Spatial and foraging behaviour, diet and morphogenesis of postlarvae and juveniles of Pempheris vanicolensis in the Gulf of Aqaba, Red Sea

Post-settlement ecology, ontogenesis of morphology and behaviour were studied in juvenile Pempheris vanicolensis (Pempheridae, Teleostei) in the Gulf of Aqaba, Red Sea. Postflexion larvae of 5.6-6.0 mm total length settled around breakwater heads and natural rocky outcrops of the subtidal zone, widely separated from adults dwelling in groups in coral reef crevices and caves. Settling juveniles formed groups of uniform age and foraged on zooplankton around their habitats. Their circadian behaviour was regulated by levels of illumination in the water, differing slightly in the various age groups. At sunset, juvenile P. vanicolensis migrated and dispersed in deeper water, returning before sunrise to their rocky habitats. Their patterns of foraging and migration behaviours were analysed. At 28.0-32.0 mm total length and 500 mg body weight, the increase in height and length ( H/L ratio) of the juvenile changed from monoto heterochronous, after which a rhomboid body shape, typical for this species, was formed. Concomitantly, the retina of the juvenile changed from a photopic to a scotopic one, the body became heavily pigmented, and the fish left the subtidal rocks, migrating to crevices in coral formations where they settled in close proximity to groups of adult P. vanicolensis .