California sea cucumber

The California sea cucumber is a soft, squishy animal that lives on the sea floor of the Pacific Ocean. It has a long, cylinder-shaped body with bumpy, leathery skin that is reddish-brown or yellowish. It is not a plant, even though it is named after a cucumber — it is a real animal, and a very gentle, curious one that spends its days pottering slowly along the bottom of the sea.

You can find this sea cucumber all down the west coast of North America, from the chilly Gulf of Alaska in the north to Baja California in the south. It likes rocky places with a current flowing past, from shallow water near the shore into deeper subtidal water — sources report different maximum depths, from tens of metres to a few hundred metres — in the cool, dim places where sunlight fades.

At one end of its body, the sea cucumber has a mouth ringed by about twenty little tentacles. These work like tiny sticky mops. The cucumber waves them through the sand and mud, or holds them up in the current, and picks up teeny bits of food floating past. Then it tucks each tentacle into its mouth, one at a time, to lick off its snack — a bit like eating from your own fingers!

To get around, the California sea cucumber uses rows of tiny tube feet on its underside. They grip the rocks and help it creep along, very, very slowly. As it travels, it acts like a little cleaner of the sea, hoovering up bits of leftover food and old scraps from the sand. Animals that tidy up like this are called recyclers, and they help keep the ocean floor healthy.

A grown-up California sea cucumber can be as long as your arm, up to about 50 centimetres, and it may live for about 10 to 12 years. The IUCN Red List rates it as Least Concern, which means it is not in danger of dying out across its whole range. In some places people do collect them for food, so scientists keep a careful eye on how many there are to make sure these squishy recyclers keep thriving.