Lee Kong Chian Natural History Museum
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Holothuroidea

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Kingdom:Animalia
Phylum/Division:Echinodermata
Class:Holothuroidea

Description

The class Holothuroidea is a group of echinoderms commonly known as sea cucumbers, characterised by a calcareous ring that encircles the pharynx or throat and a circlet of oral tentacles (modified tube feet). They have elongated soft bodies with a distinct front (mouth) and rear (anus) end. Besides excreting waste, the anus of a sea cucumber is also used for 'breathing', where the respiratory trees found near the anus extract oxygen from the water drawn in by the anus.

The tube feet of sea cucumbers can be variable, with some arranged in five rows along the body, some are arranged irregularly while others have no visible tube feet. They creep slowly on the seafloor. Many of them are burrowers. Most sea cucumbers feed on detritus by swallowing sand, mud or silt and filtering the organic matter.

Many sea cucumbers are also known to produce poison (holothurin), which can be deadly for fishes and other predators, including humans. These sea cucumbers would need to be properly treated before consumption.

There are at least 23 species of sea cucumbers found in Singapore.

The synaptid cucumbers belong to this order. These sea cucumbers have 10-25 pinnate or digitate tentacles. Structures su…
The order Aspidochirotida comprises sea cucumbers with 10-30, most often 20, peltate tentacles. The body is cylindrical …
This is a group of sea cucumbers with dendritic feeding tentacles that lack ampullae. The feeding tentacles found arouns…
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