Urechis unicinctus

Urechis unicinctus (traditional Chinese: 海腸; simplified Chinese: 海肠; pinyin: hǎicháng; Cantonese Yale: hóichèuhng; Japanese: 螠虫; rōmaji: yumushi; Korean: 개불; romaja: gaebul) is a species of the marine spoon worm. It is widely referred to as the fat innkeeper worm or the penis fish.[2] The body is about 10–30 cm long, cylindrical in shape and yellowish-brown in color. On the surface of the body there are many small papillae. This spoonworm lives in a U-shaped burrow in muddy sand and feeds on detritus. Males and females produce sperm and eggs, respectively.

Urechis unicinctus
Echiura in Korea1
Urechis unicinctus at a market in Korea.
Scientific classification
U. unicinctus
Binomial name
Urechis unicinctus
von Drasche, 1881[1]


U. unicinctus, like other species of Urechis, lives and burrows in sand and mud. It gets the name "fat innkeeper worm" because the tunnels often contain other animals.


This spoonworm is a detritivore and creates a U-shaped burrow in the soft sediment of the seabed. A ring of glands at the front of the proboscis secrete mucus which sticks to the burrow wall. The worm continues to exude mucus as it moves backwards in the burrow thus creating a mucus net. The worm draws water through its burrow by peristaltic contractions of its body and food particles adhere to the net. When enough food is gathered, the worm moves forward in its burrow and swallows the net and entangled food. This process is repeated, and in an area with plenty of detritus, may be completed in only a few minutes.[3]

Economic use

In Korea, they are eaten for food.[4] It is used as bait for fish such as flounder and sea bream. They are distributed in Korea, Japan, and the Pacific coast.

This spoon worm is commonly eaten raw with salt and sesame oil or gochujang in Korea.

In Chinese cuisine the worm is stir-fried with vegetables, or dried and powdered to be used as an umami enhancer.

It is also used for fishing bait.


Gaebul sold at a fish market at Busan, South Korea.

Korean sea worm

Urechis unicinctus served as hoe in a restaurant in South Korea.


  1. ^ van der Land, Jacob; Murina, Galina Vansetti (2012). "Urechis unicinctus (von Drasche, 1881)". World Register of Marine Species. Retrieved 2012-11-12.CS1 maint: Multiple names: authors list (link)
  2. ^ เหมียวตะปู (2018-02-04). "'ปลาจู๋' สิ่งมีชีวิตใต้น้ำที่ดันเกิดมามีรูปร่างคล้ายบางอย่าง แถมยังมีน้ำพุ่งออกมาอีกด้วย". catdumb (in Thai). Retrieved 2018-02-08.
  3. ^ Walls, Jerry G. (1982). Encyclopedia of Marine Invertebrates. TFH Publications. pp. 262–267. ISBN 0-86622-141-7.
  4. ^ "개불" (in Korean). Retrieved 2018-03-17.

External links


Dalian is a major city and seaport in the south of Liaoning Province, China. It is the southernmost city of the Liaodong Peninsula. Dalian is the province's second largest city and has sub-provincial administrative status. The Shandong Peninsula lies southwest across the Bohai Strait and Korea lies across the Yellow Sea to the east.

Today a financial, shipping and logistics centre for Northeast Asia, Dalian has a significant history of being used by foreign powers for its ports. Dalian was previously known as both "Dalniy" (Russian: Дальний; Dal'nii) and "Dairen" (Japanese: 大連). However, the city was better known as "Port Arthur" (Russian: Порт-Артур; Port-Artur) and "Ryojun" (Japanese: 旅順) from the original Port Arthur, now the city's Lüshunkou district.

In 2016, Dalian ranks 48th in the Global Financial Centres Index, the other Chinese cities on the list being Hong Kong, Shanghai, Shenzhen, Beijing and Qingdao. In 2012, Dalian ranked 82nd in the Global City Competitiveness Index. In 2006, Dalian was named China's most livable city by China Daily.


The Echiura, or spoon worms, are a small group of marine animals. Once treated as a separate phylum, they are now considered to be a subclass of Polychaeta, the bristle worms. Polychaete worms typically have their bodies divided into segments, but echiurans have secondarily lost their segmentation. The majority of echiurans live in burrows in soft sediment in shallow water, but some live in rock crevices or under boulders, and there are also deep sea forms. More than 230 species have been described.Spoon worms are cylindrical, soft-bodied animals usually possessing a non-retractable proboscis which can be rolled into a scoop-shape to feed. In some species the proboscis is ribbon-like, longer than the trunk and may have a forked tip. Spoon worms vary in size from less than a centimetre in length to more than a metre. Most are deposit feeders, collecting detritus from the sea floor. Fossils of these worms are seldom found and the earliest known fossil specimen is from the Upper Carboniferous (Pennsylvanian).

List of protected areas of China

This is a list of the nationally protected areas of China. There are many forms of protected areas in China. Based on their relative importance, each type of protected area can be further graded into two to three levels (national, provincial and prefectural/county level). Nevertheless, the highest rank for "pocket nature reserve" (social and mass-based), "no-hunting area", "no-fishing area", "no-logging area", "wild medicinal material resources conservation area", "crop germplasm resources conservation area", "forest tree germplasm resources conservation area" or "source water protection area" is practically restricted to provincial level. The local government at county level is also responsible for the delimitation and declaration of "basic farmland protection area" and "basic grassland". Qinling National Botanical Garden, said to be the world's largest (639 km2), was opened (Phase 1) to the public on September 27, 2017.

Take note that many protected areas in China have multiple official designations, and the statutory boundaries of these multi-designated PAs may be identical or may vary one from the other. For instance, the boundaries of Huangshan NP coincide with those of the Huangshan NGP, whereas Fujian province's Wuyi Mountains NNR, NP and NFP are adjacent to each other. In Heilongjiang, 27,642.14 hectares out of 115,340.27 hectares of Huzhong NFP are intersected with the experiment zone of Huzhong NNR.

Penis fish

Penis fish can refer to:

Candiru, a family of catfish that can allegedly enter the urethra

Urechis unicinctus, a species of spoon worm


Urechidae is a family of spoonworms in the subclass Echiura. The only genus in the family is Urechis, which has four species.

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