Vol. 42 No. 2, 2003
Diversity of Planktonic and Epiphytic Rotifers in the Backwaters of the
Delhi Segment of the Yamuna River, with Remarks on New Records from
Jyoti Arora and Naresh K. Mehra*
Limnology Unit, Department of Zoology, University of Delhi, Delhi 110 007, India
Jyoti Arora and Naresh K. Mehra (2003) The
backwaters of the Delhi segment of the Yamuna River are shallow, weedy,
and perennially open lentic habitats that harbor a rich variety of
zooplankton, particularly rotifers. The present study is based on
planktonic and epiphytic rotifers collected from these backwaters once
a month over a period of 1 yr (September 1997 to August 1998).
Planktonic rotifers were obtained by filtering water from the littoral
zone through a plankton net, while epiphytic specimens were collected
from the roots of Eichhornia crassipes and from floating and submerged leaves of Salvinia molesta.
In total, 110 species belonging to 39 genera of 20 eurotatorian
families were identified. Of these, five species of monogonont rotifers
are new records from India, of which 2 are new to the Oriental region.
The majority of the species were monogononts, while bdelloids were
represented only by Rotaria
sp. The largest fraction (76%) belonged to the following families:
Lecanidae > Collurelidae > Brachionidae > Trichocercidae >
Notommatidae > Flosculariidae. The fauna consisted mainly of
cosmopolitan and tropicopolitan taxa except for 3 pantropical, 2
paleotropical, 2 arctic-temperate, 1 eastern hemispheric, and 1
holarctic taxa. The relative composition of planktonic and epiphytic
rotifer species as well as the preference of the latter for the roots
of Eichhornia compared to the leaves of Salvinia are discussed. Comments are also provided on species of special taxonomic and/or zoogeographic interest.
Key words: Rotifers, Biodiversity, Backwaters, New records, India.
*Correspondence: E-mail: firstname.lastname@example.org