A Comparison of Diets and Water Agitation Methods for Larval Culture of the Edible Sea Urchin, Tripneustes ventricosus (Echinodermata: Echinoidea)

Tripneustes ventricosus (Lamarck, 1816) has been harvested for human consumption in the Caribbean for centuries, where harvest rates occasionally exceed sustainability. Historically a backreef and grass-bed urchin, the species has recently been observed on the forereef where it appears to control macroalgal growth in the absence of Diadema antillarum (Philippi, 1845) (Woodley and Gayle, 1999). Large-scale culturing has the potential to produce T. ventricosus in sufficient numbers for remediation of degraded coral reefs, restocking of nearshore habitats, and development of an aquaculture industry for one or more Caribbean islands. We report the first successful culturing of T. ventricosus from fertilization to exotrophic juvenile and the results of experiments to measure the effectiveness of agitation methods and diets applicable to large-scale larval culture. Airlift agitation was not effective in the 3.78-L (1-gal) jars used here. Cultures were successfully reared without mechanical agitation, but paddle agitation, used successfully in many small-scale experimental designs, produced the highest survival rates. Of the five algal diets tested, Rhodomonas sp., and a mixture of Rhodomonas Karsten and Isochrysis Parke, produced the most rapid development (23 d to metamorphosis). Isochrysis aff. galbana (Tahitian strain) supported slower development (36 d to metamorphosis) but produced the highest (48%) survival rate.