A giant seahorse spied off the coast of Baja, California

By Kately Nikiforuk

Hippocampus ingens, giant seahorse.  Photo by iSeahorse user afelix.

Hippocampus ingens, giant seahorse.  Photo by iSeahorse user afelix.

June’s featured seahorse is a giant seahorse (Hippocampus ingens), spied off the coast of Baja, California by iSeahorse user afelix, despite some masterful camouflage. This is the only known Hippocampus species to swim the the West Coast waters of North America, so this specimen was a cinch to identify.

These gentle giants live up to their name, clocking in at a max recorded height of 31 cm. However, H. ingens are only silver medallists when it comes to seahorse size, as H. abdominalis (the bigbelly seahorse) takes the cake with a max recorded height of 35 cm. Narrowly exceeding the length of a foot-long sandwich might not sound like a feat worthy of giant status, but bear in mind that many Hippocampus species hover around 15 cm, and the smallest ones can be less than a centimeter.

H. ingens is endemic to the eastern pacific (hence their other alias, the pacific seahorse), with a range spanning from California to Peru. Despite their wide dispersal, they are considered rare. In fact, they have been listed as a Vulnerable species by the IUCN since 1996. Like many seahorses, they are victims of habitat degradation, and are caught for the medicinal trade, live for aquariums, and for use as curios. They are also intentionally caught by tuna and accidentally caught by tuna fishers. 

They were once relatively abundant in the Galapagos, but are now quite rare in that region. And interviews conducted in 2000 with shrimp farmers off the coast of Mexico indicate a troublesome trend - the catch per unit effort went from thousands or hundreds caught per month to tens or none, a 75%-90% decline within 15-30 years. Studies indicate that they are declining all across their range, and this pattern is predicted to continue. 

While H. ingens typically cling to algae or coral, they have been known to substitute their natural lodgings for flotsam, and other anthropogenic structures.