News / Species Spotlight / Seahorses (10/29/14)

Seahorses


Taxonomy

  • Class: Actinopterygii
  • Order: Syngnathiformes
  • Suborder: Syngnathoidei
  • Family: Syngnathidae
  • Subfamily: Hippocampinae
  • Genus: Hippocampus
Description

Seahorses are among the most unusual creatures in the ocean. People are often fascinated by their strange shape and interesting behaviors. As a member of the Syngnathidae (fused-jaw) family, seahorses are closely related to pipefishes, pipehorses and seadragons. There are currently over 40 species of seahorses that have been identified. Seahorses have an upright posture, a snout with a small mouth and a strong prehensile tail for latching onto seagrasses and other objects such as sponges and gorgonians. Another truly interesting fact about these fishes is that the males possess a brood pouch for the incubation of eggs. This allows the eggs to turn into highly developed offspring before entering the world. Instead of scales, seahorses are armoured with bony plates and rings. They have gills, no teeth, and their fins are soft-rayed. Their colors can be quite variable with some being brilliant red and orange, and may even include a unique zebra pattern. Seahorses range in size from tiny (2 cm) to large (30 cm). Seahorses are carnivorous, feeding primarily on small crustaceans that are ingested whole due to their lack of teeth.

A number of seahorse species are currently being maricultured and wild caught for the aquarium trade. The species most commonly kept in aquariums are H. kuda, H. reidi, and H. erectus.

With the recent listing of seahorses to the Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES), aquarists are encouraged to only purchase tank-raised or captive-bred animals. This alleviates the pressure of wild harvest, while offering the aquarist a much hardier specimen. There are over 10 species of seahorses currently being maricultured in places such as Florida, Hawaii, Vietnam and Sri Lanka.

Natural Habitat

Seahorses range around the globe and are mostly found in tropical and subtropical environments. None of the species have a broad geographical range as was originally thought. They are generally found where there are tidal currents, benthic seagrass, sponges and other similar habitats. While some are pelagic, most are camouflaged ambush predators that match their benthic surroundings and simply wait for currents to carry prey to them. Each species has adapted to best suit their needs for diet and protection. Most seahorses in the aquarium trade are fed small crustaceans, such as mysis shrimp. Seahorses are preyed upon by a number of benthic fishes such as snappers and flatheads. Seahorses became severely over-harvested for the curio trade and traditional Chinese medicine market. This prompted all species of seahorses to be protected under CITES in 2004. While some CITES export permits are still being issued for the live aquarium trade, the collection for other purposes has been significantly reduced. The rise in available maricultured seahorses has been a huge success story. In China, there is even a seahorse farm for making seahorse wine. While most seahorse populations are quite healthy, coastal development, habitat destruction and over-collecting are some of the biggest threats to species with restricted distribution.

Aquarium Care

Like most fish, if given the right diet and water quality, seahorse do well in the aquarium. Choosing maricultured animals is the first step in achieving success with keeping seahorses. Maricultured seahorses are often raised on frozen mysis which has eliminated the need for offering live foods. Wild caught specimens may need to be fed live foods and this can sometimes be difficult and expensive. Many kinds of fishes can out-compete seahorses for food, and therefore they may do best when only kept with other seahorses or other non-aggressive feeders. This is not to say that one cannot keep seahorses in a tank with other fish and invertebrates, it is only a suggestion to improve their captive care. Frozen mysis, prawn eggs, and other appropriate foods are available, so finding the right food is as easy calling upon your local aquarium store.

While there is still much debate and lack of information on many seahorse species, some are known to live for 6-8 years. The sexes are easy to differentiate and they will readily breed in aquariums. Culturing seahorses, as with other marine species, can be time consuming and difficult. Many aquarists report breeding in the aquarium and this is usually a testament to their successful care. Seahorses prefer a tank with good water flow, but not the powerful surge and currents found in many modern stony coral reef aquariums. It is encouraged to learn more about the source of your seahorses, whether from a farm or from the ocean. This gives aquarists the best chance of reproducing the ideal environment for these amazing creatures.