Liza aurata for sustainable aquaculture: Effects of dietary fishmeal levels on growth and quality traits

Considering the increasing demand for sustainable aquafeeds, the present study aimed to evaluate the potential of dietary fishmeal inclusion in diets for Liza aurata with alternative protein sources of animal, plant, and unicellular origin. Four experimental diets were formulated with varying levels of fishmeal inclusion (FM15, FM10, FM5, and FM0, representing 15%, 10%, 5%, and 0% fishmeal, respectively) to assess their effects on growth performance, body composition, and economic viability in juvenile Liza aurata (9.14 ± 1.52 g). After three months, there were no significant differences in the survival rates or growth parameters among diets. Nonetheless, fish fed diet without fishmeal showed the lowest condition factor and mesenteric fat. The results on body composition indicated similarities among treatments in terms of amino acid and fatty acid profiles. Fish fed the diet without fishmeal obtained the lowest values of the Fish in–Fish out ratio for fishmeal (FIFO FM), the Marine protein dependency ratio (MPDR), and the Marine oil dependency ratio (MODR). Finally, polynomial regressions demonstrated a negative trend in some indices as fishmeal content was reduced. In conclusion, the findings suggest that while Liza aurata can be reared on low level of dietary fishmeal, but a minimum inclusion level of 9% fishmeal is needed to maintain optimal growth, filet quality, and the economic profitability.