Fatty acid composition and spawning quality in wild and captive broodstock of Pacific red snapper Lutjanus peru

The Pacific red snapper (Lutjanus peru) is very popular fishery that reaches high prices in the market that is distributed in tropical and subtropical climates. Most studies in fatty acid requirements for larval production are done in temperate species; in general, warm-water fish are given the same levels of DHA and EPA than cold-water fish, which increases considerably the costs of production, without apparent benefit. We analyzed spawns during lecithotrophic development, with emphasis on fatty acids, of L. peru. Three origins were compared, Wild spawns, used as the standard of better-quality larvae, Laboratory and Pond, each with some differences in the inductions of maturation and broodstock diet: Lab and Pond broodstock were fed sardines and squids and DHA-rich oil capsules were added once a week. A total of 87 spawns were sampled throughout three years of sampling. Egg and oil globule diameters before fertilization, in 1-h embryo (E) and before hatching (LE); larval total length and oil globule diameter at hatching (LH), and after 24 (L24h) and 48 h (L48h) were measured. Hatching and survival percentages were measured in triplicate for each spawn. Hatching were significantly higher from Pond spawns (75.7%) compared to Wild (60.8%). Survival at L48 hours was not significantly different among origins. Wild spawns had significantly more carbohydrates, but less phospholipids during development, compared to Lab and Pond spawns. ARA, EPA and DHA concentrations decreased in total lipids and triglycerides, but in Lab spawns they were accumulated in phospholipids. There was a more variable fatty acid composition in Pond spawns compared to Lab spawns, a result of more diversified diet in ponds. Viable eggs had two-fold higher proportion of ARA compared to non-viable eggs. A principal factor analysis revealed three positive associations between 1) female weight, egg oil globule diameter, and EPA:ARA in egg PL; 2) hatching, LH length, and DHA: ARA in egg PL; 3) L48h survival, TG and PL content in eggs. According to our results, subtropical L. peru needs less DHA and more ARA and monounsaturated fatty acids in their diet, compared to temperate marine fish.

Automated summary

This study on Pacific red snapper spawns during lecithotrophic development found that hatching rates were higher from pond spawns compared to wild spawns, and embryos with higher ARA proportions and higher EPA:ARA and DHA:ARA ratios in egg phospholipids had better survival rates at 48 hours. The analysis suggests that subtropical L. peru requires less DHA and more ARA and monounsaturated fatty acids in their diet, compared to temperate marine fish.