Who hasn’t heard of the giant squid? These large beasties have been the source of much mystery and speculation over the years. Until 2001, no pictures or video of a live giant squid had ever been taken. So lets learn a little bit more about this enigmatic cephalopod, and discover why they’re so hard to catch on camera. 

Giant squid are found all over the world’s oceans, though they are rare in tropical and polar waters. They are deep sea creatures, generally found at depths of 300 to 1,000 meters. Of course, the range and depth of giant squid is largely based on inference, as observing them in the wild is extremely difficult. 

Pictures of live giant squid are few and far between, so we have to make do with recovered specimens. This giant squid is missing its two long tentacles, but is still pretty big! NASA, Public Domain, via Wikimedia Commons.

One very important question we all have about giant squid is: how giant are they? The answer is: pretty freaking giant. The estimated maximum length of a giant squid is whopping twelve to thirteen meters, from the top of its head to the tip of its long, long tentacles. Female squids are a bit larger than males, with males only reaching a paltry ten metres in length. The giant squid’s size makes it one of the largest living invertebrates, the top spot going to another large deep-sea squid, the colossal squid.  Colossal squids aren’t  quite as long as giant squids, but are significantly heavier. 

Other parts of the giant squid are also impressively large. Their individual suckers measure two to five cm in diameter. Although this might not sound like a whole lot, keep in mind each of its eight arms and two tentacles are covered in hundred of suckers. Giant squids also have very, very large eyes. Their eyes measure at least 27 cm in diameter, which are possibly the largest eyes of any living creature (the colossal squid is a contender in this category, and extinct ichthyosaurs are the only known creature to have larger eyes than our squid friends). These massive eyes help squids see in their deep sea habitat, where very there’s little light to see by. 

Preserved sperm whale skin showing off some lovely scars, courtesy of a giant squid. NASA, Public domain, via Wikimedia Commons

While most fish use gas-filled swim bladders to stay buoyant in water, giant squid do things a bit differently. Their bodies contain an ammonium chloride solution that weighs less than seawater, thus keeping squids afloat. Apparently this makes the squids taste like salty liquorice. The fact that we know this means someone, somewhere, had to taste a giant squid or, more likely, one of its large cousins that also use this method of buoyancy. 

Speaking of eating, you’re probably wondering what giant squid eat. Their diet isn’t particularly exciting, as they feed on deep sea fishes and other squid. Their very long tentacles are used to capture prey and bring it to their beaks, where a tongue with lots of file-like teeth called a radula shreds their prey. Did I mention that the suckers on giant squid tentacles are lined with serrated, chitinous teeth? Moral of the story: don’t mess with giant squids. 

There is one animal (besides other giant squids) that famously ignores this advice: the sperm whale. Sperm whales are the only predators of adult giant squid (unless of course megalodons are still lurking in the ocean depths), and most of what we know about giant squid actually comes from specimens found inside sperm whate stomachs. Sperm whales are sometimes found with ringed scars on them, presumably from the suckers of giant squid.

The ocean is a vast, largely unexplored landscape. In the depths of this watery world, even immensely large creatures like the giant squid are nearly impossible to find. Hopefully as we explore more of our ocean we can learn more about the wonderful giant squid!

Cover image by fir0002 flagstaffotos [at] gmail.com, GFDL 1.2, via Wikimedia Commons, cropped to fit.