Head to head
Giant Squid vs Colossal Squid
They sound like the same animal, but the giant squid and the colossal squid are different species in different families, and "biggest" splits between them. One is longer; the other is heavier. Both are known mostly from carcasses and from the scars and beaks they leave in sperm whales.
| Giant Squid | Colossal Squid | |
|---|---|---|
| Family | Architeuthidae | Cranchiidae (the "glass squid" family) |
| Maximum total length | ~12–13 m (mostly tentacle) | ~10 m |
| Maximum weight | ~275 kg | ~500 kg — heavier and bulkier |
| Where it lives | Deep water in most of the world’s oceans | Deep Southern Ocean around Antarctica only |
| Arms and tentacles | Suckers with sharp toothed rings | Suckers plus rotating three-point hooks |
| Eyes | Very large — up to ~27 cm | The largest of any animal — ~27 cm, with a light organ |
| Body shape | Long and streamlined | Short, deep, and heavy |
| Main predator | Sperm whale | Sperm whale |
Giant Squid vs Colossal Squid: common questions
Which is bigger, the giant squid or the colossal squid?
It depends on the measure. The giant squid is longer, because its feeding tentacles stretch a long way, reaching a total length of 12–13 metres. The colossal squid is heavier and bulkier — around 10 metres but up to 500 kg, versus about 275 kg for a giant squid — making it the largest invertebrate by mass.
Has anyone seen either alive?
Rarely. A living giant squid was first filmed in its natural deep-sea habitat in 2012, and again since. A living colossal squid was filmed for the first time in 2025, but only a juvenile — a full-grown adult has still never been seen alive.
Do they fight sperm whales?
Sperm whales hunt both, diving to a kilometre or more to catch them, and many sperm whales carry circular scars from squid suckers and hooks. Whether the squid ever seriously injures the whale is unknown; the beaks of thousands of squid are found in some sperm whale stomachs, so the whale is clearly winning overall.