California Sea Cucumbers – at the top Parastichopus californicus (Photo credit: Lynette S.)
The first time I heard about a creature called the Sea Cucumber was the day I got to touch one at the Seattle Aquarium! I’m not usually too excited about touching sea creatures, but there was something fascinating about the squishy, thorn-covered reddish mass they said was a living animal. Little did I know it was a good thing the staff had picked out just the right kind to put on display.
Like almost everything living in the ocean, sea cucumbers are NOT plants. They are classified in the same family as sea stars and urchins (echidnoderms). And about 60 of the 1,000+ varieties of sea cucumber (aka Sea Slug, scientific title: Holothuroidae [hollow-thr-oy-dee-ah]) produce a toxin (with the clever name holothurin) that will kill nearby fish in minutes.
Three-Rowed Sea Cucumber
Sea Cucumbers have some very unusual features. They use two different organs to breathe, neither of which are lungs or gills. Some have only one type, others have both. (OK, moms, I’m going to have to get graphic here, but these things are more like earthworms than anything else. Just remember, this was God’s idea and He isn’t embarrassed about how He designed them!). Here’s the deal, they breathe through their back-end hole! One of the organs is called respiratory trees that are built in to the tail-end of their intestines. The other is called Cuvier’s Organ or tubules. Those of you who love squeamish things will get a kick out of what the Ocean Portal will tell you about this sea cucumber habit.
A sea cucumber feeding while on gravel
Sea cucumbers have been designed to get along without quite a number of things. When a predator tries to eat them, many sea cucumbers will first eject super sticky white threads to tangle the predator up. If that isn’t enough, they squirt their internal organs (including those Cuvier thingummies) out their tail end and try to escape (they soon regrow them and are fine). This doesn’t just give the fish or sea star something to snack on, it might just kill them because that’s where the “holothurin” toxin is. Sounds pretty smart to me!
But wait, how can this critter be so smart? It doesn’t have a head or even have a brain! Go figure. My guess is that it was very cleverly designed with the wisdom it needed by our great Creator God.
The way sea cucumbers eat is pretty weird, too. They all have tentacles that they extend to collect food and draw it into their mouths. When they sense danger they can pull the tentacles inside themselves (without a brain!). Some of the prettiest sea cucumbers collect food directly from the ocean current, but most are plain old scavengers.
I told you they are a lot like earthworms? They sift through the sand and stuff at the bottom of the ocean like worms. Many types of sea cucumbers bury themselves completely to dig around for tasty bits of leftover sea creatures.
The amazing thing is how popular these creatures are in the far eastern diet. Ewww!
Turns out sea cucumbers have an amazing habitat. Basically, if you are in the ocean, there are sea cucumbers underneath you! I saw a map showing their location, and the whole thing was lit except the land bits. There are sea cucumbers in the Arctic Ocean, giant ones (2m [6+ft]) in the Indonesian ocean, and really cool, strawberry cucumbers off the southern coast of NZ. The NZ ones can be found in shallow waters or depths up to 1000m [3,200ft].
The pelagic sea cucumber Enypniastes, swims so gracefully above the mud bottom that they are often confused with jellyfish.
Several varieties of sea cucumber are found throughout the tropical waters of the world including Burrowing and Sand sea cucumbers. I wonder how they managed to get around Africa or South America? Maybe they didn’t have to, because they were washed both ways when the continents split? Perhaps you can join a research group to find out more about these amazing creatures some day.
People rule over the sheep and cattle and all the wild animals.
They rule over the birds in the sky and the fish that swim in the sea.
Lord our Lord, your name is the most wonderful name in all the earth! Psalm 8:7-9 Easy-to-read Version
PS Sea Cucumbers have been sea cucumbers since the time of the fossils. Who’s surprised?
Photo gallery of high quality sea cucumbers in their amazing variety
For more info (and great pictures) check out Wild Singapore Sea Cucumbers
A coloring page of a rather attractive sea cucumber (they come in all colors, pick your favorite!)
The only pages I could find on the Elasipodida (that swimming sea cucumber) was a tiny one on Wikipedia and a PDF with no pictures and too many words. 🙁
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