Deep-sea thriller: The gothic romance of anglerfish
Updated 13:12, 18-Oct-2018
By Li Yunqi
["china"]
Deep down in the ocean where no sunlight could reach, animals live a dark life. Among them, the anglerfish stands out not only because of its ghastly looks – gnarly teeth, huge mouth, and the dangling luminous lure on its head but also because of its horrifying parasitic mating process.
Gnarly teeth of anglerfish. /VCG Photo

Gnarly teeth of anglerfish. /VCG Photo

There are only a few studies on these mysterious creatures due to the intense environment they live in. Records on how anglerfish reproduce remained in the mist until last century when the first female anglerfish with two tiny fish attached to its belly had been dissected. Only after that, scientists realized that the tiny fish they had mistook for the babies were, in fact, the male fish.
Haplophryne mollis, a species of anglerfish in the family Linophrynidae. /VCG Photo

Haplophryne mollis, a species of anglerfish in the family Linophrynidae. /VCG Photo

The male anglerfish appear to be extremely fragile compared to the females. They are usually only a fraction of the size of their mates and have no sharp teeth or lures.
A male anglerfish. /VCG Photo

A male anglerfish. /VCG Photo

While the female anglerfish use their bioluminescent lure to attract other fish and devour their prey with toothy mouths, their male counterparts have extremely sensitive eyes and nostrils which help them to detect the chemicals that female anglerfish release.
Two male anglerfish attach themselves to the a female. /VCG Photo

Two male anglerfish attach themselves to the a female. /VCG Photo

Once a male anglerfish finds its mate, it bites into the female's belly and latches on until their bodies fuse. Their skins and blood vessels join together and eventually, the two fish become one.
Footballfish (Himantolophus groenlandicus). /VCG Photo

Footballfish (Himantolophus groenlandicus). /VCG Photo

The gothic romance of the anglerfish allows the male to take all the nutrients it needs from its mate/host. The male's useless body parts such as eyes, fins and some other internal organs gradually degenerate until it is nothing more than a lump of flesh that hangs from the female and provides sperm.
Double spine seadevils(Diceratias pileatus). /VCG Photo

Double spine seadevils(Diceratias pileatus). /VCG Photo

However, not all anglerfish have extreme size differences or adopt a parasitic mating method. In many suborders of anglerfish, the males can hunt by themselves and swim independently throughout their lives. It is only necessary for some deep-sea species that rarely run into others in the abyss to follow this bizarre ritual in order to keep their mates around. Sometimes there could be up to eight males attached to one female.