This article is about the fish; for other meanings of seahorse, see Seahorse (disambiguation). ? Seahorse Seahorse (photo by NOAA) Scientific classification Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Gasterosteiformes Family: Syngnathidae Genus: Hippocampus Rafinesque, 1810 Species See text.
Hippocampus is a genus of fish known as Seahorses (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 one of only a few species where the males get pregnant. A seahorse pregnancy lasts approximately two to three weeks. Seahorses are also unusual among fish for being relatively monogamous.
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. Mostly transparent, these often don't show in pictures and even with live animals most people do not see them at first.
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 ( ).
Seahorses reproduce in an unusual way: the male becomes pregnant. 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 fertilises them. The embryos will develop for 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.
Though close relatives of seahorses, sea dragons 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.
