RECRUITMENT OF DEMOSPONGES (PORIFERA, DEMOSPONGIAE) IN ROCKY AND CORAL-REEF HABITATS OF SANTA-MARTA, COLOMBIAN CARIBBEAN

Recruitment of demosponges (Porifera, Demospongiae) was monitored bimo nthly for one year (March 1987 - March 1988) on acrylic plates, and co mpared to cover of adults, in six rocky and coral reef habitats at San ta Marta, Colombian Caribbean, an area subjected to seasonal, upwellin g-outwelling regimes. According to suggestive but not significant tren ds, recruitment rates are more positively influenced by the total spon ge cover near groups of plates than by cover at a larger (habitat) sca le; recruit mortality is lower where recruitment is higher. These find ings are in agreement with a model of higher settlement (probably due to short-distance dispersal) and lower postsettlement mortality within a few meters of adult sponges. Recruitment varied seasonally, being r elatively high from May to November-December during the rainy, outwell ing season, when seawater temperature was warmer, water turbidity high er, and benthic algal density lower; it was very low from January to A pril during the dry, upwelling season.