The Vampire Squid

With its huge red eyes, cloak-like webbing and row upon row of formidable-looking toothy spines, the Vampire Squid (Vampyroteuthis infernalis) seems aptly-named. But while it may look like something that swam out of the depths of a late-night horror movie, it actually only reaches a maximum total length of around 30 cm.

Living at depths of 600 to 900 metres (2,000 to 3,000 ft) or more and feeding on copepods, prawns and cnidarians, the gloriously sinister Vampire Squid “flies” through the pitch-black depths by flapping two specially evolved large fins at the top of its body. This layer of the ocean is known as the oxygen minimum zone – a region where the level of oxygen saturated in the water is too low to support a normal aerobic metabolism. However it manages to thrive here by having an incredibly low metabolic rate which allows it to go for long periods without feeding – a very useful evolutionary quirk considering that prey is often scarce at extreme depths.

But its metabolism isn’t the only clever adaptation it uses to survive. The squid’s entire body is covered with bioluminescent, light-emitting organs called “photophores”, and its tremendous level of control over them means that it can switch them on and off at will and even regulate their intensity, effectively turning itself into a living light show. With the photophores off, its dark, gelatinous body is all but invisible in the inky darkness, but when used to full effect, they create myriad, complex patterns that can lure prey and even disorient attackers. The flashes it produces can last for fractions of a second or for minutes at a time

As impressive as this sounds, though, the squid has one more trick hidden up its cape. Instead of releasing ink when threatened as most normal squid do, the Vampire Squid releases a thick, sticky cloud of blinding bioluminescent mucus to daze would-be predators and allow it to make a hasty exit.