Diversity and seasonal variation of fish assemblages associated with trawl catches from southeast coast of India

In the present study, the fish assemblage data of trawl catches were recorded from January 2009 to December 2010 in Cuddalore and Parangipettai, southeast coast of India. The main objective of the present study was to describe and compare the species assemblages, seasonal variation in the diversity of fin fish populations from two adjacent coastal regions. Totally 123 species of fishes belonging to 13 orders, 49 families and 82 genera were recorded from 44 hauling of otter trawls. In both the regions, family wise contribution of fish assemblages revealed that the family Leiognathidae were found to be dominant followed by Engraulidae, Clupeidae and Carangidae with maximum species ranging 7 to 10 species followed by Sciaenidae, Lutjanidae, Mullidae, Synodontidae, Terapontidae, Gerreidae, Siganidae, Bothidae and Cynoglossidae with 3 to 6 species. In the present study various diversity indices were calculated, the minimum diversity values were recorded during summer and monsoon seasons and the maximum values were recorded during premonsoon season in both the regions during the study period. This data clearly indicates that the seasonal variation in fish abundance with a noticeable decrease in the catch during the summer season.