Behaviour and morphology pattern analysis of Indian major carps fingerlings exposed to commercial diesel oil suspension

Abstract

ABSTRACT Increased demand for commercial petroleum derivatives, including diesel has increased the possibility of numerous spills and leakages into the aquatic environment worldwide that can directly or indirectly pollute waterbody disrupting the health status of fish species and other aquatic organisms. This study was conducted to understand the effects of commercial diesel oil on freshwater species of rui (Labeo rohita), catla (Catla catla), and mrigal (Cirrhinus mrigala) fingerlings. The fingerlings were exposed to four different concentrations (0; 0.25; 0.50 and 0.75 ppm) of diesel oil, each containing three replications for 96 h. After 96 h lethal concentration (LC50) for rui, 0.35 ppm; catla, 0.30 ppm; and mrigal fingerlings 0.3625 ppm, were calculated through probit analysis. Maximum mortality occurred at the highest concentration of diesel oil, and treated fingerlings showed behavioural and external morphologic alterations. Dissolved oxygen decreased with the increasing of oil concentrations, and water quality was poor among all the treatments. This study demonstrated that commercial diesel oil directly affects the survivability, behaviour, and external morphology of rui, catla, and mrigal fingerlings. It is expected that the present results will be beneficial to make awareness of the fretful effects of commercial diesel oil and other oils uses in the environment.