Squid – the inside story

Dissecting an arrow squid

Dissecting an arrow squid

It’s a lovely spring Friday morning in Wellington. What else would we (Pamela, Chris and Judy – our brave and newest squid team member) be doing other than dissecting a couple of nice fresh squid from the local wholesale fish supplier?

It’s all in the interest of bringing you a bigger and better exhibition on the colossal squid, as we come to grips with squid anatomy (literally).

We quickly discovered that not all squid are the same on the inside (surprise) and that once inside them it can be a messy business. Note to self – try to avoid puncturing the ink sac until the end.

We started with an arrowsquid. We checked the arms and the tentacles – all eight arms and two tentacles present and correct. The suckers on the arms had hard little circles, which pop out – who needs to pop bubble wrap?

Cutting through the mantle was hard work – you need a sharp pair of scissors or a good scalpel. Pulling back the folds of the mantle reveals the inner organs. Working out what they all are is a challenge but we think we identified the gills, the stomach and caecum and what we thought was the hearts. Yep, that’s right, a squid has three hearts.

The eyes were exciting to dissect. It was a thrill to extract the lenses and find that they come in two parts – just like the colossal squids, and indeed all squid. The arrowsquid lens is a lot smaller – around 0.5cm across – compared with the huge orange-sized lens of the colossal.

opening up the mantle

opening up the mantle

Arrow squid have awesome eyes

Arrow squid have awesome eyes

It was also really exciting to remove the beakfrom the really dense muscular tissue surrounding it. First we got the lower beak out, then the upper beak and we could see how they fit together. Then we came across the radula – it’s a bit like a tongue – with it’s amazing rows of sharp, raspy teeth.

 

Arrow squid beak, upper and lower

Arrow squid beak, upper and lower

Stomach contents of our squid were examined. We could feel the crunchy bits inside, and these turned out to be fish vertebrae. Last but not least we cleaned away all the messy bits to expose the mantle – and extract the gladius, or pen. This incredible structure just glides out of the mantle and looks for all the world like it’s made of plastic.

So I’m hooked on squid anatomy – there will more on the broad squid we examined next, shortly.

3 Responses

  1. emmabest

    Not sure if its still on display but the Otago Museum in Dunedin (not sure where you’re emailing from Alisa) did have a whale eye specimen in a jar up in Animal Attic which I always loved going to see…

    Reply
  2. Pamela

    Hi Alisa
    Yes, these squid eyes were pretty amazing – especially dissected out like that. I’m not sure if we can help you with an image of a whale eye outside of a whale but I’m sure someone out there studies whale eyes and whale vision.

    Te Papa’s whale expert is away in the States at the moment so I can’t ask him. We are about to open our Whales Tohorä exhibition at the National Geographic Museum in Washington DC.

    Happy to ask him for you when he’s back in NZ.

    Reply
  3. Alisa

    Those eyes are groossssss!

    I guess all eyes are gross, if they’re just sitting out like that. I want to see a whale eye that’s sitting outside of the whale.

    Reply

Leave a Reply

  • (will not be published)