Sunday 5 May 2013


Sea cucumbers are named after the cucumber fruit whose shape they resemble.  However, they are not plants but marine animals.

Sea cucumbers belong to the phylum echinoderms, and the class Holothuroidea.  They have an elongated body covered in a leathery skin

An endoskeleton is present just below the skin, which consists of calcified structures joined to connective gelatinous tissue.  

They have the ability to squeeze through very small gaps as their body wall contains collagen, which can be loosened and tighten at will.

Sea cucumbers have no brain, but have a ring of nervous tissue surrounding the mouth which sends nerves to the tentacles and pharynx. In addition there are five major nerves running down the body of the animal.

There are over 1250 species of sea cucumber, most of them in the Asia pacific region. Sea cucumbers can form dense populations, and make up 90% of animals living on the deep sea floor.  

Sea cucumbers recycle nutrients in the water by breaking down detritus and organic matter such as plankton.

Whilst defending themselves, sea cucumbers can release some of their sticky cuvierian tubules to entangle potential predators. 

 In addition, the may also release a toxic chemical called holothurin, which is a soapy like substance that can kill any animal in the vicinity.

If water temperatures increase uncomfortably sea cucumbers go into a state dormancy called aestivation. They stop eating, slow their metabolism down and lose weight. Normal functions return when temperatures are favourable again.

Sea cucumbers are taken from their habitat for human consumption.  They have been harvested for their healing properties and extracts used oil, cream and cosmetics.  

Some species are considered a gastronomic delicacy, especially in Asia. this is leading to a vast decline in sea cucumber population.

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