Seahorses compose the fish
genusIn biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Hippocampus within the family
SyngnathidaeSyngnathidae is a family of fish which includes the seahorses, the pipefishes, and the weedy and leafy sea dragons. The name is derived from Greek, meaning "fused jaw" - syn meaning fused or together, and gnathus meaning jaws. This fused jaw trait is something the entire family has in common...
, in
orderIn scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
SyngnathiformesSyngnathiformes is an order of ray-finned fishes that includes the pipefishes and seahorses.These fishes have elongate, narrow, bodies surrounded by a series of bony rings, and small, tubular mouths. Several groups live among seaweed and swim with the body aligned vertically, to blend in with the...
. Syngnathidae also includes the
pipefishPipefishes or pipe-fishes are a subfamily of small fishes, which, together with the seahorses, form the family Syngnathidae.-Anatomy:...
es. "Hippocampus" comes from the
Ancient GreekAncient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
hippos meaning "horse" and
kampos meaning “sea monster”.
There are nearly 50 species of seahorse. They are mainly found in shallow tropical and temperate waters throughout the world. They prefer to live in sheltered areas such as
seagrassSeagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...
beds,
coral reefCoral reefs are underwater structures made from calcium carbonate secreted by corals. Coral reefs are colonies of tiny living animals found in marine waters that contain few nutrients. Most coral reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps...
s, or mangroves. Colonies have been found in European waters such as the
Thames EstuaryThe Thames Mouth is the estuary in which the River Thames meets the waters of the North Sea.It is not easy to define the limits of the estuary, although physically the head of Sea Reach, near Canvey Island on the Essex shore is probably the western boundary...
. From
North AmericaNorth America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
down to
South AmericaSouth America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
there are approximately four species, ranging from the very small (
dwarf seahorseThe dwarf seahorse is a species of seahorse. It is found in the Bahamas and the United States. Its natural habitat is subtidal aquatic beds. It is threatened by habitat loss...
s are only about 2.5 cm (0.984251968503937 in)) to much larger specimens off the Pacific Coast of
Central AmericaCentral America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
(the foot-long
H. ingens).
H. erectusHippocampus erectus is a species of fish that belongs to the Syngnathidae family. Its common names may include: Lined seahorse, Northern seahorse, and Spotted seahorse.-Description:...
are larger seahorses that range from
Nova ScotiaNova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
to around
UruguayUruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
. Three species live in the
Mediterranean SeaThe Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
:
H. guttulatus (long snout),
H. hippocampus (short snout) and
H. fuscus (immigrated from the
Red SeaThe Red Sea is a seawater inlet of the Indian Ocean, lying between Africa and Asia. The connection to the ocean is in the south through the Bab el Mandeb strait and the Gulf of Aden. In the north, there is the Sinai Peninsula, the Gulf of Aqaba, and the Gulf of Suez...
). These fish form territories, with males staying in about 1 sqm of their habitat while females range about one hundred times that area. They bob around in sea grass meadows, mangrove stands, and coral reefs where they adopt murky brown and gray patterns to camouflage themselves among the sea grass. During social moments or in unusual surroundings, seahorses turn bright colors.
Description
Seahorses are named for their equine profile. Although they are bony fish, they do not have scales, but rather a thin skin stretched over a series of bony plates arranged in rings throughout their body. Each species has a distinct number of rings. Seahorses swim upright, another characteristic that is not shared by their close pipefish relatives, which swim horizontally. Seahorses have a
coronetA coronet is a small crown consisting of ornaments fixed on a metal ring. Unlike a crown, a coronet never has arches.The word stems from the Old French coronete, a diminutive of coronne , itself from the Latin corona .Traditionally, such headgear is – as indicated by the German equivalent...
on their head, which is distinct to each individual, much like a human fingerprint. They swim very poorly by using a
dorsal finA dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
, which they rapidly flutter and pectoral fins, located behind their eyes, which they use to steer. Seahorses have no caudal fin. Since they are poor swimmers, they are most likely to be found resting, with their prehensile tails wound around a stationary object. They have long snouts, which they use to suck up food, and eyes that can move independently of each other, much like a
chameleonChameleons are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, the possession by many of a...
. Seahorses eat small
shrimpShrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
, tiny
fishFish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, crustaceans and
planktonPlankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
.
Evolution and fossil record
Anatomical evidence, supported by molecular, physical, and genetic evidence, demonstrates that seahorses are highly modified
pipefishPipefishes or pipe-fishes are a subfamily of small fishes, which, together with the seahorses, form the family Syngnathidae.-Anatomy:...
. The fossil record of seahorses, however, is very sparse. The best known and best studied fossils are specimens of
H. guttulatus (though literature more commonly refers to them under the synonym of
H. ramulosus), from the
Marecchia RiverThe San Marino River is a river in the Italian peninsula. It flows through San Marino , then north into Italy. For some of its length it forms part of the border between the two countries. It flows into the Marecchia at Torello, part of the commune of San Leo ....
Formation of Rimini Province,
ItalyItaly , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, dating back to the Lower
PlioceneThe Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
, about 3 million years ago. The earliest known seahorse fossils are of two pipefish-like species,
H. sarmaticusHippocampus sarmaticus is an extinct species of seahorse, found in 2005 in the coprolitic horizon of the Tunjice hills Lagerstätte in Slovenia, along with the related Hippocampus slovenicus. The horizon dates 13 million years back to the lower Sarmatian during the middle Miocene period, making the...
and
H. slovenicusHippocampus slovenicus is an extinct species of seahorse found in 2005 in the coprolitic horizon of the Tunjice hills Lagerstätte in Slovenia along with remains of the related species Hippocampus sarmaticus. The horizon dates 13 million years back to the lower Sarmatian during the middle Miocene...
from the
coproliticA coprolite is fossilized animal dung. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour rather than morphology. The name is derived from the Greek words κοπρος / kopros meaning 'dung' and λιθος / lithos meaning 'stone'. They...
horizon of
TunjiceTunjice is a dispersed settlement in the hills west of the town of Kamnik in Upper Carniola region of Slovenia.The Parish Church, dedicated to Saint Anne, lies on a hill above the settlement and is an imposing Baroque domed building...
Hills, a middle Miocene
lagerstätteA Lagerstätte is a sedimentary deposit that exhibits extraordinary fossil richness or completeness.Palaeontologists distinguish two kinds....
in
SloveniaSlovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...
dating back about 13 million years.
Molecular datingThe molecular clock is a technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged. It is used to estimate the time of occurrence of events called speciation or radiation...
finds that pipefish and seahorses separated during the Late
OligoceneThe Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
. This has led to speculation that seahorses evolved in response to large areas of shallow-water, newly created as the result of tectonic events. The shallow water allowed the expansion of seagrass habitats that selected for the
camouflageCamouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
offered by the seahorses’ upright posture. These tectonic changes occurred in the Western
Pacific OceanThe Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
suggesting an origin there with molecular data suggesting two later and separate invasions of the
Atlantic OceanThe Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
.
Reproduction
The male seahorse is equipped with a brood pouch on the ventral, or front-facing, side. When mating, the female seahorse deposits up to 1,500 eggs in the male's pouch. The male carries the
eggAn egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s for anywhere from 9 to 45 days until they emerge, expelling fully developed, miniature seahorses in the water. Once the seahorse babies are released into the water, the male's role is done and he offers no further care.
Courtship
Before breeding, seahorses court for several days. Scientists believe the
courtshipCourtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
behavior synchronizes the animals' movements so that the male can receive the eggs when the female is ready to deposit them. During this time they may change color, swim side by side holding tails or grip the same strand of sea grass with their tails and wheel around in unison in what is known as a “pre-dawn dance". They eventually engage in a “true courtship dance" lasting about 8 hours, during which the male pumps water through the egg pouch on his trunk which expands and opens to display its emptiness. When the female’s eggs reach maturity, she and her mate let go of any anchors and snout-to-snout, drift upward out of the seagrass, often spiraling as they rise. The female inserts her
ovipositorThe ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
into the male’s brood pouch and deposits dozens to thousands of eggs. As the female releases her eggs, her body slims while his swells. Both animals then sink back into the seagrass and she swims away.
Gestation
The male releases his sperm directly into seawater where it fertilizes the eggs, which are then embedded in the pouch wall and become surrounded by a spongy tissue. The male supplies the eggs with
prolactinProlactin also known as luteotropic hormone is a protein that in humans is encoded by the PRL gene.Prolactin is a peptide hormone discovered by Henry Friesen...
, the same hormone responsible for
milkMilk is a white liquid produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals before they are able to digest other types of food. Early-lactation milk contains colostrum, which carries the mother's antibodies to the baby and can reduce the risk of many...
production in pregnant
mammalMammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s. The pouch provides oxygen as well as a controlled environment incubator. The eggs then hatch in the pouch where the salinity of the water is regulated; this prepares the newborns for life in the sea. Throughout gestation, which in most species requires two to four weeks, his mate visits him daily for “morning greetings”. They interact for about 6 minutes, reminiscent of courtship. The female then swims away until the next morning, and the male returns to vacuuming up food through his snout.
Research published in 2007 indicates the male releases sperm into the surrounding sea water during fertilization, and not directly into the pouch as previously thought.
Birth
The number of young released by the male seahorse averages 100–200 for most species, but may be as low as 5 for the smaller species, or as high as 1,500. When the fry are ready to be born, the male expels them with muscular contractions. He typically gives birth at night and is ready for the next batch of eggs by morning when his mate returns. Like almost all other fish species, seahorses do not nurture their young after birth. Infants are susceptible to predators or ocean currents which wash them away from feeding grounds or into temperatures too extreme for their delicate bodies. Less than 0.5% of infants survive to adulthood, explaining why litters are so large. These survival rates are actually fairly high compared to other fish, because of their protected gestation, making the process worth the great cost to the father. The eggs of most other fish are abandoned immediately after fertilization.
Questions surrounding reproductive roles
Reproduction is energetically costly to the male. This brings into question why the sexual role reversal even takes place. In an environment where one partner incurs more energy costs than the other,
Bateman's principleIn biology, Bateman's principle is the theory that females almost always invest more energy into producing offspring than males invest, and therefore in most species females are a limiting resource over which the other sex will compete...
suggests that the lesser contributor takes the role of the aggressor. Male seahorses are more aggressive and sometimes “fight” for female attention. According to
Amanda VincentDr. Amanda Vincent is a Canadian marine biologist, conservationist, and one of the world’s leading experts on seahorses and their relatives. She holds the Canada Research Chair in Marine Conservation at the Fisheries Centre at the University of British Columbia, Canada...
of
Project SeahorseProject Seahorse is a marine conservation organization committed to the conservation and sustainable use of the world’s coastal marine ecosystems. Founded in 1996 by Amanda Vincent and Heather Koldewey, Project Seahorse generates cutting-edge research and turns its findings into highly effective...
, only males tail-wrestle and snap their heads at each other. This discovery prompted further study of energy costs. To estimate the female’s direct contribution, researcher Heather D. Masonjones, associate professor of biology at the University of Tampa, chemically analyzed the energy stored in each egg. To measure the burden on the male, Masonjones measured its oxygen consumption. By the end of incubation, the male consumed almost 33% more oxygen than before mating. The study concluded that the female's energy expenditure while generating eggs is twice that of males during incubation confirming the standard hypothesis.
Why the male seahorse (and other members of Syngnathidae) carries the offspring through gestation is unknown, though some researchers believe it allows for shorter birthing intervals, in turn resulting in more offspring. Given an unlimited number of ready and willing partners, males have the potential to produce 17 percent more offspring than females in a breeding season. Also, females have “time-outs” from the reproductive cycle that are 1.2 times longer than those of males. This seems to be based on mate choice, rather than physiology. When the female’s eggs are ready, she must lay them in a few hours or eject them into the water column. Making eggs is a huge cost to her physically, since they amount to about a third of her body weight. To protect against losing a clutch, the female demands a long courtship. The daily greetings help to cement the bond between the pair.
Monogamy
One common misconception about seahorses is that they mate for life. Many species of seahorses form pair bonds that last through at least the breeding season. Some species show a higher level of mate fidelity than others. However, many species readily switch mates when the opportunity arises.
H. abdominalis and
H. breviceps have been shown to breed in groups, showing no continuous mate preference. Many more species mating habits have not been studied, so it is unknown how many species are actually monogamous, or how long those bonds actually last.
Although
monogamyMonogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
within fish is not common, it does appear to exist for some. In this case, the mate guarding hypothesis may be an explanation. This hypothesis states “males remain with a single female because of ecological factors that make male parental care and protection of offspring especially advantageous.” Because the rates of survival for newborn seahorses are so low, incubation is essential. Though not proven, males could have taken on this role because of the lengthy period the females require to produce their eggs. If males incubate while females prepare the next clutch (amounting to 1/3 of body weight), they can reduce the interval between clutches.
Feeding habits
Seahorses feed on small crustaceans floating in the water or crawling on the bottom. With excellent
camouflageCamouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
and a lot of patience, seahorses ambush prey that float within striking range. Mysid shrimp and other small crustaceans are favorites, but some seahorses have been observed eating other kinds of invertebrates and even larval fish.
In aquaria
While many
aquariumAn aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
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 shrimpArtemia is a genus of aquatic crustaceans known as brine shrimp. Artemia, the only genus in the family Artemiidae, has changed little externally since the Triassic period...
and are prone to stress, which damages their
immune systemAn immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
s and makes them susceptible to disease.
In recent years, however,
captive breedingCaptive breedingis the process of breeding animals in human controlled environments with restricted settings, such as wildlife reserves, zoos and other conservation facilities; sometimes the process is construed to include release of individual organisms to the wild, when there is sufficient...
has become more popular. Such seahorses survive better in captivity, and are less likely to carry diseases. They eat frozen
mysidaceaMysida is a group of small, shrimp-like crustaceans, an order in the malacostracan superorder Peracarida. Their common name opossum shrimps stems from the presence of a brood pouch, or marsupium, in females. Mysids are mostly found in marine waters throughout the world, but are also important in...
(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.
Seahorses can co-exist with many species of shrimp and other
bottom-feedingDemersal fish live on or near the bottom of the sea or lakes. They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along...
creatures.
GobiesThe gobies form the family Gobiidae, which is one of the largest families of fish, with more than 2,000 species in more than 200 genera. Most are relatively small, typically less than 10 cm in length...
also make good tank-mates. Keepers are generally advised to avoid
eelEels are an order of fish, which consists of four suborders, 20 families, 111 genera and approximately 800 species. Most eels are predators...
s, tangs,
triggerfishTriggerfishes are about 40 species of often brightly colored fishes of the family Balistidae. Often marked by lines and spots, they inhabit tropical and subtropical oceans throughout the world, with the greatest species richness in the Indo-Pacific...
,
squidSquid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
,
octopusThe octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
, and
sea anemoneSea anemones are a group of water-dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Zoantharia. Anthozoa often have large polyps that allow for digestion of larger...
s.
Animals sold as "
freshwaterFresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
seahorses" are usually the closely related
pipefishPipefishes or pipe-fishes are a subfamily of small fishes, which, together with the seahorses, form the family Syngnathidae.-Anatomy:...
, 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 seahorseThe hedgehog seahorse is a species of fish in the Syngnathidae family. It is found in Australia, Indonesia, Malaysia, the Philippines, Singapore, Sri Lanka, Taiwan, Thailand, and Vietnam. Its natural habitat is coral reefs. It is threatened by habitat loss.-Source:* Project Seahorse 2003. . ...
s. The latter is a species that can be found in brackish waters, but not actually a freshwater fish.
Use in Chinese medicine
Seahorse populations are thought to have been
endangeredAn endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
in recent years by overfishing and habitat destruction. The seahorse is used in traditional
Chinese herbologyChinese Herbology is the theory of Traditional Chinese herbal therapy, which accounts for the majority of treatments in Traditional Chinese medicine ....
, and as many as 20 million seahorses may be caught each year and sold for this purpose. Medicinal seahorses are not readily bred in captivity as they are susceptible to disease and it is believed that they have different medicinal properties from aquarium seahorses. Seahorses are also used as medicines by the Indonesians, the Central Filipinos, and many other ethnic groups around the world.
Import and export of seahorses has been controlled under
CITESCITES is a multilateral treaty, drafted as a result of a resolution adopted in 1963 at a meeting of members of the International Union for Conservation of Nature...
since May 15, 2004. However,
IndonesiaIndonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
,
JapanJapan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
,
NorwayNorway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, and
South KoreaThe Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...
have chosen to opt out of the trade rules set by CITES.
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
TCMTraditional Chinese Medicine refers to a broad range of medicine practices sharing common theoretical concepts which have been developed in China and are based on a tradition of more than 2,000 years, including various forms of herbal medicine, acupuncture, massage , exercise , and dietary therapy...
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.
Taxonomy
- Genus Hippocampus
- Big-belly seahorse
The big-belly seahorse or pot bellied seahorse, Hippocampus abdominalis, is one of the largest seahorse species in the world with a length of up to 35 cm.-Habitat:The big-belly seahorse is found in large rock pools at low tide, amidst seaweed...
, H. abdominalisThe big-belly seahorse or pot bellied seahorse, Hippocampus abdominalis, is one of the largest seahorse species in the world with a length of up to 35 cm.-Habitat:The big-belly seahorse is found in large rock pools at low tide, amidst seaweed...
Lesson, 1827 (New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
and south and east Australia)
- Winged seahorse, H. alatus Kuiter
Rudie Kuiter is an Australian underwater photographer, taxonomist, and marine biologist. He has described many new species of seahorse.He was born in the Netherlands.-Publications:* Photo Guide to Fishes of the Maldives by Rudie H. Kuiter...
, 2001
- West African seahorse
The West African seahorse is a species of fish in the Syngnathidae family. It is found in Algeria, Angola, Benin, Ivory Coast, Gambia, Ghana, Guinea, Liberia, Nigeria, São Tomé and Príncipe, Senegal, and Sierra Leone....
, H. algiricusThe West African seahorse is a species of fish in the Syngnathidae family. It is found in Algeria, Angola, Benin, Ivory Coast, Gambia, Ghana, Guinea, Liberia, Nigeria, São Tomé and Príncipe, Senegal, and Sierra Leone....
Kaup, 1856
- Narrow-bellied seahorse
The narrow-bellied seahorse, Hippocampus angustus, is a species of fish in the Syngnathidae family. It is endemic to Australia. Its natural habitat is open seas.-Source:* Project Seahorse 2002. . Downloaded on 4 August 2007....
, H. angustus Günther, 1870
- Barbour's seahorse, H. barbouri Jordan & Richardson, 1908
- Pygmy seahorse
The pygmy seahorse, also known as Bargibanti's seahorse, is a seahorse of the family Syngnathidae found in the western central Pacific Ocean. It is tiny, usually less than in size and lives exclusively on fan corals. There are two known color variations: grey with red tubercles, and yellow with...
, H. bargibanti Whitley, 1970 West Pacific area (Indonesia, PhilippinesThe Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...
, Papua New GuineaPapua New Guinea , officially the Independent State of Papua New Guinea, is a country in Oceania, occupying the eastern half of the island of New Guinea and numerous offshore islands...
, Solomon IslandsSolomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...
, etc.)
- False-eyed seahorse, H. biocellatus Kuiter, 2001
- Réunion seahorse
The Réunion seahorse is a species of fish in the Syngnathidae family. It is found in Madagascar, Mauritius, Mozambique, Réunion, South Africa, and Tanzania. Its natural habitat is subtidal aquatic beds. It is threatened by habitat loss.-Source:* Project Seahorse 2003. . Downloaded on 4 August...
, H. borboniensis Duméril, 1870
- Short-head seahorse or knobby seahorse
The knobby seahorse or short-head seahorse , Hippocampus breviceps, is a species of fish in the Syngnathidae family. It is endemic to Australia...
, H. breviceps Peters, 1869 (south and east Australia)
- Giraffe seahorse
The giraffe seahorse is a species of fish in the Syngnathidae family. It is found in Mozambique, South Africa, and Tanzania.-Source:* Project Seahorse 2003. . Downloaded on 4 August 2007....
, H. camelopardalis Bianconi, 1854
- Knysna seahorse
The cape seahorse or Knysna seahorse is a species of fish in the Syngnathidae family. It is endemic to South Africa. It lives in the Keurbooms River in Plettenberg Bay throughout the Knysna Lagoon and up to Swartvlei in Sedgefield. The limited range of this seahorse puts it at great risk of...
, H. capensisThe cape seahorse or Knysna seahorse is a species of fish in the Syngnathidae family. It is endemic to South Africa. It lives in the Keurbooms River in Plettenberg Bay throughout the Knysna Lagoon and up to Swartvlei in Sedgefield. The limited range of this seahorse puts it at great risk of...
Boulenger, 1900
- H. colemani Kuiter, 2003
- Tiger tail seahorse
The tiger tail seahorse is a species of fish in the Syngnathidae family. It is found in India, Indonesia, Malaysia, the Philippines, Singapore, Thailand and Vietnam. Its natural habitats are subtidal aquatic beds and coral reefs...
, H. comes Cantor, 1850
- Crowned seahorse
The crowned seahorse, Hippocampus coronatus, is a species of fish in the Syngnathidae family. It is endemic to Japan. Its natural habitat is subtidal aquatic beds.-Source:* Project Seahorse 2003. . Downloaded on 4 August 2007....
, H. coronatus Temminck & Schlegel, 1850
- Denise's pygmy seahorse
Denise's pygmy seahorse is a species of fish in the Syngnathidae family. Originally described from Indonesia, Hippocampus denise has also been recorded from Vanuatu, Palau, Malaysia, Solomon Islands, as well as off southern Japan, northern Australia and New Caledonia...
, H. denise Lourie & Randall, 2003
- Lined seahorse
Hippocampus erectus is a species of fish that belongs to the Syngnathidae family. Its common names may include: Lined seahorse, Northern seahorse, and Spotted seahorse.-Description:...
, H. erectusHippocampus erectus is a species of fish that belongs to the Syngnathidae family. Its common names may include: Lined seahorse, Northern seahorse, and Spotted seahorse.-Description:...
Perry, 1810 (east coast of the Americas, between Nova Scotia and Uruguay)
- Fisher's seahorse
Fisher's seahorse is a species of fish in the Syngnathidae family. It is found in the Hawaiian islands, possibly Australia and possibly New Caledonia.-Source:* Project Seahorse 2002. . Downloaded on 4 August 2007....
, H. fisheri Jordan & Evermann, 1903
- Sea pony
The sea pony is a species of fish in the Syngnathidae family. It is found in Djibouti, India, Saudi Arabia, Sri Lanka, possibly Madagascar, possibly Mauritius, possibly Réunion, and possibly South Africa. Its natural habitat is subtidal aquatic beds.-Source:* Project Seahorse 2003. . ...
, H. fuscus Rüppell, 1838 (Indian Ocean)
- Big-head seahorse
The Big-head Seahorse, Hippocampus grandiceps, is a seahorse of average size that inhabits the Gulf of Carpentaria in Northern Australia. It reaches a maximum size of about 10 centimeters....
, H. grandiceps Kuiter, 2001
- Long-snouted seahorse
-Classification and names:The long-snouted seahorse is a species of fish in the Syngnathidae family. The long-snouted seahorse is also referred to as the spiny seahorse....
, H. guttulatus Cuvier, 1829
- Eastern spiny seahorse, H. hendriki Kuiter, 2001
- Short-snouted seahorse
The short-snouted seahorse, Hippocampus hippocampus, is a species of seahorse in the family Syngnathidae. It is endemic to the Mediterranean Sea and parts of the North Atlantic, particularly around Italy and the Canary Islands...
, H. hippocampus (Linnaeus, 1758) (Mediterranean Sea and Atlantic Ocean)
- Thorny seahorse, H. histrix
Hippocampus histrix, commonly known as the Thorny or Spiny seahorse or, is a Seahorse from the Indo-Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 17cm in length....
Kaup, 1856 (Indian OceanThe Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
, Persian GulfThe Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...
, Red Sea, and the Far EastThe Far East is an English term mostly describing East Asia and Southeast Asia, with South Asia sometimes also included for economic and cultural reasons.The term came into use in European geopolitical discourse in the 19th century,...
)
- Pacific seahorse
The Pacific seahorse is a species of fish in the Syngnathidae family. It is found in Colombia, Costa Rica, Ecuador, El Salvador, Guatemala, Mexico, Panama, Peru, and the United States. Its natural habitat is coral reefs. It is threatened by habitat loss...
, H. ingens Girard, 1858 (Pacific coast of North, Central and South America)
- Jayakar's seahorse
Jayakar's seahorse is a species of fish in the Syngnathidae family. It is found in the oceans surrounding Israel, Oman, and Pakistan. Its natural habitat is subtidal aquatic beds.-Source:...
, H. jayakari Boulenger, 1900
- Collared seahorse, H. jugumus Kuiter, 2001
- Great seahorse
The great seahorse, Kellogg's seahorse, or offshore seahorse is a species of fish in the Syngnathidae family. It is found in possibly Australia, China, India, Indonesia, Japan, Pakistan, the Philippines, Taiwan, Tanzania, and Vietnam. Its natural habitat is shallow seas.-Source:* Project Seahorse...
, H. kelloggi Jordan & Snyder, 1901
- Common seahorse, H. kuda
Hippocampus kuda, also known as the common seahorse, is a member of the family Syngnathidae of the order Syngnathiformes. The common sea horse is a small, equine-like fish, with extraordinary breeding methods. Greeks and Romans believed the seahorse was an attribute of the sea god Poseidon/Neptune,...
Bleeker, 1852
- Lichtenstein's seahorse
Lichtenstein's Seahorse, Hippocampus lichtensteinii, is a species of fish in the Syngnathidae family.-Description:Lichtenstein's Seahorse is pale brown in colour without markings. It reaches a maximum length of 4.0 cm...
, H. lichtensteinii Kaup, 1856
- Bullneck seahorse
The Bullneck Seahorse is a species of fish in the Syngnathidae family. It is endemic to Australia. Its natural habitats are open seas, shallow seas, subtidal aquatic beds, coral reefs, estuarine waters, and karsts.-Source:...
, H. minotaur Gomon, 1997
- Japanese seahorse
The Japanese seahorse or lemur-tail seahorse is a species of fish in the Syngnathidae family. The Japanese seahorse reaches a maximum length of 8.0 cm, is usually dark brown and has a relatively long tail, a ridgelike coronet and flattened spines...
, H. mohnikei Bleeker, 1854
- Monte Bello seahorse, H. montebelloensis Kuiter, 2001
- Northern spiny seahorse, H. multispinus Kuiter, 2001
- H. pontohi Lourie
Lourie is a Jewish surname, a variant of Lurie. It may refer to:* Arthur Lourié , Russian composer* Don Lourie , American football player* Joel Lourie , Democratic member of the South Carolina Senate...
and Kuiter, 2008
- High-crown seahorse, H. procerus Kuiter, 2001
- Queensland seahorse, H. queenslandicus Horne, 2001
- Longsnout seahorse
The longsnout seahorse or slender seahorse is a species of fish in the Syngnathidae family. -Description:...
, H. reidi Ginsburg, 1933 (CaribbeanThe Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
coral reefs)
- Satomi's pygmy seahorse
Satomi's pygmy seahorse is the smallest known seahorse in the world with an average length of and an approximate height of ....
, H. satomiae Lourie and Kuiter, 2008
- Half-spined seahorse, H. semispinosus Kuiter, 2001
- H. severnsi Lourie and Kuiter, 2008
- Shiho's seahorse
Shiho's seahorse, Hippocampus sindonis, is a species of fish in the Syngnathidae family. It is endemic to Japan.-References:* Project Seahorse 2003. . Downloaded on 4 August 2007....
, H. sindonis Jordan & Snyder, 1901
- Hedgehog seahorse
The hedgehog seahorse is a species of fish in the Syngnathidae family. It is found in Australia, Indonesia, Malaysia, the Philippines, Singapore, Sri Lanka, Taiwan, Thailand, and Vietnam. Its natural habitat is coral reefs. It is threatened by habitat loss.-Source:* Project Seahorse 2003. . ...
, H. spinosissimus Weber, 1913
- West Australian seahorse, H. subelongatus Castelnau, 1873
- Longnose seahorse, H. trimaculatus Leach, 1814
- White's seahorse, H. whitei Bleeker, 1855 (east Australia)
- Zebra seahorse
The Zebra Seahorse is a species of fish in the Syngnathidae family. It is endemic to Australia.-Habitat:This species of fish has been found in and around coral reefs. The maximum reported depth is 69 m.-References:...
, H. zebra Whitley, 1964
- Dwarf seahorse
The dwarf seahorse is a species of seahorse. It is found in the Bahamas and the United States. Its natural habitat is subtidal aquatic beds. It is threatened by habitat loss...
, H. zosterae Jordan & Gilbert, 1882 (Gulf of MexicoThe Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
and the Caribbean)
Pygmy seahorses
Pygmy Seahorses are less than 15 millimetre (0.590551181102362 in) tall and 17 millimetre (0.669291338582677 in) wide members of the genus. Previously the term was applied exclusively to the species
H. bargibanti but since 1997, discoveries have made this term obsolete. The species
H. minotaur,
H. denise,
H. colemani,
H. pontohi,
H. severnsi and
H. satomiae have been described. Other species that are believed to be
unclassifiedBiological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
have also been reported in books, dive magazines and on the Internet. They can be distinguished from other species of seahorse by their 12 trunk rings, low number of tail rings (26–29), the location in which young are brooded in the trunk region of males and their extremely small size. Molecular analysis (of
ribosomal RNARibosomal ribonucleic acid is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity...
) of 32
Hippocampus species found that
H. bargibanti belongs in a separate
cladeA clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
from other members of the genus and therefore that the species diverged from the other species in the "ancient" past.
Most pygmy seahorses are well camouflaged and live in close association with other organisms including colonial hydrozoans (
Lytocarpus and
Antennellopsis),
coralline algaeCoralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls...
(
HalimedaHalimeda is a genus of green macroalgae. The algal body is composed of calcified green segments. Calcium carbonate is deposited in its tissues, making it inedible to most herbivores....
)
sea fanA gorgonian, also known as sea whip or sea fan, is an order of sessile colonial cnidarian found throughout the oceans of the world, especially in the tropics and subtropics. Gorgonians are similar to the sea pen, another soft coral. Individual tiny polyps form colonies that are normally erect,...
s (
Muricella,
Annella,
Acanthogorgia). This combined with their small size accounts for why most species have only been noticed in recent years.
Heraldry
In
heraldryHeraldry is the profession, study, or art of creating, granting, and blazoning arms and ruling on questions of rank or protocol, as exercised by an officer of arms. Heraldry comes from Anglo-Norman herald, from the Germanic compound harja-waldaz, "army commander"...
, a seahorse is depicted as a creature with the foreparts of a horse and the hindparts of a fish.
Threats & future
Most seahorse species are data deficient. This means there is not enough information to make a proper assessment about their risk of extinction. Because seahorse population is unknown, there is a greater risk of losing more seahorses because of the lack of information about how many are dying each year, how many are being born, how many are used for souvenirs, etc. Seahorse habitats are in great danger though. Coral reefs and seagrass beds are deteriorating, meaning seahorses have fewer places to live. Also as stated above, seahorses are used in Chinese Medicine and as souvenirs, which definitely cuts their population down significantly each year.
External links
- Vimeo.com, Video of various seahorse species at the Monterey Bay Aquarium
- ARKive
ARKive is a global initiative with the mission of "promoting the conservation of the world's threatened species, through the power of wildlife imagery", which it does by locating and gathering films, photographs and audio recordings of the world's species into a centralised digital archive. Its...
—images and movies of the pygmy seahorse (Hippocampus bargibanti)
- FusedJaw.com, Information about seahorses
- Project Seahorse, Research and Conservation Group, information about seahorses and seahorse conservation status
- Seahorse.com, Hawaii aquafarm and seahorse conservation
- Seahorse.org, Aquarium Hobby
- DiveGallery.com, Seahorse Photos
- RobertoSozzani.it, Hippocampus denise Pygmy seahorse photo galleries
- RobertoSozzani.it, Pontohi Pygmy Seahorse
- RobertoSozzani.it, Walea Pygmy Seahorse
- Arnes.si, Fossil Seahorses from Tunjice hills (Slovenia)
- QataVisitor.com n Sea horses in Qatar