Sea Cucumber

Photo: NOAA National Ocean Service

Weird Gramma here, and this is “WeirdFins,” all about strange stuff in the sea, and brought to you by the National Oceanic and Atmospheric Administration. Well, Pat in Tigard, Oregon, has heard of a cigar-shaped thing that can hurl its innards out its rear end and then grow ‘em again!

Well, Pat, this is a sea cucumber, and more than a thousand species live all over the world. They’re related to starfish and sea urchins, but they have a soft, leathery skin instead of hard spines. Some sea cukes are ugly and some are pretty, some live nearshore and some, miles down in ocean trenches. Some can swim, some hide in the sand, and some just chug along the sea floor. One kind is the size of a kidney bean, but another is 15 feet—as long as a car!

Most sea cucumbers scavenge for their food. This exposes them to crabs and other creatures that want to eat them so sea cukes have a nifty defense: They shoot a wad of sticky threads from their rear end that entangles the attacking crab while the sea cuke sneaks away to re-grow its innards. If you handle this goo, you can get a bad skin rash, and if the stuff gets in your eyes, it can cause blindness! So fishermen who harvest sea cukes tend to be real careful.

Sea cucumbers are sold for Asian cooking, where they’re called trepang or bêche-de-mer. Some species have toxins used for medical research, and some kinds are popular for home aquaria. And in the Pacific Islands, fishermen not only use them for fish bait but use the gooey threads as bandages on bleeding wounds.

Sea cucumbers are real important to healthy oceans. They grind stuff into finer particles that are part of the sea’s great nutrient cycle. So, too much fishing for them ruin bottom habitat for other animals.

You can see pictures of sea cucumbers on the on the National Marine Fisheries Service