Sargassumfish, Histrio histrio

The Sargassumfish, Histrio histrio, whose common Spanish name is pez sargazo, is a species in the Frogfish or Antennariidae Family, known collectively as ranisapos in Mexico. It is one of the more exotic and most unusual fishes in the world. Globally, there are only one species in the genus Histrio, this species which is found in Mexican waters of the Atlantic.

The Sargassumfish have somewhat compressed globular bodies with a laterally flattened appearance. They are pale cream to greenish dark brown in color with fleshy weed-like appendages that make them resemble and blend in with the Sargassum algae for which they are named and within which they live. They have smooth skin and lack the dermal spines found in other members of the family. Their head features an upturned mouth and a bulbous tipped illicium over the margin of the eyes that is continuous with the body.

The Sargassumfish are found in marine habitats at depths between 30 and 50 feet and spend their entire life associated with floating sea grass beds, mostly Sargassum algae. They reach a maximum length of 20 cm (7.9 inches). They are preyed upon by sea birds and larger fish but can avoid larger fish by jumping out of the water and onto floating seaweed. They have two distinct sexes with the eggs generated by the females in a gelatinous floating mass that the males inseminate through external fertilization.

The Sargassumfish are found throughout the tropical and subtropical seas of the world including the Indian Ocean, the Red Sea, the Western Pacific, and the Atlantic Ocean, however, they are absent from the Eastern Pacific. In Mexican waters they are found in all waters of the Atlantic.

Due to their unique appearance, the Sargassumfish cannot be confused with any other species.

The Sargassumfish are known to contain Ciguatera toxin and are thus not recommended for human consumption. They are sold commercially via the aquarium trade.

Sargassumfish (1)

Sargassumfish, Histrio histrio: Underwater photo taken at South Padre Island, Texas, May 2010. Photo courtesy of Ruben Gonzalez, South Padre Island, TX.