Night ecology and fluorescence of the fireworm, Hermodice carunculata
The marine bearded fireworm, Hermodice carunculata, is a highly mobile polychaete that is abundant on the coral reefs of Bonaire and is active at night. H. carunculata fluoresce brightly facilitating a novel approach to studying their night ecology. The purpose of this research is: 1) to document the ontogenetic fluorescence patterns of H. carunculata using a laboratory study and 2) to determine the depth distribution, habitat use and feeding behavior of H. carunculata of increasing size classes using fluorescence as an ecological tool. There are changes in fluorescence as H. carunculata grow. Polychaetes < 5cm in length fluoresced bright green whereas, worms > 5 cm displayed a banded orange pattern across the dorsum with bright green or blue outlining the dorsal surface of the body. The field study documented that more small and medium H. carunculata were found at shallower depths (2 and 6 m) whereas large H. carunculata were evenly distributed at all 3 depths (2, 6, and 15 m). All size classes were found most often on sand and rubble. Small and medium worms were found on 5 additional substrata. Large worms were found on 2 additional substrata, live and dead coral. Small and medium worms were feeding on decaying matter, algae and sponges whereas, large worms were feeding on live coral. In terms of habitat use and diet, it appears that large H. carunculata (> 3 cm) are more specialized than the smaller size classes (< 1 cm, 1 – 3 cm).