50 free Squid trivia questions with answers — nature quiz, new questions added Aug 2026.
This squid trivia quiz covers the ocean's fastest, strangest hunters, from the finger-length pygmy squid to the colossal squid of the Southern Ocean. The easy questions handle the basics: how many arms and tentacles a squid has, how it moves, what it squirts, and what it is called on a menu. The harder end goes deeper: the internal pen that is all that remains of the ancestral shell, three hearts and blue blood, the giant axon that inspired the Schmitt trigger, the Hawaiian bobtail squid's glowing bacteria, why some squid float on ammonium, the record 495 kg colossal squid, the first photograph of a live giant squid in 2004, the flying squid that glide 50 metres, Humboldt 'red devils', sperm whale stomachs full of beaks, and the sea monsters of Melville and Verne. Every answer was checked against the encyclopaedia entries before publishing and the supporting sentence is stored with each question. Our octopus, ocean and sea creatures quizzes are the natural next stop.
30 of 50 questions with answers and explanations. Play the quiz
Q 01How many limbs does a squid have, and how are they divided?
Ten: eight arms and two tentacles
The two long tentacles shoot out to grab prey; the eight arms hold and control it while the beak cuts it up.
Q 02What is the rod-like internal skeleton of a squid, made of chitin, called?
The gladius or pen
It is all that remains of the ancestral shell and gives the mantle something to attach muscles to.
Q 03Squid belong to the superorder Decapodiformes, a name from the Greek for what?
Ten-legged
Octopuses, by contrast, have eight limbs and no tentacles at all.
Q 04Despite its name, the vampire squid is more closely related to which animal?
The octopus
Bobtail squid and ram's horn squid are also taxonomically distinct from true squid.
Q 05True squid diverged from other cephalopods during which period?
The Jurassic
They only became prominent around 100 million years ago, radiating alongside the teleost fish they now resemble.
Q 06Why are squid fossils so rare compared with those of the similar belemnites?
Their soft bodies decay easily and even their beaks are fragile
Fossil beaks from Japan's Yezo Group suggest squid were already abundant by the mid-Cretaceous.
Q 07What is a squid's main means of locomotion?
Jet propulsion through the funnel
Water is drawn into the mantle cavity and blasted out of the funnel; the fins handle slow cruising.
Q 08Some squid can 'fly' out of the water and glide roughly how far?
Up to 50 m
They occasionally land on the decks of ships.
Q 09What are the specialised skin cells that let squid change colour called?
Chromatophores
Iridophores and leucophores add reflection and polarised patterns that change in milliseconds.
Q 10What is the camouflage called in which a squid produces light to match the glow from the surface above?
Counter-illumination
The firefly squid and midwater squid do it, hiding their silhouettes from predators below.
Q 11The Hawaiian bobtail squid glows thanks to which symbiotic bacterium?
Aliivibrio fischeri
The bacteria colonise a light organ within hours of hatching, and about 95% are expelled every morning.
Q 12Squid ink is a suspension of which pigment?
Melanin
It empties into the rectum, and its alkaloid nature may also jam a predator's chemoreceptors.
Q 13Squid giant axons, up to how thick, let the mantle contract all at once for maximum jet speed?
1 mm in diameter
The thick fibres became a classic model for neuroscience and inspired an electronic circuit.
Q 21Most squid are no more than how long?
60 cm
The giant squid, at up to 13 metres, is the wild exception.
Q 22What are probably the smallest squid, with mantles of just 10 to 18 mm?
Pygmy squids (Idiosepius)
They are bottom-dwellers with short bodies and stubby arms.
Q 23Which is the largest invertebrate, growing to perhaps 10 metres?
The colossal squid
A 495 kg specimen caught off Antarctica in 2007 had eyes bigger than footballs.
Q 24How much did the largest squid ever documented, caught by a New Zealand vessel in 2007, weigh?
Q 14Which electronic circuit was inspired by the squid giant axon?
The Schmitt trigger
Otto Schmitt built the comparator with hysteresis to replicate the axon's impulse propagation.
Q 15How does a squid focus its eye?
By moving the lens, like a camera
The globular lens has a depth of focus from 3 cm to infinity, and the slit pupil handles brightness.
Q 16Deep-sea squids of the family Histioteuthidae have what oddity?
Two different eyes, one tubular and looking upwards
The big left eye scans for silhouettes above; the normal right eye points forwards and down for prey.
Q 17Which organs give a squid its sense of balance, like the inner ear of a fish?
Statocysts
Without them the squid cannot keep its equilibrium; lines of hair cells on the head and arms act like a fish's lateral line.
Q 18How many hearts does a squid have?
Three
A systemic heart plus two branchial hearts that push blood through the gills, all inside the mantle cavity.
Q 19What colour is oxygenated squid blood?
Deep blue
The copper-rich protein hemocyanin carries oxygen well in cold, oxygen-poor water.
Q 20Many squid stay buoyant using a fluid-filled chamber in which heavy seawater ions are replaced by what?
Ammonium
Glass squids have a transparent chamber occupying two-thirds of their volume; unlike a swim bladder it does not compress with depth.
495 kg
Its eyes, built to spot prey in the deep Southern Ocean, may be among the largest ever to exist in the animal kingdom.
Q 25In 1978, squid claws cut up the rubber hull coating of which US Navy ship?
USS Stein
The size of the marks suggested the largest squid known at the time.
Q 26What is the scientific name of the giant squid?
Architeuthis dux
Genetic research suggests there is only one species; Steenstrup coined 'Architeuthus' in 1857.
Q 27In what year did a Japanese team obtain the first images of a living giant squid in its habitat?
2004
Kubodera and Mori's baited camera line, 900 m down off the Ogasawara Islands, took over 500 photos before the squid tore free.
Q 28How did Kubodera and Mori work out where to look for giant squid?
By tailing the movements of sperm whales
'We knew that they fed on the squid, and we knew when and how deep they dived,' Kubodera said.
Q 29Giant squid eyes can be at least how big across, among the largest of any living creature?
27 cm
Only the extinct ichthyosaurs are known to have had bigger eyes; big eyes catch scarce deep-sea light.
Q 30Which animal is the giant squid's chief predator?
The sperm whale
Sperm whales are often found with circular sucker scars around the head from their struggles.