Glycoconjugates Study in Surface Secretions of a Fresh Water Edible Catfish, Clarias gariepinus in Response to Clove Oil Anaesthesia: Experimental Investigation

The present histopathology and histochemistry study investigates the effects of clove oil anaesthesia on gills, dendritic organs and skin of a locally available fresh water edible catfish, Clarias gariepinus. The gills, dendritic organs and skin constitute surface organs in C. gariepinus and remain in direct contact with the surrounding water and provide greater surface area of absorption for any xenobiotics including the clove oil hence selected for study. Clove oil extracted from flower buds, leaves and stems of plant Syzygium aromaticum is recently introduced as an effective anaesthetic agent in fishery sector for fulfilling various needs. C. gariepinus of total length 30 ± 2 cm and total weight 200 ± 5 g were exposed to various concentrations of clove oil (LOBA CHEM. PVT. LTD, MUMBAI, Minimum assay 85%) in the range of 0.07 ml/l to 0.3 ml/l. The important behavioural changes observed in C. gariepinus during clove oil exposures include erratic swimming, bubbling, rubbing to side and bottom walls of glass aquarium and protrusion of head above water surface. Fish however become static and horizontal with ceased opercular movements and loss of equilibrium. Clove oil anaesthesia significantly alters the mucogenic property of all surface organs with secretion of more Alcian Blue pH 2.5 positive mucus and slime on surface. Wear and tear and sloughing of epithelial linings of the gills, disintegration of vascular components, oozing of blood on surface of dendritic organs and lifting of gill epithelium are the other toxic manifestations caused in C. gariepinus due to clove oil anaesthesia.