Very different to cucumbers that we eat in our salads, sea cucumbers are animals that live in our oceans. They look like a cucumber due to their shape and appearance (see pictures above and below), even if they are not always green in colour. Sea cucumbers have an incredibly important role in maintaining a healthy ocean.
Dalton Koss HQ often hear marine scientists refer to sea cucumbers as being the worms of our oceans. Sea cucumbers clean and fertilise the sand like worms clean and enrich our soils. When a sea cucumber eats sand from the ocean floor, it moves through its gut where it takes out very small pieces of food. Everything else, for example the sand, is excreted. This excreted sand is clean and contains healthy bacteria.
Apart from the amazing role sea cucumbers play in keeping our oceans clean, here are some other INCREDIBLE facts about these animals.
FACT 1: Sea cucumbers are soft to touch because their spiny skeleton has been reduced and absorbed into its leathery flesh.
FACT 2: Sea cucumbers are also called holothurians. This is because they are scientifically classified as Holothuroidea. In fact, the Class Holothuroidea belongs within the Phylum Echinodermata, which means the sea cucumbers are close relatives to sea stars, sea urchins, feather stars and brittle stars.
FACT 3: Sea cucumbers can be found in tropical and temperate oceans across the globe. They prefer to live in the subtidal zone so they are not exposed to the sun and air at low tide.
FACT 4: Sea cucumbers have two openings; a mouth at one end and an anus at the other.
FACT 5: A sea cucumber’s mouth is very different to other animals. The mouth is surrounded by tentacles. Each tentacle is made up of little tube feet that move sand up to the mouth opening, similar in function to a conveyer belt. Some sea cucumbers use their tentacles to filter feed, meaning they catch plankton and other particles drifting in the water column.
FACT 6: The respiratory system, that allows the sea cucumber to breathe, is located in its gut towards the back part of its body.
Dalton Koss HQ’s most favourite sea cucumber fact is their ability to throw out their respiratory system through their anus as a defence mechanism when they think they are being attacked. By throwing out their internal organs it distracts the predator into thinking the sea cucumber is dead. What is more amazing is that the sea cucumber can then regrow its respiratory system and continue to live.
As an animal that comes across as simple and unobtrusive, the sea cucumber plays an important role in maintaining beautiful oceans for us to enjoy.