Epifanio, C.E., S. Park, E.K. Grey, and L.A. Waidner, 2003. Interactions between the Asian Shore Crab (Hemigrapsus sanguineus) and the Common Mud Crab (Panopeus herbstii): Larval Supply vs. Post-Settlement Competition, University of Delaware.

Proceedings of the Third International Conference on Marine Bioinvasions, La Jolla, California, March 16-19, 2003, p. 38.

The Asian shore crab (Hemigrapsus sanguineus) is a recent invader of rocky intertidal habitat along the Middle Atlantic and Northeast coasts of the USA. As consequence of this invasion, H. sanguineus appears to be displacing native species of crabs.  At present the mechanisms by which this displacement is occurring are poorly understood. In this investigation we compared the magnitude of settlement of H. sanguineus larvae with that of a co-occurring native crab (Panopeus herbstii) in rocky
intertidal habitat near the mouth of Delaware Bay (approximately 38.5o N, 75.0oW). Measurements made during the summer of 2001 indicated that settlement of P. herbstii larvae was approximately 2 orders of magnitude greater than settlement of H. sanguineus during this period. However, collections made at the same location during the autumn of 2001 showed clear numerical dominance of H. sanguineus in all post-larval size classes, from the smallest juveniles to mature adults. Thus, we conclude that displacement of P. herbstii in this habitat by H. sanguineus is not a function of differential larval supply, but rather is related to some aspect of post-larval competition between the 2 species.

Contact: Charles Epifanio, College of Marine Studies, University of Delaware, 700 Pilottown Road, Lewes, DE 19958, USA
Key Words: Nonindigenous, Population_dynamics, Colonization
Product Type: Publication, Proceedings
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