What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
noun
ZoologyA sea cucumber.
- ‘Sea cucumbers are sausage-shaped holothurians that lie on the sandy floor of reef lagoons.’
- ‘In fact, crinoids, holothurians, and ophiuroids rule the floor of the deep oceans at depths below 500 metres.’
- ‘However, holothurians retain pentameral (five-rayed) symmetry, with five rows of tube feet running from the mouth along the body.’
- ‘There was significantly greater population density of holothurians when a coral reef was adjacent to the mangroves than a shoreline with coral reef alone or mangroves alone.’
- ‘The water vascular system, found in all echinoderms, accommodates the elongated body of the holothurians.’
Origin
Mid 19th century: from the modern Latin genus name Holothuria (from Greek holothourion, denoting a kind of zoophyte) + -an.
