CS17 Invasive Species
Date: Thursday, June 13, 2002
Time: 4:00:00 PM
Location: Sidney
 
HolleboneAL, Georgia Institute of Technology, Atlanta, USA, gte276s@prism.gatech.edu
Hay, M, E, Georgia Institute of Technology, Atlanta, USA, mark.hay@biology.gatech.edu
 
INVASIVE GREEN PORCELAIN CRABS, PETROLISTHES ARMATUS, ON OYSTER REEFS IN THE SOUTH ATLANTIC BIGHT: FRIEND OR FOE?
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Biological invasions can threaten the composition and integrity of ecosystems. The invasion of P. armatus into Southeastern oyster reefs raises questions concerning the crab's impacts on non-native habitat and reasons for its success. Our research addresses the invasion's ecological implications (e.g., inter- and intra-specific predation pressure, habitat preference, and food choice) as well as ecosystem susceptibility to invasion. P. armatus is selective of its habitat, significantly choosing clumps of live oysters over other options; their choice guided in part by chemical and/or visual stimuli. Although found at high densities, the crab is palatable to native crabs in laboratory assays and are subject to intense predation in the field. Despite their small size, females brood tens to hundreds of spine-bearing larvae. Laboratory assays suggest that predation on larvae by filter-feeding adult crabs and oysters is negligible. Initial stable isotope data indicate that the crabs do not consume the crude filtrate of seawater, oyster feces, or oyster biofilm, thus, probably actively distinguishing between food particles. Our research provides basic ecological information that may contribute to future broader-based studies and conservation efforts.