Species composition and monthly abundance of copepods in relation to environmental variables were studied in Cooum and Adyar estuaries of Chennai metropolis from April 1998 to March 1999. Copepods were the dominant group contributing to 55 - 60% df the total zooplankton. A total of 27 taxa of copepods were recorded. Paracalanus parvus and Stenocaris-minor were the abundant species in Adyar and Acartia major and Diaptomus similis in Cooum. Among copepods, Cyclopoida constituted 46%, followed, by Calanoida (34%) and Harpacticoida (19%) respectively. The maximum (10,500 ind/m³) and minimum (300 ind/m³) abundance were noticed in August and October 1998 at Adyar and Cooum estuaries respectively. The total abundance of copepods occurred at high salinities (>30 %o) and over a high temperature range (29⁰C to 30°C) at Cooum Estuary as against wide salinities (>I0 to 35 %o) and narrow temperature range (>26⁰ C to 32" C) at Adyar Estuary.

Esturaine copepodes, abundance diversity