Protein is the most expensive component in fish diets and also the most important factor affecting growth performance
of cultured species (Lee et al., 2002). The protein requirement, meaning the minimum amount needed to meet the amino
acid requirements and achieve optimum growth, is the first nutritional parameter to be determined for formulated feed
production for a newly established cultured fish species (Kim and Lee, 2009). To the best of our knowledge, there are no
available studies concerning the dietary protein requirement for H. wyckioides. Thus, the objective of the present study was
to investigate the optimum dietary protein level for this species with semi-purified diets.