BEHAVIORAL AND HEMATOLOGICAL INDICES OF MUDSKIPPER (Apocryptes bato) EXPOSED TO DIFFERENT SALINITY CONDITION

Abstract

Salinity is one of the ecological factors directly linked to the aquatic ecosystem and regulates the growth, physiology, and development of fish. In order to investigate the effect of salinity on the common intertidal mangrove mudskipper, Apocryptes bato were subjected to different salinities (5, 10, 12, and 15 ppt) for a period of 21 days. At first, A. bato was exposed to 200ppm of anesthetic (dygenol) solution at different salinities, and anesthesia induction and recovery time were recorded. Increased salinity was found to the induction and recovery time in this species. The behavioral observations in the aquarium did not show any alterations in the land-use pattern, number of holes and channels in the mud, jumping, and feed intake. Hematological analysis after 21 days of rearing found elevated glucose levels in fishes reared at 5 and 15 ppt salinities. The growth of A. bato was also significantly impacted by the salinities with higher growth performance at 10 and 12 ppt compared to the 5 and 15 ppt. In addition, higher frequencies of cellular and nuclear abnormalities like twin cell, nuclear budding, micronucleus, binucleus, triplet cell, tear-dropped cell, multiple nucleus, and dead cells were recorded in fishes reared at 5 and 15 ppt in comparison to the 10 and 12 ppt. The findings of the present study suggest that increased salinity significantly affected the behavior, growth, and hematology of mudskippers in the aquarium conditions.