad dada de alimento, A. fissa alcanzó una mayor abundancia (4 a 6 veces que las otras dos especies. La tasa de crecimiento poblacional (r de los rotíferos se incrementó con la disponibilidad del alga. Dependiendo de la especie de rotíferos y de las condiciones del experimento, la r varió entre -0.001 a 0.34 d-1. Se concluye que el resultado de la competencia entre las especies de estudio depende de la densidad inicial de los competidores, de la concentración de alimento así como de la interacción de los dos factores.

  6. Distribuição espacial e temporal de Kellicottia bostoniensis (Rousselet, 1908 (Rotifera em um grande reservatório tropical (reservatório de Furnas, Estado de Minas Gerais, Brasil Spatial and temporal distribution of Kellicottia bostoniensis (Rousselet, 1908 (Rotifera in a big tropical reservoir (Furnas Reservoir, state of Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo Motta Pinto-Coelho

    2002-05-01

    Full Text Available O rotífero Kellicottia bostoniensis é uma espécie planctônica comum na América do Norte, e em anos recentes, ela foi introduzida no Brasil. No sudeste do Brasil ela foi encontrada num pequeno reservatório eutrófico em Belo Horizonte e na bacia do rio Grande, no Reservatório de Furnas (20º 40’S - 46º 19’W. O objetivo do trabalho foi analisar a distribuição espacial e temporal desse rotífero ao longo de um gradiente trófico, em 12 pontos (3 no eixo central do reservatório e (9 em um dos seus principais tributários, o eixo do rio Sapucaí. As amostragens foram feitas em agosto e outubro/99 e março e julho/2000, através de arrastos verticais, com rede cilíndro-cônica de 68µm. Os organismos foram contados em câmara de Sedgwick-Rafter. Esse rotífero apareceu em toda a área amostrada, e os maiores valores de densidade foram observados em outubro e março, estação chuvosa, nos pontos meso e eutróficos. A ocorrência de K. bostoniensis nesse reservatório reflete sua alta adaptabilidade em ambientes tropicais.The rotifer Kellicottia bostoniensis is a common planktonic species in North America. This species has been introduced in Brazil recently. It is found in southeastern Brazil in a small eutrophic reservoir in Belo Horizonte (Minas Gerais state capital and in the Rio Grande Basin, Furnas reservoir (20º 40’ S- 46º 19’W. The aims of this study is to analyze this rotifer spatial and temporal distribution along a trophic gradient in 12 locations (3 in the reservoir central axis and (9 in one of its main tributaries, the Sapucaí River axis. The samplings were taken in August and October, 1999, and in March and July, 2000, through vertical tow, with a 68 µm cylindrical-conical net. The organisms were counted in a Sedgwick-Rafter cell. This rotifer was in the whole sampled area, and the higher densities were observed in October and March, rainy season, in the meso and eutrophic areas. The K. bostoniensis occurrence in this reservoir possibly reflects its high adaptability to tropical environments.

  7. Systematic Study on Nematoda Phylum,Gastrotricha Phylum and Rotifera Phylum%线虫动物门、腹毛动物门及轮虫动物门间的系统学研究

    Institute of Scientific and Technical Information of China (English)

    全仁哲; 贺福德; 陈道富; 范喜顺

    2002-01-01

    用支序分析方法对线虫动物门、腹毛动物门和轮虫动物门三者之间的系统学进行了分析,结论是三者为一单系群,其中腹毛动物门和轮虫动物门为一对姐妹群,线虫动物门则是由三者的共同祖先较早地分出的另一支.由此我们认为,应将这三者合并为一新门合胞体动物门(Syncytia),原来各门分别降为线虫纲、腹毛纲和轮虫纲;原腔动物门这一分类阶元应予废弃.

  8. Abundance of Zooplankters on a Rocky Shore of Kasenga, Southen End of Lake Tanganyika

    OpenAIRE

    KONDO, Takaki; KUMEKAWA, Hirokazu; Hori, Michio

    1997-01-01

    Abundance of zooplankters was examined by net collection on a rocky shore at the southern end of Lake Tanganyika. Zooplankters collected were copepoda, Ostracoda, shrimp larvae, Protozoa and Rotifera. No Cladocera was found. The species composition was rather simple and similar to that reported at the northwestern end of the lake. But the density of Rotifera was higher at the southern end. As the density of planktophagous fishes was higher about five times at the northwestern end than at the ...

  9. A Preliminary Study on the Diversity of Micro-and Meso-fauna Communities in the Campus of Xinjiang Normal University%新疆师范大学校园中小型土壤动物群落多样性初步研究

    Institute of Scientific and Technical Information of China (English)

    古丽布斯坦·努尔买买提; 吾玛尔·阿布力孜; 努尔夏提·努尔买买提

    2013-01-01

    The communities diversity of micro-and meso-fauna in relation to5 different habitats in campus of Xinjiang Normal University were investigated by Tullgren dry funnel method with emphasis on the composition and diversity from September to November in 2010 . The results showed that a total of 1630 soil animals was extracted and classified into 4 phyla,10 classes,and 18 orders, respectively. Collembola (25. 77%),Acariformes (17. 36%),Coleoptera (11. 53%),Dipterra(11. 17%)were the dominant groups, and they were accounting for 65. 83%, and Lumbricida ( 3 . 8%) , Gastropoda ( 7 . 67%) , Araneae ( 3 . 25%) , Isopoda ( 1 . 16%) , Chilopoda ( 4 . 66%), Orthoptera (1. 47%), Dermaptera (2. 02%), Hemiptera (3. 93%),Hymenoptera(2. 15%),Homoptera (2. 33%) and so on were common groups and they were accounting for 33. 62%., and the Thysanoptera ( 0. 06%),Rotifera(0. 18%),Symphyla(0. 31%) were rare groups, and they were accounting for 0. 55 % of total numbers. The results also suggested that the types of different habitats were affected on the individual density and group number of soil fauna community,and the in order of individual number is Bio-geography building greenland>Dormitory building greenland >Main building greenland >Library greenland >Playground greenland. The order of group number is Bio-geography building greenland >Dormitory building greenland >Main building greenland >Li-brary greenland >Playground greenland. We also analysed the community diversity indices such as diversity index ( H) , evenness index ( E) , and dominant index ( C) , and found that there were significant differences among the different greenlands. The Shannon-Wiener diversity index of Bio-geography building greenland>Dormitory building greenland >Main building greenland >Library greenland >Playground greenland. The order of evenness index ( E) of Playground Greenland >Library greenland >Main building greenland>Dormitory building greenland>Bio-geogra-phy building greenland. The dominance index of

  10. Triploblastic relationships with emphasis on the acoelomates and the position of Gnathostomulida, Cycliophora, Plathelminthes, and Chaetognatha: a combined approach of 18S rDNA sequences and morphology.

    Science.gov (United States)

    Giribet, G; Distel, D L; Polz, M; Sterrer, W; Wheeler, W C

    2000-09-01

    Triploblastic relationships were examined in the light of molecular and morphological evidence. Representatives for all triploblastic "phyla" (except Loricifera) were represented by both sources of phylogenetic data. The 18S ribosomal (rDNA) sequence data for 145 terminal taxa and 276 morphological characters coded for 36 supraspecific taxa were combined in a total evidence regime to determine the most consistent picture of triploblastic relationships for these data. Only triploblastic taxa are used to avoid rooting with distant outgroups, which seems to happen because of the extreme distance that separates diploblastic from triploblastic taxa according to the 18S rDNA data. Multiple phylogenetic analyses performed with variable analysis parameters yield largely inconsistent results for certain groups such as Chaetognatha, Acoela, and Nemertodermatida. A normalized incongruence length metric is used to assay the relative merit of the multiple analyses. The combined analysis having the least character incongruence yields the following scheme of relationships of four main clades: (1) Deuterostomia [((Echinodermata + Enteropneusta) (Cephalochordata (Urochordata + Vertebrata)))]; (2) Ecdysozoa [(((Priapulida + Kinorhyncha) (Nematoda + Nematomorpha)) ((Onychophora + Tardigrada) Arthropoda))]; (3) Trochozoa [((Phoronida + Brachiopoda) (Entoprocta (Nemertea (Sipuncula (Mollusca (Pogonophora (Echiura + Annelida)))))))]; and (4) Platyzoa [((Gnathostomulida (Cycliophora + Syndermata)) (Gastrotricha + Plathelminthes))]. Chaetognatha, Nemertodermatida, and Bryozoa cannot be assigned to any one of these four groups. For the first time, a data analysis recognizes a clade of acoelomates, the Platyzoa (sensu Cavalier-Smith, Biol. Rev. 73:203-266, 1998). Other relationships that corroborate some morphological analyses are the existence of a clade that groups Gnathostomulida + Syndermata (= Gnathifera), which is expanded to include the enigmatic phylum Cycliophora, as sister group

  11. Avaliação dos métodos de amostragem para fauna perifítica em macrófitas na Reserva da Biosfera, Serra do Espinhaço, Estado de Minas Gerais, Brasil - DOI: 10.4025/actascibiolsci.v30i3.377 Evaluation of sampling methods for periphytic fauna in macrophytes at the Espinhaço Mountain Range Biosphere Reserve, Minas Gerais State, Brazil - DOI: 10.4025/actascibiolsci.v30i3.377

    Directory of Open Access Journals (Sweden)

    Cristiane Machado López

    2008-10-01

    Full Text Available Os métodos “Jarra”, “Remocao Manual” e “Draga de Eckman modificada” foram avaliados para amostrar a fauna perifitica associada a macrofitas aquaticas. Foram coletadas 63 amostras em cinco ambientes lenticos e tres loticos na reserva da biosfera da Serra do Espinhaco (Estado de Minas Gerais, Brasil. Os testes estatisticos Anova e Tukey foram feitos para riqueza de Protista, Rotifera e Crustacea, enquanto para a abundancia de Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada e Nematoda foram avaliados os percentuais. Os protozoarios e rotiferos representaram 80% da abundancia e riqueza da comunidade. Nos ecossistemas avaliados todos os metodos foram relevantes para Protista, por outro lado, o metodo da Jarra foi o mais adequado para a analise de Crustacea. Entre os metodos, a Draga foi menos indicada para os grupos de microinvertebrados nos ecossistemas aquaticos. Os metodos Remocao Manual e Draga foram apropriados para analisar Rotifera. A abundancia de Gastrotricha e Tardigrada demonstrou melhores resultados pelo metodo da Jarra e Nematoda pelo metodo da Draga. Os tres metodos sao apropriados para amostragem da fauna perifitica em ambos os sistemas aquaticos. Entretanto, e importante estar ciente de que para cada tipo de ecossistema a amostragem da comunidade faunistica requer um metodo especifico para obter a melhor performance.The methods “Jar”, “Manual Removal” and “modified Ekman`s Dredge” were evaluated for sampling periphyton fauna associated to aquatic macrophytes. Sixty three samples were collected from five lentic and three lotic water bodies at Espinhaço Mountain Range Biosphere Reserve (Minas Gerais, Brazil. ANOVA and Tukey statistical tests were performed for Protista, Rotifera and Crustacea richness, whilst Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada and Nematoda, abundance were evaluate by percentage. Amongst the three methods, Dregde is less indicated for different water bodies systems

  12. Zooplankton Distribution in Tropical Reservoirs, South China

    Science.gov (United States)

    Lin, Qiu-Qi; Duan, Shun-Shan; Hu, Ren; Han, Bo-Ping

    2003-11-01

    The zooplankton of 18 reservoirs of South China was investigated in 2000. 61 Rotifera species, 23 Cladoceras and 14 Copepodas were identified. The most frequent Rotifera genera were Keratella, Brachionus, Trichocerca, Diurella, Ascomorpha, Polyarthra, Ploesoma, Asplanchna, Pompholyx and Conochilus. Bosmina longirostris, Bosminopsis deitersi, Diaphanosoma birgei, D. brachyurum and Moina micrura were typical of Cladocera in the reservoirs. Phyllodiaptomus tunguidus, Neodiaptomus schmackeri and Mesocyclops leuckarti were the most frequent Copepoda and M. leuckarti dominated Copepoda in most reservoirs. High zooplankton species richness with low abundance was characteristic of the throughflowing reservoir, whereas low species richness with low abundance was found in the reservoir with the longest retention time. Relative high abundance and medium species diversity were the distinction of intermediate retention time reservoirs.

  13. Zooplankton Seasonal Abundance and Vertical Distribution of Highly Alkaline Lake Burdur, Turkey

    OpenAIRE

    Gülle, Iskender; Turna, Ismail Ibrahim; Güçlü, Salim Serkan; Gülle, Pinar; Güçlü, Zekiye

    2010-01-01

    During the period from December 2003 to November 2004 a study has been held to examine the water quality and zooplankton of highly alkaline Lake Burdur. The lake showed thermal stratification between June and October. Six zooplankton taxa were determined, Hexarthra fennica, Brachionus plicatilis from Rotifera and Arctodiaptomus burduricus from Copepoda were the dominant species. Average zooplankton density was 399,074 ind.m-3 and they were 51% H. fennica, 9% B. plicatilis and 40% A. burdu...

  14. Plankton Resting Stages in the Marine Sediments of the Bay of Vlorë (Albania)

    OpenAIRE

    Fernando Rubino; Salvatore Moscatello; Manuela Belmonte; Gianmarco Ingrosso; Genuario Belmonte

    2013-01-01

    In the frame of the INTERREG III CISM project, sediment cores were collected at 2 stations in the Gulf of Vlorë to study the plankton resting stage assemblages. A total of 87 morphotypes were identified and produced by Dinophyta, Ciliophora, Rotifera, and Crustacea. In 22 cases, the cyst belonged to a species absent from the plankton of the same period. The most abundant resting stages were those produced by Scrippsiella species (Dinophyta). Some calcareous cysts were identified as fossil spe...

  15. Invertebrate communities of Nabugabo Lakes: a vital support resource for the fisheries and ecosystem diversity

    OpenAIRE

    Ndawula, L.M.; Kiggundu, V.; Pabire Ghandi, W.

    2005-01-01

    A field study of the invertebrate communities of the Nabugabo lakes(Nabugabo,Kayanja and Kayugi)showed the occurrence of copepoda, cladocera and rotifera(micro-invertebrates or zooplankton); Ephemeroptera and Diptera(macro-invertebrates or zoo-benthos). The most commonly encountered taxa were thermocyclops neglectus, moinamicrura,several rotiferan species(micro-invertebrates);P.adusta,chironomus, tanipodinae and trichoptera(macro- invertebrates). These organisms are assumed to be readily avai...

  16. The Digestive System Content of Mastacembelus mastacembelus (Banks & Solander, 1794) Inhabiting in Karakaya Dam Lake (Malatya-Turkey)

    OpenAIRE

    Pala, Güneş; Tellioğlu, Ayda; EROĞLU, Mücahit; ŞEN, Dursun

    2010-01-01

    In this study, digestive system contents of a total of 126 Mastacembelus mastacembelus (Banks & Solander, 1794) obtained from Karakaya Dam Lake were examined by means of Geometric Index of Importance (GII). In the digestive system content of examined fish, Bacillariophyta (16 taxa), Chlorophyta (6 taxa), Cyanophyta (5 taxa), Dinophyta (1 taxon) and Euglenophyta (1 taxon) which belong to plants and Rotifera (14 taxa), Cladocera (4 taxa), Copepoda (2 taxa) and Pisces (3 taxa) which belo...

  17. Aporte al conocimiento del zooplancton de agua dulce y estuarina del río Guayas. Guayaquil - Ecuador

    OpenAIRE

    Luzuriaga de Cruz, M.

    1998-01-01

    El presente trabajo corresponde al análisis de zooplancton colectado en cinco estaciones localizadas en el río Guayas. La primera estación estuvo situada 10 km. río arriba de la confluencia del río Babahoyo con el río Daule, en un pozo acuífero. Las otras estaciones se situaron en cuatro sitios consecutivos a lo largo del río Guayas. En este trabajo se han identificado 10 especies: Brachionus plicatilis (O. F. Muller) (Rotifera), Alona cambouei Guerne and Richard, 1893; Moina micrura Kurz, 18...

  18. ÇAMLIGÖZE BARAJ GÖLÜ (SİVAS-TÜRKİYE) ZOOPLANKTON FAUNASI ÜZERİNE BİR ÇALIŞMA

    OpenAIRE

    Dirican, Seher; Musul, Haldun

    2008-01-01

    Bu çalışma, Sivas ili Suşehri ilçesindeki Kelkit Çayı üzerinde kurulmuş olan Çamlıgöze Baraj Gölü’nün zooplankton faunasının belirlenmesi amacıyla Mayıs ve Kasım 2007 tarihleri arasında yapılmıştır. Çamlıgöze Baraj Gölü’nün zooplankton faunası 3 istasyondan alınan örneklerde incelenmiştir. Çamlıgöze Baraj Gölü’nün zooplankton faunasını başlıca Rotifera şubesi, Cladocera alttakımı ve Copepoda altsınıfı oluşturmaktadır. Bu çalışma sonucunda, Çamlıgöze Baraj Gölü’nde Rotifera şubesinden 11 tür, ...

  19. Beyşehir Gölü Zooplankton Türlerinin Aylık Dağılımı

    OpenAIRE

    DİDİNEN, Hakan; Yunus Ömer BOYACI

    2014-01-01

    Beyşehir Gölü'nde, Mayıs 2009-Nisan 2010 dönem aralığı aylık, 8 ayrı istasyondan su ve zooplankton örneklemesi yapılmıştır. Zooplankton olarak; Rotifera'ya ait 37, Copepoda'ya ait 5, Cladocera'ya ait 4 ve Bivalvia'ya ait 1 tür olmak üzere toplamda 47 tür tespit edilmiştir. Göl geneli toplam zooplankton yoğunluğuna göre; % 95,45'i Rotifera, % 3,66'sı Cladocera, % 0,89'u Copepoda ve < % 0,01'i Bivalvia'ya ait olduğu hesaplanmıştır. Zooplanktonun büyük bir kısmını mikro zooplankton temsil etmişt...

  20. Composition, diversity and short-term temporal fluctuations of zooplankton communities in fish culture ponds (Pindamonhangaba), SP.

    Science.gov (United States)

    Negreiros, N F; Rojas, N E; Rocha, O; Santos Wisniewski, M J

    2009-08-01

    The present study aimed at evaluating the composition, diversity and short-term temporal fluctuations of zooplankton communities in fish ponds. The study was carried out in two fish ponds, with 180 m(2) of water surface (6 x 30 m) each, located in the Aquiculture Centre of the Pindamonhangaba Fisheries Institute - São Paulo. The study was developed over eight weeks, from February 16 to April 6, 1998. The physical and chemical conditions of the water in the fish ponds were adequate for zooplankton development. The zooplanktonic community was characterised by high richness of species and a greater diversity was observed in the first fish pond, with a superior density of Rotifera. Temporal changes in zooplankton composition occurred in both ponds with Cladocera appearing in abundance later, in the fourth week, whereas copepods and rotifers were well represented since the beginning. Many species found are typical of fish ponds and are considered to constitute an excellent food source, showing high nutritional value for fish larvae, a good example being individuals from the Rotifera group and the micro-crustacean species Moina minuta and Thermocyclops decipiens. PMID:19802437

  1. Correlations between zooplankton assemblages and environmental factors in the downtown rivers of Shanghai, China

    Science.gov (United States)

    Yu, Na; Li, Erchao; Feng, Dexiang; Xiao, Baicai; Wei, Chaoqun; Zhang, Meiling; Chen, Liqiao

    2014-11-01

    Most urban rivers play an important role in urban flood control and drainage in China, but pollution is fast becoming an issue of greater importance in water management. In this study, 63 zooplankton species were recorded in four downtown rivers in Shanghai between November 2007 and October 2008. Of these, 44 species belonged to the Rotifera, 13 to Cladocera, and six to Copepoda. The three most frequently occurring zooplankton ( Brachionus calyciflorus, Microcyclops leuckarti, and Asplanchna priodonta) accounted for 80.00%, 76.84%, and 53.68%, respectively. Rotifera were found to be dominant, comprising 86.26% of total zooplankton, while cladoceran and copepod abundance amounted to 5.08% and 8.67%, respectively. Water temperature, salinity, electrical conductivity, and total nitrogen were of the greatest significance in the occurrence of zooplankton. Two species ( Schmackeria forbesi and Lepadella ovalis) were notably more sensitive to environmental factors such as salinity and electrical conductivity than other species. The population size and community were inversely correlated with the increasing nutrient levels of the four rivers, suggesting that the water quality of the four rivers had been gradually recovering from a severe eutrophic state and that water conditions of the rivers had been gradually improved.

  2. 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.

  3. Zooplankton community of Keibul Lamjao National Park (KLNP) Manipur, India in relation to the physico-chemical variables of the water

    Science.gov (United States)

    Sharma, Aribam Satishchandra; Gupta, Susmita; Singh, N. Rajmuhon

    2016-06-01

    Keibul Lamjao National Park (KLNP), a floating park in Loktak Lake, Manipur (India) was studied from Winter (WIN) to Post Monsoon (POM) for its zooplankton composition and some selected water parameters. The resultant data were subjected to multivariate techniques-Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA). Analyses of water parameters with PCA revealed that the first PC axis (PC1) accounts for maximum variance in the seasonal data, explaining a variability of 91%. The PCA revealed that the seasonal variability in water parameters was due to the wet and dry cycle of seasons and the stations were distinguished on the basis of transparency and turbidity. Zooplankton abundance was dominated by copepods followed by cladocerans. Temporally, abundance of copepods reached a maximum during Post-monsoon (POM) (3 880 ind./L). Spatially, S6 was found to be most abundant of the other stations in zooplankton. Copepodites and nauplii larvae were the major components of zooplankton. The Rotifera were the least abundant among the three zooplankton groups. Brachionus formed the major component of Rotifera zooplankton at all the stations during the study period. In the Cladocera, Macrothrix was present during all the four seasons, while Pleuroxus, Oxyurella, Kurzia and, Diaphanosoma were rare. The CCA shows that maximal temporal variability in zooplankton abundance was explained by temperature and rainfall. ANOVA revealed no significant diff erence in mean zooplankton abundance among the seasons, but there was a statistically significant diff erence among the sites.

  4. Zooplankton from a polluted river, Mula (India, with record of Brachionus rubens (Ehrenberg, 1838 epizoic on Moina macrocopa (Straus, 1820

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    Vanjare, A.I.

    2010-06-01

    Full Text Available Rotifera and Cladocera are free living zooplankton elements known to dominate freshwater habitats. Few rotifersare known to be parasitic and epizoic living in association with other organisms. Zooplankton from the polluted river Mula, Pune,Maharashtra was sampled from January to November 2009. Eighteen rotifers and ten cladocerans were recorded during the study.Samples revealed rotifer Brachionus rubens (Ehrenberg, 1838 epizoic on cladoceran Moina macrocopa (Straus, 1820, theoccurrence of which coincided with lower dissolved oxygen (DO content. The rotifers Asplanchnopus multiceps (Schrank,1793, Lacinularia elliptica (Shephard, 1897 and the cladoceran Kurzia longirostris (Daday, 1898 are new records to Maharashtrastate. The present study was an attempt to monitor a polluted habitat for zooplankton fauna. Detailed studies onorganically polluted eutrophic habitats could add new insights into zooplankton diversity and behaviour.

  5. Molecular diversity of eukaryotes in municipal wastewater treatment processes as revealed by 18S rRNA gene analysis.

    Science.gov (United States)

    Matsunaga, Kengo; Kubota, Kengo; Harada, Hideki

    2014-01-01

    Eukaryotic communities involved in sewage treatment processes have been investigated by morphological identification, but have not yet been well-characterized using molecular approaches. In the present study, eukaryotic communities were characterized by constructing 18S rRNA gene clone libraries. The phylogenetic affiliations of a total of 843 clones were Alveolata, Fungi, Rhizaria, Euglenozoa, Stramenopiles, Amoebozoa, and Viridiplantae as protozoans and Rotifera, Gastrotricha, and Nematoda as metazoans. Sixty percent of the clones had <97% sequence identity to described eukaryotes, indicating the greater diversity of eukaryotes than previously recognized. A core OTU closely related to Epistylis chrysemydis was identified, and several OTUs were shared by 4-8 libraries. Members of the uncultured lineage LKM11 in Cryptomycota were predominant fungi in sewage treatment processes. This comparative study represents an initial step in furthering understanding of the diversity and role of eukaryotes in sewage treatment processes.

  6. Marine Meiofauna in Songculan Lagoon, Songculan, Dauis, Bohol Philippines

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    Hongayo, Menelo C

    2013-04-01

    Full Text Available Meiofaunal organisms are small animals found living in the benthic zones of both freshwater and marine habitats and are considered numerically dominant metazoans. Their presence in the benthic zone is important since they serve as links to higher trophic levels in the ecosystems. This study aimed to identify meiofaunal organisms found in Songculan Lagoon, Songculan Dauis, Bohol, Philippines; determine the physico – chemical properties of water and sediments in Songculan Lagoon; and compute and compare for relative abundance of the meiofaunal taxa. This study was limited to meiofaunal taxa identification up to class level. Sampling involves coring method. The results identified eleven (11 meiofaunal taxa namely; Netamoda, Copepod, Ostracod, Turbellaria, Gastropod, Flatworms, Gastroticha, Polychaeta, Oligochaeta, Rotifera and Tardigrada.

  7. Zooplankton communities in the Krenceng Reservoair, Cilegon, Banten

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    Mufti P. Patria

    2005-11-01

    Full Text Available This research was carried out to know the structure of zooplankton communities and relations between the phytoplankton and zooplankton in the Krenceng Reservoair, Cilegon. The zooplankton abundance with used Sedwigck Rafter Counting Method, diversity and evenness were counted. Relations between zooplankton and the environmental factors as well as its relations to phytoplankton calculated with regression. The results showed that are 13 species of the zooplankton found which including in three classes with the highest abundance on Novembers 2002 and March 2003 of the Rotifera. The analysis of regression pointed out that the environmental factors such: pH, BOD5, nitrate, CO2 and abundance of phytoplankton influence the abundance zooplankton in November. While in March, the abundance of zooplankton is influenced by brigthtness, nitrate, orthophosphates and C organic. The abundance of phytoplankton influenced positively by the abundance of zooplankton.

  8. 沙溪竹洲水电站水体富营养化评价%Evaluation on Eutrophication of Zhuzhou Hydroelectri--Station in the Shaxi River

    Institute of Scientific and Technical Information of China (English)

    王钦建

    2009-01-01

    对沙溪竹洲水电站水体的富营养化评价结论:水体总氮超出评价标准,库区具有藻类生长的营养条件,磷是藻类生长限制因子.3种评价方法结果基本一致,表明水体处于贫营养向中营养过渡类型,并现出向富营养化发展的趋势.库区浮游动物种类以轮虫(rotifera)和原生动物(protozoa)为主,浮游植物种类以绿藻门(Chlorophyta)和硅藻门(Bacilariophy-ta)为主,库区应属于中营养类型.

  9. 福建省九龙江江东库区浮游动物的生态研究%The Ecological Research of Zooplankton in Jiangdong Reservoir of Jiulong River in Fujian Province

    Institute of Scientific and Technical Information of China (English)

    干建彗; 郭东晖

    2012-01-01

    The zooplankton community of Jiangdong Reservoir was investigated in Jiulong River,Fujian province from March 2010 to February 2011. The result indicated that ninety-nine species were identified,of which 20 species were Protozoa,29 species were Rotif-era,39 species were Cladocera.and 11 species were Copepoda. The annual average abundance of zooplankton was 5 486. 73 L-1 ,the a-bundance of zooplankton was mainly determined by Protozoa and Rotifera,of which Protozoa was 4 926. 90 L-1,Rotifera was 552. 91 L-1 ,Cladocera was 5. 13 L-1 ,and Copepoda was 1. 79 L-1. The highest zooplankton abundance appeared in November, while the lowest in March. Temperature was the main influence factor of zooplankton community,and the abundance of Rotifera and Copepoda showed a significant positive relationship with Chlorophyll a. Sand mining probably accelerated the development of Protozoa, decreased the Margalef index of zooplankton. The pressure of fish prey and short retention time were the main reasons for low abundance of Cladocera and Copepoda.%于2010年3月-2011年2月对福建省九龙江江东库区的浮游动物进行了生态调查研究.研究结果表明,调查期间共采集到浮游动物99种,其中原生动物20种,轮虫29种,枝角类39种,桡足类11种.浮游动物丰度年均为5 486.73L-1,浮游动物的丰度主要由原生动物和轮虫组成,其中原生动物丰度最高,为4 926.90 L-1,轮虫为552.91L-1,枝角类为5.13 L-1,桡足类丰度最低,年均为1.79 L-1.浮游动物丰度最高值出现在11月,最低值出现在3月.温度是影响浮游动物群落的主要影响因子,轮虫和桡足类丰度分别与叶绿素a(Chl a)浓度存在显著正相关性.挖沙船的频繁活动可能促进了原生动物的生长,降低了浮游动物群落丰富度.短滞留时间和鱼类的捕食压力是造成枝角类和桡足类丰度低下的主要原因.

  10. Phylogenomics of unusual histone H2A Variants in Bdelloid rotifers.

    Directory of Open Access Journals (Sweden)

    Karine Van Doninck

    2009-03-01

    Full Text Available Rotifers of Class Bdelloidea are remarkable in having evolved for millions of years, apparently without males and meiosis. In addition, they are unusually resistant to desiccation and ionizing radiation and are able to repair hundreds of radiation-induced DNA double-strand breaks per genome with little effect on viability or reproduction. Because specific histone H2A variants are involved in DSB repair and certain meiotic processes in other eukaryotes, we investigated the histone H2A genes and proteins of two bdelloid species. Genomic libraries were built and probed to identify histone H2A genes in Adineta vaga and Philodina roseola, species representing two different bdelloid families. The expressed H2A proteins were visualized on SDS-PAGE gels and identified by tandem mass spectrometry. We find that neither the core histone H2A, present in nearly all other eukaryotes, nor the H2AX variant, a ubiquitous component of the eukaryotic DSB repair machinery, are present in bdelloid rotifers. Instead, they are replaced by unusual histone H2A variants of higher mass. In contrast, a species of rotifer belonging to the facultatively sexual, desiccation- and radiation-intolerant sister class of bdelloid rotifers, the monogononts, contains a canonical core histone H2A and appears to lack the bdelloid H2A variant genes. Applying phylogenetic tools, we demonstrate that the bdelloid-specific H2A variants arose as distinct lineages from canonical H2A separate from those leading to the H2AX and H2AZ variants. The replacement of core H2A and H2AX in bdelloid rotifers by previously uncharacterized H2A variants with extended carboxy-terminal tails is further evidence for evolutionary diversity within this class of histone H2A genes and may represent adaptation to unusual features specific to bdelloid rotifers.

  11. Water quality and potamoplankton evaluation of the Nile River in Upper Egypt

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    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

  12. A subtelomeric non-LTR retrotransposon Hebe in the bdelloid rotifer Adineta vaga is subject to inactivation by deletions but not 5' truncations

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    Gladyshev Eugene A

    2010-04-01

    Full Text Available Abstract Background Rotifers of the class Bdelloidea are microscopic freshwater invertebrates best known for: their capacity for anhydrobiosis; the lack of males and meiosis; and for the ability to capture genes from other non-metazoan species. Although genetic exchange between these animals might take place by non-canonical means, the overall lack of meiosis and syngamy should greatly impair the ability of transposable elements (TEs to spread in bdelloid populations. Previous studies demonstrated that bdelloid chromosome ends, in contrast to gene-rich regions, harbour various kinds of TEs, including specialized telomere-associated retroelements, as well as DNA TEs and retrovirus-like retrotransposons which are prone to horizontal transmission. Vertically-transmitted retrotransposons have not previously been reported in bdelloids and their identification and studies of the patterns of their distribution and evolution could help in the understanding of the high degree of TE compartmentalization within bdelloid genomes. Results We identified and characterized a non-long terminal repeat (LTR retrotransposon residing primarily in subtelomeric regions of the genome in the bdelloid rotifer Adineta vaga. Contrary to the currently prevailing views on the mode of proliferation of non-LTR retrotransposons, which results in frequent formation of 5'-truncated ('dead-on-arrival' copies due to the premature disengagement of the element-encoded reverse transcriptase from its template, this non-LTR element, Hebe, is represented only by non-5'-truncated copies. Most of these copies, however, were subject to internal deletions associated with microhomologies, a hallmark of non-homologous end-joining events. Conclusions The non-LTR retrotransposon Hebe from the bdelloid rotifer A. vaga was found to undergo frequent microhomology-associated deletions, rather than 5'-terminal truncations characteristic of this class of retrotransposons, and to exhibit preference for

  13. Ecological factors affecting the distribution of the zooplankton community in the Tigris River at Baghdad region, Iraq

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    Shayma Abdulwahab

    2015-01-01

    Full Text Available Biodiversity of zooplankton in the Tigris River running in Baghdad City, central Iraq, was investigated. Fourteen physical and chemical parameters, were analyzed, these parameters include water and air temperature, pH, EC, turbidity, TDS, DO, BOD5, total hardness, Ca+2, Mg+2, chloride, nitrate and reactive phosphate. Most of these values were within of the Iraqi and international standard limits. In all, 106 taxonomy units of zooplankton were identified, including 65 taxa belonging to rotifers, 25 taxa to copepod and 16 taxa to Cladocera. Values of species richness index of rotifers varied from 1.051 to 12.98, for Cladocera from 1.285 to 3.41 and for copepod from 1.5 to 7.2. The Shannon–Weiner index of Rotifera varied from 0.67 to 3, 0.50–1.72 for Cladocera and from 0.91 to 2.51 for Copepoda. The uniformity index of zooplankton varied from 0.41 to 0.93 for rotifer, 0.33–1 for Cladocera and 0.36–1 for Copepoda. According to statistical analysis, temperature, EC, TDS and dissolved oxygen were observed as major factors which restrict the abundance and diversity of the zooplankton communities in the Tigris River.

  14. Diel vertical migration and distribution of zooplankton in a tropical Brazilian reservoir

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    Ana M. A. da Silva

    2009-03-01

    Full Text Available Diel vertical migration of zooplankton is a strategy usually employed to reduce the risk of predation, and it can also be associated with the environmental day/night shifts, particularly of light and temperature. The aim of this study was to identify the diel patterns of zooplankton vertical migration and their relationship to the environmental variables in a shallow reservoir in northeastern Brazil. Water samples were taken at a single five-meter depth sampling station (Subsurface, 50% Io, 1% Io and Bottom at four-hour intervals over a period of 24 hours. Two Cladocera species (Moina minuta and Diaphanosoma spinulosum and one Copepoda species (Notodiaptomus cearensis showed similar patterns of nocturnal migration, staying at the bottom during the day and rising toward the surface in the afternoon and during the night. Brachionus falcatus and Hexarthra mira (Rotifera showed no patterns of vertical migration and their vertical distributions were relatively homogenous. Environmental variables were poorly correlated to the species distribution, suggesting that other mechanisms may be responsible of inducing vertical migration.

  15. Zooplankton community resilience and aquatic environmental stability on aquaculture practices: a study using net cages.

    Science.gov (United States)

    Dias, J D; Simões, N R; Bonecker, C C

    2012-02-01

    Fish farming in net cages causes changes in environmental conditions. We evaluated the resilience of zooplankton concerning this activity in Rosana Reservoir (Paranapanema River, PR-SP). Samples were taken near the net cages installed at distances upstream and downstream, before and after net cage installation. The resilience was estimated by the decrease in the groups' abundance after installing the net cages. The zooplankton community was represented by 106 species. The most abundant species were Synchaeta pectinata, S. oblonga, Conochilus coenobasis, Polyarthra dolichoptera and C. unicornis (Rotifera), Ceriodaphnia cornuta, Moina minuta, Bosmina hagmanni and C. silvestrii (Cladocera) and Notodiaptomus amazonicus (Copepoda). The resilience of microcrustaceans was affected in the growing points as this activity left the production environment for longer, delaying the natural ability of community responses. Microcrustaceans groups, mainly calanoid and cyclopoid copepods, had a different return rate. The net cage installation acted as a stress factor on the zooplankton community. Management strategies that cause fewer risks to the organisms and maximize energy flow may help in maintaining system stability. PMID:22437379

  16. 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.

  17. Independent origins of parasitism in Animalia.

    Science.gov (United States)

    Weinstein, Sara B; Kuris, Armand M

    2016-07-01

    Nearly half of all animals may have a parasitic lifestyle, yet the number of transitions to parasitism and their potential for species diversification remain unresolved. Based on a comprehensive survey of the animal kingdom, we find that parasitism has independently evolved at least 223 times in just 15 phyla, with the majority of identified independent parasitic groups occurring in the Arthropoda, at or below the level of Family. Metazoan parasitology is dominated by the study of helminthes; however, only 20% of independently derived parasite taxa belong to those groups, with numerous transitions also seen in Mollusca, Rotifera, Annelida and Cnidaria. Parasitism is almost entirely absent from deuterostomes, and although worm-like morphology and host associations are widespread across Animalia, the dual symbiotic and trophic interactions required for parasitism may constrain its evolution from antecedent consumer strategies such as generalist predators and filter feeders. In general, parasitic groups do not differ from their free-living relatives in their potential for speciation. However, the 10 largest parasitic clades contain 90% of described parasitic species, or perhaps 40% of all animal species. Hence, a substantial fraction of animal diversity on the Earth arose following these few transitions to a parasitic trophic strategy. PMID:27436119

  18. Potential pest transfer mediated by international ornamental plant trade

    Science.gov (United States)

    Patoka, Jiří; Bláha, Martin; Kalous, Lukáš; Vrabec, Vladimír; Buřič, Miloš; Kouba, Antonín

    2016-01-01

    In recent years, the keeping of ornamental freshwater animals and plants in garden ponds has been growing in popularity. Water hyacinth (Eichhornia crassipes) is one of the preferred macrophytes seasonally imported mainly from South-eastern Asia throughout the world. This constitutes a secondary introduction inasmuch as the species is native to South America. Although many assemblages of aquatic invertebrates have been described as associated with this plant in the wild, there has been no research focused on their potential introduction via the international plant trade. We examined 216 specimens of water hyacinths imported for ornamental purposes from Indonesia into the Czech Republic. Numerous meio- and macroinvertebrates belonging to at least 39 species were captured. On the total number of individuals, the highest prevalence was of Tubulinea and Rotifera. Most of these were still alive and vital, including a caterpillar of the Indo–Australian invasive moth Spodoptera litura. Water hyacinths are usually placed into outdoor ponds immediately after import, which facilitates the release of non-target alien species. The present paper aims to draw attention to “hitchhikers” associated with the ornamental trade. PMID:27221025

  19. Bacterial and eukaryotic biodiversity patterns in terrestrial and aquatic habitats in the Sør Rondane Mountains, Dronning Maud Land, East Antarctica.

    Science.gov (United States)

    Obbels, Dagmar; Verleyen, Elie; Mano, Marie-José; Namsaraev, Zorigto; Sweetlove, Maxime; Tytgat, Bjorn; Fernandez-Carazo, Rafael; De Wever, Aaike; D'hondt, Sofie; Ertz, Damien; Elster, Josef; Sabbe, Koen; Willems, Anne; Wilmotte, Annick; Vyverman, Wim

    2016-06-01

    The bacterial and microeukaryotic biodiversity were studied using pyrosequencing analysis on a 454 GS FLX+ platform of partial SSU rRNA genes in terrestrial and aquatic habitats of the Sør Rondane Mountains, including soils, on mosses, endolithic communities, cryoconite holes and supraglacial and subglacial meltwater lenses. This inventory was complemented with Denaturing Gradient Gel Electrophoresis targeting Chlorophyta and Cyanobacteria. OTUs belonging to the Rotifera, Chlorophyta, Tardigrada, Ciliophora, Cercozoa, Fungi, Bryophyta, Bacillariophyta, Collembola and Nematoda were present with a relative abundance of at least 0.1% in the eukaryotic communities. Cyanobacteria, Proteobacteria, Bacteroidetes, Acidobacteria, FBP and Actinobacteria were the most abundant bacterial phyla. Multivariate analyses of the pyrosequencing data revealed a general lack of differentiation of both eukaryotes and prokaryotes according to habitat type. However, the bacterial community structure in the aquatic habitats was dominated by the filamentous cyanobacteria Leptolyngbya and appeared to be significantly different compared with those in dry soils, on mosses, and in endolithic habitats. A striking feature in all datasets was the detection of a relatively large amount of sequences new to science, which underscores the need for additional biodiversity assessments in Antarctic inland locations. PMID:26936447

  20. Plankton Resting Stages in the Marine Sediments of the Bay of Vlorë (Albania

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    Fernando Rubino

    2013-01-01

    Full Text Available In the frame of the INTERREG III CISM project, sediment cores were collected at 2 stations in the Gulf of Vlorë to study the plankton resting stage assemblages. A total of 87 morphotypes were identified and produced by Dinophyta, Ciliophora, Rotifera, and Crustacea. In 22 cases, the cyst belonged to a species absent from the plankton of the same period. The most abundant resting stages were those produced by Scrippsiella species (Dinophyta. Some calcareous cysts were identified as fossil species associated with Pleistocene to Pliocene sediment, although they were also found in surface sediments and some of them successfully germinated, thus proving their modern status. Total abundance generally decreased with sediment depth at station 40, while station 45 showed distinct maxima at 3 and 8 cm below the sediment surface. The depth of peak abundance in the sediment varied with species. This paper presents the first study of the plankton resting stages in the Bay of Vlorë. The study confirmed the utility of this type of investigation for a more correct evaluation of species diversity. In addition, the varying distribution with sediment depth suggests that this field could be of some importance in determining the history of species assemblages.

  1. Spatial heterogeneity in a deep artificial lake plankton community revealed by PCR-DGGE fingerprinting

    Science.gov (United States)

    Li, Qiang; Zhao, Yue; Zhang, Xu; Wei, Yuquan; Qiu, Linlin; Wei, Zimin; Li, Fuheng

    2015-05-01

    To explore the spatial heterogeneity of plankton communities in a deep artificial lake (Songhua Lake, China), samples were collected at seven sites. Samples were investigated by denaturing gradient gel electrophoresis (DGGE) analysis of the PCR-amplified 16S and 18S rRNA genes and specific bands were sequenced. Cluster analysis of the DGGE profiles revealed that all of the samples grouped into two distinct clusters, in accordance with sampling site; while in each cluster, the divergence of sub-clusters correlated with sampling depth. Sequence analysis of selected dominant DGGE bands revealed that most sequenced phylotypes (84%) exhibited ≥97% similarity to the closest sequences in GenBank, and were affiliated with ten common freshwater plankton phyla ( Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Bacillariophyta, Pyrrophyta, Cryptophyta, Ciliophora, Stramenopiles, and Rotifera). Several of these groups are also found worldwide, indicating the cosmopolitan distribution of the phylotypes. The relationships between DGGE patterns and environmental factors were analyzed by redundancy analysis (RDA). The results suggested that, total nitrogen, nitrate, nitrite, ammonia, and CODMn concentrations, and water temperature were strongly correlated with the variation in plankton composition.

  2. Potential pest transfer mediated by international ornamental plant trade.

    Science.gov (United States)

    Patoka, Jiří; Bláha, Martin; Kalous, Lukáš; Vrabec, Vladimír; Buřič, Miloš; Kouba, Antonín

    2016-01-01

    In recent years, the keeping of ornamental freshwater animals and plants in garden ponds has been growing in popularity. Water hyacinth (Eichhornia crassipes) is one of the preferred macrophytes seasonally imported mainly from South-eastern Asia throughout the world. This constitutes a secondary introduction inasmuch as the species is native to South America. Although many assemblages of aquatic invertebrates have been described as associated with this plant in the wild, there has been no research focused on their potential introduction via the international plant trade. We examined 216 specimens of water hyacinths imported for ornamental purposes from Indonesia into the Czech Republic. Numerous meio- and macroinvertebrates belonging to at least 39 species were captured. On the total number of individuals, the highest prevalence was of Tubulinea and Rotifera. Most of these were still alive and vital, including a caterpillar of the Indo-Australian invasive moth Spodoptera litura. Water hyacinths are usually placed into outdoor ponds immediately after import, which facilitates the release of non-target alien species. The present paper aims to draw attention to "hitchhikers" associated with the ornamental trade. PMID:27221025

  3. Feeding of the hyperbenthic mysid Neomysis integer in the maximum turbidity zone of the Elbe, Westerschelde and Gironde estuaries

    Science.gov (United States)

    Fockedey, N.; Mees, J.

    1999-10-01

    The diet of the mysid Neomysis integer in the maximum turbidity zone (MTZ) of three European estuaries (Elbe, Westerschelde and Gironde) was investigated in spring 1993. The quality and quantity of the diet were assessed through measurement of the stomach fullness and microscopical analysis of the stomach content combined with image analyses. N. integer was found to be an omnivore which mainly utilizes mesozooplankton and detritus carbon pools. The quality of the diet did not differ between the sexes or between different developmental stages, although smaller individuals consumed fewer items. In all three estuaries the diet was dominated by Copepoda Calanoida (5-10 Eurytemora affinis ind -1 for adults; 2-5 ind -1 and 2-3 ind -1 for subadults and juveniles, respectively) and was supplemented with Rotifera and Cladocera. Phytoplankton and benthic organisms, though present in the stomachs, were negligible. Macrophytal detritus and amorphous material, the latter unidentifiable under the light microscope, were very abundant food items. The amorphous detritus was found to originate from the suspended sediment flocs which are characteristic for the MTZ and mainly consist of clay minerals. The energetic value of the flocs for N. integer remains unclear.

  4. Distribution and diet of larval and juvenile Arctic cod ( Boreogadus saida) in the shallow Canadian Beaufort Sea

    Science.gov (United States)

    Walkusz, Wojciech; Paulic, Joclyn E.; Williams, William J.; Kwasniewski, Slawomir; Papst, Michael H.

    2011-02-01

    The distribution and diet of larval and juvenile Arctic cod ( Boreogadus saida) were studied during summer 2005 in the coastal Canadian Beaufort Sea. A total of 275 individuals were captured and the highest abundance was observed at station depths of 20-30 m. This corresponds well with the location of the frontal zone where the Mackenzie River plume water and open sea water meet. Diet examinations were performed on 220 Arctic cod, which were found undamaged from sampling. We observed a gradual decrease in prey number per fish and increase in prey size as larvae grew which corresponded to a shift from Rotifera and nauplii towards larger copepodid stages. However, at all sizes, the larvae remain generalists and feed on a broad range of organisms. Environmental changes due to climate warming could have a two-fold impact on fish larvae feeding in the studied region. First, the potential for increased primary production may lead to increased zooplankton production that may impact the feeding and nutrition positively. On the other hand, greater discharge of turbid water from the Mackenzie River may reduce light penetration in the water column that may negatively influence the ability of visual predators to successively forage.

  5. 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.

  6. Abundance of plankton population densities in relation to bottom soil textural types in aquaculture ponds

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    F. Siddika

    2012-06-01

    Full Text Available Plankton is an important food item of fishes and indicator for the productivity of a water body. The present study was conducted to evaluate the effects of bottom soil textural conditions on abundance of plankton in aquaculture pond. The experiment was carried out using three treatments, i.e., ponds bottom with sandy loam (T1, with loam (T2 and with clay loam (T3. The ranges of water quality parameters analyzed were suitable for the growth of plankton during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed higher ranges in T2. A total 20 genera of phytoplankton were recorded belonged to Chlorophyceae (7, Cyanophyceae (5, Bacillariophyceae (5, Euglenophyceae (2 and Dinophyceae (1. On the other hand, total 13 genera of zooplankton were recorded belonged to Crustacea (7 and Rotifera (6. The highest ranges of phytoplankton and zooplankton densities were found in T2 where low to medium-type bloom was observed during the study period. Consequently, the mean abundance of plankton (phytoplankton and zooplankton density was significantly highest in T2. The highest abundance of plankton in the T2 indicated that pond bottom with loamy soil is suitable for the growth and production of plankton in aquaculture ponds.

  7. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    Science.gov (United States)

    Tang, L.; Li, H. X.; Yan, Y.

    2012-04-01

    Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm-2 and 690.51 ± 210.64 μg 10 cm-2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 %) and polychaetes (1.39 %). Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=-0.747, Pnematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, Pnematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of their correlations and variance, the diversity of this community was likely to be influenced by environmental variations.

  8. Water quality and zooplankton in tanks with larvae of Brycon Orbignyanus (Valenciennes, 1949).

    Science.gov (United States)

    Sipaúba-Tavares, L H; Alvarez, E J da S; Braga, F M de S

    2008-02-01

    Due to the importance of water variables conditions and available food in the development and survival of fish larvae, the current research evaluates the effects of two different food treatments (ration + zooplankton and only zooplankton) and water quality in tanks with Brycon orbignyanus larvae. Total water transparency (45 cm) has been mainly associated with short residence time, continuous water flow and shallowness. Dissolved oxygen ranged between 1.32 and 7.00 mg.L(-1) in tanks with ration + zooplankton and between 1.82 and 7.60 mg.L(-1) in tanks with only zooplankton treatments. Nutrients were directly affected by the addition of ration in water, with the exception of nitrite. Ten Rotifera species were found represented by high densities, ranging between 8.7 x 10(5) and 1.3 x 10(6) org.m(-3), throughout the experimental period (January to March/1996). Cladocera had the lowest density in the four tanks under analysis and ranged between 4.7 x 10(4) and 2.1 x 10(5) org.m(-3) for the six species. Diaphanosoma birgei has been classified as the most frequent species. Since ration + zooplankton produced better larvae yield, this treatment is recommended for Brycon orbignyanus larvae.

  9. Vertical distribution of zooplankton in the water column of Lago Amapá, Rio Branco, Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Erlei Cassiano Keppeler

    2004-06-01

    Full Text Available The aim of investigation was to study the model of vertical distribution in Lago Amapá, taking into consideration the seasonality of its zooplanktonic composition. Lago Amapá (10º2'36"S and 67º50'24"W is located in the floodplain of the Rio Acre. Samplings were conducted at three different depths of the water column, to study the vertical distribution of zooplankton populations and determine some physico-chemical and biological parameters of Lago Amapá. Weekly samples were taken with a Van Dorn sampler. The species showed greater concentrations at the by means of water column. Thirty-eight zooplankton species were found in the samples represented by Rotifera (30, Cladocera (5 and Cyclopoida (3. The temperature of the water column showed a tendency toward relatively high values (about 30ºC with little variation, consequently resulting in low viscosity. Based of Jaccard's index, it was seen that during the low-water phase, S1 and S3 of the three sampling stations studied, had greater similarity (Cj = 0.7058 in the middle of the water column. Lago Amapá showed characteristics in line with the intermediate disturbance hypothesis model, favoring colonization by opportunistic species such as rotifers.O objetivo desta investigação foi observar a distribuição vertical da comunidade do zooplâncton no Lago Amapá (10º2'36"S e 67º50'24"W, localizado na planície de inundação do Rio Acre. Amostragens foram conduzidas em três diferentes profundidades da coluna da água, considerando aspectos sazonais do zooplâncton, parâmetros físicos, químicos e biológicos. Coletas foram realizadas semanalmente com Garrafa de Van Dorn. As espécies apresentaram maiores concentrações no meio da coluna da água. Foram encontradas 38 espécies, assim distribuídas: Rotifera (30, Cladocera (5 e Cyclopoida (3. A temperatura da coluna da água em geral apresentou-se alta, em torno de 30ºC, com pequena variação, resultando em baixa viscosidade. O

  10. EVALUACIÓN DE LA ROTIFEROFAUNA PRESENTE EN EL COMPLEJO DE PAJARALES DURANTE LA ÉPOCA LLUVIOSA, DEPARTAMENTO DE MAGDALENA, COLOMBIA Assessment Of The Pajarales Complex Rotiferofauna During The Rainy Season, Departamento De Magdalena, Colombia

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    SEBASTIÁN CELIS

    Full Text Available RESUMEN Con miras a evaluar posibles efectos de la recomunicación del río Magdalena con su antiguo delta, se determinó la abundancia y composición de la rotiferofauna del Complejo de Pajarales (CP, durante el período de mayor abundancia anual de zooplancton. El phylum Rotifera fue seleccionado por sus altas tasas reproductivas y eficiencia en procesos de transformación energética. Las muestras se colectaron con botella van Dorn durante la segunda temporada lluviosa de 2006. En cada una de las cuatro estaciones analizadas se registraron la salinidad, temperatura, pH y oxígeno disuelto. La diversidad se calculó empleando el índice de Shannon-Wiener H’ (log10 comparando estaciones y fechas de muestreo para establecer variaciones en el período de estudio. Gráficamente se relacionaron variables fisicoquímicas con valores de diversidad que emplearon un α de 0.05 y 95% de intervalo de confianza. En total, fueron encontrados 20 morfotipos pertenecientes a las familias Brachionidae, Lecanidae, Filiniidae, Synchaetidae, Hexarthriidae y Testudinellidae, siendo Brachionidae y Lecanidae las más abundantes. La relación entre diversidad y variables fisicoquímicas, indica que la salinidad es la principal responsable de la diversidad de rotíferos. En conclusión, la rotiferofauna actual en el CP es más abundante y diversa que hace 16 años, antes de la recomunicación con el río Magdalena. Así mismo, la concentración de oxigeno disuelto, pH y salinidad son diferentes. Teniendo en cuenta que la salinidad es el factor que más influyó en la diversidad de rotíferos, la reapertura de canales probablemente favoreció el incremento en la diversidad de rotíferos en el CP.ABSTRACT In order to assess the potential effects of the Magdalena River recommunication with its former delta, we studied the abundance and composition of the rotiferofauna of the Pajarales Complex (PC during its highest annual zooplankton abundance. We selected the Rotifera

  11. Meta-Zooplankton Investigation and Water Quality Assessment in Yelang Reservoir in Spring%夜郎湖水库春季后生浮游动物调查与水质评价

    Institute of Scientific and Technical Information of China (English)

    宁爱丽; 陈椽; 潘静; 徐兴华; 龙胜兴

    2012-01-01

    2011年3月对夜郎湖水库后生浮游动物及水质情况进行了调查.共鉴定出后生浮游动物17种,其中,桡足类2种,枝角类3种,轮虫类12种.优势种为针簇多肢轮虫(Polyarthra trigla Ehrenberg)、矩形龟甲轮虫(Keratella quadrata(Müller))、螺形龟甲轮虫(Keratella cochlearis Gosse)、曲腿龟甲轮虫(Keratella valga Ehrenberg)、透明溞(Daphnia hyalina Leydig)、长额象鼻溞(Bosmina longirostris (O.F.Müller))和近邻剑水蚤(Cyclops vicinus Uijanin).后生浮游动物数量为0.2~570.0 ind/L.利用后生浮游动物群落结构、理化指标及生物多样性指数进行综合评价,该水库水质为Ⅰ类.%Meta-zooplankton in Yelanghu reservoir was investigated; and the water quality was assessed in March 2011. The results indicated that 17 species of meta-zooplanktons were identified, consisting of 12 species of Rotifera, 2 Species of Clado-cera, and 3 species of Copepoda, The dominant species were Cyclops vicinns Uijanin, Daphnia hyalina Leydig, Bosmina lon-girostris (O.F.Müller), K. quadrata (Müller), K. cochlearis Gosse,Keratella valga Ehrenberg and Polyarthra trigla Ehrenberg. The abundance of meta-zooplankton ranged from 0.2 to 570.0 ind/L. The community structure of meta-zooplankton, physical and chemical indicators and diversity indexes were used to evaluate the water quality; and it was revealed that the water quality belonged to class I .

  12. Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk).

    Science.gov (United States)

    Staniszewska, Marta; Nehring, Iga; Mudrak-Cegiołka, Stella

    2016-06-01

    The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011-2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g(-1) dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m(-3)), the bioconcentration factor also rose (to max 46.1·10(3)), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become "diluted" in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone. PMID:26970874

  13. Spatial variations in zooplankton diversity in waters contaminated with composite effluents

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    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.

  14. Accumulation of atmospheric radionuclides and heavy metals in cryoconite holes on an Arctic glacier.

    Science.gov (United States)

    Łokas, Edyta; Zaborska, Agata; Kolicka, Małgorzata; Różycki, Michał; Zawierucha, Krzysztof

    2016-10-01

    Surface of glaciers is covered by mineral and organic dust, together with microorganisms forming cryoconite granules. Despite fact that glaciers and ice sheets constitute significance part of land surface, reservoir of freshwater, and sites of high biological production, the knowledge on the cryoconite granules still remain unsatisfactory. This study presents information on radionuclide and heavy metal contents in cryoconites. Cryoconites collected from the Hans Glacier in SW Spitsbergen reveal high activity concentrations of anthropogenic ((238,239,240)Pu, (137)Cs, (90)Sr) and natural ((210)Pb) radionuclides. The (238)Pu/(239+240)Pu activity ratios in these cryoconites significantly exceed the mean global fallout ratio (0.025). The (238)Pu/(239+240)Pu ranged from 0.064 to 0.118. The (239+240)Pu/(137)Cs varied from 0.011 ± 0.003 to 0.030 ± 0.007. Such activity ratios as observed in these cryoconites were significantly higher than the values characterizing global fallout, pointing to possible contributions of these radionuclides from other sources. Heavy metals (Pb, Cd, Cu, Zn, Fe, and Mn) in cryoconites exceed both UCC concentrations and local rocks' concentrations, particularly for cadmium. The concentration ratios of stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(206)Pb) were determined to discriminate between the natural and anthropogenic sources of Pb in cryoconites and to confirm the strong anthropogenic contribution to heavy metal deposition in the Arctic. In investigated cryoconite holes, two groups of invertebrates, both extremophiles, Tardigrada and Rotifera were detected. Our study indicate that cryoconites are aggregates of mineral and organic substances on surfaces of glaciers are able to accumulate large amounts of airborne pollutants bound to extracellular polymeric substances secreted by microorganisms.

  15. Feeding activity and influence of intraspecific competition on zooplankton communities by jundiá (Rhamdia quelen Quoy and Gaimard, 1824) in laboratory.

    Science.gov (United States)

    Brandão-Gonçalves, L; Sebastien, N Y

    2013-11-01

    Experiments were designed to determine if the juvenile forms of jundia (Rhamdia quelen) exhibit selectivity feeding on zooplanktonic organisms and the influence of intraspecific competition on the diet. The fish were maintained in 5000-L containers, and after seven days from birth, they were acclimated in experimental units with different densities and supplied with water containing plankton (natural), where they remained for 24 h in the environment with food. In the first seven days at densities of 5 and 10 fish.L-1, the fish selected the Rotifera more intensely, and at densities of 20 and 40 fish.L-1, the Cladocera were more selected. At 14 days of age, the Cladocera were the most selected for all densities of fish. At 21 days of age, the juvenile forms of jundia maintained a preference for Cladocera, and there was an increase in the capture of Copepoda at a density of 40 fish.L-1. At 28 days of age, the Cladocera were the most captured at densities of 5 to 20 fish.L-1, and the consumption of copepods increased at a density of 40 fish.L-1. The juvenile forms of Rhamdia quelen showed a high feeding preference for Cladocera at all the ages tested (7, 14, 21 and 28 days), but the density of fish per litre influenced the capture of the preferential food. This study showed that the juvenile forms of jundia had a more rapid response to the presence of food at densities of more than 10 fish.L-1, and that at higher densities the fish decreased interactions of territorial defense and formed schools, which allowed the foraging of zooplanktonic organisms, larger in size, more agile and of greater energy gain, such as the Cladocera and copepods. PMID:24789392

  16. Effects of experimental eutrophization on zooplankton community

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    Ana Maria Alves de Medeiros

    2013-06-01

    Full Text Available AIMS: The present study evaluated the role that increased nutrient concentrations play on zooplankton community, by employing an experimental laboratory approach. METHODS: Experiments were conducted in the laboratory, where three trophic state conditions were simulated, namely, mesotrophic, eutrophic and hypereutrophic. Each treatment was replicated three times and individuals of Brachionus urceolaris (10 individuals, Hexarthra mira (5 (Rotifera, Latonopsis sp. (10, Moina minuta (10 (Cladocera and Thermocyclops sp. (5 (Copepoda were introduced to each replicate. On the first experiment day, and at 7-day intervals for a 14-day period (totaling three evaluations, all water content was collected from each container and filtered to determine the densities of each zooplankton species. Two-way MANOVA and one-way ANOVA designs were used to determine zooplankton density fluctuations among treatments and throughout the study period. Further, Generalized Linear Models (GLMs were employed to assess how environmental factors affected zooplankton numbers. Phytoplankton composition was also determined in the beginning and in the end of the experiment. RESULTS: B. urceolaris and copepod nauplii, which are typical of eutrophic environments, showed higher densities on the eutrophic and hypereutrophic treatments. Furthermore, cyanobacteria such as Aphanothece sp. and Merismopedia sp. were recorded on the eutrophic and hypereutrophic treatments, respectively. CONCLUSIONS: Similarly to what is frequently observed in the wild, the eutrophic treatment showed higher densities of particular zooplankton species which are known to temporarily benefit from an increase in trophic concentrations. Positive or negative responses from zooplankton dynamics (but also phytoplankton species, provide an important bioindicator framework. Furthermore, results of the present study outline the need for implementing recovery measures on aquatic environments subject to constant nutrient

  17. [Impact of Mikania micrantha invasion on soil meso- and micro-invertebrate community structure].

    Science.gov (United States)

    Quan, Guo-ming; Zhang, Jia-en; Xie, Jun-fang; Mao, Dan-juan; Xu, Hua-qin; Jiang, Wan-bing; Wen, Du-juan

    2011-07-01

    Mikania micrantha, a notorious exotic weed of Asteraceae family, has invaded successfully in southern China, and caused serious damages to native ecosystems. In this paper, a field survey was conducted in the Huolushan Forest Park of Guangzhou, China, aimed to understand the impact of M. micrantha invasion on the soil meso- and micro-invertebrate community. Three sampling sites were installed, including M. micrantha-invaded site, ecotone, and native vegetation site. Through four samplings in 2009, a total of 5206 soil meso- and micro-invertebrate individuals were collected, belonging to 4 phyla, 10 classes, and 19 orders, among which, Nematoda was the dominant group, and Acarina, Collembolan, and Rotifera were the common groups. M. micrantha invasion altered the characteristics of soil meso- and micro-invertebrate community structure. Compared with those at the other two sampling sites, the numbers of total individuals, Nematoda, and Acarina at M. micrantha-invaded site increased significantly, but the groups of soil meso- and micro-invertebrates had less change. At M. micrantha-invaded site, the density-group index (DG) of soil meso- and micro-invertebrates was significantly higher, Margalef richness index (D) and Simpson dominance index (C) tended to ascend, but Pielou evenness index (E) and Shannon index (H') tended to descend. The similarity coefficient of soil meso- and micro-invertebrate community between M. micrantha-invaded site and ecotone was higher than that between M. micrantha-invaded site and native vegetation site. The changes of local climate conditions, plant litters, root secretions, and soil physical-chemical properties caused by M. micrantha invasion could be the major contributing factors that altered the community structure of soil meso- and micro-invertebrates at M. micrantha-invaded site. PMID:22007466

  18. Preliminary assessment of the zooplankton community composition in a region under the influence of a uranium mine (Caldas, Southeastern Brazil)

    International Nuclear Information System (INIS)

    The Ore Treatment Unit consists of an open cast mine (CM), its mining waste areas, facilities for the physical treatment of the ore, and a chemical treatment plant for uranium extraction. At CM, the processes of acid drainage create effluents, which are treated by chemical processes and, thereafter, disposed of in Antas dam. The objective of the present study was to make an inventory of zooplanktonic and describe the physicochemical characteristics of site CM and at the site of treated effluents disposal (site 41), located at Antas dam. Water samples were collected in October/08 and January/09, in order to describe the abiotic variables and the zooplankton community. The average values of conductivity at sites CM and 41 were 2415 and 422 μ/cm2, respectively. Values of pH at site CM remained acid, whereas, at site 41 we recorded values near neutrality. The concentrations of total nutrients at both sampling sites were higher in the rainy season. Zooplankton species richness present at site CM was lower than at site 41, and there were only two identified species Bosmina sp and Keratella americana. At site 41 we recorded more species, mainly of the Rotifera. Among Cladocera, we identified two species, regarding Copepoda, the orders Cyclopoida and Calanoida were present. At site CM the density values were lower compared to site 41. The preliminary assessment of the zooplankton community showed lower values of species richness and density at site CM, what may be probably explained by the adverse environmental conditions for zooplankton community. (author)

  19. Hydro biological Characteristics of Some Semi-intensive fish culture ponds of Lumding town of Nagaon district, Assam

    Directory of Open Access Journals (Sweden)

    Tapashi Gupta

    2013-04-01

    Full Text Available Hydrobiological assessment is useful for assessing the ecological quality of aquatic ecosystem since biological communities integrate the environmental effects of water chemistry. Ten fish ponds from Lumding town, which were under semi-intensive culture practice, were selected for hydrobiological investigations. Physico-chemical properties were studied for a period of two years from July 2009 to June 2011.Some selected parameters like pH, dissolve oxygen, free carbon dioxide, TDS , total alkalinity, total hardness, sp. Conductivity, transparency and BOD were studied on some fish pond water. P H ranges from 6.1 to8.5. Temperature ranges from 18 0 C-32 0 C. Color shows light green to dirty green. Transparency ranges 17-42cm, dissolve oxygen ranges from 3.2-8.0 ppm, total alkalinity ranges from 7.9-20.0ppm, Hardness ranges from 60-135 ppm, sp.conductance ranges from123-247µmhos/cm and BOD ranges from3.1-5.0ppm. The phytoplankton belonging to division Chlorophycae and Cyanophycae are predominant over the others and zooplanktons belonging to group Protozoa, Rotifers are predominant. . A total of 30 species of belonging to Chlorophycae. Cyanophycae were identified and a total of 20 species of Rotifera, 2 species of Cladocera and 1 genus of Copepods were found. The present study is expected to help achieve better and higher yield of fish by the fish farmer with increasing awareness regarding the hydrobiological feature of the pond and implement scientific management practices accordingly

  20. Development of methods for evaluating toxicity to freshwater ecosystems.

    Science.gov (United States)

    Girling, A E; Pascoe, D; Janssen, C R; Peither, A; Wenzel, A; Schäfer, H; Neumeier, B; Mitchell, G C; Taylor, E J; Maund, S J; Lay, J P; Jüttner, I; Crossland, N O; Stephenson, R R; Persoone, G

    2000-02-01

    This article presents a summary of a collaborative research program involving five European research groups, that was partly funded by the European Commission under its Environmental Research Program. The objective of the program was to develop aquatic toxicity tests that could be used to obtain data for inclusion at Level 2 of the Risk Evaluation Scheme for the Notification of Substances as required by the 7th Amendment to EC Directive 79/831/EEC. Currently only a very limited number of test methods have been described that can be used for this purpose and these are based on an even smaller number of test species. Tests based upon algae (Chlamydomonas reinhardi, Scenedesmus subspicatus, and Euglena gracilis), protozoa (Tetrahymena pyriformis), rotifera (Brachionus calyciflorus), crustacea (Gammarus pulex), and diptera (Chironomus riparius) were developed. The tests encompassed a range of end points and were evaluated against four reference chemicals: lindane, 3, 4-dichloroaniline (DCA), atrazine, and copper. The capacity of the tests to identify concentrations that are chronically toxic in the field was addressed by comparing the effects threshold concentrations determined in the laboratory tests with those determined for similar and/or related species and end points in stream and pond mesocosm studies. The lowest no-observed-effect concentrations (NOEC), EC(x), or LC(x) values obtained for lindane, atrazine, and copper were comparable with the lowest values obtained in the mesocosms. The lowest chronic NOEC determined for DCA using the laboratory tests was approximately 200 times higher than the lowest NOEC in the mesocosms. PMID:10648133

  1. Accumulation of atmospheric radionuclides and heavy metals in cryoconite holes on an Arctic glacier.

    Science.gov (United States)

    Łokas, Edyta; Zaborska, Agata; Kolicka, Małgorzata; Różycki, Michał; Zawierucha, Krzysztof

    2016-10-01

    Surface of glaciers is covered by mineral and organic dust, together with microorganisms forming cryoconite granules. Despite fact that glaciers and ice sheets constitute significance part of land surface, reservoir of freshwater, and sites of high biological production, the knowledge on the cryoconite granules still remain unsatisfactory. This study presents information on radionuclide and heavy metal contents in cryoconites. Cryoconites collected from the Hans Glacier in SW Spitsbergen reveal high activity concentrations of anthropogenic ((238,239,240)Pu, (137)Cs, (90)Sr) and natural ((210)Pb) radionuclides. The (238)Pu/(239+240)Pu activity ratios in these cryoconites significantly exceed the mean global fallout ratio (0.025). The (238)Pu/(239+240)Pu ranged from 0.064 to 0.118. The (239+240)Pu/(137)Cs varied from 0.011 ± 0.003 to 0.030 ± 0.007. Such activity ratios as observed in these cryoconites were significantly higher than the values characterizing global fallout, pointing to possible contributions of these radionuclides from other sources. Heavy metals (Pb, Cd, Cu, Zn, Fe, and Mn) in cryoconites exceed both UCC concentrations and local rocks' concentrations, particularly for cadmium. The concentration ratios of stable lead isotopes ((206)Pb/(207)Pb, (208)Pb/(206)Pb) were determined to discriminate between the natural and anthropogenic sources of Pb in cryoconites and to confirm the strong anthropogenic contribution to heavy metal deposition in the Arctic. In investigated cryoconite holes, two groups of invertebrates, both extremophiles, Tardigrada and Rotifera were detected. Our study indicate that cryoconites are aggregates of mineral and organic substances on surfaces of glaciers are able to accumulate large amounts of airborne pollutants bound to extracellular polymeric substances secreted by microorganisms. PMID:27372266

  2. Food web effects of titanium dioxide nanoparticles in an outdoor freshwater mesocosm experiment.

    Science.gov (United States)

    Jovanović, Boris; Bezirci, Gizem; Çağan, Ali Serhan; Coppens, Jan; Levi, Eti E; Oluz, Zehra; Tuncel, Eylül; Duran, Hatice; Beklioğlu, Meryem

    2016-09-01

    Over the course of 78 days, nine outdoor mesocosms, each with 1350 L capacity, were situated on a pontoon platform in the middle of a lake and exposed to 0 μg L(-1) TiO2, 25 μg L(-1) TiO2 or 250 μg L(-1) TiO2 nanoparticles in the form of E171 TiO2 human food additive five times a week. Mesocosms were inoculated with sediment, phytoplankton, zooplankton, macroinvertebrates, macrophytes and fish before exposure, ensuring a complete food web. Physicochemical parameters of the water, nutrient concentrations, and biomass of the taxa were monitored. Concentrations of 25 μg L(-1) TiO2 and 250 μg L(-1) TiO2 caused a reduction in available soluble reactive phosphorus in the mesocosms by 15 and 23%, respectively, but not in the amount of total phosphorus. The biomass of Rotifera was significantly reduced by 32 and 57% in the TiO2 25 μg L(-1) and TiO2 250 μg L(-1) treatments, respectively, when compared to the control; however, the biomass of the other monitored groups-Cladocera, Copepoda, phytoplankton, macrophytes, chironomids and fish-remained unaffected. In conclusion, environmentally relevant concentrations of TiO2 nanoparticles may negatively affect certain parameters and taxa of the freshwater lentic aquatic ecosystem. However, these negative effects are not significant enough to affect the overall function of the ecosystem, as there were no cascade effects leading to a major change in its trophic state or primary production. PMID:26901391

  3. Global isolation by distance despite strong regional phylogeography in a small metazoan

    Directory of Open Access Journals (Sweden)

    Mills Scott

    2007-11-01

    Full Text Available Abstract Background Small vagile eukaryotic organisms, which comprise a large proportion of the Earth's biodiversity, have traditionally been thought to lack the extent of population structuring and geographic speciation observed in larger taxa. Here we investigate the patterns of genetic diversity, amongst populations of the salt lake microscopic metazoan Brachionus plicatilis s. s. (sensu stricto (Rotifera: Monogononta on a global scale. We examine the phylogenetic relationships of geographic isolates from four continents using a 603 bp fragment of the mitochondrial COI gene to investigate patterns of phylogeographic subdivision in this species. In addition we investigate the relationship between genetic and geographic distances on a global scale to try and reconcile the paradox between the high vagility of this species and the previously reported patterns of restricted gene flow, even over local spatial scales. Results Analysis of global sequence diversity of B. plicatilis s. s. reveals the presence of four allopatric genetic lineages: North American-Far East Asian, Western Mediterranean, Australian, and an Eastern Mediterranean lineage represented by a single isolate. Geographically orientated substructure is also apparent within the three best sampled lineages. Surprisingly, given this strong phylogeographic structure, B. plicatilis s. s. shows a significant correlation between geographic and genetic distance on a global scale ('isolation by distance' – IBD. Conclusion Despite its cosmopolitan distribution and potential for high gene flow, B. plicatilis s. s. is strongly structured at a global scale. IBD patterns have traditionally been interpreted to indicate migration-drift equilibrium, although in this system equilibrium conditions are incompatible with the observed genetic structure. Instead, we suggest the pattern may have arisen through persistent founder effects, acting in a similar fashion to geographic barriers for larger

  4. 哈素海浮游动物群落结构季节变化规律研究%Zooplankton and Zoobenthos Investigation in Lake Hasuhai and the Estimation of Nutrition Status

    Institute of Scientific and Technical Information of China (English)

    王俊; 赵林

    2012-01-01

    2008年7月、8月和10月及2009年1月和4月,对哈素海浮游动物群落结构进行了调查,共检测出浮游动物4大类,2科28属62种.其中原生动物10属,31种;枝角类2属,6种;桡足类6属,8种.全年优势的浮游动物有无节幼体、象鼻溞、剑水蚤、龟甲轮虫、疣毛轮虫、多肢轮虫、晶囊轮虫、哲水蚤等.大型浮游动物的年均丰度为228.5个/L,年均生物量为1.934 mg/L;原生动物的年均丰度和生物量分别为1.68×104个/L和0.0499 mg/L.在各季节中夏季浮游动物量最多,春秋季次之,冬季最少.对哈素海浮游动物优势种类及丰度和生物量指标的分析结果显示,哈素海的水质状况为中富营养水体,并且受到一定程度的污染.%A monitoring of zooplankton and zoobenthos was conducted in Lake Hasuhai in July, August,2008 and January,April,2009. A total of 28 genera and 62 species of zooplankton were detected in Lake Hasuhai. These include 10 genera and 17 species of Protozoa, 10 genera and 31 species of Rotifera, 2 genera and 6 species of Cladocera,and 6 genera and 8 species of Copepods. Zooplankton of the full-year advantage include Nauplii, Bosmina, Cyclopoida, Keratella, Synchaetidae, Polyarthra, Asplanchnidae and Calanidae. The annual large zooplankton adundance was 228. 5/L and biomass was 1. 934 mg/L. The average annual abundance and biomass of the protozoan were 1. 68 × 104/L,0. 049 9 mg/L in each of seasons the quantity of Zooplankton in summer than spring and autumn,and winter at least. According to zooplankton, abundance and biomass indicators in Lake Hasuhai, the status of water quality is middle nutritional water and a certain degree of pollution.

  5. Zooplankton Community Structure and Its Seasonal Variation in the Surface Water of Lugu Lake%泸沽湖表层水体浮游动物种群结构及季节变化

    Institute of Scientific and Technical Information of China (English)

    董云仙; 王忠泽

    2014-01-01

    is the deep plateau lake on the Yunnan-Guizhou Plateau with the highest latitude and alti-tude.Study of the zooplankton community in Lugu Lake was first reported in 1983 and focused on Rotifera, Copep-oda and Cladocera, but no published research has been found on the zooplankton of Lugu Lake.To characterize zo-oplankton community structure, a seasonal investigation of the zooplankton in Lugu Lake was carried out in January, April, August and November of 2010 at nine sample sites.Characteristics of the zooplankton community including structure, species composition, distribution and seasonal variation were described and the relationship of zooplankton with water quality and macrophytes were analyzed to reveal the primary factors affecting zooplankton bi-omass.Zooplankton samples for qualitative analysis were collected with a No.25 plankton net and fixed with Lugol′s solution after filtration.For quantitative analysis of protozoa and rotifers, 1 L water samples were collected 0.5 m below surface.For quantitative analysis of copepods and cladocerans, 10 L water sample were filtered with a No.25 plankton net.Counting and species identification in all samples were carried out under a microscope.A total of 80 species of zooplankton, belong to 33 families and 58 genera were observed in Lugu Lake, including Protozoa (10 families, 13 genera and 19 species), Rotifera (10 families, 22 genera and 32 species), Cladocera (4 families, 9 genera and 13 species), Copepoda (3 families, 8 genera and 10 species), and other taxa (6 families, 6 genera and 6 species) .The range of plankton densities with average number and percent contribution to total zooplankton density in parentheses were as follows:total zooplankton, 219.4-2 200.3 ind/L (813.2 ind/L, 100%);Proto-zoan, 30.0 -2 400.0 ind/L ( 660.7 ind/L, 81.25%,); Rotifera; 3.0 -780.0 ind/L, ( 145.4 ind/L, 17.88%), Cladocera, 0 -12.0 ind/L (4.1 ind/L, 0.50%); Copepoda, 0 -13.0 ind/L (2.7 ind/L, 0.33%);other taxa, 0-4.0 ind/L, (0.3 ind

  6. 北京翠湖湿地浮游动物调查及水质评价%A Survey of Zooplankton and Assessment Water Quality in Cuihu Wetland of Beijing

    Institute of Scientific and Technical Information of China (English)

    张强

    2013-01-01

      2012年4月至10月,在翠湖湿地选6个具有代表性的采样点,分别对湿地水体内浮游动物的种类及数量进行的调查显示,在翠湖湿地共有浮游动物4大类45种,其中以轮虫和原生动物种类最多,占浮游动物总数的82.2%。翠湖湿地浮游动物数量以6月最多,4月次之,8月和10月的种类数量相差不大。E/O指数等多种评价方法结果均显示翠湖湿地水体呈富营养化状态,6月翠湖湿地水体为超富营养类型。翠湖湿地外围取水渠的水质最差,其次为荷花塘和雁鸭湖,边境湖和天鹅湖的水质相对较好。%From April to October in 2012, 6 representative samples were collected from Cuihu Wetland to analyze the species and population size of zooplankton in water body. 45 species of zooplankton belonging to 4 major categories were identified in the wetland. Among them, Rotifera and Protozoa had the highest number of species, accounting for 82.2%of the total number of zooplankton. The number of zooplankton peaked in June, and followed by April. The difference of species number between August and October was not evident. Assessment by E/O index and some other methods showed that the water body of Cuihu Wetland is in eutrophication and at a state of super eutrophication in June. Results also showed that the worst water quality was in the surrounding canals, followed by Hehua Pond and Yanya Lake, the water quality of Bianjing Lake and Tian’e Lake was relatively good.

  7. [Selectivity of zooplankton and trophic overlap between size Menidia humboldtiana fish (Atheriniformes: Atherinopsidae) in the reservoir Danxhó, Mexico].

    Science.gov (United States)

    Merino, Regina Sánchez; Benítez, Miriam Y Fermín; Estrada, Angélica Mendoza

    2009-01-01

    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 zooplankton in presence of zooplanktonic fish, and tells us if the silverside choose amongst bigger prey fish, and if there is competition for food between the native and introduced fish in the reservoir. The purpose of this study was to determine if M. humboldtiana selects its food, and in which genera, and to establish whether there was an overlap in the diet of the different sizes of silverside. The fish were catched with a 88 mm mesh net, in six sampling points during one year, from Danxh6 (19 degrees 5'17" - 53'46" N, 99 degrees 32'42" - 35'40" W) reservoir. Samples of filtered zooplankton were also taken with a 125 micron net. The analysis of stomach contents was carried out in fish grouped by regular size intervals during each season of the year, using the volumetric method and Chesson's selectivity coefficient. To evaluate the trophic overlap between the different size groups, the Morisita index, modified by Horn, was used. The zooplankton community was represented by twelve genera: Mastigodiaptomus and Cyclops (Copepoda); Bosmina, Diaphanosoma, Daphnia, Ceriodaphnia, Moina, Alonopsis and Camptocercus, (Cladocera); Asplanchna, Conochillus and Filinia (Rotifera). Mastigodiaptomus was the most abundant throughout the year. The silverside consumed only four genera: Bosmina, Mastigodiaptomus, Daphnia and Ceriodaphnia; the group measuring 5 to 8.9 cm consumed a high percentage of Bosmina, Mastigodiaptomus and Daphnia, and a lesser percentage of Ceriodaphnia. The larger fish (9 to 10.9 cm) consumed only Mastigodiaptomus and Daphnia. In accordance with the selectivity values, the small and medium size silverside selected their prey, with more intensity on the genera Bosmina and Daphnia, while the bigger fish concentrated on Daphnia and

  8. Water Quality and Planktonic Communities in Al-Khadoud Spring, Al-Hassa, Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Adel A. Fathi

    2009-01-01

    Full Text Available Problem statement: Al-Khadoud spring is one of the most important water resources in Al- Hassa Governorate, Saudi Arabia. However, much of its biotic information is still unknown. This study presented preliminary ecological information of this aquatic body. The aim of this research was to study the water characteristics and the planktonic organisms inhibiting Al-Khadoud spring and its irrigational channels for a period of 1 year. Approach: A regular visit was monitoring the spring over a period of 1 year (June 2007 to may 2008. Physico-chemical characteristics of spring water were determined. Quantitative and qualitative analysis of Plankton (Phytoplankton or zooplankton were also investigated. Results: All the water quality variables measured showed considerable seasonal variation. The data of this study showed that there were marked seasonal differences in the quantitative and qualitative composition of the phytoplankton communities in Al-Khadoud spring and its irrigation canal. The changes in total algal counts throughout the investigation coincided closely with in Chlorophyceae abundance. Thirty six species were identified allover the period of the investigation. Out of these, 9 species belong to Chlorophyceae, 17 belong to Bacillariophyceae, 7 to Cyanophyceae and 3 to Euglenophyceae. Cyclotella meneghiniana Kützing, Nitzschia closterium Ehernberg, Fragilaria capucina Desmazieres, Surirella ovalis Breb, Actinastrum sp., Chlorella vulgaris Beyerinck, Scenedesmus quadriquda Breb, Oscillatoria sp. and Oscillatoria subbrevis Schmidle were observed in a high rank of occurrence. The phytoplankton crop showed a remarkable increase as compared with the previous records. The data showed that the zooplanktonic fauna identified in this aquatic body is a typical of the permanent freshwater and brackish water. Eleven species were recorded, 5 belonged to Cladoceran, 4 belonged to Rotifera and 2 belonged to Chironomid. Zooplankton

  9. EVALUACIÓN DE LA ROTIFEROFAUNA PRESENTE EN EL COMPLEJO DE PAJARALES DURANTE LA ÉPOCA LLUVIOSA, DEPARTAMENTO DE MAGDALENA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    LEÓN JENNY A.

    2008-08-01

    Full Text Available Con miras a evaluar posibles efectos de la recomunicación del río Magdalena con su antiguo delta, se determinó la abundancia y composición de la rotiferofauna del Complejo de Pajarales (CP, durante el período de mayor abundancia anual de zooplancton. El phylum Rotifera fue seleccionado por sus altas tasas reproductivas y eficiencia en procesos de transformación energética. Las muestras se colectaron con botella van Dorn durante la segunda temporada lluviosa de 2006. En cada una de las cuatro estaciones analizadas se registraron la salinidad, temperatura, pH y oxígeno disuelto. La diversidad se calculó empleando el índice de Shannon-Wiener H’ (log10 comparando estaciones y fechas de muestreo para establecer variaciones en el período de estudio. Gráficamente se relacionaron variables fisicoquímicas con valores de diversidad que emplearon un α de 0.05 y 95% de intervalo de confianza. En total, fueron encontrados 20 morfotipos pertenecientes a las familias Brachionidae, Lecanidae, Filiniidae, Synchaetidae, Hexarthriidae y Testudinellidae, siendo Brachionidae y Lecanidae las más abundantes. La relación entre diversidad y variables fisicoquímicas, indica que la salinidad es la principal responsable de la diversidad de rotíferos. En conclusión, la rotiferofauna actual en el CP es más abundante y diversa que hace 16 años, antes de la recomunicación con el río Magdalena. Así mismo, la concentración de oxigeno disuelto, pH y salinidad son diferentes. Teniendo en cuenta que la salinidad es el factor que más influyó en la diversidad de rotíferos, la reapertura de canales probablemente favoreció el incremento en la diversidad de rotíferos en el CP.

  10. Temporal and spatial distribution of the meiobenthic community in Daya Bay, South China Sea

    Directory of Open Access Journals (Sweden)

    L. Tang

    2012-04-01

    Full Text Available Spatial and temporal biodiversity patterns of the meiobenthos were studied for the first time in Daya Bay, which is a tropical semi-enclosed basin located in the South China Sea. The abundance, biomass, and composition of the meiobenthos and the basic environmental factors in the bay were investigated. The following 19 taxonomic groups were represented in the meiofauna: Nematoda, Copepoda, Polychaeta, Oligochaeta, Kinorhyncha, Gastrotricha, Ostracoda, Bivalvia, Turbellaria, Nemertinea, Sipuncula, Hydroida, Amphipoda, Cumacea, Halacaroidea, Priapulida, Echinodermata, Tanaidacea, and Rotifera. Total abundance and biomass of the meiobenthos showed great spatial and temporal variation, with mean values of 993.57 ± 455.36 ind cm−2 and 690.51 ± 210.64 μg 10 cm−2, respectively. Nematodes constituted 95.60 % of the total abundance and thus had the greatest effect on meiofauna quantity and distribution, followed by copepods (1.55 % and polychaetes (1.39 %. Meiobenthos abundance was significantly negatively correlated with water depth at stations (r=−0.747, P<0.05 and significantly negatively correlated with silt-clay content (r=−0.516, P<0.01 and medium diameter (r=−0.499, P<0.01 of the sediment. Similar results were found for correlations of biomass and abundance of nematodes with environmental parameters. Polychaete abundance was positively correlated with the bottom water temperature (r=0.456, P<0.01. Meiobenthos abundance differed significantly among seasons (P<0.05, although no significant difference among stations and the interaction of station × season was detected by two-way ANOVA. In terms of vertical distribution, most of the meiobenthos was found in the surface layer of sediment. This pattern was apparent for nematodes and copepods, but a vertical distribution pattern for polychaetes was not as obvious. Based on the biotic indices and analyses of

  11. 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

  12. 唐山“三岛”海域小型底栖动物丰度的研究%Abundance of meiobenthos in the sea area of three islands in Tangshan

    Institute of Scientific and Technical Information of China (English)

    曹英昆; 王小瑞; 夏辉; 王东昕; 申亮; 曾昭春; 郭冉

    2015-01-01

    于2013年5月,8月和10月份对唐山“三岛”海域12个不同站位小型底栖动物进行调查采样。共鉴定出自由生活海洋线虫、桡足类、多毛类、枝角类、端足类、介形类、涡虫类、轮虫类、双壳类及等足类10个类群。最优势类群是线虫,每个站位所占比例基本大于95%,平均丰度大约735.2 ind/10 cm2。其他类群各站位所占比例不同,且都较小。结果表明,小型底栖动物各类群所占比例随月份的变化并没明显变化;不同月份,各类群的丰度有所变化,其中5月份丰度较高,10月次之,8月份丰度最低。%A three-cruise investigation on the meiobenthos in the sea of Tangshan three islands was conducted in May ,August and October 2013 .A total of ten meiobenthic groups were identified . Free-living marine nematodes ,copepoda ,polychaeta ,cladocera ,amphipoda ,ostracoda ,turbel‐laria ,rotifera ,bivalvia and isopoda .Nematodes was the most dominant group in abundance ,about 735 .2 ind/10 cm2 ,with a relative dominance of 95% .Other groups of stations with different pro‐portion ,and the smaller .The results showed that ,meiobenthos in each group had no obvious change in the proportion .The abundance of different months ,each group had the change ,which in May higher abundance ,followed in October ,August the lowest abundance .

  13. Limnological Study of River Soan (Punjab, Pakistan

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    Furhan Iqbal

    2006-06-01

    Full Text Available River Soan is one of the important aquatic systems of the Punjab province in Pakistan and flows into Indus River near Kalla Bagh (District Mianwali. In order to measure the quality of water and to evaluate planktonic community, an integrated monitoring system was applied from May to December 2001. During the study period total of 202 genera were observed of which 134 were of phytoplankton present in various phylums including Cyanophyta (22, Cyarophyta (7, Xanthophyta (5, Bacillariophyta (22, Euglenophyta (5, Chlorophyta (62, Chrysophyta (8, Pyrrophyta (1 and Cphryrotophyta (2. 53 genera of zooplankton were observed including Protozoa (33, Rotifera (8, Cladocera (7, Copepoda (4 and Aquatic insecta (1. In addition to phyto and zooplankton 3 genera of Charophyta and 11 genera of Macrophyta were observed. Diversity index of phytoplankton ranged from 4.6 to 13.5 and of zooplankton from 1.94 to 5.90. Water samples were collected on monthly basis for estimation of various physical and chemical water quality parameters i.e., water temperature (9-31 0C, light penetration (1.2-22.3 cm, viscosity (0.8570-1.0572 mNS m-2, conductivity (7-19 mv, surface tension (69.28-72.63 dynes cm-1, density (0.980-1.022 mg l-1, specifi c gravity (0.796-1.025, boiling point (95-98 0C, turbidity (0.02-0.48 mg l-1, pH (8-9, dissolved oxygen (4.6- 9.3 mg l-1, alkalinity (19-36 mg l-1, acidity 1.0-1.8 mg l-1, carbonates (0, bicarbonates (19-36 mg l-1, total solids (0.56-4.24 mg l-1, total dissolved solids (0.53-4.83 and total dissolved volatile solids (0.05-0.29. Among elements, sodium (22.50-168.75 ppm, potassium (3.94-12.31 ppm, calcium (2.75-34.25 ppm, strontium (0.00-0.47 ppm, magnesium (0.00 ppm and zinc (0.00 ppm were detected through atomic absorption while seasonal variation in planktonic diversity was analyzed by calculating the frequency of occurrence, relative abundance and diversity index of planktonic life. The overall water quality of the study site remained

  14. Limnological Study of River Soan (Punjab, Pakistan

    Directory of Open Access Journals (Sweden)

    Furhan Iqbal

    2006-10-01

    Full Text Available River Soan is one of the important aquatic systems of the Punjab province in Pakistan and flows into Indus River near Kalla Bagh (District Mianwali. In order to measure the quality of water and to evaluate planktonic community, an integrated monitoring system was applied from May to December 2001. During the study period total of 202 genera were observed of which 134 were of phytoplankton present in various phylums including Cyanophyta (22, Cyarophyta (7, Xanthophyta (5, Bacillariophyta (22, Euglenophyta (5, Chlorophyta (62, Chrysophyta (8, Pyrrophyta (1 and Cphryrotophyta (2. 53 genera of zooplankton were observed including Protozoa (33, Rotifera (8, Cladocera (7, Copepoda (4 and Aquatic insecta (1. In addition to phyto and zooplankton 3 genera of Charophyta and 11 genera of Macrophyta were observed. Diversity index of phytoplankton ranged from 4.6 to 13.5 and of zooplankton from 1.94 to 5.90. Water samples were collected on monthly basis for estimation of various physical and chemical water quality parameters i.e., water temperature (9-31 0C, light penetration (1.2-22.3 cm, viscosity (0.8570-1.0572 mNS m-2, conductivity (7-19 mv, surface tension (69.28-72.63 dynes cm-1, density (0.980-1.022 mg l-1, specifi c gravity (0.796-1.025, boiling point (95-98 0C, turbidity (0.02-0.48 mg l-1, pH (8-9, dissolved oxygen (4.6- 9.3 mg l-1, alkalinity (19-36 mg l-1, acidity 1.0-1.8 mg l-1, carbonates (0, bicarbonates (19-36 mg l-1, total solids (0.56-4.24 mg l-1, total dissolved solids (0.53-4.83 and total dissolved volatile solids (0.05-0.29. Among elements, sodium (22.50-168.75 ppm, potassium (3.94-12.31 ppm, calcium (2.75-34.25 ppm, strontium (0.00-0.47 ppm, magnesium (0.00 ppm and zinc (0.00 ppm were detected through atomic absorption while seasonal variation in planktonic diversity was analyzed by calculating the frequency of occurrence, relative abundance and diversity index of planktonic life. The overall water quality of the study site remained

  15. 生态强化法原位净化村镇污水微生物特性∗%Microbial characteristics of in-situ strengthening bioremediation of rural domestic sewage

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    尹勇; 冯国勇; 周静; 刘明元; 胡林潮; 张文艺

    2015-01-01

    To investigate the microbial characteristic of in⁃situ strengthening bioremediation of rural domestic sewage, sediment microorganisms of Qianqiao demonstration project for rural domestic sewage treatment in Wujin,changzhou as the object of investigation were examined by phospholipid fatty acid method(PLFA).Microscopic examination showed that there were protozoa,rotifera,bacteria and algae in the sediment. PLFA analysis showed that total PLFAs were composed as follows, 76�97% saturated fatty acid,19.07% monounsaturated fatty acid,3.96% polyunsaturated fatty acid. Index of PLFA biomarkers volume showed pseudomonas and aerobic bacteria were predominant in the sediment microorganisms. It was proposed showed that the pollutants were mostly removed by microbial decomposition and plant uptaking, as well as synergistic effect of algae⁃aquatic animals/plants⁃bacteria.%为揭示生态强化法原位净化村镇污水机制与微生物特性,以常州市武进区前黄镇前桥污水治理示范工程底泥中微生物为研究考察对象,通过倒置显微镜镜检、磷脂脂肪酸( PLFA)分析手段对其进行了系统研究.镜检显示底泥中含有原生动物、轮虫以及菌藻. PLFA 分析表明,底泥中饱和脂肪酸含量最为丰富,占76�97%;其次为单不饱和脂肪酸,占19.07%;最少是多不饱和脂肪酸,占3.96%.以脂肪酸生物标记量为指标,表明底泥的生态群落中是以假单胞杆菌、好氧细菌为主导.生态强化法原位净化村镇污水可能主要通过微生物的分解、水生植物的吸收以及藻类⁃水生动植物⁃细菌的协同作用实现对污染物的去除.

  16. Investigation of Zooplankton in Chengdu City%成都市区淡水浮游动物多样性初步调查

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    何先进; 吴鹏飞

    2012-01-01

    为了研究成都市区浮游动物群落多样性,对成都市区内主要河流及公园湖泊的浮游动物进行了调查.共鉴定到浮游动物18属25种,群落组成以轮生为主,群落密度变动范围在70 -260 ind · L-1,生物量在0.036~ 1.016 mg· L-1之间,表明成都市区水体处于贫营养状态.Shannon多样性指数(H)变化范围为2.61 >H >0.84,Mugalef丰富度指数(D)为2.88 >D>0.44,表明成都市区河流木体为中度污染到重度污染.不同采样点比较显示,随着河流进入人口密集的市中心区域,浮游动物群落受影响程度增大,流出城市后,所受的影响降低至入城之前的水平.因此,城市湖泊的人为管理会对湖泊中浮游动物群落产生影响;城市建筑施工向河流倾倒建筑垃圾,会对水中浮游动物群落产生严重影响.%In November 2010, investigations were made on the zooplankton in mainstream of river and lakes in Chengdu City. A tofal of 25 species were identified, including 15 Rotifera (60 % ) , 4 Cladocera ( 16 % ) , 3 Copepoda and 3 Protozoa (12 % respectively). The dominant species were Branchonus calyciflorus, Asplanchna girodi, Asplanchna priodonta and Euchlanis pellucid. In the seven sampling sites, the zooplankton's average abundance ranged from 70 to 260 ind. · L-1, and the biomass ranged from 0.036 to 1.016 mg·L-1. In addition, Shannon index( H) ranged from 0. 84 to 2.61, Margalef index from 0.44 to 2. 88, which showed that river in Chengdu city was Moderately or heavily polluted. One-way ANOVA indicated that zooplankton community density,the biomass and community diversities were significantly different among sampling sites. Further comparing results revealed the zooplankton community was influenced more when the river went through civic centre, but it recovered when the river passed downtown ,labor management could change the zooplankton community of a Lake in the public garden, and that building site would be a grave threat to

  17. The Distribution and Seasonality of Zooplankton in Sombreiro River, Niger Delta, Nigeria

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    E.N. Ezekiel

    2011-05-01

    Full Text Available The distribution and seasonality of zooplankton in Sombreiro River of the, Niger Delta area in Nigeria was studied for a period of two years (August, 2007-July, 2009. All the zooplankton species occurred in all the stations except Mysis sp that was not recorded in station 4 (Odiemudie. Also all the stations recorded seventeen species (17 each except station 4 (Odiemudie that had sixteen (16 species. Five species of Cladocera occurred in all the stations and were fairly distributed. In station 2 Alonella costata was the highest (35.7%. This was followed by Moina cacrocapa (34.2% station 2 (Ogbele. Five species of Copepoda were fairly distributed in all the stations. Acanthocyclops, carinetus (53.1% was the highest in station 1. This was followed by Cyclops stenuis (47.2% station 1. Only one specie of Decapod crustacean was recorded. This was recorded in station 1, 2 and 3 but absent in station 4. Station 1 had the highest percentage of 44.9 followed by station 3 with 28.6%. Only one specie of Euphasiacea (Meganicilphanes norvegia was recorded and it occurred in all the stations with station 1 having the highest percentage of 41.8 followed by station 4 (24.1%. Three species of Protozoa were recorded in all the stations. They were fairly distributed. Tintinopsis senensis was the highest in station 3 with a percentage occurance of 45.8. This was followed by Halteria sp. (39.2% in station 3 also. The two species of Rotifera were also fairly distributed in all the stations. Brachionus falcatus was the highest in station 3 followed by Brachionus calyciflorus (32.3 in station 3 also. Annual variation result showed that Paracyclops fimbriatus had the highest mean value 20.417±10.422 (August 2007 - July 2008, 17.333±9.306 (August 2008 - July 2009. This was followed by Cyclops stenuis 18.167±12.494 (August 2007 - July 2008 16.250±10.847 (August 2008 - July 2009 and Meganicliphanes norvegia 17.417±11.540 (August 2007 - July 2008, 14.667±6.596 (August

  18. 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

  19. INFLUENCE OF FRESHWATER DISCHARGE ON ZOOPLANKT COMMUNITY DISTRIBUTION IN THE MUDFLAT WETLANDS OF THE HANGZHOU BAY%淡水排放对杭州湾湿地浮游动物群落分布的影响

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    李共国; 屠霄霞; 王佩儿; 王自磐; 廖何朝兴; 杨季芳

    2013-01-01

    In order to understand the spatiotemporal distribution of zooplankton species composition,abundance and biodiversity in the mudflat wetlands of Hangzhou Bay,40 samples were conducted at middle to high tide levels in five sampling stations (S1-S3 for discharge area,and S4-S5 for non-discharge area) in April (spring),July (summer),October (autumn),2010 and January (winter),2011.A total of 38 species of zooplankton (15 Rotifera,4 Cladocera,19 Copepoda) were found.The annual average density (88.89 ind./L) and biomass (0.41 mg/L) of zooplankton in the discharge area were much higher than those,i.e.,4.21 ind./L and 0.10 mg/L,respectively,in the non-discharge area.The dominant species of rotifers and copepods in the discharge area were Brachionus calyciflorus and Sinocalanus dorrii,respectively,and Calanus sinicus dominated copepods in the non-discharge area.Water nutrient concentrations,community density,and biomass of the zooplankton at middle tide level in stations S2-S3 were much higher than those at high tide level.The zooplankton community in the mudflat wetlands,the effects of the freshwater discharge,tidal creek spread,and tidal conditions determined the temporal pattern of the main zooplankton species,and the tidal creek spread and tidal conditions explained differences in composition and structure between the middle and the high tide level.%于2010年4月至2011年1月对杭州湾南岸滩涂湿地5个断面(S1-S3为排水区,S4-S5为非排水区)的高潮位和中潮位分别进行浮游动物群落结构的周年调查,共发现浮游动物38种(轮虫15种,枝角类4种,桡足类19种).排水区浮游动物年平均密度88.89 ind./L,生物量0.41 mg/L,非排水区平均密度仅4.21 ind./L,生物量0.10 mg/L.排水区轮虫和桡足类的第一优势种分别为萼花臂尾轮虫(Brachionus calyciflorus)和汤匙华哲水蚤(Sinocalanus dorrii),而非排水区第一优势种为中华哲水蚤(Calanus sinicus).S2-S3断面中潮位的水体营养盐浓度、

  20. 澳门4个典型湿地的浮游动物群落特征%Characteristics of the Zooplankton Communities in Four Typical Wetlands of Macao

    Institute of Scientific and Technical Information of China (English)

    陈骞; 何伟添; 刘阳; 黄建荣

    2014-01-01

    5%formalin and concentrated to 50 mL by settling for 24 hours. Metazoan zooplankton samples were taken by passing 50 L water through plankton net (No.13) and preserved with 5%formalin.A total of 110 zooplankton species were identified, along with the dominant population of Protozoa and Rotifera at each sampling site.The number of zooplankton species showed the general tendency of summer>autumn>spring>winter and spatial variation of species number among the four wetlands following the order Fai Chi Kei>Wang de Notre Dame Bay>Lotus Flower Bridge>Nan Vam Lake.The spatial-temporal variations of the zoo-plankton density were shown as follows:winter>spring>autumn>summer and Fai Chi Kei>Lotus Flower Bridge>Wang de Notre Dame Bay>Nan Vam Lake.Strombidium globosaneum, Cyclidium glaucoma, Centropyxis acule-ate, Tintinnidium fluviatile, Brachionus angularis, Synchaeta sp.and Neodiaptomus schmackeri were the most dom-inant species and the zooplankton community in wetlands of Macao reflected obvious properties of tropical aquatic fauna.

  1. 单巢类轮虫有性生殖的研究进展与展望%Sexual reproduction in monogonont rotifers: A review

    Institute of Scientific and Technical Information of China (English)

    孙栋; 牛翠娟

    2013-01-01

    This paper focuses on the recent findings of sexual reproduction in monogonont rotifers, which account for the main bulk of phylum Rotifera. Generally, they act as one of the major groups of primary consumers in freshwater ecosystem. Thus, studies on population dynamics and their mechanisms of monogonont rotifers may provide important data to both theoretical and applied research on freshwater ecosystems. As a group with parthenogenetic life history, sexual reproductive strategy in monogonont rotifers may profoundly affect their population dynamics and evolution. This review summarized several aspects of sexual reproduction in the monogonont rotifers, such as the mechanism, pheromones, models, influence factors, and particularly, empirical evidences. More specifically, we emphasized three models about their sexual reproduction patterns: " bang-bang" model, intermediate mictic ratios model and no-delaying mixis model. Then we summarized the exogenous and endogenous factors that affect sexual reproduction. The major exogenous factors include the concentration and type of food, temperature, salinity and special bacteria, while the major endogenous factors include the maternal age, a transgenerational maternal effect induced by food concentration, mixis delay and some potential maternal effects. We especially highlighted the model, mechanism and empirical evidences of mixis delay, since this phenomenon existed widely and was deem to be a potential explanation for species or clones coexistence. We also gave some personal views on the relationship between sex allocation theory and sexual reproduction in the monogonont rotifers. Finally, several potential hotspots in the future study were highlighted.%作为轮虫动物门的主体,单巢类轮虫是淡水浮游动物的重要组成部分.它们通常作为一类主要的初级消费者在淡水生态系统中起着重要作用,因而深入了解它们在自然水体中的种群动态及其决定机制对淡水生态系

  2. Estudio de la composición y abundancia del zooplancton durante la fase de llenado del embalse Amaní, Norcasia (Caldas

    Directory of Open Access Journals (Sweden)

    Reyes Blandon Carmen

    2003-06-01

    Full Text Available La variación de la composición, abundancia y diversidad del zooplancton fue analizada durante la fase de llenado del embalse Amaní en un gradiente horizontal y vertical, a partir de trece muestreos semanales realizados entre junio y agosto de 2002. La composición del zooplancton es similar a otros ecosistemas lénticos tropicales de baja altitud y fue registrado un total 32 taxa, de los cuales se destaca el rotífero Keratella por su elevada abundancia durante junio y julio. Rotifera fue el grupo que presentó la mayor riqueza de especies (16 así como una sobresaliente dominancia numérica sobre copépodos y cladóceros, con una abundancia relativa superior al 60%. La densidades promedio del zooplancton fluctuaron de manera significativa (6 a 1525 org l-1, y de forma diferencial entre los brazos del embalse

  3. Characterization of Summer Zooplankton (Rotifer and Crustacean)Community and Water Quality Assessment of Three Typical Nanchang Lakes%南昌市3个城中湖泊夏季轮虫和甲壳类群落特征及水质评价

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    文媛; 秦海明; 胡旭仁; 胡火玲

    2015-01-01

    >0.02).The community structure was significantly different among the three lakes (P <0.05),character-ized by three obvious groups:Qingshan Lake community,Donghu Lake community and Yueliang Lake community. Canonical correspondence analysis shows that chlorophyll-a,turbidity and dissolved oxygen were the primary factors affecting the distribution of zooplankton (P <0.05).Diversity index of zooplankton and pollution indicator species of Rotifera reveal that Donghu Lake is clean,Qingshan Lake is clean to moderately polluted and Yueliang Lake is lightly to moderately polluted.Overall,Donghu Lake and Qingshan Lake are oligotrophic and Yueliang Lake is me-sotrophic.%为探究城市湖泊浮游动物群落结构特征和分布与水环境因子之间的关系,并评价南昌市典型城市湖泊夏季水质状况,运用多维尺度分析(MDS)和典范对应分析(CCA)方法,对南昌3个城市湖泊———东湖、青山湖、月亮湖的轮虫和甲壳类浮游动物群落进行了研究,分析了浮游动物的多样性指数。结果表明,轮虫是夏季城市湖泊中浮游动物的优势类群,优势度(Y)大于0.02的浮游动物分别为剪形臂尾轮虫(Brachionus forficula)、裂足臂尾轮虫(Brachionus diversicornis)、萼花臂尾轮虫(Brachionus calyciflorus)、桡足类无节幼体(Copepoda nauplii)和卜氏晶囊轮虫(Asplanchna brightwelli);3个湖泊之间浮游动物的群落结构差异显著(P <0.05),明显划分为东湖群落、青山湖群落和月亮湖群落。叶绿素 a 浓度、浊度和溶氧是浮游动物分布的显著影响因子(P <0.05)。多样性指数评价显示,东湖为清洁型水体,青山湖为清洁-中污型水体,月亮湖为轻污-中污型水体。综合评价表明,东湖和青山湖水体为寡营养水平,月亮湖为中富营养水平。

  4. SEASONAL CHANGE OF ZOOPLANKTON COMMUNITIES AND ITS RELATIONSHIP WITH AQUATIC ENVIRONMENTS IN THE YONGJIANG RIVER, NINGBO%甬江干流浮游动物群落结构季节动态与水环境的关系

    Institute of Scientific and Technical Information of China (English)

    李共国; 包薇红; 徐石林; 王艳; 谭大鹏; 黄平沙

    2015-01-01

    对采自2011年3月—2012年2月间甬江干流13个断面的水样,按照国家标准测试了9项理化指标,并应用浮游动物定性和定量方法,研究了浮游物群落结构特点和季节变化。研究共记录浮游动物95种,其中轮虫24属72种、枝角类5属10种、桡足类11属13种和4种其他门类无脊椎动物幼虫;优势种主要来自于轮虫动物的臂尾轮虫属(Brachionus)和龟甲轮虫属(Keratella),前者占了浮游动物总丰度的22.1%,后者占总丰度的20.2%。浮游动物的丰度值在各断面均呈明显的季节变化,从断面1至断面6,最大峰值出现在春季,从断面7至断面13,最大峰值多出现在夏季;全干流最大峰值出现在断面5(3160 ind./L)。浮游动物群落生物多样性指数呈上游段低,中、下游河段高的现象;应用中度干扰假说(Intermediate disturbance hy-pothesis)对此结果给予了解释。Two-way ANOSIM相似性分析和Bray-Curtis相似性等级聚类分析显示:不同断面上不同季节的浮游动物群落间均存在显著差异,分别为R=0.264、P=0.1%和R=0.234、P=0.1%,且季节性差异大于断面间差异。在季节性差异中以春季和夏季间的差异性最大。主成分分析(PCA)表明:对不同断面浮游动物群落起作用的理化因子依次为CODCr、TN、DO和BOD5;对不同季节浮游动物群落起作用的理化因子依次为pH、TN/TP、盐度和水温。%In this study, water samples were collected from 13 sections in the Yongjiang River from March 2011 to Febru-ary 2012. Physical and chemical factors were analyzed according to national standards. The structure characteristic and the seasonal changes of the zooplankton communities were measured by the qualitative and quantitative methods. 95 species in water samples were recorded. Among them, 24 genera and 72 species of Rotifera, 5 genera and 10 species of Cladocera, 11 genera and 13 species of Copepoda, and 4 other categories of invertebrate larvae were

  5. 薇甘菊入侵对中小型土壤动物群落结构特征的影响%Impact of Mikania micrantha invasion on soil meso- and micro-invertebrate community structure

    Institute of Scientific and Technical Information of China (English)

    全国明; 章家恩; 谢俊芳; 毛丹鹃; 徐华勤; 姜万兵; 文杜娟

    2011-01-01

    Mikania micrantha, a notorious exotic weed of Asteraceae family, has invaded successfully in southern China, and caused serious damages to native ecosystems.In this paper, a field survey was conducted in the Huolushan Forest Park of Guangzhou, China, aimed to understand the impact of M.micrantha invasion on the soil meso- and micro-invertebrate community.Three sampling sites were installed, including M.micrantha-invaded site, ecotone, and native vegetation site.Through four samplings in 2009, a total of 5206 soil meso- and micro-invertebrate individuals were collected, belonging to 4 phyla, 10 classes, and 19 orders, among which, Nematoda was the dominant group, and Acarina, Collembolan, and Rotifera were the common groups.M.micrantha invasion altered the characteristics of soil meso- and micro-invertebrate community structure.Compared with those at the other two sampling sites, the numbers of total individuals, Nematoda, and Acarina at M.micrantha-invaded site increased significantly, but the groups of soil meso- and micro-invertebrates had less change.At M.micrantha-invaded site, the density-group index ( DG) of soil meso- and micro-invertebrates was significantly higher, Margalef richness index ( D) and Simpson dominance index ( C) tended to ascend, but Pielou evenness index ( E) and Shannon index (H') tended to descend.The similarity coefficient of soil meso- and micro-invertebrate community between M. micrantha-invaded site and ecotone was higher than that between M.micrantha-invaded site and native vegetation site.The changes of local climate conditions, plant litters, root secretions, and soil physical-chemical properties caused by M.micrantha invasion could be the major contributing factors that altered the community structure of soil meso- and micro-invertebrates at M.micrantha-invaded site.%薇甘菊是菊科假泽兰属的恶性杂草,在我国华南地区已成功入侵并造成严重危害.为了解薇甘菊入侵对土壤动物的影响效应,采用

  6. 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

    Directory of Open Access Journals (Sweden)

    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

  7. 太湖新银鱼移植对(鳖)早期摄食和生长的影响%THE INFLUENCES TO TRANSPLANTATION OF ICEFISH (NEOSALANX TAIHUENSIS CHEN) ON EARLY-LIFE FEEDING AND GROWTH OF HEMICULTER LEUCISCULUS BASILEWSKY

    Institute of Scientific and Technical Information of China (English)

    王星璐; 向建国; 刘家寿; 柳明; 吴朗; 谢松光

    2012-01-01

    Neosalanx taihuensis Chen is an important zooplanktivorous commercial fish, which was widely introduced into Chinese freshwaters. Transplantation of this species has induced decline and even extinction of native fish species in some waters. In this study, impacts of N. Taihuensis transplantation on early growth and feeding of an indigenous zooplanktivorous fish Hemiculter leucisculus Basilewsky were investigated by comparing the juveniles of the latter in two reservoirs in the middle reach of the Yangtze River. Huangshi Reservoir (HSR) and Mengquan Reservoir (MQR) are geographically proximate and display similar nutrient regimes and native fish faunas. The major difference between the two water is that N. Taihuensis has been transplanted in HSR but not in MQR. A total of 157 juvenile H. Leucisculus was collected in late July and middle August in both reservoirs. The juveniles collected in late July aged from 14 to 23 days, and were similar in growth rate between the two waters. The juveniles collected in middle August aged from 20 to 49 days. Growth rate of juveniles in HSR was significantly smaller than those in MQR. Otolith growth trajectories showed that incremental width was not significantly different between the two reservoirs until the age of 25 days but narrower for juveniles in HSR than those in MQR after that. Diet analysis showed that food compositions of the juveniles younger than 25 days were similar between the two waters, composing mainly Rotifera, small-sized Cladocera and Cyclopoida. For juveniles older than 25 days, food compositions in HSR were similar to the younger juveniles, while the food com positions in MQR changed to large-sized Cladocera, insects, eggs and fish larvae. Spawning season of N. Taihuensis is earlier than H. Leucisculus in the middle reach of Yangtze River, and diet competition between the two species may oc cur after the later shifts from feeding on small-sized to large-sized zooplanktons. In HSR, N. Taihuensis may induce the