Cephalopholis cruentata (graysby) behavior and interspecific response to invasive Pterois volitans (lionfish) in Bonaire, Dutch Caribbean

The invasion of Pterois volitans (lionfish) is a serious concern for Caribbean coral reef health. The morphology and behavior of lionfish is novel to the reef in Bonaire, which allows lionfish to take advantage of resources at the expense of native reef fish. Cephalopholis cruentata (graysby) is a native grouper on a similar trophic level as lionfish. Other groupers show congeneric aggression, but documentation of graysby behavior is scarce. This study observed graysby behavior and investigated whether graysbys recognize lionfish as competitors. A model-bottle experiment was used to present lionfish to graysbys. Graysby responses, aggressive, neutral, and submissive, were observed. Behavior was quantified using a reactive index. No significant difference in the frequency distribution of behavior types was observed between treatments. A moderate correlation was observed between graysby size and reactive index, suggesting that graysby reactions may be size-dependent. Future studies should consider size when analyzing graysby behavior towards other species, native or invasive.

This student research was retrieved from Physis: Journal of Marine Science XIX (Spring 2016)19: 85-90 from CIEE Bonaire.