Colossal squid – the body parts

Colossal squid are the heaviest invertebrates on Earth, with specimens reported weighing in at 495kg – that’s nearly eight times as heavy as the average human! Despite their size, large colossal squid specimens in good condition are rarely available to scientists. That’s why scientists from Auckland University of Technology (AUT) are excited to undertake research on this latest find.

Many aspects of colossal squid biology remain a mystery, or are the subject of debate among researchers. This latest colossal squid will be examined thoroughly to gain as much knowledge as possible.

What parts of the squid will scientists be examining? Let’s find out…

Eye

Scientists examine tissue around the colossal squid's eye, 2008. Photographer: Jean-Claude Stahl © Te Papa

Scientists examine tissue around the colossal squid’s eye, 2008. Photographer: Jean-Claude Stahl © Te Papa

Colossal squid have the largest eyes of any animal known – ever! At 27cm in diameter, they are around the size of a soccer ball. Unfortunately for scientists, squid eyes are very delicate, and rarely in good condition when found.

Little light can penetrate the deep-sea habitat of the colossal squid, but vision is still very important. Their huge eyes are used to catch prey and to watch for predators. And they come with their own built-in headlights! Photopores (light organs) produce light using a chemical reaction involving bacteria. This light probably helps to hide the silhouette of the squid from any prey swimming underneath, making it easier for the squid to sneak up on their dinner.

Hard Parts

Colossal squid beak. Photographer: Jean-Claude Stahl © Te Papa

Colossal squid beak, 2008. Photographer: Jean-Claude Stahl © Te Papa

The hard parts of a squid – the beak, eye lenses, hooks, suckers and statoliths (small granules of calcium carbonate in the squid’s head, which enable it to sense its position in the water) – can provide insight into squid biology.

Scientists don’t know how long colossal squid live for, but the hard parts of the animal could help to solve this mystery. These hard parts contain indicators of growth, a bit like tree rings, which may enable AUT scientists to work out how old this colossal squid is – and the average colossal squid lifespan.

Muscle Tissue

colossal squid, Mesonychoteuthis hamiltoni Robson, 1925, collected 2008, Ross Sea, Antarctica. CC BY-NC-ND licence. Te Papa (M.277964)

Colossal squid, Mesonychoteuthis hamiltoni Robson, 1925, collected 2008, Ross Sea, Antarctica. CC BY-NC-ND licence. Te Papa (M.277964)

The main part of the squid is called the mantle, which is made up of muscle and skin. Colossal squid live deep under the dark Southern Ocean, so scientists have never observed one alive in its natural environment. Instead, scientists use chemical analysis of muscle tissue to try and understand more about the squid’s biology.

The colossal squid currently on display at Te Papa has a mantle of around 2.5 metres long, and 98 centimetres wide – almost the same diameter as a truck tyre!

The muscular tail fins are attached to the upper surface of the mantle. The squid swims through the water by undulating or flapping the fin. Many squid can swim “forward” and “backward” equally well while swimming with the fins. The squid can also swim by squirting water out of the funnel (below the head); rapid jet-propelled swimming is usually used when the squid need to move quickly.

Reproduction

Male colossal squid are unknown to science, and reproductive biology for many deep-sea squid is still a mystery. Reproductive structures will be investigated to determine whether this species is male or female. The colossal squid specimen dissected in 2008 was female – they were able to tell this by the eggs the squid was carrying in the mantle. All squid lay eggs, and it’s likely that colossal squid lay clusters of eggs in a large, jelly-like floating mass.

Get involved!

There’s a lot for scientists to be examine! You can watch live online on 16 September as scientists from Te Papa and Auckland University of Technology carry out their examination and research. Our presenter will be Veronika Meduna, from Radio New Zealand’s Our Changing World.

Watch on YouTube, or watch below.

If you have questions for our squid scientists, email sciencelive@tepapa.govt.nz. We’ll answer your questions during the live show.

For regular updates and the latest on the colossal squid, follow:

Visit Te Papa’s colossal squid website to find out more about this species

Schools

We’re running a special part of the live-stream just for schools. From 11.30–12 on 16 Sep, we’ll be answering questions from classrooms across New Zealand. To join in and get your class’s question answered, email:
sciencelive@tepapa.govt.nz

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