Taxonomic and zoogeographic considerations on Lecanidae (Rotifera: Monogononta) of the Balearic archipelago, with description of a new species, Lecane margalefi n.sp.

2001

Rotifera IX

One hundred and sixteen species of Rotifera are recorded from seven floodplain lakes of the Brahmaputra basin (northeastern India), the highest rotifer biodiversity recorded from these biotopes in the Indian subcontinent to date. The Australasian Brachionus dichotomus reductus and Lecane batillifer; the Oriental Keratella edmondsoni, Lecane blachei and L. acanthinula; the Palaeotropical Lecane braumi, L. lateralis, L. unguitata, Trichocerca tropis, Testudinella greeni and T. brevicaudata; the Pantropical Brachionus donneri and a rather widely distributed Horaella brehmi represent taxa of biogeographical interest. Three species are new additions to the Indian rotifer fauna and eight are new to the N.E. region. Lecanidae > Brachionidae = Colurellidae > Trichocercidae > Testudinellidae comprise the largest fraction (68.0%) of the examined fauna. Comments are made on the general nature and composition of the rotifer taxocoenosis as well as on acidophilic elements, ecology of various taxa and on the species richness of different lakes.

Section: Resultsmentioning

confidence: 99%

Biodiversity of Rotifera in some tropical floodplain lakes of the Brahmaputra river basin, Assam (N.E. India)

2001

Rotifera IX

“…The distinct richness of the littoral‐periphytonic elements and paucity of euplanktonic species in the beels and pats of northeast India suggests a lack of definitive pelagic habitats . It is worth noting that a large number of small‐sized species concomitant with low population densities characterize our collections.…”

Section: Discussionmentioning

confidence: 97%

Northeast India: An important region with a rich biodiversity of Rotifera

Internat. Rev. Hydrobiol.

2014

This study extends our previous work to investigate the planktonic rotifers of floodplain lakes (locally called as beels or pats) of Northeast India (NEI) and reviews the known rotifer diversity from the seven states of this region. To do this we examined plankton samples from numerous sites from different states, including 30 floodplain lakes (beels) of Assam and 15 floodplain lakes (pats) of Manipur. This survey yielded 238 species, making the region of NEI one of the most specious and diverse (50 genera and 23 families) of the Indian subcontinent.

“…However, the detailed observations are required to confirm these findings. The predominance of periphytic or littoral elements (76.2%) and fewer planktonic rotifers noticed presently may be attributed to the lack of definite pelagic habitats (De Manuel, 1994) in floodplain lakes, their shallow nature and the growth of aquatic macrophytes. Further, this study demonstrates a frequent occurrence of non-planktonic taxa in open waters of many beels.…”

Section: )mentioning

confidence: 94%

Rotifer communities of floodplain lakes of the Brahmaputra basin of lower Assam (N.E. India): biodiversity, distribution and ecology

2005

Hydrobiologia

The rotifer communities of 15 acidic -alkaline and soft -marginally hard water floodplain lakes of the lower Assam valley of the Brahmaputra river basin, characterized by low ionic concentrations, reveal 164 species (178 taxa) belonging to 39 genera and 20 families and represent the richest biodiversity known to date in these ecotones of the Indian subcontinent. Nine species are new to the Indian Rotifera. Cosmopolitan (59.7%) > pantropical (15.2%) > cosmotropical (12.2%) species dominate the taxocoenosis. Biogeographically interesting elements constitute a notable component (13.4%); important members of this category include six Oriental, two Australasian and seven Palaeotropical species. The examined fauna depicts a tropical character with predominance of Lecane spp. (28.0%). Littoral or periphytic rotifers (76.2%) dominate the planktonic species. Rotifers comprise a dominant qualitative (67-103, 79.1 ± 11.0 species) and an important quantitative (mean: 41.1-65.9%) component of zooplankton in all floodplain lakes, register a moderate diversity (mean: 2.036-2.642), low dominance (mean: 0.019-0.216) and high evenness (mean: 0.840-0.893). The examined material indicates several interesting acidophilous elements. Richness depicts significant inverse correlation with pH. Water temperature, conductivity, dissolved oxygen and alkalinity record significant direct relationships with the rotifer abundance. Diversity is influenced by abundance and is also directly correlated with water temperature and conductivity. Canonical analysis shows a notable cumulative impact of six abiotic factors on richness, density and diversity.