'Seahorses' are a genus of fish belonging to the family
Syngnathidae, which also includes
pipefish and
leafy sea dragons. The seahorses are found in
tropical and
subtropical coastal and reef waters all over
Pacific,
Atlantic and
Indian oceans.
Seahorses range in size from 16 mm (the recently discovered ''
Hippocampus denise''
[1]) to 35 cm. Seahorses and pipefishes are notable for being the only
species in which males become "
pregnant".
[2]
The seahorse has a
dorsal fin located on the lower body and pectoral fins located on the head near their gills. Some species of seahorse are partly transparent and are rarely seen in pictures.
Sea dragons are close relatives of seahorses but have bigger bodies and leaf-like appendages which enable them to hide among floating
seaweed or
kelp beds. Seahorses and sea dragons feed on larval fishes and
amphipods, such as small shrimp-like crustaceans called
mysids ("sea lice"), sucking up their prey with their small mouths. Many of these
amphipods feed on
red algae that thrives in the shade of the
kelp forests where the
sea dragons live.
Mating
Seahorses reproduce in an unusual way: the
male becomes pregnant. "The female inserts her
ovipositor into the male’s brood pouch, where she deposits her eggs, which the male fertilizes. The fertilized eggs then embed in the pouch wall and become enveloped with tissues."
[3] New research indicates the male releases sperm into the surrounding sea water during fertilization, and not directly into the pouch as was previously thought.
[4] Most seahorse species' pregnancies lasts approximately two to three weeks.
Hatched offspring are independent of their parents. Some spend time developing among the ocean
plankton. At times, the male seahorse may try to consume some of the previously released offspring. Other species (''H. zosterae'') immediately begin life as sea-floor inhabitants (
benthos).
Seahorses are generally
monogamous, though several species (''H. abdominalis'' among them) are highly gregarious. In monogamous pairs, the male and female will greet one another with courtship displays in the morning and sometimes in the evening to reinforce their pair bond. They spend the rest of the day separate from each other hunting for food.
Pets
While many
aquarium hobbyists will keep seahorses as pets, seahorses collected from the wild tend to fare poorly in a home aquarium. They will eat only live foods such as
brine shrimp and are prone to stress in an aquarium, which lowers the efficiency of their immune systems and makes them susceptible to disease.
In recent years, however,
captive breeding of seahorses has become increasingly widespread. These seahorses survive better in captivity, and they are less likely to carry diseases. These seahorses will eat
mysid shrimp, and they do not experience the shock and stress of being taken out of the wild and placed in a small aquarium. Although captive-bred seahorses are more expensive, they survive better than wild seahorses, and 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 in an aquarium with fast, aggressive feeders, the seahorses will be edged out in the competition for food. Special care should be given to ensure that all individuals obtain enough food at feeding times.
Seahorses can co-exist with many species of
shrimp and other
bottom-feeding creatures. Fish from the
goby family also make good tank-mates. Some species are especially dangerous to the slow-moving seahorses and should be avoided completely:
eels,
tangs,
triggerfish,
squid,
octopus, and
sea anemones.
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 ''Hippocampus aimei'' was not a real species, but a name sometimes used for individuals of
Barbour's seahorse and
Hedgehog seahorse. The latter is a species commonly found in
brackish waters, but not actually a freshwater fish.
Use in Chinese medicine

Mummified seahorse.
Seahorse populations have been
endangered in recent years by overfishing. Therefore, seahorse fishing is strictly illegal. The seahorse is used in traditional
Chinese herbology, and as many as 20 million seahorses may be caught each year and sold for this purpose.
[5] Medicinal seahorses are not readily bred in captivity as they are susceptible to disease and have somewhat different energetics than aquarium seahorses.
Import and export of seahorses has been controlled under
CITES since
May 15,
2004.
The problem may be exacerbated by the growth of pills and capsules as the preferred method of ingesting medication as they are cheaper and more available than traditional, individually tailored prescriptions of raw medicinals but the contents are harder to track. Seahorses once had to be of a certain size and quality before they were accepted by TCM practitioners and consumers. But declining availability of the preferred large, pale and smooth seahorses has been offset by the shift towards prepackaged medicines, which make it possible for TCM merchants to sell previously unused juvenile, spiny and dark-coloured animals. Today almost a third of the seahorses sold in China are prepackaged. This adds to the pressure on the species.
[6]
Adaptations
A seahorse has highly mobile eyes to watch for predators and prey without moving its body. Like the
leafy sea dragon, it also has a long snout with which it sucks up its prey. Its fins are small because it must move through thick water vegetation. The seahorse has a long, prehensile tail which it will curl around any support such as
seaweed to prevent being swept away by currents.
Species
★ Genus ''Hippocampus''
★
★
Big-belly seahorse, ''
Hippocampus abdominalis''
Lesson, 1827 (
New Zealand and south and east
Australia)
★
★
Winged seahorse, ''
Hippocampus alatus''
Kuiter, 2001
★
★
West African seahorse, ''
Hippocampus algiricus''
Kaup, 1856
★
★
Narrow-bellied seahorse, ''
Hippocampus angustus''
Günther, 1870
★
★
Barbour's seahorse, ''
Hippocampus barbouri''
Jordan & Richardson, 1908
★
★
Pygmy seahorse, ''
Hippocampus bargibanti''
Whitley, 1970 (West
Pacific area (
Indonesia,
Philippines,
Papua New Guinea,
Solomon Islands, etc)
★
★
False-eyed seahorse, ''
Hippocampus biocellatus''
Kuiter, 2001
★
★
Réunion seahorse, ''
Hippocampus borboniensis''
Duméril, 1870
★
★
Short-head seahorse, ''
Hippocampus breviceps''
Peters, 1869 (south and east
Australia)
★
★
Giraffe seahorse, ''
Hippocampus camelopardalis''
Bianconi, 1854
★
★
Knysna seahorse, ''
Hippocampus capensis''
Boulenger, 1900
★
★ ''
Hippocampus colemani''
Kuiter, 2003
★
★
Tiger tail seahorse, ''
Hippocampus comes''
Cantor, 1850
★
★ ''
Hippocampus coronatus''
Temminck & Schlegel, 1850
★
★
Denise's pygmy seahorse, ''
Hippocampus denise''
Lourie & Randall, 2003
★
★
Lined seahorse, ''
Hippocampus erectus''
Perry, 1810 (east coast of the Americas, between
Nova Scotia and
Uruguay)
★
★
Fisher's seahorse, ''
Hippocampus fisheri''
Jordan & Evermann, 1903
★
★
Sea pony, ''
Hippocampus fuscus''
Rüppell, 1838 (
Indian Ocean)
★
★
Big-head seahorse, ''
Hippocampus grandiceps''
Kuiter, 2001
★
★
Long-snouted seahorse, ''
Hippocampus guttulatus''
Cuvier, 1829
★
★
Eastern spiny seahorse, ''
Hippocampus hendriki''
Kuiter, 2001
★
★
Short-snouted seahorse, ''
Hippocampus hippocampus''
(Linnaeus, 1758) (
Mediterranean Sea and
Atlantic Ocean)
★
★
Thorny seahorse, ''
Hippocampus histrix''
Kaup, 1856 (
Indian Ocean,
Persian Gulf,
Red Sea, and the
Far East)
★
★
Pacific seahorse, ''
Hippocampus ingens''
Girard, 1858 (
Pacific coast of North, Central and
South America)
★
★
Jayakar's seahorse, ''
Hippocampus jayakari''
Boulenger, 1900
★
★
Collared seahorse, ''
Hippocampus jugumus''
Kuiter, 2001
★
★
Great seahorse, ''
Hippocampus kelloggi''
Jordan & Snyder, 1901
★
★
Spotted seahorse, ''
Hippocampus kuda''
Bleeker, 1852
★
★
Lichtenstein's Seahorse, ''
Hippocampus lichtensteinii''
Kaup, 1856
★
★
Bullneck seahorse, ''
Hippocampus minotaur''
Gomon, 1997
★
★
Japanese seahorse, ''
Hippocampus mohnikei''
Bleeker, 1854
★
★
Monte Bello seahorse, ''
Hippocampus montebelloensis''
Kuiter, 2001
★
★
Northern spiny seahorse, ''
Hippocampus multispinus''
Kuiter, 2001
★
★
High-crown seahorse, ''
Hippocampus procerus''
Kuiter, 2001
★
★
Queensland seahorse, ''
Hippocampus queenslandicus''
Horne, 2001
★
★
Longsnout seahorse, ''
Hippocampus reidi''
Ginsburg, 1933 (
Caribbean coral reefs)
★
★
Half-spined seahorse, ''
Hippocampus semispinosus''
Kuiter, 2001
★
★
Dhiho's seahorse, ''
Hippocampus sindonis''
Jordan & Snyder, 1901
★
★
Hedgehog seahorse, ''
Hippocampus spinosissimus''
Weber, 1913
★
★
West Australian seahorse, ''
Hippocampus subelongatus''
Castelnau, 1873
★
★
Longnose seahorse, ''
Hippocampus trimaculatus''
Leach, 1814
★
★
White's seahorse, ''
Hippocampus whitei''
Bleeker, 1855 (east
Australia)
★
★
Zebra seahorse, ''
Hippocampus zebra''
Whitley, 1964
★
★
Dwarf seahorse, ''
Hippocampus zosterae''
Jordan & Gilbert, 1882 (
Gulf of Mexico and the
Caribbean)
Cultural references
In
heraldry, a seahorse is depicted as a creature with the foreparts of a horse and the hindparts of a fish. See, for example, the right supporter of the
Isle of Wight Arms, the supporters on either side of the crest of the city of
Newcastle upon Tyne, or the coincidental arms of the
University of Newcastle,
Australia.
The seahorse is prominent in the logo of
Waterford Crystal and the logotype of illustrator
W. W. Denslow.
In the
Seri culture of northwestern
Mexico, the legend is that the seahorse is a person who, to escape his pursuers, fled into the sea, placing his sandals in his waistbelt at his back.
[7]
The
National Society for Epilepsy has a seahorse for its mascot named Cesar (after the Roman emperor,
Julius Caesar, who was believed to have had
epilepsy). The seahorse mascot was chosen because the
hippocampus, a part of the
brain that is resistant to damage from epileptic seizures, resembles a seahorse in shape.
Gallery
Notes
{{FootnotesSmall|resize=
Further reading
★ Amanda C.J. Vincent and Laila M. Sadler. "Faithful pair bonds in wild seahorse, ''Hippocampus whitei." Animal Behaviour'' 50(1995): 1557-1569.
★ Amanda C.J. Vincent. "A role for daily greetings in maintaining seahorse pair bonds." ''Animal Behaviour ''49 (1995): 258-260.
★ Amanda C.J. Vincent. "A seahorse father makes a good mother." ''Natural History'', 12 (1990): 34-43.
★ Ananda C.J. Vincent and Rosie Woodroffe. "Mothers little helpers: patterns of male care in mammals." ''Trends in Ecology and Evolution'', 9 (1994): 294-297.
★ Sara A. Lourie, Amanda C.J. Vincent and Heather J. Hall: ''Seahorses: An Identification Guide to the World's Species and their Conversation''. London: Project Seahorse, 1999
★ John Sparks: ''Battle of the Sexes: The Natural History of Sex. London: BBC Books, 1999
External links
★ ARKive -
images and movies of the pygmy seahorse ''(Hippocampus bargibanti)''
★
Project Seahorse
★
Pygmy Seahorses: ''Hippocampus denise'' - Description and Photo gallery
★
"Walea" Pygmy Seahorse - Description and Photo gallery
★
"Pontohi" Pygmy Seahorse - Description and Photo gallery
★
Seahorse Photos
★ Seahorse.com -
Hawaii-based Aquaculture Center and Farm Raised Seahorses