Sea cucumber


The sea cucumber is not a plant but actually a very odd invertebrate normally living on the ocean floor. Although the sea cucumber in this picture has spines, not all do. This group of animals has over 1,000 species including some that float through the ocean and look like jellyfish. Sea cucumbers also vary in size, smaller ones only being .75 inches (2 cm) and the largest ones growing up to 6.5 feet (2 m)! The larger species can also grow up to 8 inches (20 cm) thick. Sea cucumbers eat algae and tiny ocean animals which they catch using the up to 30 tentacles around their mouth. They also eat mud at the bottom of the ocean which they process in their body to take out all the dead animals which they can use as nutrients. The rest is gotten rid of. These animals live all over the world from Canada, to Antarctica, to Australia.

The soft bodies of sea cucumbers are eaten by crabs, fish, and even humans in some parts of the world. Because of these predators, the sea cucumber was created with two means of defense. First, a sea cucumber which is attacked will squirt out sticky strands which tangle up their enemy. The other way is by shooting out some of their internal organs which they then regrow in a few days. The organs of some species contain a chemical which is poisonous to marine animals which eat them but not to humans. Because of this, some people who live in the Pacific will put sea cucumber juices in the water in order to kill or stun the fish, making them easy to catch. Sea cucumbers are sometimes grown in captivity to provide products which are part of medicines, shampoos, and toothpastes. The dried outer skin of these marine marvels is what humans eat. To reproduce, the females lay eggs which the males later fertilize. When the eggs that are not eaten by predators hatch, the tiny animals start their life of up to 10 years.

Don’t forget to check out the activity sheet under sources and guess what the next animal is!

Here’s the picture of next week’s animal.



Photo Credits:

  • Sea Cucumber-Wikipedia user Maxim Gavrilyuk
  • Mystery animal-Public domain

One Response

  1. Sharon Madson
    Sharon Madson at |

    I have never heard of the sea cucumber before, and it very interesting. I am learning from you! 🙂 I think the next week’s animal is a Bison, or a yak, maybe.

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