Rearing West Australian seahorse, Hippocampus subelongatus, juveniles on copepod nauplii and enriched Artemia

Improved captive breeding techniques are required for seahorses. Artemia nauplii are generally considered a poor first feeding diet for many seahorse species. This study compared growth and survival of newborn Hippocampus subelongatus reared on cultured copepod nauplii and Artemia nauplii enriched with Super Selco®. Early growth and survival of seahorses were significantly greater when fed copepod nauplii. Copepod nauplii were well digested by juvenile seahorses whereas Artemia nauplii were not. Fatty acid requirements of seahorses could not be determined. The addition of UV water sterilisation improved seahorse survival. When offered copepod nauplii of different sizes, 5-day-old seahorses preferentially selected the largest nauplii. Maximum predation rate in these juveniles was 214 copepod nauplii/seahorse/h. Provision of copepod nauplii to juveniles improves the prospects of establishing captive breeding populations of H. subelongatus.