Sipunculus nudus | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Sipuncula |
Class: | Sipunculidea |
Order: | Sipunculiformes |
Family: | Sipunculidae |
Genus: | Sipunculus |
Species: | S. nudus |
Binomial name | |
Sipunculus nudus Linnaeus, 1766 |
Sipunculus nudus is a species of unsegmented marine worms, also known as peanut worms. The body of the adult worm is around 15 centimetres (5.9 in) in length but can reach up to 25 cm (9.8 in) in some cases.
The worm is commonly found on subtidal zones of sandy shores to seabeds 900 metres (3,000 ft) in depth in temperate or tropical waters. The worm hides in sand burrows which it makes by itself during the day and may extend its tentacles out of the burrow to feed at night. Its diet consists of plant or animal tissue fragments and any surrounding sand it may ingest with it.
Recent research indicates that it is a complex of similar species around the world rather than one species, with at least "five distinct lineages identified by phylogenetic analyses".
The species is collected and sold as a model organism for various fields of science, as fish bait, or for human consumption.
In particular, S. nudus is collected, cleaned of its innards, and eaten as a delicacy in some areas such as Vietnam where it is sometimes used to cook pho stock. S. nudus is also considered nourishment food for the royal family. The Vietnamese gather S. nudus in islands in Quang Ngai. It is also sold and exported as a dried seafood product.
The worms are also consumed in the southern Chinese provinces of Guangdong, Hainan, Guangxi, and Fujian. The worms are local delicacies in Beihai, Guangxi, where Běihǎi shāchóng (北海沙虫, lit. "Beihai sandworm") is cooked by various methods. In Xiamen, Fujian, the species is called tǔsǔn (土笋, lit. "earth bamboo shoot") and served as a gelatin (t 土笋凍, s 土笋冻, tǔsǔndòng) in local restaurants.