Oxyhemocyanin, protein, osmolality and electrolyte levels in the hemolymph of Scylla serrata in relation to size and molt cycle

Abstract

The mud crab Scylla serrata Forskal was examined for hemolymph oxyhemocyanin, protein, osmolality and ion concentrations in relation to size and the molt cycle. No significant difference in hemolymph oxyhemocyanin and protein was observed between male and female crabs. The increases in hemolymph protein, oxyhemocyanin, osmolality, Na+, Cl-, K+, and Ca2+ levels with size were considered due to migration from brackish water to sea water. With regard to the molt cycle, hemolymph protein (97.58 mg/ml) was highest at D-3 and oxyhemocyanin (0.76 mmol/l) at stage D-2. Lowest protein (68.19 mg/ml) and oxyhemocyanin (0.36 mmol/l) were measured at stage B. The fact that the hemolymph protein, osmolality, Na+, Cl-, K+ and Ca2+ levels were lower during the postmolt period, and higher during premolt were considered to be associated with water uptake at molt. (C) 1997 Elsevier Science B.V.