Giant Clam (Tridacna spp.), A Potential Candidate for Green Aquaculture of High Revenue in Jordan’s Gulf of Aqaba

The present work introduce an aquaculture attempts of the two existing species of giant clams, Tridacna squamosa and T. maxima in the Gulf of Aqaba. Recognized clam culture methods were adapted and modified to suite the prevailing environmental conditions of Red Sea. In situ gonad biopsy for both species showed that the gonad state was inversely correlated with the frequency of spent gonads (r=0.31), spawned (r=-0.25) and regressive (r=-0.29) eggs, and positively related to the frequencies of mature eggs (r=0.59, p 0.05). In laboratory, attempts were performed on the artificial induction of wild broodstock of the two species, larval to post-metamorphic rearing and in situ nursery culture. A marked seasonality was observed in the reproductive success in both species. Combined heat and serotonin induced spawning during winter showed protracted larval development and total mortality during pre and post metamorphosis. Summer spawning, however, was partially successful yielding clam juveniles of T. maxima and T. squamosa. Yet, the present culture trials yielded the pioneer stocks of clam juveniles of 2-20 and up to120 mm shell lengths (SL) at ages of 3-6 months and two years old of both T. squamosa and T. maxima, respectively. Future efforts will be on the integrated farming or polyculture of giant clams with other marine ornamental species in closed systems to demonstrate the production of high-valued commodities without harming the environment.