β-Glucuronidase activity and detritus utilization in the sea anemones Metridium senile and Anthopleura Elegantissima

Abstract

1. 1. Activity of β-glucuronidase, an enzyme associated with digestion of detritus, was measured in the intertidal sea anemone Anthopleura elegantissima and the subtidal anemone Metridium senile. The enzyme was present in freshly-collected individuals of both species. 2. 2. β-glucuronidase and chymotrypsin-like potease activities were both similar in high- and low- intertidal individuals of Anthopleura elegantissima. High-shore anemones do not appear to respond to shorter feeding times by increasing digestive capacity for detritus. 3. 3. β-glucuronidase activity increased in individuals of Metridium senile that had been fed detritus compared to starved and Artemia-fed individuals. 4. 4. Metabolic heat dissipation, measured by direct calorimetry, increased in Artemia-fed and detritus-fed individuals of Metridium senile compared to starved individuals. Increased heat dissipation is direct evidence of the potential nutritional importance of organic detritus in this species.