Improving Efficiency of Methods for Hatchery Production of the Limpet Patella Candei (patellogastropoda: Patellidae)

Patella candei d'Orbigny, 1840 is a valuable resource from the European Macaronesia. Limpet aquaculture is a recent research field that could contribute to reducing anthropogenic impact and developing appropriate restocking technologies. This study presents the results of 14 assays performed under laboratory culture conditions aimed at: (1) improving the larval production methodologies for limpets through the optimization of the artificial maturation of the oocytes and the sperm density required for fertilization and incubation, (2) validating a larviculture protocol for P. candei, and (3) evaluating rearing density effect on larvae performance until the pediveliger stage. Results obtained in the present study indicate that NH4OH is more efficient than KOH and NaOH to enhance the artificial maturation of the oocytes. The optimal combination was NH4OH at pH 9.0 for a duration of 20-30 min. The optimal sperm density was approximately 10(5) sperm cells mL(-1) as in other limpet species. The larviculture method described hereby demonstrated to be efficient to obtain viable pediveligers, that is, the larval survival was high, and the artificial maturation did not influence negatively the posterior larval development. The rearing density, within a range from 2.5 to 30 larvae mL(-1), showed minimal influence on survival and development.