Comparison of three hatchery culture methods for the giant clam Tridacna noae

This study provides a first evaluation of different hatchery culture methods for the giant clam Tridacna noae. Three culture methods (intensive, semi-intensive, and extensive) using two tank designs (60 L and 277 L) were successful in producing 30-day old T. noae juveniles. There was no statistically significant interaction between tank design and culture method when considering cumulative survival (P = 0.89) or antero-posterior growth (P = 0.20), and the two tank designs did not influence cumulative survival (P = 0.78) or antero-posterior growth (P = 0.81). Differences in cumulative survival among the extensive (0.027 +/- 0.015%), semi-intensive (0.005 +/- 0.002%), and intensive (0.004 +/- 0.001%) culture methods were non-significant (P = 0.11). The mean antero-posterior measurements at 30 days post-fertilisation among intensive (583.57 +/- 12.71 mu m), semi-intensive (530.92 +/- 11.02 mu m), and extensive methods (541.67 +/- 10.95 mu m), were also non-significant (P = 0.05). Further analysis of survival among different developmental stages identified significantly greater survival of T. noae between the pediveliger and juvenile development stages within the extensive culture method. Our results show that extensive culture methods can achieve comparable hatchery production of T. noae to semi-intensive and intensive culture methods, which require additional managerial, infrastructural, and nutritional inputs.