Seahorses are among the most fragile marine fish to keep in captivity, with high mortality rates in the aquarium trade and significant wild population decline from overcollection.
Seahorses in captivity face multiple welfare challenges: their requirement for live prey is difficult to meet consistently; their sensitivity to water quality means typical aquarium conditions cause chronic physiological stress; and their inability to compete for food with faster-moving tankmates results in starvation in mixed-species setups. Wild-caught seahorses have up to 90% mortality in their first weeks of captivity. The combination of high captive mortality and ongoing wild collection for a trade where animals routinely die creates a welfare situation where the precautionary approach is to not keep seahorses unless providing specialist conditions.