Establishment and maintenance of threatened long-snouted seahorse, Hippocampus guttulatus, broodstock in captivity

Knowledge on seahorses is generally scarce but has been increasing in recent years due to their conservation status. Seahorse culture is a quite recent activity in most countries attempting it, and captive breeding techniques are available only for some species. With the aim of contributing to the development of breeding in captivity for conservative purposes, captive broodstock of the European long-snouted seahorse (Hippocampus guttulatus) was established with 32 wild seahorses captured in Galicia (NW Spain). This study describes the methodologies applied to the maintenance of the broodstocks, with special reference to aquaria design, feeding, growth and breeding. Procedures of seahorse identification (morphologically and genetically) as a tool for broodstock management are also considered. The results achieved during the first year demonstrate a rapid adaptation of wild seahorses to captive conditions. Seahorses were fed exclusively on enriched adult Artemia and displayed high growth rates. However, fatty acid analyses performed on unfertilised eggs of captive broodstock showed a progressive decrease in the content of essential fatty acids (DHA, EPA) with time in captivity, suggesting the need for improvement in the nutritional quality of broodstock feed.