Architeuthis eye question

[kariann]

After watching last night's Discovery Channel Documentary , my mind is full of all things Archi! As I was going through some of the footage again, and doing a little bit of research online, I was wondering if anyone could clarify for me the different depiction of the architeuthis eye. On every computer model I've seen, and even shown during last night's documentary, the eye of the giant squid is rendered as completely round, with the ability to have extraocular movement, much like a human eye. However, in the live pictures both from last night, and what I've found elsewhere the giant's eye looks more almond shaped with a white sclera, like a human eye, but it seemed to be fixed, not "looking around" as is always portrayed on the computer renditions. Does anyone have any explanation or clarification to this?

Thanks in advance!

 

[mournblade]

My guess is that it was "retracting" its eye because of the bright lights. The squid that was captured in Kyoto(?) about a decade ago had the same almond/diamond shape, and I remember someone (I can't recall who) on the forums saying it was retracting its eyes because of the bright light.

I am by no means a squid expert, so take my answer with a grain of salt.

 

[Clem]

Hello Kariann.

Architeuthis's eyes do move within their orbits. I don't think they're retractable; they're so large that there's really no available space left in the head into which they could be retracted. The lozenge-shaped, relatively small ocular apertures were one of the big surprises of the Kyoto specimen, because we'd been conditioned (most of us, anyway) to expect big googly eyes. Of course, given how absolutely essential they are to the squid's survival, it makes sense that there'd be some sort of protective structure covering the sclerae; whether the squid is reeling in thrashing prey or grappling head-to-head with a mate, the potential for damage is real.

Here's a nice video of Taningia (which made a brief appearance on Sunday's program), keeping its eyes squeezed shut during an amorous encounter with an ROV.

One odd thing about Archieteuthis's ocular apertures is that they change their shape, relative to the long axis of the squid's body. In photos showing the squid in a relaxed, moribund or dead state, the corners of the eyes are at right angles to the long axis; in photos showing the squid in a more active state, with the arms at or nearing full extension, the corners align with the long axis. I suppose it's a function of the squid's skin stretching and distorting the shape of the apertures.

Clem