Stimulatory effects of neuropeptide Y on the growth of orange-spotted grouper (Epinephelus coioides)

► NPY treatment increased food intake and growth of orange-spotted grouper. ► NPY treatment stimulated grouper GH mRNA expression in vivo and in vitro. ► Recombinant grouper NPY (gNPY) was expressed successfully in Pichia pastoris. ► Recombinant gNPY has the same bioactivity as synthetic gNPY. ► Recombinant gNPY has the potential to be used as a feed additive in aquaculture.