The longsnout seahorse (Hippocampus reidi ) is the most abundant species in Brazil and plays an important ecological role as a bioindicator and regulator of the trophic chain . Population decline, caused by habitat degradation and commercial exploitation , has led to its classification as “vulnerable .” In this context , aquaculture of this species emerges as a promising alternative to reduce pressure on natural stocks. However , its captive breeding is challenging due to its strong feeding selectivity and low acceptance of inert dry diets.
The experiment was carried out at LAPOM/UFSC in a recirculating aquaculture system (26.5 ± 0.05 ºC; dissolved oxygen : 6.3 ± 0.07 mg/L; salinity : 30 ± 0.09; pH: 8.03 ± 0.01; photoperiod : 12 h), using three 30-L aquaria (n = 18). Fish were fed three times daily for 10 days using a suspended feeder designed to minimize feed waste.
Parameters evaluated included feeding preference , overall feed intake , and preference according to feeding time. Results showed that shrimp postlarvae (27.83 ± 1.61), mysids (21.17 ± 5.62), and Artemia (20.00 ± 1.73) were equally accepted (P > 0.05), whereas the dehydrated mixture (3.33 ± 1.16) was consumed significantly less . Feed intake was consistent across the three feeding times: 9 a.m. (20.50 ± 3.00), 1 p.m. (20.08 ± 1.47), and 5 p.m. (20.75 ± 2.75). However , a significant preference for mysids (26.66 ± 3.21) was observed at 1 p.m., when compared with Artemia (19.66 ± 1.52), shrimp postlarvae (21.33 ± 6.65), and the dehydrated mix (3.83 ± 1.00) .
The suspended feeder proved effective in reducing waste and improving feed management. Overall, the findings indicate that frozen diets may partially replace live feeds in the rearing of H. reidi juveniles , contributing to the feasibility of aquaculture . Conversely , the low acceptance of dehydrated feed highlights the need for further studies and the development of species-specific formulated diets.