Temporal and spatial variability of fin fish assemblage structure in relation to their environmental parameters in Pichavaram mangrove ecosystem, India

Abstract

The effect of seasonal variation and physico-chemical parameters in the fin fish assemblage structure was studied in Coleroon-Pichavaram-Vellar Mangrove Ecosystem (CPVME) from July 2010 to June 2011. Physico-chemical parameters such as, water temperature, salinity, total dissolved solids (TDS), dissolved oxygen (DO) and trace elements such as calcium (Ca) and magnesium (Mg) reflected seasonal tendency where, salinity is inversely correlated with rain fall. Totally, 45 species were identified; belonging to 38 genera, 29 families. Among these, Mugilidae (25.74 %) was the predominant family, followed by Leiognathidae (22.73 %), Terapontidae (16.15 %), Gobiidae (9.21 %) and Siganidae (6.79 %). In which, <i>Leiognathus equulus</i> (15.79 %) and <i>Liza parsia</i> (14.02 %) were dominant species in terms of density and frequency throughout the study period. The fish abundance was observed to be highest during post-monsoon and was significantly correlated with species richness and diversity. Canonical Correspondence Analysis indicated that, salinity and depth are the vital factors in shaping the fish assemblage structure in CPVME.