Abstract
A random survey of aquatic Oligochaeta was conducted in Chennai, Villupuram, Dindugal, Thiruvallur, and Sivagangai districts of Tamil Nadu from November 2010 to March 2012. Thirteen taxa were identified from a total of 644 aquatic oligochaetes examined from various qualitative samples of aquatic vegetation and sediments. Chennai district had 3 families: Naididae, Pristinidae and Tubificidae along with a polychaete. The naidids were most diverse with 5 species: Branchiodrilus semperi, Aulophorus furcatus, Dero digitata, Dero indica and Dero zeylanica, the pristinids were represented by Pristina brevichaeta and Pristina jenkinae and the tubificids by 2 species, Branchiura sowerbyi and Limnodrilus hoffmeisteri. The nine aquatic oligochaetes collected from Chennai were already reported from this region. Two naidids, Branchiodrilus semperi and D. indica, along with the tubificid Branchiura sowerbyi, were collected from Villupuram district and they constitute the first reports for that district. Limnodrilus udekemianus from Kodaikanal, Dindugal district constitutes the first report for that region of Tamil Nadu. Megadriles belonging to the family Octochaetidae (Dichogaster bolaui?) and unidentified Megascolecidae collected from Thiruvallur and Sivaganga districts respectively were found to occur in aquatic habitats.
