- Scientific name: Lophius piscatorius
- Also know as: Anglerfish, Headfish, Goosefish, Frog-fish, Sea-devil
- Size: Up to 6ft long and 250lbs, but typically half this size.
- UK minimum size: Monkfish have a minimum weight of 16lb/7kg when caught from the shore, rather than a minimum length.
- 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, English Channel and 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 massive mouth full of very sharp teeth which point inwards. Flat body which is mottled dark brown to black in colour. Blunt spines are under the loose skin. First dorsal fin is short and spiny with powerful pectoral fins. Pale underside. Flexible protuberance from the head which is used to attract fish.
- Additional notes: Not to be confused with the species angel shark, which is sometimes referred to as monkfish.
The monkfish is a strange and somewhat terrifying looking fish, but it is in fact perfectly suited for its life as a deepwater predator. Monkfish have a number of adaptations which make them adept at catching their prey. The protuberance which comes from their head (which is actually an adapted dorsal fin) can be moved in any direction and is used to attract small fish which think it is something to eat. 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 they prey fish to be held securely in the monkfish’s jaws. The monkfish also has an expandable stomach which means they can eat fish which are almost as large as itself. Footage of the monkfish carrying out an ambush attack on a prey fish can be seen here.
Monkfish will take pouting, sandeels, cod, pollock, coalfish, dogfish, all kinds of flatfish and even 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 less 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. It behaves and feeds in the same way as the more common monkfish. There are five other extant species of true 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.
Spawning Pattern 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 is shape.
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 Table Fish
Despite their appearance monkfish are highly regarded as a table fish, although it is only the tail, central body section and cheeks that provide any edible flesh. 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 vessels do not specifically target monkfish, but they are a welcome bonus when they turn up in demersal trawls for cod, haddock and flatfish. The monkfish is not endangered and the International Union for the Conservation of Nature class it as a species of Least Concern with a stable population, but Greenpeace 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.
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 family can be labelled or named monkfish in packaging or on fish counters. However, in previous decades the angel shark (Squatina squatina) was referred to as monkfish in the UK. Sometimes people will argue that the monkfish should be called anglerfish. This is not a particularly useful term as anglerfish is in fact a generic name for any fish which uses a fin or other protuberance to attract and catch prey. To complicate things further the monkfish featured on this page is called goosefish in North America, and headfish in other parts of the world, and used to go under names such as frog-fish and sea-devil which are rarely used now.