• Scientific name: Lophius piscatorius
  
• Also know as: Anglerfish, Headfish, Goosefish, Frog-fish, Allmouth, Sea-devil
• Size: Up to 6ft long and 150 – 250lbs, but typically less than half this size.
• UK minimum size: N/a
• UK shore caught record: 68lb 2oz
• IUCN Status: LC (Least Concern)
• Distribution: A deep-water fish which stays at depths of around fifty metres, and usually substantially deeper than this. Monkfish are found in the north east Atlantic and parts of the Irish Sea, the English Channel and the North Sea.
• Feeds on: Ambush hunter which feeds primarily on other fish, but will also prey on squid, cuttlefish, octopus and even crustaceans.
• Description: Large, broad head with a massive mouth full of very sharp teeth which point inwards. The flat body is mottled dark brown to black in colour. Blunt spines are present under the loose skin. The first dorsal fin is short and spiny with powerful pectoral fins. The underside is pale and there is a flexible protuberance from the head which is used to attract fish.
• Additional notes: Not to be confused with the angel shark which is sometimes referred to as monkfish.

The monkfish is a strange and somewhat terrifying-looking fish, but it is relatively common in deeper waters surrounding the British Isles. Monkfish are ambush predators which predominantly prey on fish, although they may also take squid and other sea creatures. They lie camouflaged on the seabed and use the protuberance on their head (which is known as the esca) – to attract fish which think it is a source of food. Once they are in range the monkfish snaps forward with incredible speed to devour the fish in its huge mouth. The teeth of the monkfish are hinged which allows the prey fish to be held securely in the jaws of the monkfish. The monkfish also has an expandable stomach which means they can eat fish which are almost as large as themselves. Footage of the monkfish carrying out an ambush attack on a small prey fish can be seen here.

Monkfish will take pouting, sandeels, cod, pollock, coalfish, dogfish, all kinds of flatfish and even small rays. They have also been caught with lobsters and crabs in their stomach, suggesting that monkfish are opportunistic predators that will eat pretty much anything that crosses their path.

Other Species of Monkfish

There is actually a second species of monkfish lived in UK waters – Lophius budegassa. This second species is very similar apart from the fact that it has fewer spines in the second dorsal fin, different coloured pelvic fins, and darker skin on the belly which leads to this sub-species nickname of the Black Bellied Monkfish. This species behaves and feeds in the same way as the more common monkfish. There are five other extant species of monkfish which are not found in UK waters such as Lophiodes caulinaris which is found in the Pacific Ocean along the North and South American coasts and Lophius americanus which is native to the eastern coast of the United States. As described below the angel shark was previously referred to as monkfish – see Name Confusion section below.

Spawning and Growth

Monkfish move into even deeper water to breed, seeking out places which are at least several hundred metres deep, usually at some point during the spring or early summer. The eggs float on the surface in ribbons of jelly and once hatched the larval monkfish live in mid-water, moving down to live on the seabed when they are around one year old and beginning to resemble the adult monkfish.

The vast majority of monkfish are around three feet long, with ones up to four or five long being considered large. However, like most fish species the monkfish has terminal growth, meaning that they continue to grow throughout their entire lives. This means that if monkfish avoid being caught by commercial vessels they can reach very large sizes indeed. The biggest monkfish ever recorded was substantially larger than this. It was caught off the coast of Norway in January 2012 and weighed 250lbs.

Commercial Value and Reputation as a Food Fish

Despite their appearance monkfish are highly regarded as a food fish and have a strong, meaty taste, although only a relatively small amount of edible flesh is available from the tail, central body section and cheeks of a monkfish. In Japan, monkfish livers are rubbed with salt, soaked in saki (rice wine), steamed and then served with vegetables, herbs and citrus-based sauce to create the delicacy of Ankimo. A survey by the American broadcaster CNN classed Ankimo as one of the world’s fifty most delicious foods. Commercial trawlers do not specifically target monkfish, but they are a welcome bonus when they turn up in demersal trawls for cod, haddock and flatfish. Smaller-scale fisheries may use static tangle nets to catch this species and there is a British monkfish fishery established off the coast of south west England and parts of Scotland.

Monkfish is not endangered and the International Union for the Conservation of Nature classes it as a species of Least Concern, although this is based on an assessment carried out in 2013 and the current population trend is unknown.  Greenpeace, however, has added monkfish to its Redlist due to the destructive bottom trawling methods that are used to catch this species. In 2007 supermarket chain ASDA decided to stop selling monkfish as they did not consider it a sustainable species, although they reversed their decision just three months later.

Name Confusion

There can be much confusion over what exactly a monkfish is, mostly because the name monkfish is (or has been) applied to a wide number of fish. Today in Britain monkfish is understood to be the species Lophius piscatorius which is featured on this page. Under UK labelling regulations only the genuine monkfish species from the Lophius genus can be labelled or named monkfish on product packaging or on fish counters to allow consumers to accurately identify the species they are purchasing. In previous decades the angel shark (Squatina squatina) was referred to as monkfish in the UK, with some people continuing to use this term for the angel shark, leading to confusion. To complicate things further the monkfish featured on this page is called goosefish in North America, and headfish in other parts of the world. Other names such as frog-fish and sea-devil are rarely used now.