Abstract
Feeding dominates copulatory behavior in the few opisthobranchs for which behavioral hierarchies have been established. However, the influence of starvation on the dominant role has not been investigated previously. The present study investigates copulatory activity in the ascoglossan opisthobranch Ercolania nigra (Lemche) subject to varying starvation regimes. Copulatory activity of E. nigra is significantly higher in unstarved animals than in animals starved for 2h, 6h, and 24h. The decrease in copulatory activity is independent of the duration of previous starvation within the range tested (2–24 h). Copulatory behavior dominates feeding behavior in 60–80% of the cases, regardless of the duration of previous starvation. Thus the behavioral hierarchy of E. nigra differs markedly from that of the opisthobranchs previously investigated.