Longsnout (Slender) Seahorse

Longsnout or slender seahorse (Hippocampus reidi)

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The longsnout seahorse (Hippocampus reidi) is also known as the slender seahorse or Brazilian seahorse.


As you could guess, longsnout seahorses have a long snout. They have a slender body that can grow up to about 7 inches in length. On top of their head is a coronet that is low and convoluted.

These seahorses may have brown and white dots over their skin, which is a variety of colors, including black, yellow, red-orange, or brown. They may also have a pale saddle coloration over their dorsal surface (back).

Their skin stretches over bony rings visible on their body. They have 11 rings on their trunk and 31-39 rings on their tail.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Gasterosteiformes
  • Family: Syngnathidae
  • Genus: Hippocampus
  • Species: reidi

Habitat and Distribution

Longsnout seahorses are found in the western North Atlantic Ocean from North Carolina to Brazil. They are also found in the Caribbean Sea and Bermuda. They are found in relatively shallow water (0 to 180 feet) and are often attached to seagrasses, mangroves, and gorgonians or among floating Sargassum, oysters, sponges, or man-made structures.

Females are thought to range farther than males, possibly because males have a brood pouch which decreases their mobility.


Longsnout seahorses eat small crustaceans, plankton, and plants using their long snout with a pipette-like motion to suck in their food as it passes by. These animals feed during the day and rest at night by attaching to structures in the water such as mangroves or seagrasses.


Longsnout seahorses are sexually mature when they are about 3 inches long. Like other seahorses, they are ovoviviparous. This seahorse species mates for life. Seahorses have a dramatic courtship ritual in which the male may change color and inflate his pouch and the male and female perform a "dance" around each other.

Once courtship is complete, the female deposits her eggs in the male's brood pouch, where they are fertilized. There are up to 1,600 eggs that are about 1.2mm (.05 inches) in diameter. It takes about 2 weesk for the eggs to hatch, when seahorses about 5.14 mm (.2 inches) are born. These babies look like miniature versions of their parents.

The lifespan of longsnout seahorses is thought to be 1-4 years.

Conservation and Human Uses

The global population of the species is listed as near-threatened on the IUCN Red List as of an October 2016 assessment.

One threat to this seahorse is harvest for use in aquariums, as souveniers, as medicinal remedies, and for religious purposes. They also are caught as bycatch in shrimp fisheries in the U.S., Mexico, and Central America and are threatened by habitat degradation.

The genus Hippocampus, which includes this species, was listed in CITES Appendix II, which prohibts export of seahorses from Mexico and increases permits or licenses required to export live or dried seahorses from Honduras, Nicaragua, Panama, Brazil, Costa Rica, and Guatamala.


  • Bester, C. Longsnout Seahorse. Florida Museum of Natural History.
  • Lourie, S.A., Foster, S.J., Cooper, E.W.T. and A.C.J. Vincent. 2004. A Guide to the Identification of Seahorses. Project Seahorse and TRAFFIC North America. 114 pp.
  • Lourie, S.A., A.C.J. Vincent and H.J. Hall, 1999. Seahorses: an identification guide to the world's species and their conservation. Project Seahorse, London. 214 p. via FishBase.
  • Project Seahorse 2003. Hippocampus reidi. The IUCN Red List of Threatened Species. Version 2014.2.
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Kennedy, Jennifer. "Longsnout (Slender) Seahorse." ThoughtCo, Aug. 28, 2020, thoughtco.com/longsnout-seahorse-profile-2291566. Kennedy, Jennifer. (2020, August 28). Longsnout (Slender) Seahorse. Retrieved from https://www.thoughtco.com/longsnout-seahorse-profile-2291566 Kennedy, Jennifer. "Longsnout (Slender) Seahorse." ThoughtCo. https://www.thoughtco.com/longsnout-seahorse-profile-2291566 (accessed March 28, 2023).