Abundance and size distribution of the bearded fireworm Hermodice carunculata on sand flats and coral reefs in Bonaire
Hermodice carunculata the bearded fireworm is abundant in Bonaire‘s coral reefs. The corallivorous fireworm is a voracious eater, and a generalist predator. H. carunculata’s foraging behaviors play a role in coral reef community structure and building. This study looked at the abundance of the bearded fireworm in two environments, coral reefs and sand flats, during dusk and night hours. Within these two substrates size, abundance, and fluorescent color morphologies of the fireworms were studied. Sizes were separated into four length categories: 9 cm. Due to the active nature of fireworms and sampling at night, BlueStar flashlights and yellow barrier filters were used to locate the fireworms in the dark. Field surveys were conducted using 10 m transects and a t-bar to estimate abundance in both environments. Wire box traps were also placed along the coral reef and sand flats to estimate abundance of fireworms in the area. H. carunculata were found to be less abundant on coral reefs at dusk than at night. Furthermore, fireworms in the size class >9 cm were only found on coral reefs, indicating an ontogenetic shift in habitat and size. An ontogenetic shift was also found in the fluorescent color morphologies. Green fluorescence was most abundant in the 0-6 cm size range, and completely absent in the >9 cm size class. The green body with orange bands was an intermediate fluorescent pattern found predominantly in 3-9 cm size range. The orange body with orange bands coloration was found in the largest size class, possibly being the terminal fluorescent phase.
This student research was retrieved from Physis: Journal of Marine Science XIII (Spring 2013)19: 1-9 from CIEE Bonaire.