Effect of Food Deprivation on Plasma Cortisol, Carbohydrate Metabolism, and Histomorphology in Clarias batrachus.

The nutritional status of fish is essential for its health, experimental studies, and aquaculture practices. The current study investigated the impact of food deprivation on biochemical parameters, histology of skin, gill, and kidney tissues, and ultrastructure of gills in Clarias batrachus. Fish were subjected to food deprivation for 2, 7, and 15 days resulting in (a) significant increase in plasma cortisol levels, (b) no significant changes in plasma osmolality and plasma glucose content, and (c) significant decrease in liver and muscle glycogen contents.

Plasma thyroxine and cortisol profiles and gill and kidney Na+/K+-ATPase and SDH activities during acclimation of the catfish Heteropneustes fossilis (bloch) to higher salinity, with special reference to the effects of exogenous cortisol on hypo-osmoregulatory ability of the catfish.

When the stenohaline catfish Heteropneustes fossilis was transferred from fresh water (FW) to 30% seawater (SW), the Na(+)/K(+)-ATPase activity significantly increased in the kidney, while in gills it remained more or less constant. A reverse pattern was observed for succinic dehydrogenase (SDH) activity inasmuch as it significantly increased in gills and remained unchanged in the kidney. Plasma osmolality significantly increased within 3 days of transfer to 30% SW and remained significantly higher throughout the duration of experiment.