Abstract
Fishmeal (FM) remains the protein source of choice in carnivorous fish diets because of its optimal essential amino acid profile, high nutrient digestibility, polyunsaturated fatty acid content, and minimallevels of antinutritional factors. However, increasing the use of wild pelagic fish stocks for FM production is unsustainable at environmental, economic, and social levels, and current production is insufficient tomeet the growing demand for aquaculture feed ingredients. Consequently, the search for sustainable alternative protein sources is critical. Insect meals, such as black soldier fly larvae meal (BSFLM,Hermetia illucens L), is emerging as a promising terrestrial animal protein source. The dusky kob (Argyrosomus japonicus) is one of the marine finfish species currently under investigated for itsaquaculture potential in South Africa. To reduce dependency on FM, this study investigates the replacement of FM with BSFLM in the diets of juvenile dusky kob. Four isonitrogenous, isolipidic, andisocaloric experimental diets were formulated, replacing FM with BSFLM at 0, 33, 66, and 100%, respectively. A total of 480 juvenile dusky kob (average wet weight: 20.10 ? 0.34 g/fish) were randomlydistributed across four treatments (triplicates per treatment) and reared for 96 days. Fish were monitored fortnightly for weight and standard length to evaluate growth. Results on growth, feedconversion ratio, and survival will be presented.