AN ASSESSMENT ON THE WATER CHEMISTRY, HABITAT TYPE AND ICHTHYOSPECIES DIVERSITY OF RIVER KARNAFULI IN MIZORAM, INDIA

The present investigation was intended to assess the physico-chemical parameters, habitat type and fish diversity of river Karnafuli located within a geographical location of 22°54′ 20.5″ N and 92°27′ 58.9″ E in Mizoram. The physico chemical parameters include Air and Water temperature (AT and WT), pH, dissolved oxygen (DO), free CO2, total alkalinity (TA), transparency, turbidity (TU), conductivity, phosphate, nitrate etc. and were analysed by following standard methods of American Public Health Association (APHA). The habitat types were recorded following key standard format of NBFGR and the fishes were collected by using different experimental fishing gears viz., cast nets, gill nets, drag nets, triangular scoop nets and a variety of traps and then identified by following standard literatures and keys during the study period. The values of physico-chemical parameters were found to be within the range of WHO standards portraying the better condition of the habitat for fishes. During study period, the micohabitats had been recorded as bedrocks, gravels, cobbles in the upstream rheophilic region; and, principally of fine sand in the downstream. Fish covers portrayed mainly overhanging vegetation and bottom free boulders. The riparian vegetation included mainly shrubs and trees; while, the riparian land use pattern depicted mainly human habitation, agriculture and various anthropogenic factors resulted in soil erosion and siltation. Fish diversity study revealed 45 species of fishes belonging to 35 genera, 14 families and 7 orders have been recorded from River Karnafuli during the study period. Among them, fishes belonging to the order cypriniformes (48%) were found to be the most abundant followed by beloniformes (2%) and synbranchiformes (2%), the least.