Lophius

Species

The seven recognized extant species in this genus are:

Fossils

• †Lophius brachysomus Agassiz, 1835 (Monte Bolca, or Eocene anglerfish)

Description

The head is large, broad, flat, and depressed, with the remainder of the body appearing merely like an appendage. The wide mouth extends all around the anterior circumference of the head, and both jaws are armed with bands of long, pointed teeth, which are inclined inwards, and can be temporarily depressed so as to offer no impediment to an object gliding towards the stomach, while still preventing its escape from the mouth. The pectoral and ventral fins are so articulated as to perform the functions of feet, the fish being enabled to walk on the bottom of the sea, where it generally hides itself in the sand or amongst seaweed. All around its head and also along the body, the skin bears fringed appendages resembling short fronds of seaweed. These structures, combined with the ability to change the colour of the body to match its surroundings, assists the fish greatly in concealing itself in its lurking places, which are selected for their abundance of prey.

Species of Lophius have three long filaments sprouting from the middle of their heads; these are the detached and modified three first spines of the anterior dorsal fin. As with all Anglerfish species, the longest filament is the first, which terminates in an irregular growth of flesh, the esca (also referred to as the illicium), and is movable in all directions; this modified fin ray is used as a lure to attract other fish, which the monkfish then seize with their enormous jaws, devouring them whole. Whether the prey has been attracted to the lure or not is not strictly relevant, as the action of the jaws is an automatic reflex triggered by contact with the esca.

Monkfish, like most anglerfish, are also characterised by an enormously distensible stomach, which allows an individual monkfish to fully swallow prey as large as itself. Monkfish grow to a length of more than 150 cm (4.9 ft); specimens of 100 cm (3.3 ft) are common.

Reproduction

The spawn of this genus consists of a thin sheet of transparent gelatinous material 60–100 cm (2.0–3.3 ft) wide and 8–10 m (26–33 ft) in length. The eggs in this sheet are in a single layer, each in its own little cavity. The spawn is free in the sea. The larvae are free-swimming and have the pelvic fins with elongated filaments.

Habitat

The East Atlantic species is found along the coasts of Europe, but becomes scarce beyond 60°N latitude; it occurs also on the coasts of the Cape of Good Hope. The species caught on the North American side of the Atlantic is usually Lophius americanus. A third species (Lophius budegassa), inhabits the Mediterranean, and a fourth (L. setigerus) the coasts of China and Japan.

The black (L. budegassa) and white (L. piscatorius) anglerfish both live in shallow, inshore waters from 800 metres (2,600 ft) to deeper waters (greater than 1,000 metres, 3,300 ft). These two species are very similar to one another with only a few distinctions between them. These include: the colour of the peritoneum (black for L. budegassa and white for L. piscatorius) and the number of rays in the second dorsal fin (L. budegassa, 9–10 and L. piscatorius, 11–12). Also, minor differences in their distribution occur. Black anglerfish tend to have a more southern distribution (Mediterranean and eastern North Atlantic from the British Isles to Senegal), whereas the white anglerfish are distributed further north, (Mediterranean, Black Sea and eastern North Atlantic from the Barents Sea to the Strait of Gibraltar). Despite these differences, the overall distribution of the black and white anglerfish tend to overlap greatly. A map of the distribution of anglerfish in the waters surrounding Europe and North Africa can be found in the external links section. The movements of both species of anglerfish indicate a mixing of both northern and southern species could have strong implications for the geographical boundaries of the stocks from a management perspective. Both species of Lophius are important because they are commercially valuable species usually caught by trawl and gillnetting fleets.

Concern is expressed over the sustainability of monkfish fishing. The method most commonly used to catch monkfish, beam trawling, has been described as damaging to seafloor habitats. In February 2007, the British supermarket chain Asda banned monkfish from their stores.