This sausage or cucumber-shaped animal is known as a sea cucumber, and there are around 1,200 species of sea cucumber worldwide!

Sea Cucumber

It belongs to a group of animals known as ‘echinoderms’, meaning spiny-skinned, which also includes sea urchins, brittle stars, feather stars and sea stars.

Echinoderms have a dermal skeleton consisting of hard plates under the skin, giving it a spiny texture. They are ‘radially symmetrical’ – which means their body can be divided into radial parts, like rays extending out from the centre. Echinoderms also have water-filled ‘tube feet’ which may be used for moving around, breathing and collecting food.

Sea cucumbers lie on the sea floor and move using their tube feet or by squeezing up and then stretching out their bodies like a caterpillar. They are found all over the world, from shallow coastal waters down to the deepest parts of the ocean. Sea cucumbers make up around 90% of all macrofauna found below 8,900m, with some even found as deep as 10,687m

Sea cucumbers are primarily detrivores, scavenging for algae, plankton and detritus on the seafloor. They feed by sucking sand through their mouth and filtering out any organic material for food. The clean, filtered sand is then expelled out through their anus. Sea cucumbers play a vital role, helping to recycle nutrients and break down detritus in marine ecocystems. If you are snorkeling or scuba diving, you can often see these trails of sand being left behind.

Other sea cucumbers feed using tentacles around their mouths, which are actually modified tube feet. The tentacles extend to pick up plankton and other organic particles of food before passing it into their mouths.

Did you know…
If threatened, some sea cucumbers will eviscerate, which involves ejecting out their internal organs, to scare any potential predators. This can be regenerated in a few days. Gross!