Optimum level of fish liver oil as enrichment for Artemia fed to the tiger tail seahorse Hippocampus comes for reproduction and juvenile survival

Reproductive performance of broodstocks and juvenile stress resistance of seahorse Hippocampus comes fed Artemia enriched with varying fish liver oil (FLO) were evaluated. Artemia was enriched in seven media with 0%, 1%, 2%, 3%, 4%, 5% and 10% FLO supplemented with egg yolk, baker's yeast and vitamins 12 h before feeding to seahorse broodstocks. In general, response parameters increased at lower concentration of FLO, peaked at 5% and decreased at 10%; thus, for parabolic relationships, the quadratic regression was appropriate to estimate quantitative optimum level. Artemia enrichment with FLO increased considerably its saturated FA content in the form of myristic acid and the total HUFA content, particularly DHA and arachidonic acid. Feeding seahorse broodstock with FLO enriched Artemia resulted in: (1) significant increase in brood size both during the first and second brooding, (2) significant shortening of interbrooding period, and (3) significant extension of the time to total mortality during the salinity shock test of juveniles. Quantitative estimates of mean optimum FLO level for the enrichment of Artemia fed to H. comes was 6.3% (range 5.9-7.0%) using each response parameter fitted in a quadratic model.