Monkfish, primarily belonging to the genus Lophius, are large, bottom-dwelling marine predators known for their distinctive, flattened bodies and enormous heads. Often referred to as anglerfish, they are perfectly adapted to life on the seabed, employing a unique hunting style. The monkfish is an obligate carnivore, meaning its entire diet consists of other animals it catches. Its specialized feeding mechanics allow it to consume a wide range of prey, making it an opportunistic and highly effective predator.
Primary Prey Categories
The monkfish diet is dominated by fish, which often make up over 90% of the consumed biomass by weight. This piscivorous diet includes species such as Atlantic cod, whiting, and various flatfish like flounder. These prey reflect the availability of demersal and benthopelagic species in the monkfish’s habitat.
The second most important prey category is Mollusca, mainly represented by cephalopods, particularly squid. Monkfish also consume a variety of large crustaceans, including crabs, lobsters, and shrimp.
Hunting Strategy and Technique
Monkfish are classic ambush predators, relying on stealth and camouflage rather than active pursuit. They possess a mottled, brownish coloration that allows them to blend seamlessly with the sandy or muddy seafloor, where they lie motionless or partially buried. This sit-and-wait strategy conserves energy while they wait for unsuspecting prey to swim within striking distance.
Their most remarkable adaptation is the illicium, a modified first spine of the dorsal fin that functions as a “fishing rod.” At the end of this flexible rod is the esca, a fleshy tip that acts as a lure. The monkfish wiggles the esca to mimic the movements of a smaller fish or worm. When a curious fish or crustacean approaches the lure, the monkfish executes a lightning-fast strike.
The attack involves a rapid opening of its massive, upward-facing mouth, which creates a powerful vacuum that sucks in the prey. This strike is aided by rows of long, sharp, inwardly curved teeth lining both jaws, ensuring that escape is impossible once captured. The monkfish’s expansive jaws and elastic stomach allow it to engulf whole animals that seem disproportionately large for its size.
Variations in Diet
The monkfish’s diet changes significantly as it grows. Larval monkfish feed on plankton, but juveniles transition to consuming smaller prey, such as small crustaceans and worms. Once they reach a certain size, usually around 20 centimeters, their diet becomes predominantly piscivorous, shifting to larger fish species.
Geographical location and local environment also introduce variation in the diet, as the monkfish consumes whatever is most abundant in its specific habitat. For example, in some European waters, their primary prey may be Norway pout and blue whiting, while in the Irish Sea, whiting and Norway lobster are more common. Monkfish have even been found with unusual prey items in their stomachs, including sea birds and sea otters.