CS06 Benthos
Date: Friday, June 14, 2002
Time: 8:45:00 AM
Location: Colwood
 
KicklighterCE, Georgia Institute of Technololgy, Atlanta, USA, gt7853a@prism.gatech.edu
Hay, M, E, Georgia Institute of Technology, Atlanta, USA, mark.hay@biology.gatech.edu
 
CHEMICAL DEFENSES OF SOFT SEDIMENT ORGANISMS
image
Chemical defenses are important predator deterrents for many organisms inhabiting predator-rich enviornments, such as coral reefs. However, the significance of these defenses is poorly understood for species inhabiting soft-sediment envrionments. To investigate this question, marine worms (e.g., annelids, hemichordates, nemerteans, etc.) found in mudflats off the coast of Georgia, USA were examined for palatability to sympatric epibenthic predators. Chemical traits and refuge use were examined for the role they play in determining palatability and susceptibility to consumers. Species with body parts exposed to predation for long periods of time (such as during feeding) are unpalatable and chemically-defended from predators while species that live completely buried beneath the sediment, or inhabit a tube, are more palatable. These patterns agree with those observed for species found on coral reefs. For marine worms in general, the use of a chemical defense within a taxonomic group is not an absolute. Not all members may utilize a chemical defense or there may be variation in which body parts are defended. Among related species, ecological exposure to predation is an important determinant of palatability.