The high commercial value and the increasing demand for sea cucumbers has resulted in over-exploitation, and is likely negatively impacting vulnerable benthic ecosystems. Overfishing is catalyzing the need to develop aquaculture technologies for sea cucumbers to meet the market demand and to create new economic opportunities. Warty sea cucumber (WSC) Apostichopus parvimensis is one commercial species along the Pacific coast of the U.S. Wild populations of WSC have reached levels of concern due to overfishing, and it is now listed on the International Union for the Conservation of Nature Red List of Threatened Species. Thus, there is an urgent need to develop WSC aquaculture to take pressure off wild resources and offer the capability of restoring the depleted stocks through out-planting of cultured animals, while simultaneously supplying data to help improve fishery management.
In this study, we present the results on artificial breeding of WSC, describing the spawning induction, larval development, optimizing temperature and settlement inducers in larval rearing, aimed at developing rearing protocols for this species. Four methods to induce spawning in WSCs were tested - neuronal peptide (NGLWYamide) injection, thermal shock, algal/diet stimulation and mechanical shock. Peptide injection proved to be the most effective method for obtaining healthy WSC gametes. To test the upper thermal tolerance of WSC larvae, survival and development were measured under four temperature treatments of 22, 24, 26 and 28 °C to the pentactula stage. The upper limit for WSC larvae was 24 °C (Fig 1). At 26 °C and beyond, the larvae stopped developing and shrank. Settlement of larvae at the Doliolaria stage was induced by exposing them separately to several kinds of food inducers (Fig 2). Larval WSC exhibited similar settlement rates using attached Navicula sp., attached wild diatoms, Spirulina powder painting, and AlgaMac 3050, AlgaMac Protein Plus. The results of this study will help establish hatchery production protocols for WSC and aid in the further development of the aquaculture of this species.