Cultivo de juvenis recém nascidos do cavalo-marinho Hippocampus reidi Ginsburg, 1933, com diferentes protocolos de alimentação e manejo

Abstract

The main bottleneck for seahorse production is the low survival of the juveniles during the early stages of development. Although the causes for low survival are not totally understood, feeding is considered critical as success on marine fish larval breeding is dependent, among others factors, on the size and nutritional content of the prey organisms. This study evaluated the growth and survival of newborn seahorses Hippocampus reidi fed on different preys. The experiment was conducted on 38 liter aquaria connected to a seawater recirculation system, which contained mechanical and biological filters, UV sterilizer and protein skimmer. Each aquarium had two aeration points near the water surface. Six treatments were tested: Art00h – newly hatched Artemia nauplii (5 ind ml-1); Art24h – 24 hours enriched Artemia metanauplii (5 ind ml- 1); Rot+Art24h - Brachionus plicatilis rotifers (10 ind ml-1) from day 1 until day 7 followed by enriched Artemia metanauplii (5 ind ml-1); Cop – Tisbe biminiensis (2 ind ml-1); and Cop+Art24h – mixed diet with T. biminiensis (2 ind ml-1) and 24 hours enriched Artemia metanauplii (5 ind ml-1). In the treatment Starvation, no food item was provided. All the treatments, except the starvation, received microalgae Nannochloropsis oculata every other day at concentrations that ranged from 2.2 x 105 to 3.2 x 106. Each experimental unit received 100 newborn seahorses. At the end of the experiment, all remaining seahorses were measured and weighed. Treatment Cop+Art24h resulted in a significantly higher survival (33.5 ± 5.4%), followed by Cop (6.6 ± 4.8%), Art00h (6.0 ± 8.3%) and Rot+Art24h (0.3 ± 0.5%), which were not significantly different. No survivors were observed in the remaining treatments. Growth parameters were significantly higher in Cop+Art24h and Art00h. The results from this study suggest that the feeding copepods T. biminiensis increases growth and survival of the seahorse H. reidi during the first two weeks of life.