Metabolism and habitat competition in the polychaete Nereis virens

Abstract

The relationship between metabolism and performance during habitat competition in the polychaete Nereis virens (Sars) was determined. Twenty paired habitat competition experiments were initiated between individuals of similar body mass. The outcome of the competition and the time spent competing for the burrow were noted for each encounter. Protein and lipid contents as well as enzyme activity (cytochrome C oxidase, lactate dehydrogenase, and pyruvate kinase) were compared between winners and losers. There were no significant differences between winners and losers for all parameters. There was, however, a significant relationship between fight duration and enzyme activity for winners. Individuals that won a fight rapidly had more cytochrome C oxidase activity than individuals who fought longer to gain access to the burrow. We conclude that metabolic capacities are not correlated with the outcome of habitat competition but that aerobic capacity is an important predictor of fight duration.