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Sample records for bdelloidea rotifera syndermata

  1. A checklist of the freshwater rotifer fauna of Thailand (Rotifera, Monogononta, Bdelloidea

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    Phannee Sa-Ardrit

    2013-08-01

    Full Text Available We provide a checklist of the freshwater Rotifera recorded from Thailand, based on a review of available literature. Approximately 398 species of rotifers are recorded. The rotifer fauna of Thailand has been investigated quite comprehensively and these studies focus on four main parts of the country: the northern, north-eastern, central and southern. The number of rotifers on record is the highest in the north-eastern part (275, followed by the southern part (261, the central part (182 and the northern part (115. The majority of Thai Rotifera belongs to family Lecanidae (24.4%, Lepadellidae (11.3%, Brachionidae (11.1%, Trichocercidae (9.0% and Flosculariidae (9.0%. The most diverse genus is Lecane followed by Trichocerca, Lepadella and Brachionus. Although most Thai rotifers are cosmopolitan, there are a number of Oriental endemics, including some strict Thai or regional endemics. Illoricate rotifers and bdelloids are understudied, while experimental and molecular approaches promise to add most to our knowledge and understanding of the role of rotifers in ecosystem functioning.

  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. A mitogenomic re-evaluation of the bdelloid phylogeny and relationships among the Syndermata.

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    Erica Lasek-Nesselquist

    Full Text Available Molecular and morphological data regarding the relationships among the three classes of Rotifera (Bdelloidea, Seisonidea, and Monogononta and the phylum Acanthocephala are inconclusive. In particular, Bdelloidea lacks molecular-based phylogenetic appraisal. I obtained coding sequences from the mitochondrial genomes of twelve bdelloids and two monogononts to explore the molecular phylogeny of Bdelloidea and provide insight into the relationships among lineages of Syndermata (Rotifera + Acanthocephala. With additional sequences taken from previously published mitochondrial genomes, the total dataset included nine species of bdelloids, three species of monogononts, and two species of acanthocephalans. A supermatrix of these 10-12 mitochondrial proteins consistently recovered a bdelloid phylogeny that questions the validity of a generally accepted classification scheme despite different methods of inference and various parameter adjustments. Specifically, results showed that neither the family Philodinidae nor the order Philodinida are monophyletic as currently defined. The application of a similar analytical strategy to assess syndermate relationships recovered either a tree with Bdelloidea and Monogononta as sister taxa (Eurotatoria or Bdelloidea and Acanthocephala as sister taxa (Lemniscea. Both outgroup choice and method of inference affected the topological outcome emphasizing the need for sequences from more closely related outgroups and more sophisticated methods of analysis that can account for the complexity of the data.

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

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    Raquel Aparecida MOREIRA

    2016-01-01

    Full Text Available Los rotíferos desempeñan un importante papel en los ciclos biogeoquímicos y en la productividad orgánica de los ecosistemas de agua dulce como consecuencia de sus elevadas tasas metabólicas. Es relevante la información sobre la filtración, su principal proceso de adquisición de energía, la cual es todavía escasa para la región tropical. Los rotíferos de la subclase Bdelloidea se alimentan por filtración o raspaje, consumiendo pequeños elementos alimentícios, como bacterias, algas, levaduras o materia orgánica particulada. Sabemos poco del papel que desempeñan en la dinámica trófica de los hábitats que ocupan, y por eso el objetivo de este estudio fue cuantificar en laboratorio las tasas de filtración e ingestión del rotífero Philodina roseola , alimentado con Raphidocelis subcapitata . El experimento consistió en la exposición de diez adultos por tratamiento en concentraciones entre 1x10 4 y 1x10 7 células mL -1 y bajo temperatura de 25±1 °C. Los experimentos tuvieron la duración de una hora y las concentraciones iniciales y finales de la suspensión algal fueron cuantificadas por conteo numérico de las células en cámara de Neubauer. No fueron encontradas diferencias significativas entre las concentraciones iniciales y finales de células en los controles, lo cual indica que no se presentó crecimiento algal. Las tasas de filtración de P. roseola variaron entre 0,09 y 0,25 mL ind -1 h -1 . Teniendo en cuenta que la filtración es el principal proceso de adquisición de energía de la Philodina roseola , así como de los demás rotíferos, y que comprende cuestiones importantes relacionadas con la dinámica trófica de los ecosistemas acuáticos, es importante ampliar la información con experimentos usando otros tipos de alimento y diferentes combinaciones de las condiciones experimentales.

  5. Colonization of maritime glacier ice by bdelloid Rotifera.

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    Shain, Daniel H; Halldórsdóttir, Katrín; Pálsson, Finnur; Aðalgeirsdóttir, Guðfinna; Gunnarsson, Andri; Jónsson, Þorsteinn; Lang, Shirley A; Pálsson, Hlynur Skagfjörð; Steinþórssson, Sveinbjörn; Arnason, Einar

    2016-05-01

    Very few animal taxa are known to reside permanently in glacier ice/snow. Here we report the widespread colonization of Icelandic glaciers and ice fields by species of bdelloid Rotifera. Specimens were collected within the accumulation zones of Langjökull and Vatnajökull ice caps, among the largest European ice masses. Rotifers reached densities up to ∼100 individuals per liter-equivalent of glacier ice/snow, and were freeze-tolerant. Phylogenetic analyses indicate that glacier rotifers are polyphyletic, with independent ancestries occurring within the Pleistocene. Collectively, these data identify a previously undescribed environmental niche for bdelloid rotifers and suggest their presence in comparable habitats worldwide.

  6. Faunal diversity of rotifers (Rotifera: Eurotatoria of Nokrek Biosphere Reserve, Meghalaya, India

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    B.K. Sharma

    2011-02-01

    Full Text Available Plankton samples collected from the Nokrek Biosphere Reserve of Meghalaya (Northeast India revealed 70 species of Rotifera belonging to 24 genera and 15 families. Eight species are new records from the state of Meghalaya. The Oriental Lecane blachei and the palaeotropical L. unguitata are biogeographically interesting elements. The Rotifera taxocoenosis of Nokrek Biosphere Reserve is characterized by a distinct richness of the tropic-centered genus Lecane, paucity of Brachionus species, greater diversity of littoral-periphytonic elements and a general tropical character with cosmopolitan (71.4% > tropicopolitan (17.1 % species.

  7. PENYIMPANAN ROTIFERA INSTAN (Brachionus rotundiformis PADA SUHU YANG BERBEDA DENGAN PEMBERIAN PAKAN MIKROALGA KONSENTRAT

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    Erlania Erlania

    2016-11-01

    Full Text Available Keberhasilan kegiatan budidaya perikanan harus ditunjang dengan ketersediaan benih yang berkesinambungan. Oleh karena itu, diperlukan juga ketersediaan pakan alami larva berupa rotifera (Brachionus rotundiformis. Desain percobaan berupa rancangan faktorial dengan dua faktor dan lima ulangan diaplikasikan dalam penelitian ini. Sebagai perlakuan berupa suhu ruang penyimpanan (suhu kamar, suhu ruang AC, dan suhu refrigerator/lemari es dan pakan mikroalga konsentrat (monospesies dan multispesies. Bakteri probiotik juga digunakan sebagai pengontrol kualitas air. Spesies mikroalga yang digunakan adalah Nannochloropsis sp., Dunaliella sp., Isochrysis sp., dan Pavlova sp. Parameter yang diukur adalah kelimpahan rotifera dan parameter kualitas air media kultur (pH, salinitas, DO, dan NH3. Analisis data terdiri atas analisis regresi, analisis ragam, dan uji keparalelan. Hasil pengukuran parameter kualitas air selama penyimpanan menunjukkan kondisi media yang relatif stabil dan merupakan kisaran optimum bagi pertumbuhan B. rotundiformis. Kelimpahan maksimum tertinggi dari B. rotundiformis baik pada perlakuan pakan monospesies maupun multispesies alga adalah pada suhu kamar. Dari interaksi kedua perlakuan, diperoleh kelimpahan akhir tertinggi pada suhu ruang AC–pakan multispesies. Hal ini menunjukkan bahwa rotifera dapat disimpan lebih lama pada suhu ruang AC dengan pemberian pakan multispesies alga. The success of any aquaculture practices should be supported by sustainable supply of fish fry. Therefore, the availability of rotifers (Brachionus rotundiformis as natural feed for fish larvae is required. The research was arranged in factorial design with two treatments and five replications. Treatments consisted of different room storage temperatures (refrigerator, room temperature, and room with air conditioner/AC and microalgae concentrate added as rotifer feed (monospecies and multispecies algae. Probiotic bacteria was used to control water quality

  8. Deepor Beel revisited: new records of rotifers (Rotifera: Eurotatoria with remarks on interesting species

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    B.K. Sharma

    2011-01-01

    Full Text Available Plankton samples collected (April 2009 - March 2010 from Deepor Beel, a Ramsar site, revealed 21 species of the Phylum Rotifera belonging to 12 genera and eight families as new records. Amongst these, Brachionus durgae is a new record for northeastern India. The recorded species included the Australasian Brachionus dichotomus reductus and Notommata spinata; two Oriental endemics, namely, Keratella edmondsoni and Lecane blachei while Lecane lateralis, L haliclysta, Lepadella benjamini, Platyias leloupi, Mytilina acanthophora, Macrochaetus longipes, Trichocerca bicristata and T. flagellata are examples of regional distribution interest. The present report increases the number of species recorded from this important wetland of northeastern India to 134 species which, in turn, is the richest rotifer diversity known till date from any aquatic ecosystem of South Asia.

  9. Rotifera diversity of a floodplain lake of the Brahmaputra river basin of lower Assam, Northeast India

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    Sharma, B.K.

    2012-07-01

    Full Text Available This study analyzed diversity and ecology of planktonic Rotifera of Ghorajan beel, a floodplain lake of the Brahmaputrariver basin of lower Assam region of Northeast India. Plankton samples collected (January–December, 2010 fromlittoral (station 1 and semi-limnetic regions (station 2 of this tropical wetland revealed a fairly rich rotifer fauna (84 and 80species with distinct variations (range, average ± SD in monthly richness (35–55, 46±6 and 24–54, 36±5 species andcommunity similarities (46.6–80.4 and 37.0–95.9 % at both sampling stations. The richness followed unclear annual patterns.The rotifers mainly contributed (53.3±5.1 and 55.6± 3.6 % to zooplankton abundance variations and showed high abundancefrom June through November at both stations. Brachionidae > Lecanidae exhibited high number of individuals; Asplanchnidaeand Flosculariidae were also quantitatively important families; specifically, Asplanchna priodonta, Sinantherina socialis, Brachionusfalcatus and Lecane bulla were important species for their abundance. Single abiotic factors exerted a more limited influence on richness than on abundance. Canonical correspondence analysis (CCA explained 55.6 % and 59.5 % cumulative variance of the rotifer assemblages along axis 1 and 2, respectively; the CCA indicated the importance of transparency and rainfall at station 1, and of transparency, dissolved oxygen and rainfall at station 2. Consequently, the littoral and semi-limnetic stations are characterized by micro-environmental differences.

  10. Biodiversity of freshwater rotifers (Rotifera: Eurotatoria of Mizoram, Northeast India: composition, new records and interesting features

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    Bhushan Kumar Sharma

    2015-10-01

    Full Text Available The plankton and semi-plankton samples examined from Mizoram state of northeast India (NEI revealed speciose and diverse Rotifera assemblage including a total richness (S of 162 species belonging to 19 families and 35 genera. The reports of six species new to India, four species new to NEI and 76 new records to Mizoram merit biodiversity interest. The occurrence of one Australasian, one Oriental, seven Paleotropical, one Holarctic, one cosmo (sub tropical and five other interesting species imparts biogeographical value while several species indicate regional distribution importance. Lecanidae > Lepadellidae > Brachionidae > Trichocercidae collectively comprised 69.7% of total richness (S. Lecane > Lepadella > Trichocerca are diverse genera (~52.0% of S while Brachionus spp. (~8.0% deserve cautious mention. The rotifer diversity pattern is predominantly ‘tropical’ with a large component of cosmopolitans (~71.0% of S while tropicopolitan and pantropical species contributed ~16.0%. This study indicated high richness of the littoral-periphytonic and relative paucity of planktonic taxa. Analysis of periphytic, sessile, colonial and benthic taxa, and of cryptic diversity in certain species-groups merit attention for further biodiversity update and we estimate occurrence of 250+ rotifer species in Mizoram.

  11. 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. 

  12. 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.

  13. 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.

  14. 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

  15. Phylogenetic analyses of endoparasitic Acanthocephala based on mitochondrial genomes suggest secondary loss of sensory organs.

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    Weber, Mathias; Wey-Fabrizius, Alexandra R; Podsiadlowski, Lars; Witek, Alexander; Schill, Ralph O; Sugár, László; Herlyn, Holger; Hankeln, Thomas

    2013-01-01

    The metazoan taxon Syndermata (Monogononta, Bdelloidea, Seisonidea, Acanthocephala) comprises species with vastly different lifestyles. The focus of this study is on the phylogeny within the syndermatan subtaxon Acanthocephala (thorny-headed worms, obligate endoparasites). In order to investigate the controversially discussed phylogenetic relationships of acanthocephalan subtaxa we have sequenced the mitochondrial (mt) genomes of Echinorhynchus truttae (Palaeacanthocephala), Paratenuisentis ambiguus (Eoacanthocephala), Macracanthorhynchus hirudinaceus (Archiacanthocephala), and Philodina citrina (Bdelloidea). In doing so, we present the largest molecular phylogenetic dataset so far for this question comprising all major subgroups of Acanthocephala. Alongside with publicly available mt genome data of four additional syndermatans as well as 18 other lophotrochozoan (spiralian) taxa and one outgroup representative, the derived protein-coding sequences were used for Maximum Likelihood as well as Bayesian phylogenetic analyses. We achieved entirely congruent results, whereupon monophyletic Archiacanthocephala represent the sister taxon of a clade comprising Eoacanthocephala and monophyletic Palaeacanthocephala (Echinorhynchida). This topology suggests the secondary loss of lateral sensory organs (sensory pores) within Palaeacanthocephala and is further in line with the emergence of apical sensory organs in the stem lineage of Archiacanthocephala.

  16. 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.

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

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    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)

  18. Diversity and distribution of Brachionidae (Rotifera in Thailand, with a key to the species

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    Sujeephon Athibai

    2013-08-01

    Full Text Available We investigated the diversity of brachionid rotifers in Thailand. Rotifers were collected from a wide range of habitat types (294 sites, 508 samples including canals, lakes, peat swamps, ponds, reservoirs, rice fields, rivers, swamps and temporary ponds from April 1998 to January 2004. Twenty-eight species including 11 infrasubspecific forms belonging to five genera were identified. The most frequently encountered species was Brachionus falcatus (50.7% of the sampling sites, followed by Keratella cochlearis (50%, B. angularis (49.7%, K. tropica (46.3% and B. forficula (45.9%. Less frequently encountered species were B. caudatus, B. durgae and B. urceolaris. These species were found in low abundances and only in a single site. Two sites in the Northeast – Nong Changpeuak and Bueng Srithat – recorded the greatest richness with 15 taxa, whereas no brachionid rotifers were found in 31 sites. On average, the species richness was five taxa per sampling site. A key to the genera and species of Thai brachionid rotifers is provided.

  19. 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.

  20. 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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    Ignacio Alejandro Pérez-Legaspi

    2014-05-01

    Full Text Available 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.

  5. On Pulchritia new genus, with a reappraisal of the genera of Trichotriidae (Rotifera, Monogononta

    Directory of Open Access Journals (Sweden)

    Yongting Luo

    2013-10-01

    Full Text Available During the study of rotifers collected in Eastern DR Congo, we rediscovered specimens that correspond to Monostyla dorsicornuta Van Oye, 1926. This species, which we redescribe, had not been seen since it’s summary description, and lacked type material. Our analysis reveals that the animal belongs to Trichotriidae rather than to Lecane (presently considered to include Monostyla or Lecanidae, but is nevertheless characterised by a foot structure that is remarkably convergent to that of Lecanidae, and different from all other genera of Trichotriidae.We conclude that the species and the closely related South American Macrochaetus kostei (José de Paggi, Branco & Kozlowsky-Suzuki, 2000 belong to a new genus of Trichotriidae; the two offer a rare example of African-South American vicariance in rotifers.We further provide emended diagnoses of the remaining genera of Trichotriidae, to conform these to the new information and to address some inconsistencies in these.

  6. Age-related environmental gradients influence invertebrate distribution in the Prince Charles Mountains, East Antarctica.

    Science.gov (United States)

    Czechowski, Paul; White, Duanne; Clarke, Laurence; McKay, Alan; Cooper, Alan; Stevens, Mark I

    2016-12-01

    The potential impact of environmental change on terrestrial Antarctic ecosystems can be explored by inspecting biodiversity patterns across large-scale gradients. Unfortunately, morphology-based surveys of Antarctic invertebrates are time-consuming and limited by the cryptic nature of many taxa. We used biodiversity information derived from high-throughput sequencing (HTS) to elucidate the relationship between soil properties and invertebrate biodiversity in the Prince Charles Mountains, East Antarctica. Across 136 analysed soil samples collected from Mount Menzies, Mawson Escarpment and Lake Terrasovoje, we found invertebrate distribution in the Prince Charles Mountains significantly influenced by soil salinity and/or sulfur content. Phyla Tardigrada and Arachnida occurred predominantly in low-salinity substrates with abundant nutrients, whereas Bdelloidea (Rotifera) and Chromadorea (Nematoda) were more common in highly saline substrates. A significant correlation between invertebrate occurrence, soil salinity and time since deglaciation indicates that terrain age indirectly influences Antarctic terrestrial biodiversity, with more recently deglaciated areas supporting greater diversity. Our study demonstrates the value of HTS metabarcoding to investigate environmental constraints on inconspicuous soil biodiversity across large spatial scales.

  7. Age-related environmental gradients influence invertebrate distribution in the Prince Charles Mountains, East Antarctica

    Science.gov (United States)

    White, Duanne; Clarke, Laurence; McKay, Alan; Cooper, Alan; Stevens, Mark I.

    2016-01-01

    The potential impact of environmental change on terrestrial Antarctic ecosystems can be explored by inspecting biodiversity patterns across large-scale gradients. Unfortunately, morphology-based surveys of Antarctic invertebrates are time-consuming and limited by the cryptic nature of many taxa. We used biodiversity information derived from high-throughput sequencing (HTS) to elucidate the relationship between soil properties and invertebrate biodiversity in the Prince Charles Mountains, East Antarctica. Across 136 analysed soil samples collected from Mount Menzies, Mawson Escarpment and Lake Terrasovoje, we found invertebrate distribution in the Prince Charles Mountains significantly influenced by soil salinity and/or sulfur content. Phyla Tardigrada and Arachnida occurred predominantly in low-salinity substrates with abundant nutrients, whereas Bdelloidea (Rotifera) and Chromadorea (Nematoda) were more common in highly saline substrates. A significant correlation between invertebrate occurrence, soil salinity and time since deglaciation indicates that terrain age indirectly influences Antarctic terrestrial biodiversity, with more recently deglaciated areas supporting greater diversity. Our study demonstrates the value of HTS metabarcoding to investigate environmental constraints on inconspicuous soil biodiversity across large spatial scales. PMID:28083092

  8. 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.

  9. Population dynamics of Brachionus calyciflorus (Rotifera: Brachionidae) in waste water from food-processing industry in Mexico

    OpenAIRE

    Arévalo Stevenson, Raymundo Alfredo; Sarma, S SS; Nandini, S

    2015-01-01

    Se usó aguas de desecho de la industria de la masa y la tortilla (aguas de nixtamal o nejayote) para crecer rotíferos de agua dulce, Brachionus calycijlorus. El nejayote sin dilución no permitió el desarrollo del rotífero. Sin embargo, cuando se diluyó, B. calycijlorus aprovechó la materia orgánica. El agua de desecho por sí misma (sin alimento algal adicional) fue comparable al agua con densidades del alga Chlorella de 2 X 106 células m¡-I. Concentraciones de nejayote por encima del 8% no pe...

  10. 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.

  11. A report on Lecanidae (Rotifera: Monogononta from Andhra Pradesh, India, including six new distribution records with notes on their contemporary taxonomic nomenclature

    Directory of Open Access Journals (Sweden)

    S.Z. Siddiqi

    2013-07-01

    Full Text Available The Lecane-species complex taxonomy the world over, witnessed a state of flux, causing confusion and controversies, among world taxonomists over the treatment of various subgenera, taxa and sub and or infraspecific categories of the species rich genus Lecane Nitzsch 1827, on the basis of structure/shape of key, morphological features like foot/toes, lorica, etc. The taxonomic scenario in India, relying heavily on the classical, divergent taxonomic approaches presented a picture of more chaos/confusion, following poor accessibility to contemporary revisionary studies until the recent past. Despite revisionary studies across the world, a few notable Indian studies continued to be burdened with old nomenclature. This short communication reports for the first time ever, 33 valid species of lecanid rotifers (Lecanidae, including six new distributional records from Greater Hyderabad region and the entire state of Andhra Pradesh too with comments on their current nomenclature. Further, limnobiological correlation between five physicochemical parameters and rotifer associations revealed, L. bulla, L. closterocerca, L. hamata, L. ludwigi, L. luna and L. papuana as euryokous species, showing tolerance to a wide range of abiotic factors and habitats too.

  12. A report on Lecanidae (Rotifera: Monogononta) from Andhra Pradesh, India, including six new distribution records with notes on their contemporary taxonomic nomenclature

    OpenAIRE

    S. Z. Siddiqi; M. Paingankar; M. Karuthapandi

    2013-01-01

    The Lecane-species complex taxonomy the world over, witnessed a state of flux, causing confusion and controversies, among world taxonomists over the treatment of various subgenera, taxa and sub and or infraspecific categories of the species rich genus Lecane Nitzsch 1827, on the basis of structure/shape of key, morphological features like foot/toes, lorica, etc. The taxonomic scenario in India, relying heavily on the classical, divergent taxonomic approaches presented a picture of more chaos/...

  13. Mytilina (Rotifera: Monogonota: Mytilinidae) from Congo Basin%刚果盆地的棘管轮属(轮虫门;单巢亚纲;棘管轮科)

    Institute of Scientific and Technical Information of China (English)

    罗永婷; 吴波; SEGERSHendrik

    2016-01-01

    研究了2010年4月到5月和2012年6月二次采集自刚果盆地的水样,共发现棘管轮属Mytilina Bory de St.Vincent 1826的8个种,其中2个种M.crassipes(Lucks,1912)和M trigona(Gosse,1851)是非洲新纪录种;M.macrocera (Jennings,1894)和M.bisulcata (Lucks,1912)是刚果盆地多个样点的常见种;Mventralis(Ehrenberg,1830)和M.trigona,在刚果盆地个别样点比较多见;M.michelangllii Reid & Turner,1988,M.crassipes和M.brevispina(Ehrenberg,1830)在此次刚果盆地的调查中非常罕见;描述了一种棘管轮,其形态奇特,可能是新种.

  14. Rotifers from Thuy Tien lake and Nhu Y river in central Vietnam, with a description of Ploesoma asiaticum new species (Rotifera: Monogononta

    Directory of Open Access Journals (Sweden)

    Mau Trinh Dang

    2013-08-01

    Full Text Available We surveyed Thuy Tien lake and Nhu Y river, Thua Thien Hue province, Vietnam, for rotifers from March to August 2010, and additionally in February 2012 in Thuy Tien lake. A total of 98 species-level taxa are identified, belonging to 31 genera and 21 families. Of there, 52 are first records for Vietnam, Filinia minuta (Smirnov, 1928 is new to the Oriental region and Ploesoma asiaticum n. sp. is new to science. These results increase the rotifer record for Vietnam from 122 to 174 taxa. In addition to describing the new taxon, we provide comparative illustrations including trophi scanning electron microscopy photographs of Ploesoma hudsoni (Imhof 1891.

  15. 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.

  16. Nearly complete rRNA genes from 371 Animalia: updated structure-based alignment and detailed phylogenetic analysis.

    Science.gov (United States)

    Mallatt, Jon; Craig, Catherine Waggoner; Yoder, Matthew J

    2012-09-01

    This study presents a manually constructed alignment of nearly complete rRNA genes from most animal clades (371 taxa from ~33 of the ~36 metazoan phyla), expanded from the 197 sequences in a previous study. This thorough, taxon-rich alignment, available at http://www.wsu.edu/~jmallatt/research/rRNAalignment.html and in the Dryad Repository (doi: http://dx.doi.org/10.5061/dryad.1v62kr3q), is based rigidly on the secondary structure of the SSU and LSU rRNA molecules, and is annotated in detail, including labeling of the erroneous sequences (contaminants). The alignment can be used for future studies of the molecular evolution of rRNA. Here, we use it to explore if the larger number of sequences produces an improved phylogenetic tree of animal relationships. Disappointingly, the resolution did not improve, neither when the standard maximum-likelihood method was used, nor with more sophisticated methods that partitioned the rRNA into paired and unpaired sites (stem, loop, bulge, junction), or accounted for the evolution of the paired sites. For example, no doublet model of paired-site substitutions (16-state, 16A and 16B, 7A-F, or 6A-C models) corrected the placement of any rogue taxa or increased resolution. The following findings are from the simplest, standard, ML analysis. The 371-taxon tree only imperfectly supported the bilaterian clades of Lophotrochozoa and Ecdysozoa, and this problem remained after 17 taxa with unstably positioned sequences were omitted from the analysis. The problem seems to stem from base-compositional heterogeneity across taxa and from an overrepresentation of highly divergent sequences among the newly added taxa (e.g., sequences from Cephalopoda, Rotifera, Acoela, and Myxozoa). The rogue taxa continue to concentrate in two locations in the rRNA tree: near the base of Arthropoda and of Bilateria. The approximately uncertain (AU) test refuted the monophyly of Mollusca and of Chordata, probably due to long-branch attraction of the highly

  17. Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes).

    Science.gov (United States)

    Golombek, Anja; Tobergte, Sarah; Struck, Torsten H

    2015-05-01

    Gnathostomulida is a taxon of small marine worms, which exclusively inhabit the interstitium. The evolution of Gnathostomulida has been discussed for decades. Originally regarded as primitive animals with affinities to flatworms, the phylogenetic position of Gnathostomulida has been debated. Given the lack of an anus a close relationship to Platyhelminthes has been maintained (i.e., Plathelminthomorpha hypothesis). Alternative hypotheses proposed Gnathostomulida as being close to Gastrotricha due to the presence of a monociliary epidermis (i.e., Monokonta/Neotrichozoa hypothesis) or to Syndermata based on the complicated jaw apparatus (i.e., Gnathifera hypothesis). Molecular analyses using only few genes were inconclusive. Recent phylogenomic studies brought some progress by placing Gnathostomulida as sister to Syndermata, but support for this relationship was low and depended on the analytical strategy. Herein we present the first data of complete or nearly complete mitochondrial genomes for two gnathostomulids (Gnathostomula paradoxa &G. armata), one gastrotrich (Lepidodermella squamata) and one polyclad flatworm (Stylochoplana maculata) to address the uncertain phylogenetic affinity of Gnathostomulida. Our analyses found Gnathostomulida as sister to Syndermata (Gnathifera hypothesis). Thorough sensitivity analyses addressing taxon instability, branch length heterogeneity (also known as long branch attraction) and base composition heterogeneity showed that the position of Gnathostomulida is consistent across the different analyses and, hence, independent of potential misleading biases. Moreover, by ameliorating these different biases nodal support values could be increased to maximum values. Thus, our data support the hypothesis that the different jaw apparatuses of Syndermata and Gnathostomulida are indeed homologous structures as proposed by the Gnathifera hypothesis.

  18. Inducible colony formation within the Scenedesmaceae: adaptive responses to infochemicals from two different herbivore taxa

    NARCIS (Netherlands)

    Verschoor, A.M.; Van der Stap, I.; Helmsing, N.R.; Lürling, M.; Van Donk, E.

    2004-01-01

    We studied the occurrence of colony formation within 40 different strains of Scenedesmaceae (Chlorococcales, Chlorophyta) in response to grazing-released infochemicals from the herbivorous zooplankters Brachionus calyciflorus Pallas (Rotifera) and Daphnia magna Strauss (Cladocera). With the exceptio

  19. Inducible colony formation within the Scenedesmaceae: Adaptive responses to infochemicals from two different herbivore taxa

    NARCIS (Netherlands)

    Verschoor, A.M.; Stap, I.; Helmsing, N.R.; Lürling, M.F.L.L.W.; Donk, van E.

    2004-01-01

    We studied the occurrence of colony formation within 40 different strains of Scenedesmaceae (Chlorococcales, Chlorophyta) in response to grazing-released infochemicals from the herbivorous zooplankters Brachionus calyciflorus Pallas (Rotifera) and Daphnia magna Strauss (Cladocera). With the exceptio

  20. Occurrence of the freshwater jellyfish Craspedacusta sowerbii (Lankester, 1880) (Hydrozoa, Limnomedusae) in a calcareous lake in Mato Grosso do Sul, Brazil

    OpenAIRE

    Silva,William Marcos; Roche, Kennedy Francis

    2007-01-01

    The occurrence of the freshwater jellyfish Craspedacusta sowerbii (=sowerbyi) Lankester, 1880 was recorded in April 2006 in the Lagoa Misteriosa water body, a calcareous lake (doline) in Mato Grosso do Sul State, Brazil. Only Rotifera composed the zooplankton community was composed only of Rotifera and the environment was meso-eutrophic system. The nomenclature of C. sowerbii is discussed with regard to the use of the correct spelling and an alternative one. The distributions of C. sowerbii i...

  1. Effects on the population dynamics of Brachionus rubens (Rotifera) caused by mercury and cadmium administered through medium and algal food Chlorella vulgaris%在培养基和食料中添加铅和镉对轮虫种群动态的影响

    Institute of Scientific and Technical Information of China (English)

    S.S.S.SARMA; Hilda Fabiola NUNEZ-CRUZ; S.NANDINI

    2005-01-01

    Due to industrial activities,heavy metal concentrations in aquatic systems of Mexico,are on the rise.Zooplankton,particularly rotifers,being sensitive and common components of freshwater,are widely used in ecotoxicological tests for establishing water quality criteria.Depending on the route of exposure (i.e.via medium or algal food),the toxicity of heavy metals varies.In the present study we evaluated the effect of cadmium and mercury exposed through medium and via algal food for the rotifer B.rubens.For both the heavy metals,we exposed rotifers via medium containing Chlorella at 0.5×106 cells/ml or fed daily on previously exposed (1,2 and 4 h) alga to the toxicants (using 5 times the value of LC50 for B.rubens).For cadmium toxicity through medium,we used 3 toxicant levels (0.1,0.2 and 0.4 mg/L) and for mercury,we used 0.005,0.010 and 0.015 mg/L.Based on the LC50,B.rubens was 24 times more sensitive to mercury (0.035±0.002 mg/L) than cadmium.At a concentration of 0.4 mg/L,cadmium through the medium caused increased lag phase of B.rubens.When grown on Chlorella exposed for different durations to cadmium,the rotifer density decreased with the increasing duration of algal exposure to the heavy metal.When mercury was used in the medium or via algal food,the trends in the population growth of B.rubens were similar to those for cadmium.An increase in heavy metal concentration in the medium resulted in a decrease of the rate of population increase per day (r).The r varied from 0.33 (in control) to 0.02 d-1 (in heavy metal treatment) depending on the mode of exposure though medium or via algal food[Acta Zoologica Sinica 51(1):46-52,2005].%由于工业活动的影响,墨西哥水体环境中的重金属浓度在上升.浮游动物,尤其是轮虫类,由于对环境变化十分敏感而且是淡水中的常见组成部分,因此被广泛用于生态毒理试验以确定水质标准.在不同的胁迫途径下(如通过培养基或食料),重金属的毒性是不同的.在本研究中,通过在轮虫Brachionus rubens的培养基和食料中添加重金属这两种途径,我们评估了镉和铅的效应.对于这两种重金属,均采用将轮虫置于含0.5×106个/ml绿藻的培养基中或每天喂食经5倍于LC50值的金属处理(1,2和4h)的绿藻.对于在培养基中添加镉,使用了三个毒性水平(0.1,0.2和0.4 mg/L),铅的浓度分别为0.005,0.010 和0.015 mg/L.基于LC50的数据,B.rubens对铅的敏感性要比镉高24倍.镉浓度为0.4 mg/L时,培养基中加入镉造成B.rubens的生长趋缓.而喂食经不同时间处理的绿藻后,轮虫的密度随着食料在重金属中处理时间的延长而减小.培养基中或食料中添加铅时,轮虫种群生长的的趋势与在镉处理下的情况类似.随着培养基中重金属浓度的增加,每天种群增长率(r值)会减小.在培养基和食料处理两种不同途径下,r值会在0.33(对照)到0.02 d-1(经重金属处理)间变化[动物学报 51(1):46-52,2005].

  2. 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

  3. Marine meiofauna, carbon and nitrogen mineralization in sandy and soft sediments of Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Rysgaard, S.; Christensen, P.B.; Sørensen, Martin Vinther;

    2000-01-01

    belonging to Platyhelminthes, Rotifera, Gastrotricha, and Protodriloidae (Polychaeta) occurred only at the sandy locality, whereas Kinorhyncha, Foraminifera, and Cumacea (Crustacea) occurred only at the muddy stations. The larger number of meiofauna individuals at the sandy locality may in part be explained...

  4. 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

  5. Limnology of Priyadarshani Lake, Schirmacher Oasis, Antarctica

    Digital Repository Service at National Institute of Oceanography (India)

    Ingole, B.S.; Parulekar, A.H.

    in Schinnacher Oasis (Antarctica), was surveyed during the austral summers of 1984-85 and 1986-87 in limnological and benthic studies. Benthic microfaWla included seven taxonomic groups, dominated numerically by protozoa, rotifera, nematoda, turbellaria... insulation during the harsh winter (Goldman and others 1972). Seven microfaunal groupswer~recorded, in which ten genera and four species were identified. Most ofthese are exclusively benthic animals ofboth peripheral and littoral zones. Protozoa (ciliata...

  6. Rotifer communities of Deepor Beel, Assam, India: richness, abundance and ecology

    Directory of Open Access Journals (Sweden)

    B.K. Sharma

    2010-07-01

    Full Text Available Plankton samples collected from two sampling stations of Deepor Beel (a Ramsar site in Assam, northeastern India between November 2002 and October 2003, reveal 110 and 100 species of Rotifera, exhibit monthly richness ranging between 43-65 (56 plus or minus 6 and 38-60 (52 plus or minus 7 species and record 48.9-88.1 and 53.1-89.7% community similarities respectively. Rotifera (231 plus or minus 60 and 198 plus or minus 70 n/l comprise between 48.7 plus or minus 6.1 and 42.6 plus or minus 4.1% of zooplankton abundance at station I and II respectively, and follow trimodal annual patterns with peaks during winter. Brachionidae (90 plus or minus 43, 79 plus or minus 39 n/l > Lecanidae (45 plus or minus 13, 29 plus or minus 9 n/l form important quantitative components of Rotifera while Asplanchnidae > Synchaetidae > Trochosphaeridae are other notable families. Lecane > Brachionus > Keratella > Asplanchna > Platyias contribute notably to temporal variations of the rotifers. Asplanchna priodonta, Keratella cochlearis, Platyias quadricornis, Lecane leontina, Polyarthra vulgaris, Keratella tropica and Brachionus falcatus are important species. Analysis of variance comparisons indicate significant temporal variations in richness and abundance of Rotifera between stations and months. The rotifer communities exhibit higher species diversity, higher evenness, lower dominance and lack of quantitative dominance of any individual species. The present results show no definite periodicity of richness and abundance of this group, families or species. Individual abiotic factors register limited influence on richness and abundance while multiple regression exhibits higher cumulative influence of ten abiotic factors on these parameters at both sampling stations.

  7. A Parasite of Marine Rotifers: A New Lineage of Dinokaryotic Dinoflagellates (Dinophyceae

    Directory of Open Access Journals (Sweden)

    Fernando Gómez

    2015-01-01

    Full Text Available Dinoflagellate infections have been reported for different protistan and animal hosts. We report, for the first time, the association between a dinoflagellate parasite and a rotifer host, tentatively Synchaeta sp. (Rotifera, collected from the port of Valencia, NW Mediterranean Sea. The rotifer contained a sporangium with 100–200 thecate dinospores that develop synchronically through palintomic sporogenesis. This undescribed dinoflagellate forms a new and divergent fast-evolved lineage that branches among the dinokaryotic dinoflagellates.

  8. Composition and abundance of zooplankton in the limnetic zone of seven reservoirs of the Paranapanema River, Brazil

    Directory of Open Access Journals (Sweden)

    E. V. SAMPAIO

    Full Text Available The species composition and abundance of the zooplankton community of seven reservoirs of the Paranapanema River, located between 22º37'-23º11'S and 48º55'-50º32'W, were analysed over four periods, in the year of 1979. The zooplankton community was composed of 76 species of Rotifera, 26 species of Cladocera and 7 species of Copepoda. For a large part of the period under study the Rotifera were dominant, followed by Copepoda. The Piraju and Salto Grande reservoirs, which occupy intermediate positions in the cascade of reservoirs, were richest in species, most of them belonging to Rotifera and Cladocera. In the reservoirs Rio Pari and Rio Novo, lateral to the cascade of reservoirs, a lower species richness was observed, although higher densities of organisms were found than in the other reservoirs located in the main river body. Different rotifer species occurred in succession, being abundant in different periods, with no defined pattern. Among the copepods, Thermocyclops decipiens predominated in the majority of the reservoirs. Ceriodaphnia cornuta was the most abundant cladoceran in the intermediate reservoirs of the cascade, and Daphnia gessneri, Bosminopsis deitersi and Moina minuta, in the reservoirs lateral to the cascade. The most frequent zooplankton species were Notodiaptomus conifer, Thermocyclops decipiens, Ceriodaphnia cornuta cornuta and C. cornuta rigaudi, Daphnia gessneri, Bosmina hagmanni, Keratella cochlearis and Polyarthra vulgaris. Some relationships were found between the trophic state of the reservoirs and the zooplankton community.

  9. Nervous system and ciliary structures of Micrognathozoa (Gnathifera): evolutionary insight from an early branch in Spiralia

    Science.gov (United States)

    Worsaae, Katrine

    2016-01-01

    Recent studies show that Gnathifera, comprising Rotifera, Gnathostomulida and Micrognathozoa, constitute the sister group to the remaining Spiralia (containing, e.g. flatworms, segmented worms and molluscs). Therefore, a better understanding of Gnathifera is central for unravelling the evolution of the highly diverse Spiralia. Here, we describe the previously unstudied nervous system and ciliary structures of Micrognathozoa, using immunohistochemistry and confocal laser scanning microscopy. The nervous system is simple with a large brain, paired sub-esophageal ganglia, two trunk commissures, two pairs of ventral longitudinal nerves and peripheral nerves. The paired ventro-lateral nerve cords are confirmed to be a symplesiomorphy of Gnathifera (possibly even Spiralia), whereas the paired ventro-median nerves are not previously reported in Gnathifera. A pharyngeal ganglion is described for Micrognathozoa: a complex structure with two apical tufts of ciliary receptors, now shown to be shared by all Gnathifera. The ventral pattern of external ciliophores is re-described, and protonephridia with multi-ciliated collecting tubules similar to those of Rotifera are confirmed. A range of new details from a simple nervous system and complex set of ciliary structures in a microscopic metazoan are hereby unravelled. The many resemblances with Rotifera corroborate their close relationship, and shed more light on the evolution of Gnathifera. PMID:27853545

  10. Telomere analysis of platyhelminths and acanthocephalans by FISH and Southern hybridization.

    Science.gov (United States)

    Bombarová, Marta; Vítková, Magda; Spakulová, Marta; Koubková, Bozena

    2009-11-01

    We examined the composition of telomeres in chromosomes of parasitic worms, representatives of the flatworm groups Monogenea and Cestoda (Platyhelminthes), and thorny-headed worms (Syndermata: Acanthocephala) by fluorescence in situ hybridization (FISH) with different telomeric repeat probes. Our results show that the (TTAGGG)n sequence, supposed to be the ancestral telomeric repeat motif of Metazoa, is conserved in Monogenea (Paradiplozoon homoion) and Cestoda (Caryophyllaeus laticeps, Caryophyllaeides fennica, and Nippotaenia mogurndae) but not in Acanthocephala (Pomphorhynchus laevis and Pomphorhynchus tereticollis). In the Pomphorhynchus species, no hybridization signals were obtained with the "nematode" (TTAGGC)n, "arthropod" (TTAGG)n, and bdelloid (TGTGGG)n telomeric probes using FISH with their chromosomes and Southern hybridization with P. laevis DNA. Therefore, we suggest that parasitic Acanthocephala have evolved yet unknown telomeric repeat motifs or different mechanisms of telomere maintenance.

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

    Directory of Open Access Journals (Sweden)

    Helena Lúcia Menezes Ferreira

    2008-07-01

    Full Text Available The methods “Jar”, “Manual Removal” and “modified Ekman Dredge” wereevaluated for sampling periphyton fauna associated with aquatic macrophytes. Sixty-three samples were collected from five lentic and three lotic water bodies at the Espinhaço Mountain Range Biosphere Reserve (Minas Gerais State, Brazil. Anova and Tukey statistical tests were performed for Protista, Rotifera and Crustacea richness, whereas the abundance of Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada and Nematoda was evaluated by percentage. Of the three methods, the Dredge is less indicated for different water bodies systems in which there is interest in analyzing various microinvertebrate groups. The Protista and Rotifera represent 80% of the total abundance and richness in the invertebrate community. In the ecosystems evaluated, all methods are relevant for Protistaanalysis; on the other hand, Crustacea analysis required the Jar method. Manual Removal and Dredge methods are appropriate for Rotifera analysis. Gastrotricha and Tardigrada abundance presented better results with the Jar method; Nematoda with the Dredgemethod. The three methods are appropriate for periphyton fauna sampling in both water body systems; nevertheless, it is important to be aware that for each fauna community in a specified ecosystem, there is a specific method for best performance.Os métodos “Jarra”, “Remoção Manual” e “Draga de Eckman modificada” foram avaliados para amostrar a fauna perifítica associada à macrófitas aquáticas. Foram coletadas 63 amostras em cinco ambienteslênticos e três lóticos na reserva da biosfera da Serra do Espinhaço (Estado de Minas Gerais, Brasil. Os testes estatísticos Anova e Tukey foram feitos para riqueza de Protista, Rotifera eCrustacea, enquanto para a abundância de Protista, Rotifera, Crustacea, Gastrotricha, Tardigrada e Nematoda foram avaliados os percentuais. Os protozoários e rotíferos representaram 80% daabund

  12. PENGARUH INTENSITAS CAHAYA TERHADAP PEMANGSAAN LARVA IKAN CLOWN (Amphiprion ocellaris PADA AWAL PEMELIHARAAN

    Directory of Open Access Journals (Sweden)

    Ketut Maha Setiawati

    2016-11-01

    Full Text Available Penelitian pemangsaan larva ikan clown (Amphiprion ocellaris pada awal pemeliharaan dan umur sepuluh hari dilakukan menggunakan tangki serat kaca (fiberglass volume 200 L. Pakan zooplankton rotifera disediakan sejak telur menetas dengan kepadatan 5 ind./mL. Mulai D-8 zooplankton nauplii Artemia ditambahkan dengan kepadatan 1.700 ind./tangki. Pengambilan sampel dilakukan pada umur 1 hari dan sepuluh hari, masing-masing 10 ekor larva/sampling dengan interval waktu 3 jam. Larva diukur kemudian dibedah dan dianalisis jumlah pemangsaaannya dengan bantuan stereoscopic microscope. Hasil analisis menunjukkan peranan intensitas cahaya dalam aktivitas pemangsaannya sebesar 5 individu rotifera dengan intensitas cahaya 70 lux pada pagi hari, sedang pemangsaan tertinggi terjadi pada pukul 13.00—16.00 dengan pemangsaan 57 individu rotifera pada saat intensitas cahaya menurun. Spektrum warna cahaya diduga lebih berperanan pada kemampuan maksimal memangsa dari larva ikan laut. Observation on feeding activity of clown fish (A. ocellaris larvae have been conducted in 200 L. fiberglass tanks. Zooplankton rotifers were used as initial feed at a rate of 5 ind./mL. After eight days culture, nauplii Artemia were added at rate of 1,700 ind./ tank. Sampling was done on D-1 and D-10 at 10 individuals even sampling at three hours interval. The larvae were measured under a stereoscopic microscope, examining the digestion apparatus to count number of rotifers and nauplii Artemia as well. The result showed that the role of light intensity in feeding: 5 individual rotifer at 70 lux in early morning for D-1 larvae. The highest feeding occurred at 13.00-16.00 in the after noon at 57 individual rotifer when light intensity decreased. Color spectrum of light were predicted having more roles related to the maximum feeding rate  of clown fish larvae.

  13. A new record of Craspedacusta sowerbii, Lankester 1880 (Cnidaria, Limnomedusae in Northern Italy

    Directory of Open Access Journals (Sweden)

    Alessandro MARIENI

    2010-02-01

    Full Text Available A new record of the freshwater jellyfish Craspedacusta sowerbii in Northern Italy is reported. The medusae bloom occurred in a small oligo-mesotrophic artificial lake during July, 2009. At the time of sampling, the medusae were all immature, reached low density and showed feeding preference towards the Daphnia complex of species, the most abundant zooplanktonic species in the lake. Negative feeding selectivity towards small Rotifera was demonstrated. The occasional occurrence of a C. sowerbii bloom in this lake suggests the distribution range of this species may be largely underestimated, and its potential impact on the zooplankton community remains unknown.

  14. A decade of predatory control of zooplankton species composition of Lake Michigan

    Science.gov (United States)

    Makarewicz, Joseph C.; Bertram, Paul; Lewis, Theodore; Brown, Edward H.

    1995-01-01

    From 1983 to 1992, 71 species representing 38 genera from the Calanoida, Cladocera, Cyclopoida, Mysidacea, Rotifera, Mollusca and Harpacticoida comprised the offshore zooplankton community of Lake Michigan. Our data demonstrate that the composition and abundance of the calanoid community after 1983 is not unlike that of 1960s and that species diversity of the calanoid community is more diverse than the cladoceran community in the 1990s as compared to the early 1980s. Even though the relative biomass of the cladocerans has remained similar over the 1983-1993 period, the species diversity and evenness of the Cladocera community in the early 1990s is unlike anything that has been previously reported for Lake Michigan. Cladocera dominance is centered in one species, Daphnia galeata mendotae, and only three species of Cladocera were observed in the pelagic region of the lake in 1991 and 1992. Nutrient levels, phytoplankton biomass, and the abundance of planktivorous alewife and bloater chub and Bythotrephes are examined as possible causes of these changes in zooplankton species composition. The increase in Rotifera biomass, but not Crustacea, was correlated with an increase in relative biomass of unicellular algae. Food web models suggest Bythotrephes will cause Lake Michigan's plankton to return to a community similar to that of the 1970s; that is Diaptomus dominated. Such a change has occurred. However, correlational analysis suggest that alewife and bloater chubs (especially juveniles) are affecting size and biomass of larger species of zooplankton as well as Bythotrephes.

  15. 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.

  16. Biodiversity and community structure of zooplankton in the Sub-basin of Rio Poxim, Sergipe, Brazil

    Directory of Open Access Journals (Sweden)

    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.

  17. Correspondence between zooplankton assemblages and the Estuary Environment Classification system

    Science.gov (United States)

    Lucena-Moya, Paloma; Duggan, Ian C.

    2017-01-01

    We tested whether variability in zooplankton assemblages was consistent with the categories of estuarine environments proposed by the 'Estuary Environment Classification' system (EEC) (Hume et al., 2007) across a variety of North Island, New Zealand, estuaries. The EEC classifies estuaries in to eight categories (A to F) based primarily on a combination of three abiotic controlling factors: ocean forcing, river forcing and basin morphometry. Additionally, we tested whether Remane's curve, which predicts higher diversities of benthic macrofauna and high and low salinities, can be applied to zooplankton assemblages. We focused on three of the eight EEC categories (B, D and F), which covered the range of estuaries with river inputs dominating (B) to ocean influence dominating (F). Additionally, we included samples from river (FW) and sea (MW) to encompass the entire salinity range. Zooplankton assemblages varied across the categories examined in accordance with a salinity gradient predicted by the EEC. Three groups of zooplankton were distinguishable: the first formed by the most freshwater categories, FW and B, and dominated by rotifers (primarily Bdelloidea) and estuarine copepods (Gladioferans pectinatus), a second group formed by categories D and F, of intermediate salinity, dominated by copepods (Euterpina acutifrons), and a final group including the purely marine category MW and dominated also by E. acutifrons along with other marine taxa. Zooplankton diversity responded to the salinity gradient in a manner expected from Remane's curve. The results of this study support others which have shown salinity to be the main factor driving zooplankton community composition and diversity.

  18. Water quality and zooplankton composition in a receiving pond of the stormwater runoff from an urban catchment.

    Science.gov (United States)

    Jose de Paggi, Susana; Paggi, Juan; Collins, Pablo; Collins, Jorge; Graciela, Bernal

    2008-09-01

    Six storm periods were monitored from November 2002 to September 2005 at two stations of a receiving pond of the stormwater runoff from a small urban catchment of the city of Santa Fe, Argentina. Weekly samples were taken before and after rain events under different conditions of temperature, pluvial precipitation, and duration of the previous dry period. A sampling station was established at the outlet of the catchment (S1) and another one near the outlet of the receiving pond (S2). Both stations differed significantly in their dissolved oxygen (DO) concentration, temperature, transparency, and zooplankton composition. The concentrations of nutrients and BOD5 values indicated permanently eutrophic condition at both stations. After rainstorms, the concentrations of lead, zinc and suspended solids showed a marked increase. The zooplankton composition at S1 was characterized by the abundance of protozoans (Dexiostoma campylum (Stokes) Didinium nasutum Muller, Plagyopila cf nasuta, and Bdelloidea rotifers (Philodina sp and Rotaria sp), while Monogononta rotifers and small cladocerans were dominant at S2. The most abundant species were the rotifers Platyias quadricornis (Ehrenberg), Mytilina ventralis (Ehrenberg) and Lepadella ovalis (Muller), and the cladoceran Chydorus pubescens Sars.

  19. 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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    Waidi O. Abdul

    2016-09-01

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

  2. Evolution and Structure of Neuromuscular Systems in Spiralian Meiofauna

    DEFF Research Database (Denmark)

    Bekkouche, Nicolas Tarik

    into their evolution: Lobatocerebrum is an aberrant annelid showing only few common traits with Annelida, yet, our detailed studies unravel putative resemblances of muscular, nervous and glandular system to previous findings in annelids. Micrognathozoa shows more resemblances with Rotifera than Gnathostomulida (these...... on the evolution of this group. Diuronotus aspetos shows a unique combination of muscular traits not easily traceable, but in contrast the nervous system traits can be compared in high details, hereby bridging to other Chaetonotida (Gastrotricha). Moreover, we describe new gastrotrich characters...... such as the ciliary pattern or a system of pharyngeal canals of possible importance for future comparative approaches. These different studies show that information on rare and phylogenetically isolated animals with their unique combination of neural and muscular characters are necessary to understand the evolution...

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Documenting the fauna of a small temporary pond from Pune, Maharashtra, India

    Directory of Open Access Journals (Sweden)

    Mihir R. Kulkarni

    2015-05-01

    Full Text Available Most of the limnological studies in India have focussed on a few taxa of large, permanent water bodies, and pond ecosystems, and related temporary water bodies are neglected.  We present here a faunal inventory, with representative photographs, for a single, small temporary pond, reporting over 125 species of strictly aquatic fauna and 25 species of associated fauna, even though we did not identify some groups such as Protozoa, Diptera and nymphs of Odonata, etc.  The identified species belong to seven taxa of vertebrates and invertebrates together. Arthropoda and Rotifera were the most species rich groups, observed with 83 and 45 representatives, respectively. Coleoptera were the most numerous in terms of species number.  Such a small water body holds some endemics as well as otherwise very rare animals and so deserves better attention.  We also highlight the potential and importance of such habitats for research and conservation.   

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. Environmental DNA sequencing primers for eutardigrades and bdelloid rotifers

    Directory of Open Access Journals (Sweden)

    Martin Andrew P

    2009-12-01

    Bdelloidea and Eutardigrada in a variety of soils.

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

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed El-Otify

    2015-06-01

    Full Text Available Aim: The composition, abundance, community structure of potamoplankton and major physical and chemical variables of the Nile water in Upper Egypt were investigated to assess its status in different seasons during 2007.MethodsWater samples were collected seasonally during 2007 from six investigated sites from variable depths at levels of 0, 2.5 and 5 m. The area of this investigation is defined as the southern 120 Km of the main stream of the Nile in Upper Egypt (24° 04’ – 25° 00’ latitudes and 32° 51’ – 32° 54’ longitudes, downstream of Aswan Old Dam.ResultsAltogether, 121 potamoplankton species, of which 85 related to phytoplankton and 36 appertaining to zooplankton were recorded. Most numerous phytoplankton were Chlorophyceae (42 species followed by Bacillariophyceae (30 species. Cyanobacteria and Dinophyceae were less numerous with only 11 and 2 species, respectively. Zooplankton species were mainly belonging to three systematic groups namely; Rotifera (24 species, Copepoda (3 species and Cladocera (9 species. Besides, other rare zooplankton including Platyhelminthes, Nemata and Ciliophora were sparsely encountered. The main hydrological conditions characterizing the investigated area include water level fluctuations (˂82 - ˃85 m above sea level, relatively high current velocity (0.8 - 1.3 m sec–1 and disposal of wastewater. Plankton populations were variably but rather weakly dependent on the major nutrients due to their excessive availability in accessible form for uptake by the producers. For phytoplankton, the community structure was categorized in relation to temperature, pH, SO42– and Mg2+. For zooplankton, the community structure was categorized in relation to conductivity as well as Mg2+. Sampling intervals were inadequate to demonstrate the existing successional pattern of the Nile potamoplankton community. Alterations in the phytoplankton community structure accompanied changes in water temperature represented

  10. DESCRIPTION DE LA ZOOÉPIBIOSE DE L’ÉCREVISSE SIGNAL (PACIFASTACUS LENIUSCULUS, DANA EN ASTACICULTURE

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    CUELLAR M. C.

    2002-07-01

    Full Text Available Des recherches ont été effectuées concernant la zooépibiose de l’écrevisse signal (Pacifastacus leniusculus, D., provenant d’un centre d’astaciculture espagnol, au cours de la période 1997-1998. Les organismes épibiotiques dominants trouvés sur l’exosquelette appartiennent aux groupes zoologiques d’Invertébrés suivants : Mastigophora (Bodo, Cilliophora (Stentor, Epistylis, Zoothamnium, Acineta, Turbelaria (Temnocephala, Rotifera (Brachionus, Annelida (Branchiobdella, Acarina (Hygrobates et Ostracode (Eucypris ou Enthocytera, on souligne le nombre élevé de Branchiobdellides de l’espèce Branchiobdella instabilia M., dont les quantités minimum et maximum, en mâles et femelles, oscillent de 12 à 139 et de 7 à 130, respectivement. Les hyperbranchiobdelloses provoquent des automutilations, des décollements des pinces et autres appendices, des mues anormales, des lésions cuticulaires, de l’hémocytopénie et des changements éthologiques. Les colonisations maximales d’Ostracodes de l’espèce Eucypris virens, J.O., Enthocytera heterodonta, R., dans les poches d’incubation des femelles donnent lieu à une coloration rougeâtre des oeufs et à leur perte postérieure. Compte tenu de leur nombre limité et de la période d’épibiose, les genres des sous-types Mastigophora, Ciliophora, Turbelaria, Rotifera et Arachnida ne représentent aucun danger pour les écrevisses. En ce qui concerne la zooépibiose associée aux appendices et aux régions du corps des écrevisses du Pacifique, les chélipèdes ou pinces constituent le substrat où se place de préférence le genre Branchiobdella ; le céphalothorax sert de support à tous les groupes taxonomiques d’épibiontes identifiés.

  11. Use of rotifers for the maintenance of monoalgal mass cultures of Spirulina

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, S.A.; Richmond, A.

    1987-01-01

    Zooplankton was successfully used for the biological control of unicellular algal contaminants in Spirulina mass cultures even under conditions adverse to the growth of Spirulina (maximal winter daily temperature of approximately 10 degrees C and very low bicarbonate concentration). Brachionus plicatilis (Rotifera) was the most successful species of zooplankton used. The interrelationships between Spirulina, green unicellular contaminant, and B. plicatilis were studied under various conditions. Two species of unicellular contaminant were used; Monoraphidium minutum was isolated from local cultures and Chlorella vulgaris, obtained from contaminated Spirulina cultures in Israel. The rotifer B. plicatilis successfully controlled the population size of both contaminants whether they were introduced in a single addition or as a daily dose. The biological control of the unicellular contaminants allows Spirulina to be cultured in a medium low in bicarbonate, thereby reducing the cost of the medium and increasing the quantity of CO2 that may be freely absorbed from the atmosphere at the optimal pH for Spirulina cultivation. (Refs. 9).

  12. 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.

  13. Zooplankton-based assessment of the trophic state of a tropical forest river in Nigeria

    Directory of Open Access Journals (Sweden)

    Imoobe T.O.T.

    2009-01-01

    Full Text Available In this study, we explore the usefulness of zooplankton as a tool for assessing the trophic status of a Nigerian forest river. The river was sampled monthly and investigated for water physico-chemistry and zooplankton community structure using basic statistical measurement of diversity indices to characterize the zooplankton fauna. The trophic sta­tus of the river evaluated from its physico-chemical parameters indicates that the river is oligotrophic. The zooplankton composition was typical of a tropical freshwater river, with a total of 40 species, made up of 16 rotifers, 12 cladocerans, and 12 copepods and their developing stages in the following order of dominance: Rotifera > Cladocera > Cyclopoida > Calanoida. There were strong correlations between the lake's trophic status and its zooplankton communities. The zoo­plankton community was dominated by numerous species of rotifers and crustaceans, which are typical of oligotrophic to mesotrophic systems, such species including Conochilus dossuarius and Synchaeta longipes. However, the most dominant zooplankton species in West African freshwater ecosystems, viz., Keratella tropica, Keratella quadrata, Brachionus angularis, Trichocerca pusilla, Filinia longiseta, Pompholyx sulcata, and Proales sp., and others that are indicator species of high trophic levels, were not recorded in the river. The river is very clear and can be used for all manner of recreational activities.

  14. Rotifers as experimental tools for investigating aging

    Science.gov (United States)

    Snell, Terry W.; Johnston, Rachel K.; Gribble, Kristin E.; Mark Welch, David B.

    2015-01-01

    Comparative biogerontology has much to contribute to the study of aging. A broad range of aging rates have evolved to meet environmental challenges, and understanding these adaptations can produce valuable insights into aging. The supra Phylum Lophotrochozoa is particularly understudied and has several groups that have intriguing patterns of aging. Members of the Lophotrochozoan phylum Rotifera are particularly useful for aging studies because cohort life tables can be conducted with them easily, and biochemical and genomic tools are available for examining aging mechanisms. This paper reviews a variety of caloric restriction (CR) regimens, small molecule inhibitors, and dietary supplements that extend rotifer lifespan, as well as important interactions between CR and genotype, antioxidant supplements, and TOR and jun-N-terminal kinase (JNK) pathways, and the use of RNAi to identify key genes involved in modulating the aging response. Examples of how rapamycin and JNK inhibitor exposure keeps mortality rates low during the reproductive phase of the life cycle are presented, and the ease of conducting life table experiments to screen natural products from red algae for life extending effects is illustrated. Finally, experimental evolution to produce longer-lived rotifer individuals is demonstrated, and future directions to determine the genetic basis of aging are discussed. PMID:25642019

  15. Food of forage fishes in western Lake Erie, 1975-76

    Science.gov (United States)

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

    2016-05-01

    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.

  18. Light and electron microscopic studies on the excretory system of Macrobiotus richtersi Murray, 1911 (Eutardigrada).

    Science.gov (United States)

    Weglarska, B

    1980-01-01

    The excretory system of Macrobiotus richtersi consists of one dorsal and two lateral components and shows a high degree of structural complexity. In each of these a tricellular external lobe and a column can be distinguished, the two parts being connected distally. The surface of the lobe cells is increased by deep basal infoldings and fingerlike processes which form a labyrinth next to the basal lamina. Their cytoplasm contains numerous mitochondria, a well developed rough endoplasmic reticulum, dictyosomes, and granules in amounts depending on the physiological state of the animal. Excretory crystals occur in caveolae located in the lobe: between the fingershaped processes of the cell and in the space enclosed by the basal lamina on one side and the column on the other. The column faces an extracellular channel meandering along its whole length which is surrounded on the outside by a basal lamina. Morphologically the column is similar to the protonephridial channel of Rotifera. At the ultrastructural level, the cytoplasm of the column shows numerous mitochondria, rough endoplasmic reticulum, lysosomes, and a well developed Golgi apparatus. The lumen of the channel is coated by glycocalyx. At the base of the column several small cells form the proximal part of a duct that communicates with the gut. The morphology and ultrastructure of the excretory system of M. richtersi have been compared with similar a system in Isohypsibius megalonyx (Greven, 1979), and on these grounds a proposal is put forward to call the excretory organs of Tardigrada "nephridia" instead of "Malpighian tubules" .

  19. Tardigrades in Space Research - Past and Future

    Science.gov (United States)

    Weronika, Erdmann; Łukasz, Kaczmarek

    2016-10-01

    To survive exposure to space conditions, organisms should have certain characteristics including a high tolerance for freezing, radiation and desiccation. The organisms with the best chance for survival under such conditions are extremophiles, like some species of Bacteria and Archea, Rotifera, several species of Nematoda, some of the arthropods and Tardigrada (water bears). There is no denying that tardigrades are one of the toughest animals on our planet and are the most unique in the extremophiles group. Tardigrada are very small animals (50 to 2,100 μm in length), and they inhabit great number of Earth environments. Ever since it was proven that tardigrades have high resistance to the different kinds of stress factors associated with cosmic journeys, combined with their relatively complex structure and their relative ease of observation, they have become a perfect model organism for space research. This taxon is now the focus of astrobiologists from around the world. Therefore, this paper presents a short review of the space research performed on tardigrades as well as some considerations for further studies.

  20. 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.

  1. 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.

  2. 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.

  3. Respostas da comunidade zooplanctônica à formação do reservatório de Dona Francisca, Rio Grande do Sul, Brasil

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    Catarina da Silva Pedrozo

    2012-06-01

    Full Text Available Nós investigamos as mudanças na riqueza, densidade e composição da comunidade zooplanctônica em resposta à formação de um reservatório na área da usina hidrelétrica Dona Francisca. Amostras de zooplâncton foram coletadas trimestralmente durante quatro anos, compreendendo dois anos antes e dois anos após a formação do reservatório. A riqueza de espécies e a densidade de Cladocera, Copepoda e Rotifera aumentaram após o enchimento do reservatório. Além disso, a comunidade zooplanctônica apresentou uma nítida alteração na composição de espécies entre os períodos antes e após a formação do reservatório. A distinta composição de espécies entre os dois períodos esteve relacionada às alterações nas características limnológicas decorrentes da formação do reservatório.

  4. Feed of Siamese fighting fish, Betta splendens, (Regan, 1910 in open pond: live and formulated diets

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    L. H. Sipaúba-Tavares

    Full Text Available Abstract The growth rate and percent survival of Betta splendens when submitted to formulated diet and live food treatments are evaluated. The three different diets were used and designated as: formulated diet (basal diet; live food diet (plankton and mixed diet (formulated diet with plankton. The live food diet contained plankton belonging to an open pond. High mortality was reported with live food (plankton treatment whereas higher percent survival occurred with formulated diet. Highest specific growth rate, weight gain and final weight were reported in the mixed diet treatment and were significantly different (p<0.01 from those in formulated diet and live food treatments. The gut contents of B. splendens in mixed diet and live food treatments comprised, Rotifera and Bacillariophyceae species in high percentages or rather, over 78% of total organisms. Lecane sp. was the most ingested zooplankton species by B. splendens in both treatments (mixed diet and live food, with the phytoplankton species Asterionella sp. and Melosira sp. respectively in mixed diet and in live food, respectively. Results indicated that the formulated diet influenced the water parameters dissolved oxygen, total suspended solids, total dissolved solids and pH. The live food in the open pond was not enough to improve the growth rate and percent survival of B. splendens. The growth performance of B. splendens; had the best results with mixed diet which was capable of maintaining species’s survival (82% and development in artificial conditions, benefiting the culture management of ornamental fish.

  5. Feed of Siamese fighting fish, Betta splendens, (Regan, 1910) in open pond: live and formulated diets.

    Science.gov (United States)

    Sipaúba-Tavares, L H; Appoloni, A M; Fernandes, J B K; Millan, R N

    2016-06-01

    The growth rate and percent survival of Betta splendens when submitted to formulated diet and live food treatments are evaluated. The three different diets were used and designated as: formulated diet (basal diet); live food diet (plankton) and mixed diet (formulated diet with plankton). The live food diet contained plankton belonging to an open pond. High mortality was reported with live food (plankton) treatment whereas higher percent survival occurred with formulated diet. Highest specific growth rate, weight gain and final weight were reported in the mixed diet treatment and were significantly different (psplendens in mixed diet and live food treatments comprised, Rotifera and Bacillariophyceae species in high percentages or rather, over 78% of total organisms. Lecane sp. was the most ingested zooplankton species by B. splendens in both treatments (mixed diet and live food), with the phytoplankton species Asterionella sp. and Melosira sp. respectively in mixed diet and in live food, respectively. Results indicated that the formulated diet influenced the water parameters dissolved oxygen, total suspended solids, total dissolved solids and pH. The live food in the open pond was not enough to improve the growth rate and percent survival of B. splendens. The growth performance of B. splendens; had the best results with mixed diet which was capable of maintaining species's survival (82%) and development in artificial conditions, benefiting the culture management of ornamental fish.

  6. 册田水库浮游生物资源调查%Investigation on the Plankton in Cetian Reservoir

    Institute of Scientific and Technical Information of China (English)

    刘小艳

    2012-01-01

    2011年5月—11月对册田水库浮游生物资源进行了全面调查。共检出浮游植物7门43种属,平均生物量50.37 mg/L,优势种群为蓝藻门、绿藻门和硅藻门。浮游动物4门26种,平均生物量为4.42 mg/L,优势种群为原生动物的板壳虫和轮虫。评价属重度富营养型水库。%The resource of Plankton in Cetian Reservoir was investigated from May to November in 2011.The results show:there are 43 species(genera)of Phytoplankton from 7 phyluns and its average biomass is 50.37 mg/L,and in which Cyanophyta,Chlorophyta and Bacillariophyta are the predominant species composition;there are 26 species Zooplankton from 4 phyluns and its average biomass is 4.42mg/L,among them Coleps and Rotiferas are dominant species.By assesment,Cetian Reservoir belong to heavy eutrophication level.

  7. Abundance, food habits, and breeding season of exotic T ilapia zillii and native O reochromis niloticus L. fish species in Lake Zwai , Ethiopia

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    Padanillay C. Prabu

    2008-05-01

    Full Text Available Relative abundance, diet and breeding season overlap in the reproduction of exotic Tilapia zillii and native Oreochromis niloticus in Lake Zwai were studied from samples collected over 12 months. Younger fish of both species collected were also evaluated for food composition.Food items from stomachs of both species were collected and analysed using the frequency of occurrence method. In terms of number, T. zillii dominated O. niloticus at the sampling sites. In both species, macrophytes, detritus, blue green algae, diatoms, green algae, Ceratium, Euglena,and Phacus constituted foods of plant origin, whereas chironomid larvae, Copepoda, Cladocera,Rotifera, Nematoda, fish eggs, and fish scales constituted foods of animal origin. Foods of the latter type such as Ephemeroptera and mollusks were also noted in the diet of adult T. zillii.Despite the extensive overlap in food habits of the two species, however, the food items were found in the diet of the species with different average percentage frequencies of occurrence. The level of gonad maturation and gonadosomatic index (GSI values showed that in Lake Zwai breeding was year-round for both T. zillii and O. niloticus, with a peak during April-September and February-August respectively, indicating extended breeding season overlap in reproduction. The two species were always found together in the catches from the sampling sites, which indicated some niche overlap between them.

  8. 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. 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

  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. 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

  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 < 0.05). In most cases, greater 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.

  13. 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 .

  14. 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.

  15. 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.

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

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    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

  17. Small effects of a large sediment contamination with heavy metals on aquatic organisms in the vicinity of an abandoned lead and zinc mine.

    Science.gov (United States)

    Ciszewski, Dariusz; Aleksander-Kwaterczak, Urszula; Pociecha, Agnieszka; Szarek-Gwiazda, Ewa; Waloszek, Andrzej; Wilk-Woźniak, Elżbieta

    2013-12-01

    The effects of the long-term contamination of water reservoirs with mine effluents were investigated at an abandoned mine site in Upper Silesia, southern Poland. The studies covered metal content and mobility in bottom sediments as well as water chemistry in relation to the content of metals in selected macrophytes and their physiology and the composition of phyto- and zooplankton communities. Although it is 40 years since mining ceased, reservoir sediments are still heavily contaminated with cadmium, zinc and lead with concentrations (mg/kg), which vary roughly between 130–340, 10,000–50,000 and 4,000–12,000, respectively. About 50–80 % of these elements are associated with the reducible phase, and only a small percentage, <10%, is present in the most mobile exchangeable phase. Despite the high total metal concentration in sediments, their content in the submerged plants Myriophyllum spicatum and the emerged plants Phragmites australis was low. The observed effects of heavy metal contamination on photosynthetic activity in the leaves of P. australis were negligible, whereas those in M. spicatum show up only as a difference in the distribution of photosynthetic activity in leaves of different ages, which seems to be related to the very good water quality and to the generally small concentrations of metals in pond water. The physicochemical properties of water also seem to control the presence of planktonic species more than does sediment contamination. However, a shift toward groups of species known to be more resistant to heavy metals (diatoms, green algae and Rotifera) indicates some adaptative changes related to the longlasting contamination of ponds.

  18. Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm

    Directory of Open Access Journals (Sweden)

    LH. Sipaúba-Tavares

    Full Text Available Plankton communities and macrofauna associated to aquatic macrophyte stands in a shallow water-supply reservoir (21°14′09″S; 48°18′38″W on an aquaculture farm were compared to evaluate the relationship between organism densities and some abiotic features of the reservoir. Water and communities associated were sampled at two sites, one in an area with the predominance of Eichhornia azurea (Sw. Kunth and the other with the predominance of Salvinia auriculata Aublet. Communities associated with macrophytes were sampled with floating quadrants (0.5 m2; the macrophytes were washed and plankton and macrofauna were fixated with 4% formalin and 1% lugol iodine; the specimens were then identified and counted. Plankton and macrofauna communities associated with S. auriculata and E. azurea had a similar diversity of species but different (p<0.05 in the abundance of associated organisms. Eichhornia azurea had the highest contents in dry and wet weight, total phosphorus, total nitrogen and organic matter. Planktonic algae were directly correlated with biomass of E. azurea. The taxa with highest densities were Rotifera and Zygnematophyceae. Results showed that the environmental variables associated with macrophytes presence in the shallow reservoir is a strong predictor of favourable conditions to maintain great diversity plankton community and macrofauna associated with plants. The role of macrophytes is important for not only stabilising the clear-water state and maintaining high diversity of organisms associated, but also it seems to be a good alternative to maintaining desirable water-supply quality for aquaculture farms.

  19. 我国水生生物水质基准推导的物种选择%Species Selection for Deriving Water Quality Criteria for Protection of Aquatic Organisms in China

    Institute of Scientific and Technical Information of China (English)

    苏海磊; 吴丰昌; 李会仙; 冯承莲; 张瑞卿; 常红

    2012-01-01

    水生生物水质基准旨在保护水生生物不受水体中化学物质的有害影响,是水质基准体系的重要组成部分.不同区域水生态系统的生物区系不同,导致基准值也会存在差异.在综合研究美国、欧盟、加拿大、荷兰、澳大利亚和新西兰等国家和地区在推导水生生物水质基准的物种选择及其考虑因素的基础上,初步研究我国水生生物水质基准推导的物种选择原则.结果表明:推导我国水生生物水质基准需要选择来自8科的水生生物,分别为鲤科鱼类、硬骨鱼纲中的另一科、两栖动物纲的一科、浮游动物中节肢动物门和轮虫动物门各一科、底栖动物中节肢动物门和环节动物门各一科及一种最敏感的大型水生植物(或浮游植物),可全面代表我国水生态系统不同的营养级和生命形式.%As an important component of the water quality criteria system, the aquatic life criteria aim to protect aquatic biota from hazardous chemicals. The water quality values differ within ecosystems and in geographical regions. Based on overall analysis of the species selection for deriving aquatic life criteria in the United States, Europe, Canada, the Netherlands, Australia and New Zealand, the species selection required for deriving water quality criteria in China was discussed. The results showed that the aquatic organisms required for deriving the aquatic life criteria in China should come from eight different families; Cyprinidae, another family in Osteichthyes, a family in Amphibia, a family in Arthropoda and a family in Rotifera from zooplankton, a family in Arthropod a and a family in Annelida from Zoobenthos, and a macrophyte (or phytoplankton). These can comprehensively represent different trophic levels and life forms in the aquatic ecosystem.

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

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    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

  1. 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 .

  2. 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

    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.%  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。

  3. 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.

  4. 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

    Lugu Lake 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

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

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    SEBASTIÁN CELIS

    2008-01-01

    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 zoo- plancton. El phylum Rotifera fue seleccionado por sus altas tasas reproductivas y efi- ciencia 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 perío- do 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 proba- blemente favoreció el incremento en la diversidad de rotíferos en el CP.

  6. 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.

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

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    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

  8. 净化槽处理民俗餐饮废水的中试研究%PILOT SCALE STUDY ON FOLK CATERING WASTEWATER TREATMENT BY JOHKASOU

    Institute of Scientific and Technical Information of China (English)

    郭浩; 赵岩; 叶建东; 马伟芳

    2013-01-01

    对净化槽处理民俗餐饮废水进行中试研究,试验结果表明,BOD5、TN、TP的平均去除率分别为93%、88%、90%,出水BOD5、TN、TP的平均质量浓度分别为10.57、4.03、0.32 mg/L,满足北京市水污染排放标准(DB 11/307-2005)一级B标准.通过微生物镜检观察中试装置好氧区填料可以看到密实的菌胶团,并且生物相由早期的草履虫和线虫这类浮游微生物,发展到后期大量的累枝虫和轮虫这类固着型微生物;通过ESEM-EDS分析可以看出,生长在火山岩表面的生物膜具有一定的层次,可清晰地看到生物膜内部用于物质交流的孔洞和通道.%Pilot scale study on folk catering wastewater treatment was performed by using JOHKASOU. The research results indicated that the average removal rates of BOD5, TN, TP are 93%, 88%, 90%, respectively. The average concentrations of BOD5, TN, TP in the effluent are 10.57 mg/L, 4.03 mg/L, 0.32 mg/L, respectively. It had reached the I B level of the wastewater discharge standard for Beijing (DB 11/307-2005). The zoogloea in pilot plant oxic zone is dense by EMS observation, and the biofacies changed from the paramecium and nematode to epistylis and rotifera. ESEM-EDS analysis shows the biomembrane on the volcanic surface have many levels, and the holes and passageways for substance exchange also apparent clearly.

  9. 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

  10. Limnological Study of River Soan (Punjab, Pakistan

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    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

  11. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  12. 黄河兰州市区段秋季浮游动物群落结构特征%Characteristics of Zooplankton Community Structure for the Yellow River in Lanzhou City

    Institute of Scientific and Technical Information of China (English)

    白海锋; 王丰; 张星朗; 袁永锋; 问思恩; 沈红保; 李瑞娇; 张军燕

    2015-01-01

    from the 1990′s investigation of the Lanzhou section of the Yellow River.Zooplankton sampling was carried out in November of 2014 along seven transects with three sampling sites at each transect:transects H1 -H3 were located upstream (industrial),H4 -H6 in the middle reaches (resi-dential)and H7 downstream (less developed).A total of 27 phytoplankton species from 4 taxa were observed;9 species (genera)of protozoa,10 species (genera)of rotifera,5 species (genera)of cladocera and 3 species of co-pepoda,accounting,respectively,for 33.3%,37.1%,18.5% and 11.1% of the total species.Zooplankton spe-cies composition was dominated by rotifera and protozoa.Zooplankton density ranged from 1.88 ind /L to 11.09 ind /L,with an average value of 4.64 ind /L and biomass ranged from 1.3 μg/L to 4.4 μg/L,with an aver-age value of 2.5 μg/L.Five dominant species (genus)of zooplankton were recorded and Vorticella microstoma was the most dominant (0.539).The Shannon-Weiner diversity index (H′),Pielou evenness index (J)and Margalef richness index (D)of the zooplankton community were 1.89,0.58 and 1.94,respectively.Cluster analysis, based on the density of zooplankton,showed the seven transects were clustered into two groups:H1 -H6 transects in one group and H7 transect in the other.Water quality in the Yellow River flowing by Lanzhou city is lightly-mod-erately polluted according to the species diversity index.To improve water quality in the Lanzhou section of the Yellow River,it will be necessary to strengthen pollution control and management.

  13. Ecological features of zooplankton community of Hongshan Reservoir in Xinjiang%新疆红山水库浮游动物群落结构特征

    Institute of Scientific and Technical Information of China (English)

    袁林; 孙玲霜; 朱新英; 黄硕琳; 薛俊增; 吴惠仙

    2011-01-01

    红山水库位于新疆阿勒泰地区吉木乃县境内,为了解水库浮游动物群落动态特征,于2008年7月平水期、10月枯水期以及2009年5月丰水期对该水库进行了浮游动物调查,共采集鉴定浮游动物52属81种,其中原生动物22属38种,占浮游动物总物种数的46.9%;轮虫15属22种,占27.2%;桡足类9属14种,占17.3%;枝角类6属7种,占8.6%.水库浮游动物群落结构呈现以小型原生动物、轮虫为主,大型浮游甲壳动物占少数的特征.调查结果显示红山水库浮游动物不同时期优势种不尽相同,某些优势种仅在特定水文期出现.浮游动物各类群间生物密度和生物量均存在显著差异,但水库浮游动物总生物量无明显季节差异(p>0.05),生物密度则具有季节性特征(p<0.01).库区生物密度变化趋势为:枯水期( 16.23±3.01×103 ind/L)>丰水期(7.99±1.60×103 ind/L)>平水期(7.61±2.57×103 ind/L).%Hongshan Reservoir (85°51'58"E, 47°2'10"N) locates in Jeminay county of Xinjiang's Altay Prefeture. The Musidao glacier is the only water source place of this county. In recent years, the global climate becomes warming and humanity's frequent activity; the Musidao glacier's snow line has been decreased 500 meters. The zooplankton which has a significant impact on the plankton community is the major component groups of aquatic plankton and a culture of quality fishing bait. Based on the data collected from the flow period, dry period and flood period, the species composition, community structure and species diversity of the zooplankton were determined inHongshan Reservoir. Results show that 81 species of 52 genera in total was identified, of which 38 species of 22 genera were protozoa, 22 species of 15 genera were rotifera, 14 species of 22 genera were copepod and 7 species of 6 genera were cladocera, it was higher than that of other reservoirs in the same latitude of China. The number of species for protozoa, rotifera

  14. 湘江浮游生物资源状况的调查与分析%Investigation and analysis of the status of plankton in Xiangjiang river

    Institute of Scientific and Technical Information of China (English)

    曾亚英; 王晓清; 熊钢; 张建国; 马晓; 夏建海; 秦溱

    2012-01-01

    2009年4月至2010年11月,在不同季节对湘江流域浮游生物的资源状况进行调查.结果表明,湘江浮游植物有127种,隶属8个门,其中,绿藻门44种,硅藻门38种,蓝藻门13种,裸藻门9种,隐藻门7种,黄藻门6种,甲藻门和金藻门各5种.浮游植物平均密度为2.91万个/L,平均生物量0.15mg/L,其中硅藻门生物量最大,占总量的41.8%,优势种为颗粒直链藻、尖针杆藻和缘花舟形藻;浮游动物91种,其中,轮虫最多,有38种,枝角类有19种,原生动物有18种,桡足类有16种,浮游动物平均数量为13.94个/L,平均生物量为0.24mg/L,其中桡足类生物量最大,占总量的47.7%,优势种为剑水蚤和哲水蚤.从种类组成来看,湘江浮游生物属于典型的河流型浮游生物群落结构,其种群结构特征表明湘江水体属于贫-中营养型.%The status of plankton in Xiangjiang river was investigated in different seasons from April 2009 to November 2010. The results showed that there were 127 species of phytoplankton, belonging to 8 phyla including 44 species of Chlorophyta, 38 species of Bacillariophyta, 13 species of Cyanophyta, 9 species of Euglenophyta, 7 species of Cryptophyta, 6 species of Xanthophyta, and 5 species of Pyrrophyta and Chrysophyta respectively; the average density of phytoplankton was 2.91×l04 ind/L, and the biomass was 0.15 mg/L; the biomass of the Bacillariophyta was the largest, accounting for 41.8% of the total biomass, and the predominant species were Melosira granulate, Synedra acus and Navicula radiosa. There were 91 species of zooplankton, among which 38 species belonged to Rotifera, 19 species belonged to Copepoda, 18 species belonged to Protozoa and 16 species belonged to Cladocera; the average density of zooplankton was 13.94 ind/L, and the biomass was 0.24 mg/L; the biomass of the Cladocera was the largest, accounting for 47.7% of the total biomass; Cyclops and Calanus were the predominant species appearing all over the year

  15. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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. Canonical Correspondence Analysis between the Plankton Community and Environmental Factors in Hongfeng Lake Reservoir in Winter and Spring%红枫湖水库冬春季浮游生物群落与环境因子的典范对应分析

    Institute of Scientific and Technical Information of China (English)

    夏品华; 马健荣; 李存雄; 林陶; 詹金心; 伍庆

    2011-01-01

    The plankton community in Hongfeng Lake Reservoir, which is located in Guiyang City, Guizhou Province of China,was investigated and analyzed from January to May 2010. A total of 95 phytoplankton were identified, consisting of 53 species of green algae, 20 species of diatoms, 18 species of blue-green algae, two species of dinoflagellates, and only one species each of euglenoids and golden algae. In addition, 36 species of meta-zooplankton (22 Rotifera, 8 Cladocera, 6 Copepods) were identified.Phytoplankton and mefs-zooplankton abundance ranged from 0. 6 x 106 to 39. 4 × 106 L-1 and from 3.3 to 448 L-1 respectively.The biomass varied from 0. 56 to 20. 06 mg/L and 0. 0l to 0. 98 mg/L respectively. The Shannon-Weiner diversity index (H) varied from 0. 45-1.02 and 0. 62-0. 92 respectively. Canonical Correspondence Analysis ( CCA ) showed that total nitrogen,conductivity, temperature, nitrate, dissolved oxygen saturation and Daphnia (Daphnia) hyalina were important factors influencing the distribution of the phytoplankton community. Temperature, ammonia nitrogen, conductivity, pH, Tetraedro minimun,Coccomyxa dispar and Asterionella formosa were important factors influencing the distribution of the meta-zooplankton community.CCA ordination explained preferably the relationship between spatial distribution of the plankton community and environmental factors in the reservoir systems.%2010年1-5月对贵州省贵阳市红枫湖水库的浮游生物群落进行了调查和分析.共鉴定出浮游植物95种,绿藻在种类组成上占绝对优势,共53种,其次为硅藻20种,蓝藻18种,甲藻2种,裸藻和金藻各1种;后生浮游动物36种,其中轮虫22种,枝角类8种,桡足类6种.浮游植物、后生浮游动物的丰度分别为0.6×106~39.4×106L-1和3.3~448 L-1,生物量分别为0.56~20.06和0.01~0.98 mg/L,Shannon-Weiner多样性指数(H)分别为0.45~1.02和0.62~0.92.典范对应分析(CCA)显示:p(TN),电导率,温度,p(NO3--N),溶解氧饱和

  18. 东江干流浮游动物群落结构特征及与水质的关系%COMMUNITY STRUCTURE OF ZOOPLANKTON AND ITS RELATION WITH WATER QUALITY IN DONGJIANG RIVER

    Institute of Scientific and Technical Information of China (English)

    王博; 廖剑宇; 刘全儒; 江源

    2013-01-01

    对东江干流浮游动物进行调查,并分析了其群落结构、生物量和丰度的空间分布特征及与主要环境因子的关系.46个采样点中共发现52种浮游动物,浮游动物的密度范围在1~3640 L-1之间,其中原生动物与轮虫类占总浮游动物密度的77%.优势种属为钟虫(Vorticella)、侠盗虫(Strobilidium)、团睥睨虫(Askenasiavolvox)、砂壳虫(Difflugia)、针簇多肢轮虫(Polyarthra trigla )、颈沟基合溞(Bosminopsis deiteris )、广布中剑水蚤(Mesocyclops leuckarti ).根据浮游动物各项指标值显示,东江干流水质良好.相关分析结果表明:浮游动物密度以及属类数均与叶绿素 a、CODMn、DO、电导率呈极显著的正相关关系(P<0.01);不同类浮游动物与水质因子相关性程度不同,原生动物与电导率呈极显著正相关,轮虫与CODMn及温度呈极显著正相关,枝角类和桡足类均与 DO 呈极显著正相关.浮游动物的空间分布与水体水质因子关系密切.%Community structure of zooplankton in Dongj iang river such as genus richness,density and biodiversities was investigated, regression analysis between community index of phytoplankon and water quality parameters were performed.Fifty two genus of zooplankton were identified.Density of phytoplankton was found to be from 1~3 640 L-1 ,with 77% protozoa and rotifera.Vorticella sp.,Strobilidium sp., Askenasia volvox,Difflugia sp.and Polyarthra trigla were found to be dominant in algae community. Judging from values of zooplankton comprehensive index,Dongjiang river was not seriously polluted.Density of zooplankton was found to be positively correlated with CODMn,conductivity value,DO and Chla (P<0.01). Water quality factor correlation degree was different with different zooplankton.Protozoa was positively correlated with conductivity,rotifer was positively correlated with CODMn and temperature,cladocera and copepoda was positively correlated with DO. Zooplankton was

  19. 贵州草海高原湿地浮游动物群落结构与水质评价%Zooplankton Community Structure and Water Quality Assessment of Caohai Plateau Wetland, Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    蔡国俊; 周晨; 林艳红; 喻理飞; 安苗

    2016-01-01

    Zooplankton plays an important role in aquatic ecosystems and biological productivity at the base of the food chain since they eat phytoplankton, bacteria and detritus, and provide food for fish and other aquatic organisms. The community structure and succession of zooplankton are greatly affected by the physical-chemical factors in waters. Knowledge of zooplankton community dynamics and its relationship with environmental factors is crucial in understanding the changes in aquatic ecosystems. Caohai is one of the three Plateau Freshwater Lakes in China, with a good natural location in the Yunnan-Guizhou Plateau, playing an essential part in regional ecosystem balance .However, since the lake was restored in 1982, there have been only two reports published thus far professionally about zooplankton community in Caohai Lake, information of zooplankton community dynamics and its relationship with environmental factors in Caohai seems rather limited. Investigation and research on zooplankton community to fill the lack of information on zooplankton community in Caohai Lake is necessary and urgent. In order to explore the characteristics and long-term changes of zooplankton community structure, status of water quality, and their relationships with environmental factors in Caohai Lake, we investigated the species composition, density, spatial distribution of zooplankton and water quality parameters in Caohai Lake in Summer and Autumn, 2014. There were 151 species identified which belonging to 83 genera, including 60 Protozoa belonging 31 genera, 55 Rotifera belonging to 26 genera, 18 Copepoda belonging 15 genera, and 18 Cladocera belonging 11 genera. Dominant species included 3 Copepoda, 1 Protozoa and 1 Rotifera, the main dominant species was Sinodiaptomus sarsi of Copepoda;The significant spatial heterogeneity environment caused the low Shannon-Wiener diversity index and Margalef richness index, they both were 1.14 and 0.47 respectively. There was a significant variation

  20. 鄱阳湖国家级自然保护区浮游生物群落结构及空间分布%COMMUNITY STRUCTURE AND SPATIAL DISTRIBUTION OF PLANKTON IN THE POYANG LAKE NATIONAL NATURE RESERVE, CHINA

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    张婷; 马行厚; 王桂苹; 李德亮; 金斌松; 秦海明

    2014-01-01

    To evaluate the plankton characteristics of the Poyang Lake National Nature Reserve after the drought oc-curred in spring 2011, the community structure and spatial distribution of plankton in the Poyang Lake National Nature Reserve were investigated and analyzed in August, 2011. A total of 97 phytoplankton and 42 zooplankton species were identified, which belonged to 49 and 23 genera, respectively. The zooplankton were consisted of 13 species of protozoa, 23 species of rotifera, 3 species of cladocera and 3 species of copepoda. The numbers of plankton species in Lake Da-huchi and Zhushihu were more than that of the other lakes and rivers. The abundances of plankton among each lake and river were significantly different, and varied from 260 to8.18×106 cells/L for phytoplankton and 3630 to 73173 ind./L for zooplankton, respectively. The results showed that the abundances of plankton in Xiu River and the lakes that lo-cated at the west of Gan River, were significantly higher than that of Gan River and the other lakes. Statistical analysis indicated that the dominant species of phytoplankton in the Poyang Lake National Nature Reserve wereAnabaena flos-aquae, Scenedesmus quadricauda,S.bijuga,Melosira granulatavar. angustissima,M. granulate,M. graunlatavar. angustissima f. spiralis,Synedra acus andFragilaria capucina,while the dominant species of zooplankton wereStentor amethysinus,Difflugia lobostoma,Centropyxis discoides,Strombidim viride,Brachionus diversicornis,B. bennini, Trichocerca rousseleleti,T. longiseta andAsplanchna girodide. The maximum values of diversity indices (H′) and evenness (J) of both phytoplankton and zooplankton were 2.41 and 0.96, respectively. The values of abundance (Dm) of plankton were both less than 3. Evaluated with the diversity indices (H′), evenness (J) and abundance (Dm) of plankton, the water qualities of lakes and rivers in the Poyang Lake National Nature Reserve wereβ-type of pollution, except Lake Banghu and Meixihu.%为评

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

    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.

  2. 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

  3. 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

  4. Community diversity and its seasonal dynamics of soil fauna in Fukang oasis of Xinjiang, Northwest China%新疆阜康绿洲不同生境土壤动物群落多样性及其季节动态

    Institute of Scientific and Technical Information of China (English)

    吾玛尔·阿布力孜; 古丽布斯坦·努尔买买提; 阿布都肉苏力·吐孙; 木开热木·阿吉木; 吴松林

    2013-01-01

    为了查明阜康绿洲不同生境土壤动物群落多样性特征及其变化动态,2010年4、7、9及11月中旬分别以该绿洲的用材林、防护林、苗圃、耕地、盐碱地、灌木林及荒草地生境为研究对象,采用手捡法、改良干漏斗法和湿漏斗法分离0~20 cm土层中的土壤动物,并分析了不同生境土壤动物的群落结构、分布特征及季节动态.共获得土壤动物1 1098只,共35类,其中线虫类、轮虫类和弹尾类为优势类群.在7种不同生境土壤动物类群、个体数和多样性以及不同季节之间均存在显著差异(P<0.05),其中Shannon多样性指数依次为用材林>防护林>灌木林>耕地>盐碱地>苗圃>荒草地;时空分布调查发现,不同生境土壤动物群落分布具有明显的表聚性特征,并在不同土层及季节间均有显著性差异(P<0.05),季节动态变化依次为秋季最多、其次春季和冬季,夏季最少;不同生境土壤动物群落间的Jaccard相似性指数属于中等不相似(处于0.25~0.50).不同生境组间聚类和排序结果表明,将7种不同生境分为人工林生境型、人为干扰生境型、灌木生境型及荒漠生境型4大类型.结果表明,阜康绿洲不同生境土壤动物群落组成和多样性具有明显的生境和季节差异特征.%In order to understand the community diversity and its dynamic changes of soil fauna in different habitats of Fukang oasis,a field investigation was conducted in April,July,September,and mid November,2010.Seven different habitats including timber forest,shelter forest,nursery,cropland,saline-alkaline land,shrub land,and desert grassland were chosen,and hand-sorting and modified Tullgren and Baermann methods were adopted to isolate the soil fauna in 0-20 cm layer,with the community structure,distribution characteristics,and seasonal dynamics of soil fauna analyzed.A total of 11098 individuals were collected,belonging to 35 groups,among which,Nematoda,Rotifera