Choosing tropical portunid species for culture, domestication and stock enhancement in the Indo-Pacific

Abstract

Large and long-term investments in research, development and technology verification are required for the successful culture, domestication and coastal stock enhancement of any species, including crabs. As more species options are sought for culture, the choice of candidate species could be guided by ex-ante assessments to help identify suitable species and anticipate future constraints and opportunities. Focusing on tropical Indo-West Pacific Portunidae, we propose multiple criteria for domestication and stock enhancement that include life cycle, diet and feed conversion efficiency, behavior, disease resistance, growth rate, marketability, farming systems, profitability and environmental impact. The chief candidate species (four species of Scylla, Portunus pelagicus, P. sanguinolentus, and Charybdis feriatus) are considered against the criteria. Experience in the stock enhancement of P. trituberculatus, a subtropical portunid, is reviewed. We conclude that full domestication will not occur in the next 5 to 10 years and that the main constraints to be overcome are the aggressive behavior of the crabs, their carnivorous diet and competition for suitable coastal farm sites. We also recommend considering the tropical Portunus and Charybdis species examined here as additional or alternative options to the Scylla species. Stock enhancement may be feasible in some locations, provided suitable fisheries management and industry institutions are created.