SPONGES INHABITING A MEDITERRANEAN RED CORAL POPULATION

A coastal red coral [Corallium rubrum (L.)] population, whose age stru cture and demographic parameters have been previously analysed, harbou rs 10 species of endobiotic sponges. This sponge assemblage differs co nsiderably from that inhabiting other calcareous substrata of the surr ounding area, suggesting some selectivity for red coral. The two most common endobiotic species, Spiroxya heteroclita TOPSENT and Cliona sar ai MELONE, are described in detail. The percentage of infested coral c olonies increases according with colony age, with a sharp increment at four years. An increase in coral colony mortality observed al this ag e may be related to the increment of endobiotic sponge infestation.