Reproductive performance and egg and larvae quality from first generation peruvian grunt Anisotremus scapularis (Tschudi, 1846): a comparative analysis with spawns from wild broodstock

Abstract

Anisotremus scapularis is a marine fish distributed along the Peruvian coast that is commercially important in local markets. IMARPE started research on this species aimed to condition breeders and control reproduction in captivity and avoid dependence on wild broodstock. Therefore, the present study characterized and compared the reproductive performance, quality of eggs and larvae between a first generation domesticated broodstock (F1B) and a wild broodstock (WB). The F1B and WB broodstocks were conditioned in recirculation systems (RAS) to spawn naturally from August 2021 to August 2022. The following parameters were recorded for each spawn, the total number of eggs, percentages of viable eggs and fertilization, and hatching, and biochemical analyses on each spawn were performed. Progeny from each spawning were assessed for survival activity index (SAI), and at 20 days’ post-hatch (DPH), the temperature tolerance index (TTI) was analyzed. WB had significantly higher (P<0.05) egg production, egg diameter, oil globule diameter, and SAI than those of F1B. However, the percentage of viable eggs and hatching showed significantly higher values (P<0.05) in F1B spawns. A low correlation (r<0.50) was observed between the evaluated reproductive parameters in A. scapularis broodstock; nevertheless, it was significant in some cases. No significant differences were observed in protein, lipid, carbohydrate, or ash content in eggs, but ash content in the 20 DPH larvae differed, with higher values in F1B. A principal component analysis (PCA), indicated a strong relationship between F1B broodstock eggs and fatty acids DHA, 16:0, 18:1n-9, and 18:2n-6; whereas fatty acids 18:0, 20:4n-3, 22:5n-3, and EPA had a high connection with WB eggs. At 20 DPH, F1B larvae had a strong link with 18:1n-9, DHA, and 18:2n-6; while WB larvae were found to have a high association with 16:1n-7, EPA, 22:5n-3, and ARA. Based on these results we concluded that F1B broodstock has better egg quality in terms of egg viability and hatching rate and similarity in most larval quality parameters compared to WB, making the F1 domesticated broodstock (F1B) an alternative to establish a broodstock under captive conditions and thus contributing to the aquaculture development of the species.