Seahorse

Seahorse (also written sea-horse and sea horse) is the name given to 45 species of small marine fish in the genus Hippocampus. "Hippocampus" comes from the Ancient Greek hippokampos (ἱππόκαμπος hippókampos), itself from hippos (ἵππος híppos) meaning "horse" and kampos (κάμπος kámpos) meaning "sea monster".[3][4] Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail.[5]

Seahorses
Temporal range: Lower Miocene to present – 23–0 Ma
Hippocampus
Hippocampus sp.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Syngnathiformes
Family: Syngnathidae
Subfamily: Hippocampinae
Genus: Hippocampus
Rafinesque, 1810[1][2]
Type species
Hippocampus heptagonus
Rafinesque, 1810
Species

see Species.

Synonyms

Habitat

Seahorses are mainly found in shallow tropical and temperate saltwater throughout the world, from about 45°S to 45°N.[6] They live in sheltered areas such as seagrass beds, estuaries, coral reefs, and mangroves. Four species are found in Pacific waters from North America to South America. In the Atlantic, H. erectus ranges from Nova Scotia to Uruguay. H. zosterae, known as the dwarf seahorse, is found in the Bahamas.

Colonies have been found in European waters such as the Thames Estuary.[7]

Three species live in the Mediterranean Sea: H. guttulatus (the long-snouted seahorse), H. hippocampus (the short-snouted seahorse), and H. fuscus (the sea pony). These species form territories; males stay within 1 m2 (11 sq ft) of habitat, while females range about one hundred times that.

Description

Hippocampus hystrix (Spiny seahorse)
Spiny seahorse H. histrix from East Timor holding on to soft coral with its prehensile tail

Seahorses range in size from 1.5 to 35.5 cm (0.6 to 14.0 in).[8] They are named for their equine appearance with bent necks and long snouted heads followed by their distinctive trunk and tail. Although they are bony fish, they do not have scales, but rather thin skin stretched over a series of bony plates, which are arranged in rings throughout their bodies. Each species has a distinct number of rings.[9] The armor of bony plates also protects them against predators, and because of this outer skeleton, they no longer have ribs.[10] Seahorses swim upright, another characteristic not shared by their close pipefish relatives, which swim horizontally. Razorfish are the only other fish that swim vertically. They swim upright propelling themselves by using the dorsal fin. The pectoral fins located on either side of the head are used for maneuvering. They lack the caudal fin typical of fishes. Their prehensile tail can only be unlocked in the most extreme conditions. They are adept at camouflage with the ability to grow and reabsorb spiny appendages depending on their habitat.[11]

Unusual among fish, a seahorse has a flexible, well-defined neck. It also sports a crown-like spine or horn on its head, termed a "coronet," which is distinct for each species.[12]

Seahorses swim very poorly, rapidly fluttering a dorsal fin and using pectoral fins (located behind their eyes) to steer. The slowest-moving fish in the world is H. zosterae (the dwarf seahorse), with a top speed of about 5 ft (1.5 m) per hour.[13] 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 their eyes can move independently of each other like those of a chameleon.[14]

Evolution and fossil record

Anatomical evidence, supported by molecular, physical, and genetic evidence, demonstrates seahorses are highly modified pipefish. 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 River Formation of Rimini Province, Italy, dating back to the Lower Pliocene, about 3 million years ago. The earliest known seahorse fossils are of two pipefish-like species, H. sarmaticus and H. slovenicus, from the coprolitic horizon of Tunjice Hills, a middle Miocene lagerstätte in Slovenia dating back about 13 million years.[15] Molecular dating finds that pipefish and seahorses diverged during the Late Oligocene. 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 would have allowed the expansion of seagrass habitats that selected for the camouflage offered by the seahorses’ upright posture.[16] These tectonic changes occurred in the western Pacific Ocean, pointing to an origin there, with molecular data suggesting two later, separate invasions of the Atlantic Ocean.[17] In 2016, a study published in Nature found the seahorse genome to be the most rapidly evolving fish genome studied so far.[18]

Reproduction

Seahorse lifecycle
Seahorse life-cycle

The male seahorse is equipped with a pouch on the ventral, or front-facing, side of the tail. When mating, the female seahorse deposits up to 1,500 eggs in the male's pouch. The male carries the eggs for 9 to 45 days until the seahorses emerge fully developed, but very small. The young are then released into the water, and the male often mates again within hours or days during the breeding season.[19]

Courtship

Before breeding, seahorses may court for several days. Scientists believe the courtship behavior synchronizes the animals' movements and reproductive states so 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 "predawn 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 drift upward snout-to-snout, out of the sea grass, often spiraling as they rise. They interact for about 6 minutes, reminiscent of courtship. The female then swims away until the next morning, and the male returns to sucking up food through his snout.[20] The female inserts her ovipositor 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 sea grass and she swims away.[21]

Phases of courtship

Seahorses exhibit four phases of courtship that are indicated by clear behavioral changes and changes in the intensity of the courtship act. In phase one, the initial courtship phase typically takes place in the early morning one or two days before physical copulation. During this phase the potential mates brighten in colour, quiver, and display rapid side to side body vibrations. These displays are performed alternately by both the male and the female seahorse. The following phases, 2 through 4, happen sequentially on the day of copulation. Phase 2 is marked by the female pointing, a behaviour in which the female will raise her head to form an oblique angle with her body. In phase 3 males will also begin the same pointing behaviour in response to the female. Finally, the male and female will repeatedly rise upward together in a water column and end in mid water copulation, in which the female will transfer her eggs directly into the male’s brood pouch.[22]

This initial courtship behaviour takes place about 30 minutes after dawn on each courtship day, taking place until the day of copulation. During phase one the males and females will remain apart during the night, but after dawn they will come together in a side by side position, brighten, and engage in courtship behaviour for about 2 to 38 minutes. In this phase, courtship is characterized by repeated instances of reciprocal quivering. Reciprocal quivering beings when the male approaches the female, brightens and begins to quiver. The female will follow the male with her own display in which she will also brighten and quiver about 5 seconds later. As the male quivers, he will rotate his body towards the female who will then rotate her body away. During phase one the tails of both seahorses are positioned within 1 cm of each other on the same hold-fast and both of their bodies are angled slightly outward from the point of attachment. However, the female will shift her tail attachment site causing the pair to circle their common hold-fast.[22]

The second phase of the seahorse mating ritual begins with the female beginning her pointing posture. She begins this behaviour by leaning her body towards the male who will simultaneously lean away and quiver. This phase can last up to 54 minutes. Following phase two is a latency period that typically lasts between 30 minutes and four hours. During the latency period seahorses display no courtship behaviour and females are not bright during this period; males will usually display a pumping motion with their body.[22]

Seahorse mating dance
Seahorses in Phase 2 of courtship

The third phase begins with the females brightening and assuming the pointing position. The males then reciprocate by responding with their own brightening and pointing display. This phase ends with the male departing. It usually lasts nine minutes and can occur one to six times during courtship.[22]

The final courtship phase includes 5-8 bouts of courtship. Each bout of courtship begins with both the male and female anchored to the same plant about 3 cm apart; usually they are facing each other and are still bright in colour from the previous phase. During the first bout, following the facing behaviour, the seahorses will rise upward together anywhere from 2 to 13 cm in a water column. During the final rise the female will insert her ovipositor and transfer her eggs though an opening into the male's brood pouch[22]

Fertilization

During fertilization in Hippocampus kuda the brood pouch was found to be open for only six seconds while egg deposition occurred. During this time seawater entered the pouch where the spermatozoa and eggs meet in a seawater milieu. This hyperosmotic environment facilitates sperm activation and motility. The fertilization is therefore regarded as being physiologically ‘external’ within a physically ‘internal’ environment after the closure of the pouch.[23] It is believed that this protected form of fertilization reduces sperm competition among males. Within the Syngnathidae (pipefishes and seahorses) protected fertilization has not been documented in the pipefishes but the lack of any distinct differences in the relation of testes size to body size suggests that pipefishes may also have evolved mechanisms for more efficient fertilization with reduced sperm competition.[24]

Gestation

Tehotny morsky konik
Pregnant male seahorse at the New York Aquarium

The fertilized eggs are then embedded in the pouch wall and become surrounded by a spongy tissue.[25] The male supplies the eggs with prolactin, the same hormone responsible for milk production in pregnant mammals. The pouch provides oxygen, as well as a controlled environment incubator. Though the egg yolk contribute nourishment to the developing embryo, the male sea horses contribute additional nutrients such as energy-rich lipids and also calcium to allow them to build their skeletal system, by secreting them into the brood pouch that are absorbed by the embryos. Further they also offer immunological protection, osmoregulation, gas exchange and waste transport [26]

The eggs then hatch in the pouch, where the salinity of the water is regulated; this prepares the newborns for life in the sea.[20][27][28] Throughout gestation, which in most species requires two to four weeks, his mate visits him daily for “morning greetings”.

Birth

The number of young released by the male seahorse averages 100–1000 for most species, but may be as low as 5 for the smaller species, or as high as 2,500. 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.[28]

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 principle 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 Vincent of Project Seahorse, 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, researchers chemically analyzed the energy stored in each egg. To measure the burden on the males, oxygen consumption was used. 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.[20]

Why the male seahorse (and other members of the Syngnathidae) carries the offspring through gestation is unknown, though some researchers believe it allows for shorter birthing intervals, in turn resulting in more offspring.[29] Given an unlimited number of ready and willing partners, males have the potential to produce 17% more offspring than females in a breeding season. Also, females have “time-outs” from the reproductive cycle 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.[30]

Monogamy

Though seahorses are not known to mate for life, many species form pair bonds that last through at least the breeding season. Some species show a higher level of mate fidelity than others.[31][32] 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.[33]

Although monogamy 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.”[34] 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 a third of body weight), they can reduce the interval between clutches.

Feeding habits

Black Sea fauna Seahorse
Seahorses rely on stealth to ambush small prey such as copepods. They use pivot feeding to catch the copepod, which involves rotating their snout at high speed and then sucking in the copepod.[35]
Hippocampus kuda (Estuary seahorse)
Seahorse hiding using camouflage

Seahorses use their long snout in order to eat their food with ease. However, they are slow to consume their food and have extremely simple digestive systems that lack a stomach, therefore, must eat constantly to stay alive.[36] Seahorses are not very good swimmers, and for this reason they need to anchor themselves to seaweed, coral or anything else that will anchor the seahorse in place. They do this by using their prehensile tails to grasp their object of choice.[37] Seahorses feed on small crustaceans floating in the water or crawling on the bottom. With excellent camouflage and patience, seahorses ambush prey that floats within striking range, merely sitting and waiting until the appearance of an optimal moment.[36] Mysid shrimp and other small crustaceans are favorites, but some seahorses have been observed eating other kinds of invertebrates and even larval fish. In a study of seahorses, the distinctive head morphology was found to give it a hydrodynamic advantage that creates minimal interference while approaching an evasive prey. Therefore, the seahorse has the ability to come within a very close range of the copepods on which it preys.[35][38] After successfully closing in on the prey without alerting it, the seahorse gives an upward thrust rapidly rotates the head aided by large tendons that store and release elastic energy, to bring its long snout close to the prey. This step is crucial for prey capture, as oral suction only works at a close range. This two-phase prey capture mechanism is termed pivot-feeding.[38][39] Seahorses have three distinctive feeding phases: preparatory, expansive, and recovery. During the preparatory phase, the seahorse slowly approaches the prey while in an upright position, after which it slowly flexes its head ventrally. In the expansive phase, the seahorse captures its prey by simultaneously elevating its head, expanding the buccal cavity, and sucking in the prey item. During the recovery phase, the jaws, head, and hyoid apparatus of the seahorse return to their original positions.[40]

The amount of available cover influences the seahorses feeding behaviour. For example, in wild areas with small amounts of vegetation, seahorses will sit and wait, but an environment with extensive vegetation will prompt the seahorse to inspect its environment, feeding while swimming rather than sitting and waiting. Conversely, in an aquarium setting with little vegetation, the seahorse will fully inspect its environment and makes no attempt to sit and wait.[41]

Threats of extinction

Because data is lacking on the sizes of the various seahorse populations, as well as other issues including how many seahorses are dying each year, how many are being born, and the number used for souvenirs, there is insufficient information to assess their risk of extinction, and the risk of losing more seahorses remains a concern. Some species, such as the Paradoxical Seahorse, H. paradoxus,[42] may already be extinct. Coral reefs and seagrass beds are deteriorating, reducing viable habitats for seahorses.[43] Additionally, bycatch in many areas causes high cumulative effects on seahorses, with an estimated 37 million individuals being removed annually over 21 countries.[44]

Aquaria

Seahorses scorpions skewer
Seahorse and scorpion skewers as street food

While many aquarium hobbyists keep them 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,[45] 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 with low flow and placid tank mates. They are slow feeders, so fast, aggressive feeders will leave them without food.[45] Seahorses can coexist with many species of shrimp and other bottom-feeding creatures. Gobies also make good tank-mates. Keepers are generally advised to avoid eels, tangs, triggerfish, squid, octopus, and sea anemones.[46]

Water quality is very important for the survival of seahorses in an aquarium. They are delicate species which should not be added to a new tank. The water parameters are recommended to be as follows although these fish may acclimatise to different water over time:

  • Temperature: 23–28 °C (73–82 °F)
  • pH: 8.1–8.4
  • Ammonia: 0 mg/l (0 ppm) (0.01 mg/l (0.01 ppm) may be tolerated for short periods)
  • Nitrite: 0 mg/l (0 ppm) (0.125 mg/l (0.125 ppm) may be tolerated for short periods)
  • S.G.: 1.021–1.024 at 23–24 °C (73–75 °F)

A water-quality problem will affect fish behaviour and can be shown by clamped fins, reduced feeding, erratic swimming, and gasping at the surface.[47] Seahorses swim up and down, as well as using the length of the aquarium. Therefore, the tanks should ideally be twice as deep as the length of the adult seahorse.

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 is not a valid species, but a synonym sometimes used for Barbour's and hedgehog seahorses. The latter, which is often confused with the former, can be found in estuarine environments, but is not actually a freshwater fish.[48]

Use in Chinese medicine

Seahorse Skeleton Macro 8 - edit
Dried seahorse

Seahorse populations are thought to be endangered as a result of overfishing and habitat destruction. Despite a lack of scientific studies or clinical trials,[49][50] the consumption of seahorses is widespread in traditional Chinese medicine, primarily in connection with impotence, wheezing, nocturnal enuresis, and pain, as well as labor induction.[51] Up to 20 million seahorses may be caught each year to be sold for such uses.[52] Preferred species of seahorses include H. kellogii, H. histrix, H. kuda, H. trimaculatus, and H. mohnikei.[51] Seahorses are also consumed by the Indonesians, the central Filipinos, and many other ethnic groups.

Import and export of seahorses has been controlled under CITES since 15 May 2004. However, Indonesia, Japan, Norway, and South Korea 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 seahorses. Pills are cheaper and more available than traditional, individually tailored prescriptions of whole seahorses, 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. Declining availability of the preferred large, pale, and smooth seahorses has been offset by the shift towards prepackaged preparations, which makes it possible for TCM merchants to sell previously unused, or otherwise undesirable juvenile, spiny, and dark-coloured animals. Today, almost a third of the seahorses sold in China are packaged, adding to the pressure on the species.[53]

Dried seahorse retails from US$600 to $3000 per kilogram, with larger, paler, and smoother animals commanding the highest prices. In terms of value based on weight, seahorses retail for more than the price of silver and almost that of gold in Asia.[54]

Species

Based on the newest overall taxonomic review[55] of the genus Hippocampus with further new species and partial taxonomic review,[56][57][58] the number of recognized species in this genus is considered to be 45 (retrieved August 2018):

Hippocampus kuda (Estuary seahorse)
H. kuda, known as the "common seahorse"
Hippocampus elongatus
H. subelongatus, known as the "West Australian seahorse"
Hippocampus whitei 1
H. whitei, known as "White's seahorse"

Pygmy seahorses

HSatomiaeJohnSear
Hippocampus satomiae (Satomi's pygmy seahorse) attached to coral

Pygmy seahorses are those members of the genus that are less than 15 mm (0.6 in) tall and 17 mm (0.7 in) wide. 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, H. satomiae, H. waleananus, and H. japapigu have been described. Other species that are believed to be unclassified 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.[59] Molecular analysis (of ribosomal RNA) of 32 Hippocampus species found that H. bargibanti belongs in a separate clade from other members of the genus and therefore that the species diverged from the other species in the ancient past.[60]

Most pygmy seahorses are well camouflaged and live in close association with other organisms including colonial hydrozoans (Lytocarpus and Antennellopsis), coralline algae (Halimeda) sea fans (Muricella, Annella, Acanthogorgia). This combined with their small size accounts for why most species have only been noticed and classified since 2001.[59][61]

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Further reading

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 (14 in), and is the largest in Australia. Seahorses are members of the family Syngnathidae, and are teleost fishes. They are found in southeast Australia and New Zealand, and are listed on Appendix II of CITES.

Boydtown, New South Wales

Boydtown is a village on Twofold Bay near Eden, on the far south coast of New South Wales, Australia. It was the original settlement in the bay, founded by Benjamin Boyd in 1843 to service his properties on the Monaro plains. The remains of whaling stations and the local landmark Boyd's Tower, a stone spotting tower used to look for whales, are all nearby.

Boyd imported sandstone from Sydney to construct a lighthouse on south head. He also commissioned inns and churches, housing and store rooms, wharves and stock-yards.When Boyd's finances collapsed, the town was abandoned from the 1840s until the first renovation of the Seahorse Inn in the 1930s.In modern times, Boydtown is the smaller of the two towns in the bay, consisting mainly of housing, tourist caravan parks and the more recently (2006) refurbished Seahorse Inn.

HMS Seahorse (1794)

HMS Seahorse was a 38-gun Artois-class fifth-rate frigate of the Royal Navy. She was launched in 1794 and broken up in 1819.

HMS Seahorse (98S)

HMS Seahorse was a first-batch S-class submarine (often called the Swordfish class) built for the Royal Navy during the 1930s. Ordered in March 1931, she was laid down at Chatham Dockyard in September 1931 and launched on 15 November 1932.

At the start of World War II, Seahorse was conducting a patrol southwest of Stavanger, Norway. While returning to port after her first and uneventful patrol, Seahorse was erroneously attacked with depth charges by a British aircraft. After repairs, she conducted a second war patrol, sighting the surfaced submarine U-36 on 13 November 1939. Her torpedoes missed their target, however. During her next patrol on 30 October, Seahorse sighted another German submarine, U-21, but it submerged before torpedoes could be launched. On 18 November, Seahorse spotted two German ships, very probably the destroyers Z21 Wilhelm Heidkamp and Z19 Hermann Künne, but failed to maneuver into an attack position. On 26 December, Seahorse departed for her sixth and last war patrol, off Heligoland Bight, with orders to patrol off Heligoland then shift to the mouth of the Elbe on 30 December, then return to port on 9 January 1940, but she did not return on her due date. It was originally thought that she had struck a mine, but German records, examined after the war, suggest she was sunk by the German First Minesweeper Flotilla, which reported an attack on an unidentified submarine on 7 January 1940. It is, however, also possible that she was rammed and sunk by the German Sperrbrecher IV/Oakland southeast of Heligoland on 29 December 1939.

Hippocampus kuda

Hippocampus kuda, also known as the estuary seahorse, yellow seahorse or spotted seahorse is a seahorse of the family Syngnathidae native to the Indo-Pacific. The common name sea pony has been used for this species under its synonym Hippocampus fuscus.

Hydrocycle

A hydrocycle is a bicycle-like watercraft. The concept was known in the 1870s under the title 'water velocipede' and the name was in use by the late 1890s.Power is collected from the rider via a crank with pedals, as on a bicycle, and delivered to the water or the air via a propeller. Seating may be upright or recumbent, and multiple riders may be accommodated in tandem or side-by-side.Buoyancy is provided by two or more pontoons or a single surfboard, and some have hydrofoils that can lift the flotation devices out of the water.Brands include Seacycle, Hydrobike, Water Bike, Seahorse (Cross Trek) and itBike. Kits exist to temporarily convert an existing bicycle into a hydrocycle.

Lined seahorse

The lined seahorse (Hippocampus erectus), northern seahorse or spotted seahorse, is a species of fish that belongs to the family Syngnathidae. H. erectus is a diurnal species with an approximate length of 15 cm (5.9 inches) and lifespan of one to four years. The H. erectus species can be found with a myriad of colors, from greys and blacks to reds, greens, and oranges. The lined seahorse lives in the western Atlantic Ocean as far north as Canada and as far south as the Caribbean, Mexico, and Venezuela. It swims in an erect position and uses its dorsal and pectoral fins for guidance while swimming.

Lined seahorses feed mainly on minute crustaceans and brine shrimp, which they suck in through their snout. They are able to suck their prey by creating a current of water leading directly into its snout. Since seahorses are weak swimmers, they must ambush their prey by blending into their surroundings, which they do rather easily. The lined seahorse's eyes can move independently of one another, allowing it to effectively scan its surroundings. The species is sexually dimorphic and it is easy to distinguish between a male and female lined seahorse. The males are larger and also have longer tails. The lined seahorse is monogamous and performs ritual dances every morning to reestablish the bond with its mate. In addition, they create clicking sounds while embracing their partner. This action occurs when they initially find their mate. The intensity of their bond is also conveyed in how they handle the death of their partner: If either the male or female should die, the mate does not automatically replace the deceased mate with a new one. Often, it fails to find a new mate in its short lifespan.

Like with other seahorses, the male lined seahorse is the caregiver. During intercourse, the female sprays her eggs into the male's brood pouch where the eggs will incubate for 20–21 days. When the juveniles are ready to hatch, the male attaches its tail to a stationary structure and begins to arch its back, back and forth, releasing the juveniles into the water column. The juveniles are approximately 11 mm at birth. They quickly begin to learn and mimic the behavior of its parent. Courtship between the male and female parents begin immediately after birth.

The habitat of the lined seahorse is diminishing due to coastal growth and pollution, which ultimately is the cause of the decreasing population. The lined seahorse is also used as Chinese medicine and is common in the aquarium trade, contributing to its "vulnerable" status.

List of ships named Seahorse

A number of ships have been named Seahorse or Sea Horse after the marine creature, including:-

Pygmy seahorse

The pygmy seahorses comprise several species of tiny seahorse in the syngnathid family or Syngnathidae (seahorses and pipefish). Family Syngnathidae is part of order Syngnathiformes, which contains fishes with fused jaws that suck food into tubular mouths. They are found in Southeast Asia in the Coral Triangle area. They are some of the smallest seahorse species in the world, typically measuring less than 2 centimetres (0.79 in) in height.The first pygmy seahorse known to science was Hippocampus bargibanti. At least six more species were named after 2000. The first species discovered lives exclusively on fan corals and matches their colour and appearance. So effective is pygmy seahorse camouflage that it was discovered only when a host gorgonian was being examined in a laboratory. In 1969 a New Caledonian scientist, Georges Bargibant, was collecting specimens of Muricella spp gorgonians for the Nouméa museum and whilst one of these was on his dissection table he happened to notice a pair of tiny seahorses. The next year they were officially named by Whitley as Bargibant's pygmy seahorse. Other species live on soft corals or are free-ranging among seagrasses and algae.

Ryukoku Seahorse football

The Ryukoku Seahorse football program represents Ryukoku University in college football. Ryukoku is a member of the Kansai Collegiate American Football League.

Sanchi (tanker)

Sanchi was the final name of a 2008-built Panamanian-flagged Suezmax crude oil tanker that was operated by the National Iranian Tanker Company (NITC) under a variety of ship registries and names. On January 6, 2018, it collided with a cargo ship, CF Crystal in the East China Sea and caught fire. After drifting for eight days and several explosions Sanchi sank, causing extensive pollution.

Seahorse (software)

Seahorse is a GNOME front-end application for managing PGP and SSH keys. Seahorse integrates with Nautilus, gedit and Evolution for encryption, decryption and other operations. It has HKP and LDAP key server support. The program is based on GNU Privacy Guard (GPG) and is released as free software under the GNU General Public License (GPL).

Seahorse ROUV

Seahorse (Hai-Ma or Haima, 海马) remotely operated underwater vehicle (ROUV) is a Chinese ROUV developed by Shanghai Jiao Tong University (SJTU), and it received state certification in mid 2014.Seahorse ROUV program begun in 2008 and Professor Ma Xia-Fei (马厦飞) is the program manager, and the general designers of Seahorse ROUV are Professor Lian Lian (连琏) and Professor Ren Ping (任平). Seahorse ROUV is designed to dive to a maximum depth of forty-five hundred meters, and from April 20, 2014 thru April 22, 2014, Seahorse UAV conducted more than seventeen dives in three different phases of sea trial, reaching the maximum designed depth to 4502 meter. After the successful sea trials, state certification is received soon after, and there are plans to develop different models based on the original Seahorse. Seahorse ROUV is designed to perform a variety of research missions and it is equipped with sonar, cameras, mechanical arms, and in addition to research missions, Seahorse ROUV is also capable of performing maintenance work on scientific equipment on seabed. Seahorse utilizes modular design concept to enable different tools to be replaced rapidly based on mission needs while sharing a common chassis. During deployment, Seahorse ROUV is usually carried by Chinese scientific research vessel Ocean 6 (Hai-Yang or Haiyang 6, 海洋6号), though it can also be carried by other Chinese ships equipped to handle ROUVs.

Seahorse Seashell Party

"Seahorse Seashell Party" is the second episode of the tenth season of the American animated television series Family Guy, an episode produced for season 9. It originally aired on Fox in the United States on October 2, 2011. The episode mainly centers around the Griffin family, who are riding out an oncoming hurricane. In their attempt to pass the time, they participate in numerous activities and games. After being condemned by her family, Meg lashes out and confronts them. Meanwhile, Brian consumes magic mushrooms which cause him to hallucinate.

"Seahorse Seashell Party" is the second part of the Night of the Hurricane block with The Cleveland Show and American Dad!. The episode was first announced by Seth MacFarlane at the 2010 San Diego Comic-Con International. It was written by Wellesley Wild and directed by Brian Iles. Originally scheduled to air on May 1, 2011 as the sixteenth episode of the ninth season of Family Guy, the episode was postponed due to the 2011 Super Outbreak subsequently coinciding with the timing of the scheduled episodes.

Reception of "Seahorse Seashell Party" by television critics has been negative, with its humor and main plot receiving the most criticism. An estimated 6.91 million viewers tuned into the episode upon its initial airing, while also garnering a 3.5/8 rating in the 18–49 demographic according to the Nielsen ratings. The episode featured guest performances by Ioan Gruffudd, Dee Bradley Baker, Debra Wilson, Kat Purgal, and Colin Ford along with several other recurring guest voice actors for the series.

Sikorsky H-34

The Sikorsky H-34 (company designation S-58) is a piston-engined military helicopter originally designed by American aircraft manufacturer Sikorsky as an anti-submarine warfare (ASW) aircraft for the United States Navy. It has seen extended use when adapted to turbine power by the British licensee as the Westland Wessex and Sikorsky as the later S-58T.

H-34s served, mostly as medium transports, on every continent with the armed forces of 25 countries. It saw combat in Algeria, the Dominican Republic, Nicaragua, and throughout Southeast Asia. Other uses included saving flood victims, recovering astronauts, fighting fires, and carrying presidents. It was the last piston-engined helicopter to be operated by the United States Marine Corps, having been replaced by turbine-powered types such as the UH-1 Huey and CH-46 Sea Knight. A total of 2,108 H-34s were manufactured between 1953 and 1970.

SpongeBob SquarePants (season 3)

The third season of the American animated television series SpongeBob SquarePants, created by Stephen Hillenburg, aired on Nickelodeon from October 5, 2001 to October 11, 2004, and consists of 20 episodes. The series chronicles the exploits and adventures of the title character and his various friends in the fictional underwater city of Bikini Bottom. The season was executive produced by series creator Hillenburg, who also acted as the showrunner. Hillenburg halted production on the show to work on the 2004 film adaptation of the series, The SpongeBob SquarePants Movie. After production on the film, Hillenburg resigned from the show as its showrunner, and appointed staff writer Paul Tibbitt to overtake the position. Season 3 was originally set to end the series after the release of the film, but the success prevented the series from ending, leading to a fourth season.

The season received critical acclaim from media critics and fans. During its run, SpongeBob SquarePants became (and remains) the highest rated children's show on cable, with over 50 million viewers a month. The show received several recognitions, including its nomination at the Primetime Emmy Awards for Outstanding Children's Program. The episodes "New Student Starfish" and "Clams" were nominated for Outstanding Animated Program (for Programming Less Than One Hour) category, while the entry "SpongeBob B.C. (Ugh)" won the same category. The season was also the first time the show received a nomination at the Kids' Choice Awards and won. It won the 2003 Kids' Choice Awards for Favorite Cartoon, and also won the following year's Kids' Choice Award for the same category. Celebrities—including Justin Timberlake, Kelly Osbourne, Britney Spears, Bruce Willis, Noel Gallagher, rapper Dr. Dre, and Mike Myers—have been reported to be fans of the show.Several compilation DVDs that contained episodes from the season were released. The SpongeBob SquarePants: The Complete 3rd Season DVD was released in Region 1 on September 27, 2005, Region 2 on December 3, 2007, and Region 4 on November 8, 2007.

USS Seahorse (SS-304)

USS Seahorse (SS-304), a Balao-class submarine, was the first submarine and second ship of the United States Navy to be named for the seahorse, a small fish whose head and the fore part of its body suggest the head and neck of a horse.

The first submarine Seahorse (SS-304) was laid down on 1 August 1942 by the Mare Island Navy Yard, Vallejo, Calif.; launched on 9 January 1943; sponsored by Mrs. Chester C. Smith; and commissioned on 31 March 1943, Comdr. Donald McGregor in command.

USS Seahorse (SSN-669)

USS Seahorse (SSN-669), a Sturgeon-class attack submarine, was the second submarine and third ship of the United States Navy to be named for the seahorse.

Waterford Crystal

Waterford Crystal is a manufacturer of crystal, named after the city of Waterford, Ireland. The brand is owned by WWRD Group Holdings Ltd., a luxury goods group which also owns and operates the Wedgwood and Royal Doulton brands, and which was acquired on 2 July 2015 by the Fiskars Corporation.In January 2009, the main Waterford Crystal base was closed due to the insolvency of Waterford Wedgwood PLC. In June 2010, Waterford Crystal relocated almost back to its original roots, on The Mall in Waterford city centre. This new location is now home to a manufacturing facility that melts over 750 tons of crystal a year, although most Waterford Crystal is now produced outside Ireland. This new facility offers visitors the opportunity to take guided tours of the factory and also offers a retail store, showcasing the world's largest collection of Waterford Crystal.

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