ASSESSMENT OF ACUTE TOXICITY, GROWTH PERFORMANCE, HEPATOSOMATIC INDEX AND HISTOMORPHOMETRY OF LABEO ROHITA EXPOSED TO CR+CD MIXTURE

This research work was designed to check the impacts of waterborne chromium (Cr) + cadmium (Cd) mixture on the growth performance, hepatosomatic index and liver histo-morphometry of Labeo rohita.In the initial stage of the experiment, the 96-h LC50 and lethal concentration of a Cr + Cd mixture were assessed using an acute toxicity bioassay, resulting in values of 18.65 mg/L and 31.22 mg/L, respectively.In the second phase, fish was exposed to 1/3 of LC50 value of Cr + Cd-mixture for 8 weeks to assess the growth performance, hepatosomatic index and liver histomorphometry of fish.The Cr + Cdtreated fish showed significant decrease in growth parameters; daily weight gain, daily length gain, specific growth rate, condition factor and feed conversion ratio in comparison to control group during 8 weeks of experimental period.Hepatosomatic index also decreased in Cr + Cd-treated fish but increased in control group.The histomorphological analysis Cr + Cd-treated fish liver showed significantly reduced hepatocyte diameter and increased sinusoid width compared to the control group.Additionally, various histological abnormalities were observed in the liver viz.hemorrhage, irregular shaped hepatocytes (loss of their polygonal shape), enucleated, eccentrically situated nuclei, vacuolization and necrosis were also seen in Cr + Cd-treated fish.