While many aquarium hobbyists keep seahorses as pets, seahorses collected from the wild tend to fare poorly in home aquaria. Many eat only live foods such as brine shrimp and are prone to stress, which damages their immune systems and makes them susceptible to disease.
In recent years, however, captive breeding has become more popular. Such seahorses survive better in captivity, and are less likely to carry diseases. They eat frozen mysidacea (crustaceans) that are readily available from aquarium stores, and do not experience the stress of moving out of the wild. Although captive-bred seahorses are more expensive, they take no toll on wild populations.
Seahorses should be kept in an aquarium to themselves, or with compatible tank-mates. Seahorses are slow feeders, and fast, aggressive feeders will leave them without food.
Animals sold as "freshwater seahorses" are usually the closely related pipefish, of which a few species live in the lower reaches of rivers. The supposed true "freshwater seahorse" called H. aimei was not a real species, but a name sometimes used for Barbour's and Hedgehog seahorses. The latter is a species that can be found in brackish waters, but not actually a freshwater fish.