Verification of a hatchery protocol for green mussel Perna viridis spat production in the Philippines using industry-scale facilities

Hatchery seed production of mussels has been identified as a sustainable method to address the problem of low production due to insufficient seed supply. We conducted the first hatchery production trials of the Asian green mussel Perna viridis spats in the Philippines to demonstrate the feasibility of producing a sufficient and reliable seed supply for grow-out operations. However, results of small-scale experiments cannot be directly rolled-out commercially unless these are verified in bigger-scale facilities approximating those of commercial hatcheries. Thus, techniques on broodstock collection, spawning, and larval rearing, developed by the project in the laboratory during the experimental trials, were applied and verified in a production run using industry-scale tank facilities. Mature broodstocks collected from traditional mussel growing areas were successfully spawned in the hatchery. Eggs were fertilized, and these developed into D-hinged larvae, pediveliger, and metamorphosed into early spat before fully developing into the spat stage. Successful larval rearing up to the spat stage required the use of appropriate algal species and rates of feeding, close monitoring of larval stages, and water quality management. The survival from eggs to D-hinged larvae, D-hinged larvae to pediveliger, pediveliger to early spat, D-hinged larvae to early spat, and early spat (1 mm) to fully grown spat was 77, 64, 6.4, 3.1, and 72%, respectively. This study has established the feasibility of producing P. viridis in commercial-scale hatchery facilities.