Relationships between absence of functional swimbladder, calculosis and larval mortality in hatcheryreared gilthead sea bream, Sparus aurata L.

Abstract. The relationship between absence of functional swim-bladder, calculosis and larval mortality of hatchery-reared sea bream, Sparus aurata L., was observed. There was a temporal variation in the main causes of mortality, i.e. not inflated swim-bladder appears to be the main cause up to the 47th day, and the presence of calculi around the 55th day. Histological sections, semi-quantitative analysis and scanner electron microscope photographs were carried out.