Ecology and distribution of tanaids in a large tropical estuary along the Southwest Coast of India

Abstract

The crustacean order Tanaidacea consists of macrobenthic invertebrates, which constitute a major food source for higher trophic levels in estuarine and marine environments. Based on seasonal sampling in the Kochi Backwaters (KBW), the largest monsoonal estuary along the west coast of India, we present here the distribution of tanaids in relation to the major environmental variables. The results showed that tanaids form one of the most dominant macro-benthic communities in the KBW, regardless of the seasons. Altogether five species of tanaids were recorded from this seasonal sampling in the KBW including two recently described species, Pagurapseudopsis kochindica and Ctenapseudes indiana. Salinity and sediment texture were found to significantly influence the abundance and distribution of tanaids in the KBW. Multivariate methods showed that tanaids most abundantly occur in mesohaline conditions (5-15 salinity) and clayey silt bottom sediment.