The Creepy Sex-Death of the Male Anglerfish

The term 'anglerfish' can be applied to over 300 different kinds of animal, spanning almost twenty species, named for their method of hunting prey with a fleshy lure dangling off its head which can be wriggled in such a way that prey believe it is food. This development of the anglerfish is an ingenious twist of nature; it is not only practical, but has made it somewhat famous in the animal kingdom, not only for its scarily accurate portrayal in Finding Nemo.

The first thing you notice about the anglerfish is that it is fuck ugly. In every species. It is hideous. It has protruding teeth and bulging eyes and some species are covered in spiny hairs and others look like they are already decaying so that they fit in with the scum on the ocean floor. Most of them live at the bottom of the sea where it is so dark that everything is ugly, but the ones that glow have no excuse. The bioluminescence has evolved to attract prey, but it would seem only sensible to avoid something with a face like this...

And that's the female.

Actually, all of the big, scary ones are female. The males are rather more puny and not half as repulsive. They aren't as worried about feeding, so they don't have to be as predatory as the females. They don't need the big teeth, distending jaw, expanding stomach or light-proof gut lining (so they don't get caught having eaten something luminescent). They are a hell of a lot smaller than the females and their eyes and teeth aren't half as daunting. The male Photocorynus spiniceps is only a quarter of an inch long, one of the smallest vertebrate in the animal kingdom; it is near enough half a million times smaller than its female counterpart.

Some of them are even quite cute.

Sort of.

All that matters with the males is their testicles and their primary concern is mating.

They have very sensitive eyes to seek out their mates in the gloom of the ocean. They also have an amazing sense of smell with which they can sniff out the pheromones of females through the water. Once they have sought out a mate, they latch onto her with their sharp little teeth. He bites into her skin and releases an enzyme that digests the skin of his mouth and her side so that they fuse together. Over the next couple of weeks, his whole body is absorbed into her until all that remains of him is a pair of testicles attached to her side.

In response to the to hormones in the female's bloodstream, the testicles release sperm into her system so that she has an available mate whenever she is ready to breed. Many males can latch onto any given female. A female was once discovered with eight pairs of testicles hanging off her.

In most species, if the male does not find a female with which to mate, he dies. In some species, however, the males are able to swim away into a dark and private part of the ocean where they grow massively and turn into a female in place of their missing mate.

It really puts it into perspective how great it is to be a creature that doesn't die just because it can't get laid...