The sargassum fish, anglerfish, or frog fish (''Histrio histrio'') is a frogfish of the family Antennariidae, the only species in its genus. It lives among '' Sargassum''

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

which floats in

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

oceans. The scientific name comes from the Latin ''histrio'' meaning a stage player or actor, and refers to the fish's feeding behaviour.''Histrio''
Charlton T. Lewis, Charles Short, A Latin Dictionary. Retrieved 2012-01-04.

Description

''Histrio histrio'', a strange-looking fish, blends well with its surroundings in its seaweed habitat. It is laterally compressed and its length can reach . The colour of the body and the large oral cavity is very variable, but is usually mottled and spotted yellow, green, and brown on a paler background, and the fins often have several dark streaks or bands. The fish can change colour rapidly, from light to dark and back again.Frogfish (''Histrio histrio'')
Marine Species Identification Portal. Retrieved 2012-01-04. The body and the fins are covered with many weed-like protrusions, but other than these, the skin is smooth without dermal spines. The dorsal fin has three spines and 11–13 soft rays. The front spine is modified into a slender growth on the upper lip known as an illicium, which is tipped by a fleshy lump, the esca. The junction between the head and body is indistinct because no gill slits are present; the gills open as pores near the base of the pectoral fins.
Florida Museum of Natural History. Retrieved 2012-01-04. The anal fin has no spines and seven to 13 soft rays. The pelvic fins are large and the pectoral fins have 9-11 rays and are stalked and able to grip objects. The outer rays of the tail fin are simple, but the central rays are forked.
FishBase. Retrieved 2012-01-04.
Bahamas Wildlife. Retrieved 2012-01-04.

Distribution and habitat

The sargassum fish has a

cosmopolitan distribution In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...

in tropical and subtropical seas down to a depth around . It is found in parts of the Atlantic Ocean and the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

Ocean, where drifting seaweed accumulates. In the western Atlantic, it ranges from the Gulf of Maine south to Uruguay. It has been reported from northern Norway, but that sighting is likely to be as a result of its having been carried along by the North Atlantic Current.

Biology

The sargassum fish is a voracious ambush predator that is also a cannibal. One individual was dissected and found to have 16 juveniles in its stomach. It stalks its prey among the tangled weeds, relying on its

cryptic Cryptic may refer to: In science: * Cryptic species complex, a group of species that are very difficult to distinguish from one another * Crypsis, the ability of animals to blend in to avoid observation * Cryptic era, earliest period of the Earth ...

camouflage for concealment. It can clamber through and cling to the seaweed stalks with its prehensile pectoral fins. It dangles its esca as a fishing lure to attract small fish, shrimp, and other invertebrates. It is able to dart forward to grab its prey by expelling water forcibly through its gill openings. It can expand its mouth to many times its original size in a fraction of a second, drawing prey in via

suction Suction is the colloquial term to describe the air pressure differential between areas. Removing air from a space results in a pressure differential. Suction pressure is therefore limited by external air pressure. Even a perfect vacuum cannot ...

, and can swallow prey larger than itself. It is

dioecious Dioecy (; ; adj. dioecious , ) is a characteristic of a species, meaning that it has distinct individual organisms (unisexual) that produce male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproductio ...

. At breeding time, the male courts the female by following her around closely. When ready to spawn, the female ascends rapidly to the surface, where she lays a mass of eggs stuck together by gelatinous mucus. This egg raft adheres to the seaweed, where it is fertilised by the male. On hatching, each larva is surrounded by an integumentary envelope and has a large, rounded head, fully formed fins, and eyes with double notches. As the larva develops into a juvenile, this envelope fuses with the skin. This fish is preyed on by larger fish and sea birds. To avoid underwater threats, it can leap above the surface onto mats of weed. It can survive for some time out of water.

References

{{Taxonbar, from=Q1113162 Antennariidae Fish of Hawaii Fish described in 1758 Fish of the Atlantic Ocean Monotypic fish genera Taxa named by Carl Linnaeus