A Comparison of spatial and temporal pattern of fish diversity of Matla river and adjacent mudflats in Sunderban biosphere reserve, India

Estuaries consist of a complex mixture of distinctive habitats, which make it among the most productive and valuable ecosystems on Earth. Intertidal mudflats of Sundarbans -part of the world's largest active delta, occupy a significant component of the total estuarine habitat available to fishes and play important roles as nursery and foraging grounds. The present study was aimed to examine spatial and temporal patterns of fish assemblage attribute of the Matla River and adjoining mudflats of Indian Sundarbans.

A total of 71 piscine species under 11 orders were collected over one year of monthly sampling. Assemblage attributes (species richness, species evenness and diversity) varied significantly between adjoining biotopes. Discrete temporal gradients were noticed in fish diversity in both riverine and mudflat systems. Dominating species (Tenualosa ilisa in riverine and Periophthalmus novemradiatus in mudflats) had the greatest effect on the observed pattern of fish assemblages. Disparity in assemblage composition hence reflected the degree of hydrological connectivity. The present work therefore supports the view that the influence of spatial coupling of adjacent ecosystems affect diversity-productivity pattern of local populations leading to regional persistence of species that are of great importance as bio-resource. This has the potential to provide novel fundamental insights into the dynamics and functioning of ecosystem leading to its stabilization and subsequent conservation of the whole community.