Feeding longsnout seahorse Hippocampus reidi broodstock at different frequencies influences production of eggs and quality of the offspring

Abstract

Abstract This study determined the optimum feeding frequency for Hippocampus reidi breeders by evaluating their zootechnical and reproductive parameters, the quality of the larvae (resistance to starvation), and the fatty acid profile of oocytes. Twelve breeding couples (aprox. 27g; 18 cm per individual) were fed daily with enriched caridean shrimp Palaemon sp. until apparent satiation during 101 days. Four feeding frequencies were tested in triplicate: one (F1), two (F2), three (F3) and four (F4) feedings per day. Breeders from both sexes fed just once a day had lower weight gain and specific growth rates than the other treatments (P<0.05). Newly born larvae weight and size values (2.06 ± 0.11 mg; 7.9 ± 0.06 mm) from couples in F3 and F4 treatments were higher than in the couples receiving one or two daily feedings (1.62 ± 0.17 mg; 6.7 ± 0.05 mm). Number of larvae per parturition in F3 and F4 (928.5) was almost double the number of larvae in F1 and F2. The longest time of larvae resistance to food deprivation was observed in F3 and F4, where 100% of mortality occurred in 96 hours. A higher concentration of polyunsaturated fatty acids, arachidonic acid (AA) and docosahexaenoic acid (DHA) was observed in F4 than in the other treatments. It is therefore recommended that when H. reidi breeders are fed enriched shrimp, three to four daily times per day feedings should be offered to obtain the best zootechnical performance of them, and the highest quality and quantity of larvae produced.