Baseline physiological data and enzymatic valorization of fishery waste for female Odontesthes argentinensis nutrition

This study investigated the energy storage patterns in wild female Odontesthes argentinensis collected during autumn in the coastal waters of Mar del Plata (Argentina) to assess their suitability as breeders and explored innovative enzyme-based feeding strategies to improve food quality, nutrient utilization, and nutritional management of breeders in this species. Biochemical analyses showed that the liver was the primary storage organ for lipids and proteins, while the fatty acid profiles were consistent with a capital breeding strategy associated with seasonal reproduction. However, because this study was based on a single seasonal sampling and lacked ovarian stage classification, gonadosomatic or hepatosomatic indices, and a temporal series, these findings should be interpreted as preliminary evidence and should not be taken as sufficient to definitively classify the reproductive strategy. To improve the nutritional value of soybean meal, enzymatic treatment with peptidases from Urophycis brasiliensis under acidic conditions (pH 2) reduced antinutritional compounds while preserving bioactive molecules, thereby enhancing protein quality. In addition, in vitro combination of exogenous peptidase extracts from fisheries waste with digestive enzymes of O. argentinensis increased proteolytic activity, suggesting synergistic interactions that warrant testing in future feeding trials. Together, these findings provide physiological and nutritional insights that can contribute to the development of feeding strategies for O. argentinensis females. Furthermore, the use of fishery waste as sources of digestive enzymes represents a promising biotechnological approach to improve feed digestibility while promoting more sustainable aquaculture practices. Nevertheless, further studies assessing digestibility, fish performance, extraction yields, safety, economic feasibility, and environmental impacts are needed to substantiate these potential benefits.