Periodicity of otolith check formation in the juvenile plaice Pleuronectes platessa

Abstract

Juvenile (Pleuronectes platessa L.) were sampled in the intertidal zone of Port Erin Bay (Isle of Man, Irish Sea) by push-net in the summers of 1990 and 1992. Check formation on the sagittal otoliths was examined to test the hypothesis that tidal and light cycles periodically disrupt the growth of 0-group plaice. Otolith checks occurred mostly at weekly (7-8 d) intervals (range 3-21 d). This periodicity matched activity patterns that were lowest at both spring and neap tides. Check formation may reflect ontogenetic changes in feeding and activity, as measured by diurnal and seasonal variations in catches.