ABSTRACT: In laboratory experiments, we determined the relative amount of predation before, during and after settlement with winter flounder Pleuronectesamericanus as prey and sevenspine bay shrimp Crangonseptemspinosa as predators. Wild-caught winter flounder at various stages of morphological development and settlement [from presettled, pre-eye-migration (<=11 mm standard length, SL) to eyes fully migrated, settled individuals (10.0 to 34.3 mm SL)] were exposed to predation by adult shrimp (47 to 74 mm total length). Mortality in treatments involving small settled flounder (78%) was twice that of presettled individuals (30 to 45%). However, subsequent mortality decreased with flounder size, and was 0% for flounder >=20 mm SL. Predator density affected rate of predation on settled juveniles (8.7 to 19 mm SL); mortality increased from 0 to 80% as predator density increased from 0 to 10.6 m^-2. At densities >=10.6 m^-2, mortality reached an upper asymptote of 80 to 90%. These experiments suggest that predation by shrimp may be an important determining factor of habitat selection, size and mortality during settlement of winter flounder and other benthic fishes.

KEY WORDS: Predation . Settlement . Shrimp . Winter flounder

Published in MEPS Vol. 123 (1995) on July 20
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1995