Facts About Sea Cucumbers

Holothuria, or sea cucumbers, can be called one of the strangest, most interesting, and unusual inhabitants of the waters. From the point of view, they are animals, but their characteristic features and way of life make some people think that they are closer to plants. However, this is not true at all, but it does not prevent us from wondering how evolution created this bizarre creature in the first place.

Sea Cucumber

20 Facts about sea cucumbers

  • There are as many as 1150 species of sea cucumbers in the world, many of which are edible. There are about a hundred of them in Russian waters.
  • Judging by archaeological finds, the first sea cucumbers appeared on Earth about 440 million years ago. They are older than many dinosaur species.
  • The bodies of sea cucumbers are symmetrical, but very peculiar. For example, our bodies are symmetrical on two sides, but their bodies are symmetrical on five.
  • The importance of holothuria to the world’s ecology cannot be overstated. They recycle 80-90% of all plant and animal debris deposited at the bottom of the world’s oceans (interesting facts about ecology).
  • As funny as it may sound, sea cucumbers breathe with the help of the cloaca, or anal opening. Through it they draw water into their body, from which they absorb oxygen.
  • Carapus fish hide inside the holothuria when they are not looking for food. And it enters it through the same aforementioned body hole.
  • Sea cucumbers feed by sucking sand and soil into their body, absorbing useful substances from it and throwing waste back.
  • These amazing creatures are able to make their bodies both rigid and almost liquid. This allows them to seep into the narrowest of crevices.
  • Sea urchins and sea stars are the closest relatives of holothuria (interesting facts about sea stars).
  • Sea cucumbers of the largest species can reach a length of up to 5 meters when mature, while the smallest can reach only 3 centimeters.
  • The mouth of the holothuria is surrounded by small tentacles, of which there are up to 30 pieces.
sea cucumber on hand

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  • Some species of sea cucumbers in case of danger throw out their insides together with the liquid, which is poisonous to most other marine organisms.
  • In some Asian countries dried sea cucumbers are used as a folk painkiller.
  • If a sea cucumber suddenly loses its intestines, it can grow a new one in a month or two.
  • No bacteria has ever been found in the cells of holothuria.
  • Because of the popularity of edible sea cucumbers in some countries, they are purposefully bred in special sea farms.
  • Over the year, sea cucumbers of medium-sized species (about the size of a human hand) sift through their bodies about 150 tons of sand and soil.
  • The life span of Holothuria can reach 10 years.
  • Most of their species spend their entire lives at the bottom, but some live right in the water column without sinking down.
  • In traditional Chinese medicine, sea cucumbers are still actively used today, as well as in local cooking.