Starvation effects on physiological parameters and biochemical composition of the hepatopancreas of the southern king crab Lithodes santolla (Molina, 1782)

Abstract

This study evaluates the effects of starvation on the physiological aspects of the southern king crab, Lithodes santolla. Adult males of this crab species were maintained in starving conditions for 12 days. Every 3 days (i.e. 0, 3, 6, 9 and 12), subgroups were taken to evaluate oxygen consumption, ammonia excretion, O:N atomic ratio and biochemical composition of the hepatopancreas. The hepatosomatic index (calculated individually as the percentage of henpatopancreas wet mass in relation to the total body wet weight) was lower at 12 day starving period, coincidentally with the minor amount of hepatopancreatic protein No significant differences in the relative biochemical composition (percentage of water, organic matter and ash) were detected. The lipid content was not significantly different during the experiment, nevertheless the higher value was detected at 3 days of starvation. Between the 3 and 9 days of fasting period ammonia excretion and hepatopancreatic protein were higher and the trypsin activity, lower. These results could indicate that protein catabolism was the most important in these periods. Besides, the lower values of O:N detected for all periods confirm this effect. On the ninth day of starvation oxygen consumption increased together with a high value of ammonia excretion probably due to an extra energy demand produced by starvation. We conclude that L. santolla in the experimental time-range study uses protein as the primary source of energy.