Hatchery experience and useful lessons from Isostichopus fuscus in Ecuador and Mexico

This paper summarises lessons learned from captive breeding of the sea cucumber Isostichopus fuscus in land-based installations on the coast of Ecuador and Mexico. This species has been intensively fished in Mexico, along mainland Ecuador and around the Galapagos Islands. Management efforts have traditionally been challenged by local economic and social conditions. Populations of I. fuscus have thus been severely depleted over the past decades, generating interest in aquaculture and restocking. Spawning, fertilisation, larval rearing, disease control and juvenile growth have been documented in two privately owned hatcheries. Data from trials conducted in Ecuador over several years indicate that, under optimal conditions, juveniles can be grown to a size of ~8 cm in length in 3.5 months and to commercial size in ~18 months. Preliminary tests have shown that growing juvenile sea cucumbers in shrimp ponds is feasible. In Mexico, successful spawnings were restricted to late summer and autumn/fall months, when cultures of larvae and early juveniles yielded growth rates similar to or greater than those recorded in Ecuador. Grow-out of juveniles in shrimp ponds was impeded in both countries by skin infections, leading to high mortality rates, whereas juveniles placed in cages in the ocean (in Mexico) exhibited reasonable growth rates and better survival (to 90%). Overall, studies demonstrate that, with proper disease control, millions of juvenile I. fuscus can be reared in captivity annually, thus providing an alternative to fisheries, or a way to maintain sustainable harvests and eventually contribute to restoration of the natural populations.