Seahorse

Related Topics:
Seahorses,_The :: Seahorses

Seahorses are marine fish belonging to the genus Hippocampus of the family Syngnathidae. They are found in temperate and tropical waters all over the world.

Seahorses range in size from 16 mm (the recently discovered Hippocampus denise ^*) to 35 cm. They are notable for being the only species where the males become pregnant.

The seahorse is a true fish, with a dorsal fin located on the lower body and pectoral fins located on the head near their gills. Some species of seahorse are partly transparent, hence are often not spotted in aquariums despite being there and are also not often seen in pictures.

Seahorse populations have been endangered in recent years by overfishing. The seahorse is used in traditional Chinese herbology, and as many as 20 million seahorses may be caught each year and sold for this purpose. ^*

Import and export of seahorses is controlled under CITES since May 15, 2004.

Sea dragons are close relatives of seahorses but have bigger bodies and leaf-like appendages which enable them to hide among floating seaweed or kelp beds. Sea dragons feed on larval fishes and amphipods, such as small shrimp-like crustaceans called mysids ("sea lice"), sucking up their prey with their small mouths. Many of these amphipods feed on red algae that thrives in the shade of the kelp forests where the sea dragons live.

Reproduction

Seahorses reproduce in an unusual way: the male becomes pregnant. Most seahorse species pregnancies lasts approximately two to three weeks.

The male seahorse has a brood pouch where he carries eggs deposited by the female. The mating pair entwine their tails and the female aligns a long tube called ovipositor with the male's pouch. The eggs move through the tube into the male's pouch where he then fertilizes them. The embryos will develop between ten days and six weeks, depending on species and water conditions. When the male gives birth he pumps his tail until the baby seahorses emerge.

The males pouch regulates salinity for the eggs, slowly increasing in the pouch to match the water outside as the eggs mature. Once the offspring hatch, the male releases them and is done caring for them. Most will not consume their own offspring, however it isn't unheard of.

Once released, the offspring are independent of their parents. Some spend time among the ocean plankton developing before settling down and hitching as their parents do. At times, the male seahorse may try to consume some of the previously released offspring. Other species (H. zosterae) hitch immediately and begin life in the benthos.

Seahorses are frequently monogamous, though several species (H. zosterae and H. abdominalis amount them) are highly gregarious. In monogamous pairs, the male and female will greet one another with courtship displays in the morning, and in the evening to reinforce their pair bond. They spend the rest of the day separate from each other hunting for food.

As Pets

While many aquarium hobbyists keep seahorses as pets, seahorses collected from the wild do not tend to fare well in a home aquarium.They will only feed on live foods such as brine shrimp and are prone to stress in an aquarium, which lowers their immune systems and exposes them to diseases.

In recent years, however, captive breeding of seahorses has become increasingly widespread. These seahorses tend to do much better in captivity, and they are less likely to carry diseases. These seahorses will accept frozen foods such as mysid shrimp, and they are not exposed to the shock and stress of being taken out of the wild and placed in a small aquarium. Captive-bred seahorses are more expensive, but are a better investment as they are much hardier and don't take a toll on wild populations.

Seahorses should be kept in an aquarium to themselves. Seahorses are slow feeders, and in an aquarium with fast, aggressive feeders, the seahorses will be edged out during feeding. For this reason, they should be maintained by themselves and special care should be given to assure that all individuals obtain enough food during times of feeding.

Species

There are approximately 35 known species of seahorse including:

Hippocampus abdominalis : (Big-belly seahorse) which is found off the coast of New Zealand and south and east Australia
Hippocampus algiricus : (West African Seahorse)
Hippocampus angustus: (Narrow Bellied Seahorse)
Hippocampus barbouri : (Barbour's seahorse or Zebra-snout seahorse)
Hippocampus bargibanti (Pygmy Seahorse) which is found in the West Pacific area (Indonesia, Philippines, Papua New Guinea, Salomon Islands, etc.)
Hippocampus borboniensis : (Réunion Seahorse)
Hippocampus breviceps: (Short Snouted Seahorse) which is found off the coast of south and east Australia
Hippocampus camelopardalis: (Giraffe Seahorse)
Hippocampus capensis: (Knysna Seahorse)
Hippocampus colemani: (Coleman's Seahorse)
Hippocampus comes: (Tiger Tail Seahorse) which is found in the Far East
Hippocampus coronatus: (Crowned Seahorse)
Hippocampus denise: (Denise's Seahorse)
Hippocampus erectus: (Lined Seahorse) which is found off the east coast of the Americas, between Nova Scotia and Uruguay
Hippocampus fisheri: (Fisher's Seahorse)
Hippocampus fuscus: (Sea Pony) which is found in the Indian Ocean
Hippocampus guttulatus: (Speckled Seahorse)
Hippocampus hippocampus: (European Seahorse) which is found in the Mediterranean Sea and Atlantic Ocean
Hippocampus histrix: (Thorny Seahorse) which is found in the Indian Ocean, Persian Gulf, Red Sea, and the Far East
Hippocampus ingens: (Pacific Seahorse) which is found off the Pacific coast of North, Central and South America)
Hippocampus jayakari: (Jayakar's Seahorse)
Hippocampus kelloggi: (Great Seahorse)
Hippocampus kuda: (Spotted Seahorse)
Hippocampus lichtensteinii: (Lichtenstein's Seahorse)
Hippocampus minotaur: (Bullneck Seahorse)
Hippocampus mohnikei: (Japanese Seahorse)
Hippocampus procerus: (Hippocampus procerus)
Hippocampus reidi: (Brazilian Seahorse) which is found in the Caribbean in coral reefs
Hippocampus sindonis: (Shiho's seahorse)
Hippocampus spinosissimus: (Hedgehog Seahorse)
Hippocampus subelongatus: (Tigersnout Seahorse or West Australian Seahorse)
Hippocampus trimaculatus: (Three-Spot Seahorse)
Hippocampus tuberculatus: (Knobby Seahorse)
Hippocampus whitei: (White's Seahorse) which is found off the coast of east Australia
Hippocampus zebra: (Zebra Seahorse)
Hippocampus zosterae: (Dwarf Seahorse) which is found in the Gulf of Mexico and the Caribbean)

Gallery

Image:PotbellySeahorse_TNAquarium.jpg|Potbelly seahorse pair link tails at the Tennessee Aquarium. Image:Seahorse head closeup.jpg|Closeup on the head of a seahorse.

External links

References

Syngnathiformes