''Ogcocephalus radiatus'' or the polka-dot batfish is an arrow-shaped

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Ogcocephalidae Ogcocephalidae is a family of anglerfish specifically adapted for a benthic lifestyle of crawling about on the seafloor. Ogcocephalid anglerfish are sometimes referred to as batfishes,pectoral fins Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

that sit flat on the bottom of the sea floor. It uses its pectoral fins and

pelvic fins Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

to "walk" along the bottom in a side-to-side shuffling motion.

Description

The polka-dot batfish is a bottom-dwelling fish that can measure up to from head to tail. It is a broad, dorso-ventrally flattened, arrow-shaped fish similar in appearance to a

ray Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (g ...

. The

are located further forward than the broad,

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s which flare out on both sides, supported by arm-like stalks. The polka-dot batfish looks similar to the short-nose batfish (''

Ogcocephalus nasutus ''Ogcocephalus'' is an anglerfish genus in the batfish family Ogcocephalidae. Species There are currently 13 recognized species in this genus: * ''Ogcocephalus corniger'' Bradbury, 1980 (Longnose batfish) * ''Ogcocephalus cubifrons'' J. Rich ...

''), although the pectoral fins of the polka-dot batfish are speckled with small spots whereas those of the short-nose are plain. The colouring of the polka-dot batfish is variable; it is usually brown with darker spots, some rimmed with white, and scattered patches of reddish or orangish-brown. This colouration provides camouflage as the fish lies on the seabed waiting for prey. The top of the head and body are covered in

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projection ...

s, giving it a rough texture and warty appearance; it does not have

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

. The polka-dot batfish has an elongated

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

(a unicorn-like projection between the eyes) on its large bony head. The dorsal fin has become modified to a single spine located under the rostrum.

Distribution

The polka-dot batfish is native to the Atlantic coast of the United States with its range extending from

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

, the

Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...

and the

Campeche Bank Campeche Bank is part of the Gulf of Mexico and extends from the Yucatan Straits in the east to the Tabasco-Campeche Basin in the west.Campeche Bankin Geonames.org (cc-by)/ref> The Campeche ocean bank is from Mexico's geography of Campeche naut ...

off the coast of Mexico. They have been found in waters up to deep, but most are found at shallower depths. It is a

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

(bottom dweller) fish, usually found on sandy or muddy seabeds, coral rubble or

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 ...

Behaviour

The polka-dot batfish preys on juvenile fish, crabs, shrimps, molluscs, and worms. It hunts by clinging to the bottom with its pectoral fins and wiggling the moveable, modified dorsal fin beneath its rostrum to attract prey. The rostrum also contains a chemical that helps attract the prey. When the prey is sufficiently close, it snatches the victim with its circular mouth. They sit and wait for their prey to come to them instead of chasing after their prey. They are very stealthy and stalk their prey before attacking. If approached by predators, the batfish bury themselves in the sand with their pectoral fins or scurry across the ocean bottom like a crab.

References

External links

* {{Taxonbar, from=Q2693725 Ogcocephalidae Fish described in 1818