Most of the deep sea is still an alien place to us. But while the ocean remains largely unexplored, we occasionally get a glimpse of the weird and wonderful creatures that eke out a living in the deep.
Six hundred feet is all that separates you from an alien world, right here on Earth. Descend that far into the ocean, and you enter the ‘twilight zone’ of the deep sea, where the Sun’s rays gradually fade away and animals play a deadly game of hide-and-seek with predators in the shadows.
Take a look at some of the most bizarre animals discovered in the dark sea so far.
Dive down beyond 3,000 feet and you’re in the ‘midnight zone’, a vast darkness punctuated by flashes of light from life forms that hunt for food and seek mates here. It’s a world with terrifying teeth, like those of the fangtooth fish. But don’t let this weird creature scare you: it only eats other fish.
Ocean animals often have early stages in their life cycles that are very different from their adult form. This transparent leptocephalus larva will eventually develop into an adult eel, transforming the shape of its body.
But having a thin, see-through body in its early life may help it to survive the myriad of predators in the ocean. Because the larvae and adults look so different, larval forms were often described as different species from the adults, until marine biologists realised they were different stages of one life cycle.
The stoplight loosejaw fish is one of the stealthiest predators in the deep. Its lower jaw is an open frame of bone with no fleshy floor across it, which means it can snap shut very quickly like a mousetrap. And it’s called ‘stoplight’ because the bioluminescent organs near its eyes produce red light.
This bizarre creature has a clear advantage over its prey. Most bioluminescence in the deep ocean is blue, as that color travels well through water, and the eyes of many deep-sea animals aren’t sensitive to red light. But the stoplight loosejaw can see red, so it can light up its prey without alerting them to the danger.
The glass squid gets its name from its transparent body – a neat trick to avoid casting a shadow that could be spotted by predators in the deep sea. Their eyes are more opaque than the rest of their body, so each eye also has a bioluminescent organ to mask its shadow.
Boxer snipe eel
Thos ribbon-like fish is about 1.5 meters long, with streamers twice as long on its tail, which gives this fish its name. Its other name is the ‘tube-eye fish’ thanks to the binocular-like lenses of its eyes, which are used to spot the shadows of prey in the twilight zone. So unusual is the tube-eye fish, that it’s the only species in the entire taxonomic order.
The boxer snipe eel feeds by sweeping its long jaws through the water, snagging the appendages of passing crustaceans on its fine teeth.
The terrifying appearance is not the only weird thing about the Anglerfish. It also goes to the extreme to find a partner for mating.
The males are much smaller than the females, and when boy meets girl, he gives her body a kiss that lasts the rest of his life. The male’s blood supply joins up with the female’s through his lips, and he lives off her while she carries around, and he fertilizes her eggs when she releases them.