Cock-eyed Squid

Image: Richard E. Young
Flowervase Jewel Squid, Stigmatoteuthis hoylei

Symmetry. Sexy, sexy symmetry. We all love a bit of symmetry. In fact, we're sexually attracted to symmetry. Leonardo da Vinci used it during his short-lived career as a purveyor of softcore filth. Mathematicians and physicists can't get enough of the stuff, the dirty buggers. Sure, one can get away with certain, limited instances of culturally acceptable asymmetry - a good left side-parting, for example - just keep it under your asymmetrically placed hat.

When it comes to animals, we're truly spoilt for choice. If it's big enough for the eye to see, it's probably symmetrical. At least on the outside. And innards are unattractive no matter how you arrange them.

There's this one, weird thing, though; all those cartoons you get nowadays where the characters all have one eye bigger than the other. A bit of zaniness never goes amiss in a madcap cartoon, but what about real life?

Enter the Cock-eyed Squid. There are about 19 of these deep sea cephalopods in the Histioteuthidae family. The biggest one reaches 33 cm (13 in) mantle length, or 120 cm (47 in) if you include the tentacles, while others may only reach about 5 cm (2 in) long

Image: David Shale
Umbrella Squid, Histioteuthis bonnellii

Some Cock-eyed Squid are covered in amazing colours, patterns and photophores, such that they are sometimes called Jewel Squid. However, the main thing about them is that one, crazy eye...

Image: Richard E. Young
Is that a cock-eye in your face or are you just pleased to see me?

It's not just that their left eye is a little bigger than the right one. It's more that the left eye is twice as big as the right one, kind of tubular in shape, a bit yellow in colour and it bulges out of the head, sometimes horribly and dangerously so. It's like they're wearing a monocle! Or that weird, "eye-popping" thing that happens when a humanoid wolfman sees an attractive Homo sapiens female. I guess only half their brain noticed her.

But what on earth could a perfectly good squid want with that one, monstrous eye? Well, since there's nothing to suggest that female Cock-eyed Squid are attracted to a really big, bulbous cock-eye (and indeed the females have one too), it can only be about eating.

1. Sex
2. Food
3. Personal growth as an artist

Those are pretty much the options.

Image: L. Madin, NOAA, Census of Marine Life, 2006

Most Cock-eyed Squid live in the ocean's Twilight Zone. This is where it isn't quite pitch black, as enough of the sun's light gets through to render everything a dark, hazy blue. This is where you'd normally say that a good pair of eyes are still useful, but clearly you don't need a pair, you just need one.

That massive eye points upward, seeking out the silhouette of prey going about their business in the gloom above.

Many creatures try to hide their silhouette with bioluminescence, lighting their underside in a shade and intensity that matches the twilight. This is called counter-illumination. The yellow tint of the Cock-eye could be used to counter counter-illumination.

The yellow pigment would filter out some of the blue colour, such that the twilight haze could end up appearing utterly black. If a fish is attempting counter-illumination but hasn't got the colour quite right, it will now be apparent as something that isn't black shining against a black background.

That's the kind of technological innovation required to fight against such ninja tactics.

Image: Richard E. Young
Histioteuthis cerasina

Here's looking at you. But not with his giant, sticky-out, googly-eye. Not on a first date, anyway.