DEVELOPMENT OF A BREAK-THROUGH NEW ARTIFICIAL BREEDING APPROACH FOR SEA CUCUMBERS USING NEUROPEPTIDES

Wild sea cucumber resources have been exhausted rapidly and need to be restocked by proactive actions to produce seed through artificial breeding. Artificial induction of oocyte maturation followed by in vitro fertilization represents an innovative approach that could help increase production. The inducers of oocyte maturation are naturally synthesised within neural tissue, which in sea cucumbers includes radial nerve cords. In this study, we found that mature female radial nerve extract (RNE; 233 µg/ml) induced in vitro oocyte maturation at 98.9% efficiency, based on germinal vesicle breakdown. RNE-matured oocytes were then fertilized (99%) with conspecific sperm, and larvae developed to late auricularia stage (25 days post-fertilisation). Furthermore, we have found a sea cucumber neuropeptide called RGP (relaxin-like gonad-stimulating peptide) that when produced as a recombinant and injected into mature individuals, could induce spawning behavior (head waving) and spawning within 1 hour. Our results provide a key finding for the development of a break-through new artificial breeding approach in sea cucumber aquaculture.