The good news is that you still have until the 29 October to enjoy our incredibly popular temporary exhibition the Robot Zoo and interact with the larger than life animatronic animals that inhabit the gallery. In even better news, there is still one final species in the exhibition to have not yet been investigated by the Specimen of the Month blog series, hoorah, and that is the Giant Squid (Architeuthis). NB: There is no bad news in the Specimen of the Month blog series.
Squid or Cuttlefish?
Today is International Squid and Cuttlefish Day, so let’s start with the difference between a squid and a cuttlefish as let’s be honest, probably not everyone has nailed it. Cuttlefish are a type of squid so, that’s confusing for a start. What we’re really asking is - what’s the difference between a cuttlefish-squid and all of the other types of squid that we call squid, ‘traditional squid’ if you prefer. The answer - Cuttlefish have a lovely fringe that skirts their entire body like a tutu, and a face that looks like it got stuck in a spiralizer. A squid-squid, on the other hand, could be compared to an ice cream cone with an octopus stuck on the top. The tutu is restricted to two triangular ‘wings’, one on either side of the mantle, that in some species form an arrow-shaped ‘tail’.
Unlike their close relative, the octopus, whose anatomy is restricted to just the eight appendages, both squid and cuttlefish have eight arms and two tentacles as well for good measure. The arms are covered in suckers, which in the Giant Squid can measure 5 cm across. Tentacles tend to be much longer than the arms and have sucker-covered ‘tentacular clubs’ on the tips. The tentacles are used in the same way as rocket-propelled net launchers; they are flung out at prey with great speed in ambush attacks. Once they’ve got a hold, the tentacles bring the prey in closer to where the arms can get involved and help guide the prey back to the mouth at their base.
Left: A Cuttlefish showing the tutu that surrounds the body (mantle). Right: A common squid showing the triangular wing on either side.
They don't make it easy
Incredibly, despite extensive efforts by scientists to study them, no Giant Squid had ever been seen alive until 2004 when Japanese scientists managed to get the first photographs of a living animal. It took another two years for scientists to hook one and pull it to the surface, thus making history with the first human (on record) to ever clap eyes on a live Giant Squid. In 2012, scientists used a submersible and both saw and recorded a Giant Squid feeding in its natural habitat.
The story of how they acquired the footage that had scientists around the world drooling over their laptops is quite wonderful. Given how vast the world’s oceans are, rather than going in search of a Giant Squid they decided it would be much more efficient to attract a squid to them. The Giant Squid doesn’t prey on jellyfish (that we know of) but jellyfish luminesce when predators are nearby, and jellyfish predators are what the Giant Squid eats. So the research team attached a series of bioluminescent lures to the outside of their submersible in an ingenious effort to mimic panicked jellyfish, and, as you can see from this clip beneath, the ingenuity paid off.
20,000 leagues under the sea
There is a lot of misinformation about the Giant Squid, specifically in relation to its size. It doesn’t help that what we do know about their dimensions is largely based on carcasses that have washed up on beaches half decayed, with tentacles and arms missing, and often bloated with water. Without a doubt, the Giant and Colossal Squid are the two largest invertebrates on the planet (currently known to science), yet because they are so elusive, and we can’t just go out and catch a good sample of specimens, we don’t know realistic maximum body lengths.
Putting aside anecdotes from fishermen who report 900 foot monsters far out at sea - the Giant Squid is thought to be responsible for the myth of the Kraken for example - the largest scientifically recorded Giant Squid specimen was 13 metres. That is a massive animal with enough wow-factor to not warrant exaggeration in my book, but exaggeration is human nature I suppose. Measurements for the largest Colossal Squid on record vary greatly but most references seem to acknowledge the Giant Squid as being the larger of the two.
The final thing I want to tell you about the Giant Squid is how they got so big. The best guess scientists have come up with is this species has evolved larger and larger in an eight-arms race with predators. The only (known) predator of an adult Giant Squid is the Sperm Whale, which in itself is a huge beast and imagining epic battles between these two colossal creatures makes one's inner geek salivate.
Although this has never been witnessed (presumably their encounters occur many fathoms below the surface) beak parts of Giant Squid are regularly recovered from the stomachs of Sperm Whales, and in a tit-for-tat scenario that suggests a battle rather than clear-cut predation, many Sperm Whales are found to be covered in scars from giant suckers, duh duh duuuuuh...