Harlequin fish, O. dentex, are endemic to Australia and occur from Victoria to Western Australia, with South Australia being central to its natural geographic range. This species has a very attractive appearance and appealing fresh texture and taste. According to the preliminary assessment of Prof Gong, who has more than 15 years’ experiences in promoting and marketing unique fish species in China, this product would fetch a market price similar to, if not higher than, the most expensive fish species sold at the top end restaurants in China, such as fresh tuna and sea cucumbers. However, the basic knowledge required for the aquaculture development of this species is lacking. This proposal seeks to commence a systematic approach to address this need. The time period required to grow harlequin fish to market size (0.8 to 1.0 kg in weight is anticipated) is unknown. There is a need to obtain information on this critical factor that will influence the research and investment strategies in the subsequent stages. There is also a need to gather preliminary biological information that is currently not available (e.g. capacity to capture broodstock, potential to hold the species in farm tanks, the species readiness to feed on manufactured diets). Finally, a basic desktop cost – benefit analysis is needed to prepare a business case to evaluate the economic viability of harlequin fish aquaculture in South Australia.