The colossal squid was first described in 1925 based on specimens from the stomach of a commercially hunted sperm whale. A century later, an international voyage captured the first confirmed video of this species in its natural habitat - a 30cm juvenile, at a depth of 600 metres near the South Sandwich Islands. Colossal squid can grow up to seven metres and weigh as much as 500kg, making them the heaviest invertebrate on the planet. But little is known about their life cycle. The footage of a yo...