Discovered in the deep: the sea cucumber that lives a jellyfish life

The Pelagothuria natatrix is an extremely rare species of sea cucumber - with a gelatinous body, it spends most of its time swimmingDiscovered in the deep: the incredible fish with a transparent headWafting through the deep sea is a diaphanous creature that resembles a jellyfish, but is in fact something else entirely. Pelagothuria natatrix, meaning swimming sea cucumber, belongs to a group of animals better known for lying around on the seabed like giant, rubbery worms.This sea cucumber was first named in the late 19th century, but for a long time it was only known from a few battered specimens brought up in scientific trawl nets. "They're extremely fragile, almost to the point of being sort of intangible," says Chris Mah, a biologist at the Smithsonian Institution in Washington DC. "The fact that they're gelatinous makes them extremely difficult to study." Continue reading...