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Colossal Squid Size: How Big Is the Heaviest Invertebrate?
The heaviest invertebrate on Earth weighs as much as a grand piano. Here's how big the colossal squid really gets – the record specimen, its giant eyes and beak, and what we still don't know.
The colossal squid is the heaviest invertebrate – animal without a backbone – on the planet. But how big is it really? The honest answer: bigger than anything else like it, and probably bigger than we’ve ever measured.
How big is a colossal squid?
The biggest colossal squid ever measured weighs about 1,100 lb (495 kg) – roughly as much as a grand piano. Its total length came to 14 ft (4.2 metres). It was caught by a fishing boat in the Ross Sea off Antarctica in February 2007 and is now on display at Te Papa museum in Wellington, New Zealand.
When the squid was first pulled up, people estimated it at 26–33 ft (8–10 metres) long. But after 14 months in a freezer it had dried out and shrunk, and scientists also realised that the colossal squid simply isn’t as long as it is heavy. It’s built like a heavyweight wrestler, not a basketball player.
Colossal squid vs. giant squid: which is bigger?
It depends on how you measure. The giant squid is longer – up to around 39 ft (12 metres) including its two long tentacles – but it’s slimmer and lighter. The colossal squid has a shorter, much bulkier body and is far heavier. By weight, the colossal squid wins easily. The full showdown is in Colossal Squid vs. Giant Squid.
Shorter than its giant cousin, heavier than a grand piano, armed with rotating hooks. The colossal squid doesn’t need length.
How big are a colossal squid’s eyes?
About 11 in (27 cm) across – the size of a football, and the largest eyes of any known animal. Each one has its own built-in light organ. Scientists think the eyes are that big to spot the faint glow stirred up by an approaching sperm whale, the colossal squid’s main enemy, in time to escape.
How big is a colossal squid’s beak?
Like all squid and octopuses, the colossal squid has a hard, parrot-like beak in the middle of its arms. Its beak is the largest of any known squid. Beaks are made of a tough material that doesn’t digest, so they pile up in the stomachs of sperm whales – which is how scientists know these whales eat colossal squid regularly.
How big can colossal squid get?
Nobody knows for sure. Only a handful of adult colossal squid have ever been examined, all of them caught by accident. Because the record specimen is likely not the biggest one out there, it’s very possible that colossal squid grow heavier still. Remember: until 2025, nobody had even filmed a live one in its home.
Strange but trueThe first video of a living colossal squid in the wild, filmed in March 2025 near the South Sandwich Islands, showed a juvenile just about 12 in (30 cm) long – a see-through baby of the heaviest invertebrate on Earth.
Curious where the colossal squid fits among other deep-sea giants? Read Deep-Sea Gigantism.
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