![]() ![]() Molecular dating implies that pipefish and seahorses diverged during the Late Oligocene. slovenicus, from the coprolitic horizon of Tunjice Hills, a middle Miocene lagerstätte in Slovenia dating back about 13 million years. The earliest known seahorse fossils are of two pipefish-like species, H. ramulosus), from the Marecchia River formation of Rimini Province, Italy, dating back to the Lower Pliocene, about 3 million years ago. The best known and best studied fossils are specimens of Hippocampus guttulatus (though literature more commonly refers to them under the synonym of H. The fossil record of seahorses, however, is very sparse. Evolution and fossil record Īnatomical evidence, supported by molecular, physical, and genetic evidence, demonstrates that seahorses are highly modified pipefish. ![]() 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. Since they are poor swimmers, they are most likely to be found resting with their prehensile tail wound around a stationary object. zosterae (the dwarf seahorse), with a top speed of about 1.5 m (5 ft) per hour. The slowest-moving fish in the world is H. Seahorses swim very poorly, rapidly fluttering a dorsal fin and using pectoral fins to steer. It also sports a crown-like spine or horn on its head, termed a "coronet", which is distinct for each species. Unusually among fish, a seahorse has a flexible, well-defined neck. They are adept at camouflage, and can grow and reabsorb spiny appendages depending on their habitat. Their prehensile tail is composed of square-like rings that can be unlocked only in the most extreme conditions. They lack the caudal fin typical of fishes. The pectoral fins, located on either side of the head behind their eyes, are used for steering. Razorfish are the only other fish that swim vertically. Seahorses swim upright, propelling themselves using the dorsal fin, another characteristic not shared by their close pipefish relatives, which swim horizontally. The armor of bony plates also protects them against predators, and because of this outer skeleton, they no longer have ribs. Each species has a distinct number of rings. 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. They are named for their equine appearance, with bent necks and long snouted heads and a distinctive trunk and tail. Seahorses range in size from 1.5 to 35 cm (0.6 to 13.8 in). These species form territories males stay within 1 m 2 (10 sq ft) of habitat, while females range over about one hundred times that. hippocampus (the short-snouted seahorse), and H. guttulatus (the long-snouted seahorse), H. Three species live in the Mediterranean Sea: H. zosterae, known as the dwarf seahorse, is found in the Bahamas.Ĭolonies have been found in European waters such as the Thames Estuary. In the Atlantic, Hippocampus erectus ranges from Nova Scotia to Uruguay. Four species are found in Pacific waters from North America to South America. They live in sheltered areas such as seagrass beds, estuaries, coral reefs, and mangroves. Seahorses are mainly found in shallow tropical and temperate salt water throughout the world, from about 45°S to 45°N. Along with the pipefishes and seadragons ( Phycodurus and Phyllopteryx) they form the family Syngnathidae. Having a head and neck suggestive of a horse, seahorses also feature segmented bony armour, an upright posture and a curled prehensile tail. "Hippocampus" comes from the Ancient Greek hippókampos ( ἱππόκαμπος), itself from híppos ( ἵππος) meaning "horse" and kámpos ( κάμπος) meaning "sea monster" or "sea animal". A seahorse (also written sea-horse and sea horse) is any of 46 species of small marine fish in the genus Hippocampus. ![]()
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