Selective feeding of the polychaete Hermodice carunculata Pallas on Caribbean gorgonians

Abstract

Feeding preferences of the errant polychaete Hermodice carunculata Pallas for the gorgonian prey species Plexaura flexuosa Lamouroux, Pseudoplexaura spp., Briareum asbestinum Pallas and Plexaura A (an undescribed species) were assessed in laboratory feeding experiments. Feeding was measured as the number of branch tips fed on and the amount of tissue consumed. H. carunculata preferred the gorgonians in the order: B. asbestinum > P. flexuosa > Pseudoplexaura spp. > Plexaura A in controlled experiments. In situ feeding on gorgonians was monitored within marked areas on reefs in the San Blas Islands, Panama, and a reef at La Parguera, Puerto Rico. In the San Blas, Pseudoplexaura spp. and P.flexuosa were grazed more often than predicted by species-specific colony abundance. P. flexuosa and Plexaura homomalla were the most preferred species at La Parguera. Data comparing species abundance based on colony height with frequency of damage at the La Parguera site suggest that H. carunculata preferred B. asbestinum, Eunicea spp.,P. flexuosa and P. homomalla. H. carunculata preferences do not correlate with differences in gorgonian ash-free dry weight nor with known differences in gorgonian secondary chemistry.