Ex-situ growing out of early stages of wild seahorses: Envisioning conservation options for threatened populations

Abstract

Rafting has been proposed as a dispersive mechanism for some species of seahorses. Juvenile Hippocampus patagonicus rafting on the sea surface have been reported. This life stage has high mortality in nature due to ecological and environmental factors usually affecting juvenile planktonic teleosts (e.g. predation). In this study, 50 juvenile seahorses were captured while rafting at the beginning of the reproductive season (December). They were grown out under a standard protocol in a recirculating aquaculture system for 120 days until they reached maturity. During this period, only three seahorses died (6%). Mature seahorses were 65 ± 7 mm average height and showed variable coloration and pigmentation pattern (n = 47; 94%). The availability of juvenile seahorses during the reproductive season and their high survival performance ex situ highlight the feasibility of developing protocols in which juvenile seahorses serve as a novel source of broodstock.