Supplementation of corn oil Ω-6 fatty acids in feed for reproduction performance of threadfin rainbowfish Iriatherina werneri Meinken, 1974

Abstract

Rainbow fish (Iriatherina werneri) is a type of partial spawner fish with the little number of eggs production. The high contain of essential fatty acid (Linoleic acid 18:2 Ω-6) in corn oil was widely used as a source of fatty acid in the broodstock feed. The aim of this study was to evaluate the additional of LA fatty acid in feed for reproduction performance of rainbow fish. This study used a complete random design consists of three treatments and six replicates with different doses of corn oil LA in feed, Ω-6 0%, Ω-6 1%, and Ω-6 2%. Rainbow fish broodstock as sampel test with body weight 0.10-0.18g for females 0.21 ± 0.001 g, were kept separately in each tanks (size 30 cm x 30 cm x 30 cm) with density 15 fish per tanks. Broodstock were given diet three times daily at 08:00 am, 12:00 am and 17:00 pm by at satiation. The trial feed was administrated for 30 days before conducted the mass spawning for seven days with ratio of the male and female broodstock was 1:3. The results showed that treatment without supplementation of Ω-6 corn oil performed highest number of eggs 290 ± 125, hatching rate 55,99 ± 14,80%, survival rate 8,43% and the proportion of vitellogenic cell was more dominant, but the best of larval performance was observed in tretament of Ω-6 1% of highest larval length 3.00 mm and 100% percentage of normal larvae. It can be concluded that the supplementation of 1 % the Ω-6 fatty acid corn oil in the feed to produce reproductive performance was supported by the results of the histology of the eggs and larvae of the best performance in rainbowfish.