''Sipunculus nudus'' is a cosmopolitan species of unsegmented marine worm of the phylum

Sipuncula The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of unsegmented marine annelid worms. The name ''Sipuncula'' is from the genus name ''Sipunculus'', and comes from the Latin ' ...

, also known as peanut worms.

Description

As in all peanut worms, the body of ''S. nudus'' consists of a sac-like portion called the trunk and an eversible proboscis called the introvert. The mouth is located at the anterior end of the introvert and is surrounded by a group of tentacles. The body of the adult worm is around in length but can reach up to in some cases, of which about to correspond to the introvert. The epidermis contains a series of longitudinal coelomic canals that are connected to the main coelomic cavity by pores. Below the epidermis there are circular muscles surrounding the body which, as the coelomic canals, are marked on the surface, making the animal's surface be marked by rectangular ridges.

Distribution

''Sipunculus nudus'' is commonly found on subtidal zones of sandy shores to seabeds deep in temperate or tropical waters worldwide. The worm hides in sand burrows which it makes by itself during the day and may extend its

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s 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".

Uses

On sale in Guangzhou Sipunculid worm jelly

The species is collected and sold as a model organism for various fields of science, as fish bait, or for human consumption. It is also sold and exported as a dried seafood product. In particular, ''S. nudus'' is collected, cleaned of its innards, and eaten as a delicacy in the South Chinese provinces of

Guangdong Guangdong (, ), alternatively romanized as Canton or Kwangtung, is a coastal province in South China on the north shore of the South China Sea. The capital of the province is Guangzhou. With a population of 126.01 million (as of 2020) ...

Hainan Hainan (, ; ) is the smallest and southernmost province of the People's Republic of China (PRC), consisting of various islands in the South China Sea. , the largest and most populous island in China,The island of Taiwan, which is slightly l ...

Guangxi Guangxi (; ; Chinese postal romanization, alternately romanized as Kwanghsi; ; za, Gvangjsih, italics=yes), officially the Guangxi Zhuang Autonomous Region (GZAR), is an Autonomous regions of China, autonomous region of the People's Republic ...

, and

Fujian Fujian (; alternately romanized as Fukien or Hokkien) is a province on the southeastern coast of China. Fujian is bordered by Zhejiang to the north, Jiangxi to the west, Guangdong to the south, and the Taiwan Strait to the east. Its capi ...

. The worms are local delicacies in

Beihai Beihai (; Postal romanization: Pakhoi) is a prefecture-level city in the south of Guangxi, People's Republic of China. Its status as a seaport on the north shore of the Gulf of Tonkin has granted it historical importance as a port of internation ...

, Guangxi, where ''Běihǎi shāchóng'' (, lit. "Beihai sandworm") and sold in dried form to be fried as a snack or braised as an ingredient for a soup stock. In

Xiamen Xiamen ( , ; ), also known as Amoy (, from Hokkien pronunciation ), is a sub-provincial city in southeastern Fujian, People's Republic of China, beside the Taiwan Strait. It is divided into six districts: Huli, Siming, Jimei, Tong'an, ...

, Fujian, the species is called ''tǔsǔn'' (, lit. "earth bamboo shoot") and is braised and allow to gel in the liquid as eaten as

aspic Aspic or meat jelly () is a savory gelatin made with a meat stock or broth, set in a mold to encase other ingredients. These often include pieces of meat, seafood, vegetable, or eggs. Aspic is also sometimes referred to as ''aspic gelée'' or ...

''tǔsǔndòng'') in local restaurants. ''Sipunculus nudus'' is also collected on islands in the northern Vietnamese province of Quang Ninh where ''sá sùng'' (local pronunciation of ) is used as an ingredient for

pho Phở or pho (, , ; ) is a Vietnamese soup dish consisting of broth, rice noodles (), herbs, and meat (usually beef (), sometimes chicken ()). Phở is a popular food in Vietnam where it is served in households, street stalls and restaurants ...

stock.

References

External links

Friday Fellow: Common Peanut Worm
at Earthling Nature.

{{Taxonbar, from=Q1930845 Sipunculans Animals described in 1766 Taxa named by Carl Linnaeus