PREDATION EFFECT OF 3 FISH SPECIES AND A SHRIMP ON MACROBENTHOS AND MEIOBENTHOS IN MICROCOSMS

The responses of macrofaunal and meiofaunal benthic communities to predation by three fish species and a penaeid shrimp were examined to evaluate the potential for epibenthic predators to reduce abundance of benthos. Experiments conducted in 1987 analysed only the macrofaunal community and indicated capitellid polychaete abundance was significantly reduced in the presence of white shrimp [Penaeus setiferus (Linneaus)], while mummichogs [Fundulus heteroclitus (Linneaus)] had no significant effect on any macrobenthic taxon. Experiments in 1988 using mullet (Mugil cephalus Linneaus) as predators resulted in significantly decreased abundances of total meiofauna and the copepod Enhydrosoma propinquum (Brady), while abundances of macrofaunal prey were not significantly reduced. Abundances of the polychaete Streblospio benedicti Webster, total macrofauna and total copepods were significantly reduced by spot (Leiostomus xanthurus Lacépéde) predation. While these experiments were designed with sufficient power to demonstrate that epibenthic predators are possibly capable of causing significant reductions in the populations of macrofaunal and meiofaunal prey, a general paucity of significant impacts indicates that these predators may be but one of many factors influencing benthic abundance in the field. The microcosm experiment approach must incorporate multifactorial designs in the future. © 1992 Academic Press Limited.