Contributions to the rotifer fauna of Kerala (India) with two new records and remarks on some species

Abstract

The present study reports on rotifer fauna from two low-saline backwaters namely Veli-Aakulam (latitude 8o 25' – 8o 30' N & longitudes 76o 55' - 77o 00' E) and Poonthura - Thiruvallam (latitude 8o 25' – 8o 35'N & longitude 76o 50' – 76o 58' E) along the southern part of Kerala, India. The survey for rotifers was carried out from February 2000 to January 2001. A total of 42 species of rotifers belonging to 16 genera and 12 families are recorded. Of these, the family Brachionidae is represented by the highest number of 22 species followed by Lecanidae (5 species), Filinidae (4 species) and Mitilinidae (2 species). The rotifers, Brachionus dichotomus reductus (Koste & Shiel) and B. kostei (Shiel) are reported here for the first time from Indian waters while B. quadridentatus mirabilis (Daday), B. calyciflorus borgerti (Apstein), Mytilina crassipes (Lucks), Filinia opolensis (Zacharias) and F. cornuta (Weisse) are reported for the first time from Kerala waters. The existence of B. forficula keralaiensis (Nayar & Nair) and B. rotundiformis (Tschugunoff) in Kerala waters is confirmed through the present study since they have been reported so far only from Kerala. Diagnostic features of some interesting species are also illustrated in the present account with remarks on their distribution in India.