Abstract:

Aquatic oligochaetes were studied in 2 lowland regions (the Chennai and Tiruvallur districts) and a mountainous area (Ooty) in Tamil Nadu, southern India. Quantitative core samples, 2.5 cm in diameter, were collected monthly from April 2005 to March 2006 in Kodungaiyur Swamp and Pandinellur Swamp, the 2 main sites commercially exploited for aquatic Oligochaeta in Chennai. Random qualitative samples were collected from other sites using corers or strainers. In total, 9 naidids and 4 tubificids were identified during this survey. Dero indica, D. zeylanica, D. digitata, and Pristina jenkinae are first reports from Chennai. L. hoffmeisteri, the worm commercially marketed here as "Tubifex," was the only tubificid species collected from Chennai. Tubifex tubifex and Limnodrilus udekemianus were recorded only from the cooler waters of Ooty. The finding of L. udekemianus constitutes a first report from India. Branchiodrilus semperi, Dero dorsalis, Aulophorus michaelseni, Pristina breviseta, and Branchiura sowerbyi constitute first reports for Tiruvallur. The diversity of the naidids was more than that of the tubificids in Chennai and Tiruvallur, but only tubificids were recorded in the samples collected from Ooty.

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