The Pacific seahorse, also known as the giant seahorse, (''Hippocampus ingens'') is a species of

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the family

Syngnathidae The Syngnathidae is a family of fish which includes seahorses, pipefishes, and seadragons ('' Phycodurus'' and '' Phyllopteryx''). The name is derived from (), meaning "together", and (), meaning "jaw". The fused jaw is one of the traits that ...

. Their genus name (''Hippocampus'') is derived from the Greek word ''hippos'', which means "horse" and ''campus'', which means "sea monster." This species is the only seahorse species found in the eastern

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

Description

''Hippocampus ingens'' are one of the largest seahorses, with adult pacific seahorses ranging in size from in height, with a maximum known size of . Offspring are approximately 9 mm after birth. While large compared to others of their kind, their size hinders them in the conservation world. Minimum size limits are a common and favored conservation tool, usually starting at 10 cm. Thus, it is crucial that Pacific seahorses are accurately measured when they reach sexual maturity, for it determines if they will be protected or not. Pacific seahorses can be a variety of colors, including green, brown, maroon, grey, and yellow. Males can be distinguished from females by their prominent keel. Pacific seahorses share the common traits of seahorses, including a prehensile tail used for anchoring, skin instead of scales, a digestive tract without a distinct stomach, no teeth, and the ability to move each eye independently. It is one of the six species listed as "under the greatest threat from unsustainable levels of harvest and international trade" by the Convention on International Trade in Endangered Species of Wild Fauna (CITES).

Distribution and habitat

The pacific seahorse is distributed in the Pacific Ocean from

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, with an additional transient population off of

San Diego San Diego ( , ) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. With a population of over 1.4 million, it is the List of United States cities by population, eighth-most populous city in t ...

.The only known oceanic island population occurs around the Galapagos Islands with some additional populations also located in Northern Peru. Pacific seahorses are nocturnal and known to inhabit a variety of sub-tidal habitats to a maximum depth of . Habitats include

mangroves A mangrove is a shrub or tree that grows mainly in coastal saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen and remove sal ...

seagrass meadow A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

s, rocky reefs,

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in group ...

s and

sponge Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and a ...

s. Other common habitats are sea kelp and

eelgrass Eelgrass is a common name for several plants and may refer to: * '' Zostera'', marine eelgrass * '' Vallisneria'', freshwater eelgrass See also *'' Potamogeton compressus'', known as eel-grass pondweed {{Short pages monitor