EFFECT OF WATER–SOLUBLE FRACTIONS (WSF) OF KEROSENE ON THE OSMOREGULATION OF THE PENAEID SHRIMP METAPENAEUS AFFINIS H. MILIN–EDWARDS (CRUSTACEA: DECAPODA: PENAEIDAE)

Abstract

In the present study, the effect of water soluble fractions (WSF) of kerosene on the osmoregulation of penaeid shrimp M. affinis was studied. The shrimp was exposed to concentration of 300 ppb of kerosene WSF for a period of 30 days. The osmotic concentration of the haemolymph of the shrimp was measured by freezing point determination once a week. The ability of shrimp to maintain haemolymph osmolality was significantly decreased (p<0.05) after one week exposure to the WSF of kerosene. The shrimp was also exposed to acute kerosene WSF pollution for 24 hours period. It was then placed in pure sea water for a recovery period of three weeks. The ability of shrimp to maintain haemolymph osmolality was reduced two weeks after exposed to acute oil pollution but it was retuned within three weeks.