Identification of effective plant-based oils for use in aquafeed: An evaluation of impact on gamete quality and developmental success using zebrafish (Danio rerio) as a screening organism

Abstract

To evaluate the effectiveness of zebrafish as a screening system for identifying appropriate plant oils (POs) for aquafeed, Artemia nauplii (AN) were enriched with three single- cultivar olive oils (OO): Koroneiki, Parseh, and Arghavan. The resulting AN (ANKor, ANPar, ANArg, and AN36 [36 h starved AN, control]) were then fed to 360 fish (3.5 cm) for one month. The fatty acid (FA) profile of the AN was reflected in the ova and influenced both sperm motility and density, which in turn affected the fertilizability. The highest fertilizability and accelerated hatching were observed in the ANKor group. In this group, fish produced sperms with the highest motility and ova characterized by higher levels of 18:1n-9, 22:6n-3/20:5n-3 and lower 18:3n-3/18:2n-6, 20:5n-3/20:4n-6, 14:0, 16:1n-7, and 18:1n-7. Embryos produced by pairs fed ANArg exhibited delayed hatching but developed into larvae with the highest survival. Changes in ova FA and sperm quality indicate that, in zebrafish, gametes are directly influenced by parental diet, making the species an effective rapid screening system. Diet-induced changes in ova FA resulted in significant effects on hatchability, larval body morphometrics (BM), and survival. These findings indicate that zebrafish performance across embryonic-larval stages provides a sensitive model for screening POs, with survival serving as a conclusive endpoint. Survival was primarily linked to the ratio between LC-PUFAs and other FAs in ova. POs promoting these interactions are superior for aquafeeds. These ratios also guide broodstock diets to improve larval success and nutritional programming.