Monkfish

October 10, 2016 The silent predator with the big mouth

The flattened grotesque head opens up suddenly, revealing rows and rows of teeth. Before the victim can react, it is sucked into the huge mouth. A split second later, all is silent again, except for the settling sediment and perhaps some glittering bits of the unfortunate prey. Then, once again, the predator wiggles its lure, and awaits its next victim.

Many have described the monkfish as an ugly fish. However, this isn't necessarily true — it just looks a little peculiar. Its gigantic flat head and large mouth with pointed teeth are disproportionately large compared to its small body. In addition, there are the stiff appendages on its head, which resemble the unkempt beard of a down-and-out sailor in a tavern along the harbour. Its thoracic fins, used as feet, look quite odd as the fish "walks" on them slowly and deliberately on the seabed.

The monkfish Species: 28 in 4 genera
English: Monkfish (German: Sea devil)
Order: Lophiidae
Size: usually up to 1 metre
Appearance: Large, flat fish with huge head and mouth. Good at camouflage. Habitat: Bottom-dweller, 10 to 1.000 metres deep
Food: mostly fish
Distribution: North-eastern Atlantic Ocean and neighbouring oceans
Often mistaken as: Wobbegong (carpet sharks) in Australia, and crocodile fish in Red Sea
Economic importance: Excellent food source

A fish fishing for prey

Like the anglerfish, spines protrude from the top of the monkfish's head. The first and longest filament, called an illicium, ends in a fleshy growth called an esca. The monkfish wiggles this lure to attract prey into the vicinity. Once an unsuspecting fish comes within reach, the monkfish suddenly opens its mouth, creating a vacuum that causes the prey to be swiftly sucked into its throat. The next second, everything is over. All that remains is the unassuming, peculiar-looking monkfish wiggling its lure, waiting for its next victim.

Using its fins to move around

Monkfish belong to the order of Lophiiforme. A direct translation of the German name of the order (Lophiiforme) is "fins like arms", which aptly describes how the monkfish moves. In the case of the closely related anglerfish, such movement is particularly beautiful, as they use their fins to slowly crawl and hop on the seabed.
(Note: This is akin to our own arms, which can be considered as evolutionary breast-fins, which evolved into front legs for our ancestors and which have now become our arms. As for the belly fins, they became our legs).

Reproduction

When the monkfish reaches sexual maturity at about six years of age, the male is about 40cm long and the female is about 70cm. When they spawn, the couple releases about a million violet eggs which are attached to a gelatinous sheet about the size of the flag on a flag pole. Drifting freely in the ocean, the sheet is eventually torn apart by the current and waves. The larvae are free-swimming, and convert to a ground-based existence when they are about seven centimetres long.