Effects of the relative abundance of predatory mud crabs (Panopeus obesus and Eurytium limosum) on abundances of snails and fiddler crabs in a Georgia salt marsh

Predatory mud crabs (Panopeus obesus and Eurytium limosum) are two of the main resident infaunal predators in southeastern US salt marshes. Little is known, however, about their effects on important prey species. These influences are llikely to be dependent on the identity and relative abundances of the two predator species. We therefore manipulated the relative abundances of Panopeus and Eurytium in experimental cages in the field (at Airport Marsh, Sapelo Island, GA). We maintained the treatments over 4 months (July - October 2011), before assessing impacts on predator limb loss (an indicator of interspecific antagonism) and prey densitities (small and large mud fiddler crabs and marsh periwinkles).