Experimental studies of decapod and fish predation on seagrass macrobenthos

The effects of 1 fish and 3 decapod crustaceans were examined in laboratory and field predator enclosure experiments in the Indian River Lagoon, Florida, USA. Results of laboratory and field experiments were similar in most cases. The fish Lagodon rhomboides and the crab Callinectes sapidus had relatively little effect on macrofaunal abundances. In contrast, the shrimps Palaemonetes intermedius and particularly Penaeus duorarum exerted marked negative effects on the density of almost all macrobenthic taxa present. The role of shrimps and other decapods in regulating densities of seagrass macrobenthos may be much greater than previously thought. The decapod crustaceans appear to be important keys to the understanding of trophic complexity in seagrass ecosystems.