THE SUITABILITY OF SEVERAL INTRODUCED SPECIES OF ABALONE (GASTROPODA,HALIOTIDAE) FOR LAND-BASED CULTURE WITH POND-GROWN SEAWEED IN ISRAEL

Abalone, a macroalgivore gastropod mollusc, is in high demand in world seafood markets. The production of these gastropods is limited by the short supply of their food, marine seaweed. At the National Center fo r Mariculture (NCM) in Eilat (Gulf of Aqaba, Red Sea), Israel, we have developed a culture system that can produce marine macroalgivores on large quantities of nutritious seaweed cultured in seawater fishpond e ffluents. Two valuable species of abalone, Haliotis fulgens from Calif ornia and Haliotis discus hannai from Japan, have been brought to the NCM as new candidates for intensive culture, in addition to the previo usly introduced Haliotis tuberculata. Despite the differences between Eilat and their natural habitats in climate and in chemical and physic al conditions, both species acclimated and reproduced well in Eilat. S urvival of the spat of all species fell to less than 5% by 8 weeks. Th e surviving spats grew in one year to 31, 14 and 28 mm in H. fulgens, H. discus hannai and H. tuberculata, respectively. Middle-sized animal s (19-37 mm) of these three species grew daily 0.21%, 0.17% and 0.23%, respectively, with survival of 99%, 96% and 80%, respectively, and an FCR (food conversion ratio, in g fresh feed consumption/g weight gain ) of 14, 22 and 26, respectively. In these growth trials, all size-gro ups of H. fulgens, like H. tuberculata, grew much faster than reported in the literature. Thus, both of these species seem like good candida tes for commercial culture in Israel. On the contrary, H. discus hanna i, for as yet unknown reasons, grew slower than in published reports, hence it is not yet ready for commercial culture in Israel.