'We’re constantly surprised': The strange deep-sea creatures that eat whales

From bone-eating snot-flowers to snowboarding scale worms, when a whale dies it becomes a colossal island of nutrients – attracting weird and wonderful creatures to feast.

Whales are the big rigs of the ocean. They can transport up to 150 tonnes (300,000 lbs) of food stuffs – meat, blubber and bone – far across oceans, and from the surface to the depths. Their bodies are a veritable feast in the making.

Whales usually die far out to sea, scattered along their often vast migration paths, says Greg Rouse, curator of benthic invertebrates at Scripps Institution of Oceanography in San Diego, California. At first, the carcass may float as the gases inside make it swell up like a balloon. Then the whale sinks – through the sunlight, twilight and midnight zones – eventually reaching the darkness of the abyss, its final resting place.

In death, the whale gives life, becoming an immense island of food. Nutrients usually arrive in the deep sea as tiny particles of organic matter, known as marine snow. But when a whale sinks to the seabed, it is said to be the "largest organic input" to reach the deep ocean floor at any one time. A single whale can be equivalent to several thousand years' worth of marine snow – and its bounty can feed a whole ecosystem for decades. (Read more about the importance of whale fall to deep-sea biodiversity.)

First come the scavengers

The "deep water scavenging community" are the first to arrive, says Adrian Glover, deep-sea ecologist at the Natural History Museum in London, UK. "Which includes vertebrates like hagfish and sleeper sharks, and lots of scavenging amphipods – crustaceans like shrimps. They eat the flesh, exposing the bone." This "mobile scavenger phase", he says, can last years.

Hagfish are the only known living animals that have a skull but no vertebrae. These fish burrow face-first into their food, eating it from the inside out. Hagfish have an extraordinarily slimy self-defence tactic. When attacked, a hagfish will exude mucous which forces a predator to retreat or suffocate.

Rattail fish can grow up to a metre in length (3.2ft) and live at depths of up to 4,000m (13,100ft). Down there, far beyond the reach of the sun, the only light is made by living organisms – and the rattail's big blue eyes can glimpse even the tiniest flickers of bioluminescence that give its prey away. Whisker-like barbels on its chin, too, sense any movement by tasty morsels – crustaceans or wriggling worms – that might be hiding just under the surface of the muddy ocean floor. A keen sense of smell, meanwhile,........

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