How big are squid?
There are over 300 species of squid. They range in size from 2.5cm to 13 metres, with a Giant Squid able to grow up to 10 metres in length.
The largest squid ever found was 17 metres long and the smallest species of squid is the northern pygmy squid – they grow to about 15 millimetres.
Betty Wills (Atsme), Wikimedia Commons, License CC-BY-SA 4.0
What do squid eat?
Squid are predators and mostly eat fish and crustaceans. They even feed on each other, especially when caught in fishing nets.
They have a hard parrot-like beak that helps them to kill and eat their prey.
What do squid use their tentacles for?
Squid tentacles are primarily used to capture prey. They have two tentacles near their mouths which are used to grab hold of prey, while the other sucker-laden tentacles are used to keep the prey still whilst it is eaten.
How do squid communicate?
Squid can subtly glow, using light producing organs in their muscles. They can also change colour using pigment filled cells called chromatophores. These changing patterns of light and dark pigment on a squid’s skin help them to communicate with each other, something they particularly do as they hunt.
Squid live both alone and in schools. They have short life spans and normally die not long after mating, something that usually takes place at around one year old.
Do squid squirt ink?
When escaping from prey a squid might squirt ink as a defence mechanism. The ink acts as a kind of smokescreen, enabling the squid to escape – think of it as a magician disappearing in a puff of smoke.
The ink is typically black but could also be brown, reddish or dark blue.
The ink is a combination of black ink from the ink sac and mucus. You’ll be pleased to know that ‘squid ink’ in food doesn’t include the mucus part.
How many hearts do squid have?
Squid have three hearts. Two of them pump blood to the gills to get oxygen, whilst the third heart pumps the oxygenated blood around the body.
How do squid swim?
Unlike Octopuses, squid have an internal shell that gives their body structure. When wanting to move through the water they suck water into a long tube and then push it back out, pushing them through the water.
Are squid endangered?
Squid aren’t classified as endangered, but they are at risk of overfishing.
Squid are intelligent creatures. In the UK squid are legally recognised as being sentient beings, that feel pain and pleasure. Because of this, their welfare is considered when policy making.
Squid in popular culture
When you think of squid you may well think of an old illustration, depicting a squid in a tentacley battle with sailors. Giant squid feature in many tales of ocean travel, although there are no real life reports of squid fighting sailors.
One of the most famous depictions of a giant squid is in Jules Verne’s Twenty Thousand Leagues Under the Seas, where Captain Nemo’s submarine fights seven giant squid. Giant squid are also featured in Moby Dick, Harry Potter, Finding Dory and even in the James Bond book Mr No.
Find out more
Visit The Robot Zoo for a chance to learn more about how squid move around the ocean. Take part in jet-propelled squid racing, plus more interactive games and challenges.
Lead image: Klaus Steifel CC BY-NC 2.0