343 research outputs found
The Indian species of Testudinella (Rotifera: Flosculariacea: Testudinellidae) and their distribution
Our plankton and semi-plankton collections from India revealed 14 species of Testudinella including two undetermined species yet awaiting descriptions. The Oriental endemic T. insinuata is a new record from India while the Australasian T. walkeri and the palaeotropical T. brevicaudata and T. greeni are other globally interesting species. Testudinella amphora, T. brevicaudata, T. dendradena, T. greeni, T. parva semiparva, T. tridentata and T. walkeri are characterized by distribution restricted till date to northeast India (NEI); T. insinuata is restricted to the floodplains of the Kashmir valley of Jammu and Kashmir state of western Himalayas; and T. incisa and T. mucronata are known for valid reports from Tamil Nadu and Jammu and Kashmir, respectively. T. emarginula, T. patina and T. tridentata are believed to be cryptic species-complexes and thus desired ecological and genetic analysis of local populations. This study merits interest vis-à -vis biodiversity and distribution of the Indian Rotifera
Biodiversity of freshwater rotifers (Rotifera: Eurotatoria) of Mizoram, Northeast India: composition, new records and interesting features
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 âtropicalâ 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
Zooplankton Diversity of a Soft-water and Highly De-mineralized Reservoir of Meghalaya (Northeast India): The Spatio-temporal Variations and Influence of Abiotic Factors
Hydrobiological survey of a âsoft-waterâ and âhighly de-mineralizedâ reservoir of Meghalaya state of northeast India is undertaken to analyze zooplankton diversity with reference to the spatio-temporal variations and influence of abiotic factors. The littoral and limnetic zooplankton assemblages of this subtropical reservoir without aquatic vegetation reveal total 36 species, and record lower abundance, quantitative dominance of Rotifera, sub-dominance of Cladocera and Copepoda and moderate species diversity. Keratella cochlearis, Bosmina longirostris, Polyarthra vulgaris, Mesocyclops leuckarti, Conochilus unicornis and Asplanchna priodonta influence abundance, species diversity, dominance and equitability of zooplankton. We report differential spatial influence of individual abiotic factors with the relatively more importance at the limnetic region, and the canonical correspondence analysis registers 72.5% and 78.8% cumulative influence of 10 abiotic factors on the littoral and limnetic assemblages, respectively. The spatial differences of various diversity aspects and the influence of abiotic factors suggest habitat heterogeneity amongst the two regions. This study is a useful contribution to zooplankton diversity of the subtropical environs, and soft and de-mineralized waters in particular. Our results mark a distinct contrast to the lowest richness and abundance of zooplankton noted from India vide the preliminary 1990-91 survey of this reservoir
Phytoplankton Diversity of a Demineralized Urban Wetland of Meghalaya State of Northeast India: The Spatio-temporal Variations and the Role of Abiotic Factors
The authors analyze phytoplankton diversity of a small urban wetland of Meghalaya to assess biodiversity and limnology interest of small water bodies. This âslightly acidic-circumneutral, demineralized and soft waterâ subtropical wetland reveals diverse phytoplankton (64 species), indicates high desmid richness and highlights the speciose littoral constellations of up to 55-58 species per sample. Phytoplankton comprises dominant quantitative component of net plankton and registers Charophyta dominance; Chlorophyta > Bacillariophyta > Dinozoa > Chrysophyta > Cyanobacteria depict sub-dominance, and Euglenozoa and Cryptophyta show poor abundance at the littoral and semi-limnetic regions. The richness of phytoplankton and abundance of phytoplankton, Charophyta, Chlorophyta, Dinozoa, Chrysophyta and Cyanobacteria follow bimodal spatio-temporal variations. Closterium, Cosmarium, Staurastrum, Micrasterias, Netrium, Staurodesmus and Scenedesmus are notable genera, and 14 species collectively influence phytoplankton abundance. Phytoplankton registers high species diversity, lower dominance and high evenness. Amongst 15 abiotic factors, only the rainfall and sulphate exert notable influence individually, while the canonical correspondence analysis registers lower cumulative influence of the selected 10 factors on the littoral and semi-limnetic phytoplankton assemblages. This study merits interest for neglected biodiversity and ecology of small aquatic biotopes of India and urban wetlands in particular
The rotifers (Rotifera: Eurotatoria) from the Kashmir Himalayan floodplains and Rotifera biodiversity of Jammu and Kashmir, north India
Our plankton and semi-plankton collections from the floodplain wetlands of the Kashmir valley reveal 140 rotifer species belonging to 43 genera and 22 families. The richness forms ~81% of 173 species, belonging to 51 genera and 23 families, recognized as validly known from Jammu and Kashmir (J&K) vide the present biodiversity evaluation. The rotifer assemblages of the Kashmir Himalayan wetlands and J&K comprise ~33% and ~41%, respectively of the Indian Rotifera; their biodiverse nature is hypothesized to habitat diversity and ecological heterogeneity of aquatic environs of this state of north India. One species is new to India and 25 species are new to northwest India. Lecanidae > Brachionidae form ~33% and Trichocercidae = Lepadellidae > Notommatidae > Euchlanidae comprise ~31% of the rotifer fauna of J&K which includes species of global and regional biogeographic interest and, a large component of cosmopolitan species (~81%). Lecane > Trichocerca > Brachionus = Lepadella collectively comprise ~39%; Keratella > Euchlanis > Synchaeta are notable (~12%); and Notholca and Cephalodella species deserve attention from J&K. Rotifera of the Kashmir Himalayan floodplains and J&K indicate the littoral-periphytic character, cold-water elements, small-sized species, and the relative paucity of Brachionus, Lepadella and Lecane richness. We estimate 260+ rotifer species from J&K pending analysis of intensive latitudinal and longitudinal collections including samples from Ramsar sites, high altitude lakes and other water bodies with emphasis on colonial, sessile and benthic taxa, and analysis of likely cryptic diversity of certain species
Learning from âthe Outsider Withinâ: The Sociological Significance of Dalit Womenâs Life Narratives
Dalit women have long occupied marginal positions and been excluded from two major Indian social movements: The Feminist Movement and the Dalit Movement. The researcher examines how Dalit women have made creative use of their marginalityâtheir âoutsider-within\u27 statusâand have represented their lived experiences. The study scrutinizes select life narratives of Dalit women writers: Bama\u27s Sangati: Events (2005), Urmila Pawarâs The Weave of My Life (2015), and Baby Kambleâs The Prisons We Broke (2008) to discuss and explore the sociological significance of three characteristic themes in these narratives: (1) the interlocking nature of Dalit womenâs oppression, (2) endurance and resilience, (3) their role in the transformation of the Dalit community. Thus, the perspectives of Dalit women writers create new knowledge about their lives, families, and communities. Their perspectives may well provide a preparatory point for the development of the Dalit Feminist Standpoint. This study may help other marginalized sections or social scientists by putting greater trust in the creative potential of their narratives and cultural biographies
Ecosystem diversity of Cladocera (Crustacea: Branchiopoda) of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India
Plankton and semi-plankton samples collected from twelve floodplain lakes (beels) of Majuli River Island of the Brahmaputra river basin, Upper Assam reveal rich Cladocera assemblage of 48 species belonging to 32 genera and 7 families. This report assumes biodiversity value as ~65.0% and ~37.0% of the species, and ~78.0% and ~72.0 of genera of the taxon known from Assam state of northeast India (NEI) and India, respectively. Picripleuroxus quasidenticulatus (Smirnov) is a new record from the Indian sub-region. Biogeographically important elements include one Australasian, three Indo-Chinese and two Oriental species. Total cladoceran richness in individual beels ranged between 16-38 (26 ± 6) species while monthly and seasonal richness in six beels each varied between 8 ± 3-13 ± 3 species and 11 ± 4-17 ± 3 species, respectively and showed lack of any pattern of temporal variations. The community similarities (40.1-86.5% vide SĂžrensen's index) and the hierarchical cluster analysis affirm heterogeneity in Cladocera composition in different beels. Individual abiotic factors indicated insignificant influence on richness except for significant positive correlation with alkalinity only in Khorkhoria beel
Rotifer assemblages (Rotifera: Eurotatoria) of the floodplain lakes of Majuli River Island, the Brahmaputra river basin, northeast India
Our plankton and semi-plankton collections from twelve floodplain lakes (beels) of Majuli River Island, Upper Assam reveal 124 rotifer species (32 genera and 17 families); these merit biodiversity value as ~52.0% and ~30.0% of species, ~68.0 and ~45.0% of genera and ~74.0 and ~65.0% of the families of the Phylum known from northeast India (NEI) and India, respectively. Two species are new to India with Trichocerca uncinata as new record to the Oriental region. Eleven species are new to the study area and we provide an updated list (144 species) for following meta-analyses of Majuli Rotifera. Biogeographically important elements include one Australasian, four Oriental, four Palaeotropical and one cosmo (sub) tropical species while several species are of regional distribution interest. The rotifer fauna is predominantly tropical and Lecanidae > Lepadellidae collectively include ~53.0% species but it records paucity of Brachionus species. Individual beels record total richness of 60-100 (77 ± 12) species, monthly richness between 24 ± 7-34 ± 7 species and maximum up to 54 species/sample. The results are characterized by high community similarities (59.7-90.4% vide SĂžrensenâs index), more rotifer homogeneity amongst beels, lack of any pattern of temporal richness variations and much limited influence of abiotic parameters
Phytoplankton diversity of floodplain lakes of the Majuli River Island of the Brahmaputra river basin, Assam, northeast India
Phytoplankton of three floodplain lakes (beels) of the Majuli River Island of upper Assam, northeast India (NEI), sampled during September 2010âAugust 2012, revealed rich diversity (108 species) with Ghotonga > Holmari â„ Bhereki beels; richness of Chlorophyta and of Cosmarium > Staurastrum > Euastrum in particular. The monthly richness and community similarities affirmed heterogeneity in phytoplankton composition. Phytoplankton comprised between 59.5±12.5, 57.1±12.3 and 48.6±13.5% of net plankton abundance of Bhereki, Holmari and Ghotonga beels, respectively. Bacillariophyta > Chlorophyta showed quantitative importance in Bhereki while Chlorophyta > Bacillariophyta recorded importance in Holmari and Ghotonga beels. Cyanophyta showed sub-dominance and Dinophyta > Euglenophyta showed low densities in the three beels. Phytoplankton richness and abundance followed oscillating monthly variations; ANOVA registered insignificant richness variations amongst beels. The results are characterized certain monthly and annual variations but mean values depicted high species diversity, low dominance and high equitability. Individual and cumulative influence (vide CCA) yielded limited insight on the role of seventeen abiotic factors on phytoplankton in Holmari and Bhereki beels
Rich freshwater rotifer fauna of small lentic ecosystems of south Andaman, Andaman Sea, India (Rotifera: Eurotatoria)
Small lentic
ecosystems are hypothesized to be interesting habitats for metazoan diversity. This study is undertaken to
document Rotifera of small freshwater bodies of south Andaman, India. A total of
11
2
species (S), belonging to 32 genera and
19 families, recorded i
n our intensive February 2017 collections, indicate rich and diverse assemblage of the taxon. Total
richness comprises ~ 27 % of the rotifer species known from India and thus affirms biodiversity interest and habitat diversit
y of
the sampled habitats. This
report adds 42 species, seven genera and three families to the taxa reported till date from freshwaters
of the Andaman and Nicorbar islands. Rotifera meta
-
analysis indicates distinct increase in richness of Lecanidae > Brachionidae
> Trichocercidae and tw
o
-
fold increase in
Brachionus
species. The biogeographically interesting elements comprise 8.0 % of S
and several species indicate regional distribution importance. The rotifer fauna shows high richness of cosmopolitan species
(~68% of S) and a number of t
ropical and subtropical species (~22 % of S). The present study highlights distinct scope to
augment Rotifera diversity of the Andaman and Nicorbar islands freshwaters vis
-
Ă
-
vis intensive sampling of varied habitats
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