Physicochemical parameters influence the temporal and spatial distribution of catfish assemblages in Kushiyara River, Bangladesh

TEMPORAL AND SPATIAL DISTRIBUTION OF CATFISHES IN KUSHIYARA RIVER

Abstract

A yearlong study was carried out to assess the influences of physico-chemical parameters on the temporal and spatial dispersal and biodiversity status of catfishes in the Kushiyara River, Bangladesh. Five fishing boats equipped with various fishing gears namely seine net, gill net, lift net, and cast net were used fortnightly to harvest fish. Water quality parameters were assessed on spot. Twenty catfish species belonging to 8 families were identified from Kushiyara River. Shannon-Weaver diversity index, Margalef species richness, and Simpson dominance index significantly varied between seasons (p<0.05), where in the summer season the indices values were low. Total dissolve solids (TDS) and transparency were identified as two most striking factors shaping the catfish assemblage structure. Canonical correspondence analysis ordination plot revealed that Clupisoma garua, Ompok bimaculatus and Ailia coila had the highest level of TDS preference than the other parameters. In similarity percentage at 85.65%, three groups were attained while summer season showed separate clustering from other groups. The Non-metric Multidimensional Scaling showed similarity at 60% in all seasons based on Bray-Curtis similarity matrix, and summer was found to form a distinct group. Findings of the present study are expected to be helpful for the respective researchers, policy makers and conservationist as baseline information for the sustainable management of this water body.