The common name “monkfish” is used to describe several distinct species of fish, including fish in the genera Lophius and Squatina. As a general rule, the fish which share this common name have a number of traits in common as well, including a regrettable level of ugliness. These bulgy, slightly flattened fish tend to live near the seafloor, leading biologists to classify them as benthic or bottom dwelling fish, and they are found primarily in the Atlantic Ocean.
One distinguishing characteristic of monkfish is the head, which is broad and flattened with large lips. Monkfish also have several filaments which project from their heads; one of the filaments has a bulb of flesh, which is designed to act as bait to attract smaller fish. When fish approach, the monkfish snaps them up, typically swallowing them whole. These filaments are believed to be residual remainders of the upper fin of these fish, and a number of benthic fish use such tactics to attract dinner.
Monkfish are brown, with warty skin. Their tails are extremely thick and muscular, powering them along the ocean floors that they call home. Monkfish vary in size; three to six feet (one to two meters) are common lengths, and some fishermen have recorded even bigger specimens. Like other angler fish, fish which use biological adaptations to essentially fish for prey, the stomach contents of monkfish can sometimes be quite intriguing.
Originally, fishermen viewed monkfish as a useless bycatch, and in fact many thought of monkfish as monsters. Many works of art depicting sea monsters are actually drawings of monkfish, typically with their characteristic jaws agape. Some species also have cowled heads, explaining the common name of “monkfish.” Depending on species and regional dialect, monkfish are also called goosefish, frogfish, sea devils, bullmouths, bellyfish, and allmouths, in a reference to their huge mouths.
People have also used monkfish as a source of food. The dense, slightly sweet tail meat has been a popular alternative to lobster, for example. Unfortunately, research on monkfish fisheries has suggested that they are overfished, and consumers may want to seek out different types of fish to ensure that monkfish populations stay healthy. The fish also bioaccumulate mercury, which can be very dangerous for pregnant women and developing children. The United States Food and Drug Administration has also warned consumers that inedible species of fish are sometimes sold as “monkfish,” capitalizing on consumer demand and potentially putting people in danger.