Assessment of nutritional supplementation in phospholipids on the reproductive performance of zebrafish, Danio rerio (Hamilton, 1822)

Abstract

The objectives of this study were to determine the effects of a tailor made purified diet (PUR) supplemented with phosphatidylcholine (PC) or phosphatidylethanolamine (PE) on the reproductive performance, gamete quality, embryo development and growth as well as skeletal malformations of the larvae in zebrafish, Danio rerio. The PUR diet was tested against a commercial diet as a negative control (CD). For each diet, one experimental group of eight adult zebrafish (three males, five females) was maintained in 3-L tanks in a water recirculating system under continuously controlled conditions (photoperiod 14 h light: 10 h dark; water flow rate 7.3 L h−1; 28°C; pH 7.5; 700 μS). Two trials were performed to confirm the results. The CD treatment resulted in the highest final weight of the breeders (0.60 ± 0.18 g); however, the fish failed to spawn. The PC supplemented diet promoted a reasonable final weight of the breeders (0.48 ± 0.10 g) similar to the CD and with a mean hatching rate of 93.80 ± 6.9%. Nevertheless, the PC treatment induced the highest rate of skeletal malformations in progeny (82.40 ± 4.1%), which could be related to the low larval survival at 28 days post-fertilization (dpf) (48.00 ± 11.3%). In comparison to the control groups, broodstock fed the PE diet showed the best results in sperm quality, which was revealed by higher total and progressive motility and higher velocities than sperm from males fed the CD and PUR diets. Furthermore, the PE group produced significantly higher egg diameters (1.20 ± 0.05 mm) when compared to the PUR diet (1.14 ± 0.03 mm). This study highlights the importance of phospholipids in zebrafish gamete quality, and that supplying PE in broodstock diets can improve the reproductive performance of zebrafish.