Transport conditions in the planktonic phase for seahorses Hippocampus reidi Ginsburg, 1933 (Teleostei: Syngnathidae)

Abstract

Thousands of seahorses are traded every year as marine ornamental species. Although packing methods for live adult seahorses have already been addressed, there is no information on the transportation of juvenile seahorses. Thus, this study aimed to evaluate the possibility of packing and transportation for newly-birthed seahorses. Three batches of newborn long-snout seahorses Hippocampus reidi were transported in three independent events from Ubatuba, north coast of São Paulo, to the city of São Paulo, covering 248 km in each trip, with an average duration of 3.5 h. A mean of 350 offspring of one day old was distributed in 1 L containers with round borders at equal densities, provided with constant aeration by portable pumps. Aeration was kept so that large bubbles would create an ascending flow keeping juveniles in suspension throughout transportation. Values of survival achieved in this study, even after 10 days post-transportation, were surprisingly high, reaching over 70%. No significant shift in water temperature, pH, or salinity was observed for any transportation events. For oxygen levels, although portable pumps were used, a drop of around 15% in DO level was recorded. In view of the trending ornamental fish market, considering the limited swimming capacity of newly born seahorses and that a great number of marine fish undergo a planktonic phase, this study provides important directions to a better understanding on seahorse transportation and yet, directions for the design of new transport methodology for an efficient shipping protocol for other species.