SUBSTRATE USE AND TEMPORAL PATTERN OF RECRUITMENT IN JUVENILE FISHES OF THE MEDITERRANEAN LITTORAL

The microhabitat use and seasonality of the juveniles of 24 littoral s pecies in the north-west Mediterranean Sea were studied between March 1993 and March 1994. Labrids species recruit during summer months, fro m July to September, whereas sparids recruit at different times of the year. Canonical correspondence analysis revealed that the species rec ruit in well-defined habitats. Sparid species recruit primarily in the shallowest zone (0 to 2 m), and most of them prefer varied bottoms (s and, gravel or small blocks). Some species of the genus Diplodus have similar habitat requirements, but show a clear seasonal segregation, w ith each species occupying successively the same zones at a different time of the year. Labrid species show a high degree of seasonal and sp atial co-occurrence, and are normally found on rocky substrates with h igh algal cover. Two species (Mullus surmuletus and Symphodus cinereus ) recruit mainly in Posidonia oceanica beds, while other species (Serr anus cabrilla, Coris julis, Symphodus ocellatus, S. rostratus), are ab undant in both seagrass beds and on rocky substrates.