Tylorrhynchus heterochetus, also known as the Japanese palolo[1] is a species of edible ragworm.
| Tylorrhynchus heterochetus | |
|---|---|
| |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Clade: | Pleistoannelida |
| Subclass: | Errantia |
| Order: | Phyllodocida |
| Family: | Nereididae |
| Genus: | Tylorrhynchus |
| Species: | T. heterochetus
|
| Binomial name | |
| Tylorrhynchus heterochetus (Quatrefages, 1866)
| |
The species can be commonly found in estuaries of the Yellow Sea, East China Sea and South China Sea. Its mature size is circa 5.65 cm.[2][3]
The worm inhabits the muddy soil of estuaries and rice paddies. During the reproductive season in November and December, the worms swim up to the surface and migrate to sea at high tide. The males will turn to a white milky colour, whereas females will attain a white-green colour. As the worms reach the higher salinity seawater, they will release their gametes and die.[2]
Due to pollution and changes to their natural environments, they are nowadays less numerous, and entirely extinct in some habitats.[2]
The up to 35 cm deep burrows made by the worm in muddy sea beds help to bring oxygen to nitrifying bacteria.[4]
Relationship with humans
editAs food
editIt is eaten as a local delicacy in the Chinese coastal provinces of Guangdong, Fujian and Zhejiang and in Northeast Vietnam.[2] The worm has high nutritional value in protein and fats.[5]
In Vietnam, it is mainly used in a dish called chả rươi,[6] which has been known as a delicacy for centuries, especially in the area of Tứ Kỳ district, Hải Dương province.[7]
As it occurs only during its breeding season, farmers can earn relatively high incomes from harvesting the worms. In some areas, this has resulted in overfishing.[7][8]
As medicine
editIt is also used in traditional Chinese medicine. A study has shown that consumption of the worm has an anti-fatigue effect on mice.[9]
Other uses
editSince the worms are sensitive to changes in their environmental conditions, they are sometimes used by researches to monitor the quality of marine habitats.[10]
References
edit- ^ "Palolo worm | Polychaete, Marine Species, Reproduction | Britannica". www.britannica.com. Retrieved 2023-12-28.
- ^ a b c d Nguyen, Ngoc Tuan (April 2018). "Biological characteristics and effects of salinity on reproductive activities of marine worm (Tylorrhynchus heterochaetus, Quatefages, 1865) in summer season in Hai Phong – Viet Nam". SNRU Journal of Science and Technology. 10 (1).
- ^ Zhang, Wenxia; Wang, Zexiong; Ganesan, Kumar; Yuan, Yingzhi; Xu, Baojun (2022-06-22). "Antioxidant Activities of Aqueous Extracts and Protein Hydrolysates from Marine Worm Hechong (Tylorrhynchus heterochaeta)". Foods. 11 (13): 1837. doi:10.3390/foods11131837. ISSN 2304-8158. PMC 9265576. PMID 35804653.
- ^ Satoh, Hisashi; Nakamura, Yoshiyuki; Okabe, Satoshi (2007-02-15). "Influences of Infaunal Burrows on the Community Structure and Activity of Ammonia-Oxidizing Bacteria in Intertidal Sediments". Applied and Environmental Microbiology. 73 (4): 1341–1348. Bibcode:2007ApEnM..73.1341S. doi:10.1128/AEM.02073-06. ISSN 0099-2240. PMC 1828680. PMID 17189445.
- ^ Wu, Yugang (2005-10-24). "疣吻沙蚕营养成分分析与评价" [Analysis and evaluation of nutritional components of Nereis verrucosa]. Water Conservancy and Fisheries. 26 (3).
- ^ "Cha Ruoi ( Sandworm omelettee )- a specialty in Hanoi when autumn comes". 9 December 2013. Archived from the original on 20 December 2018.
- ^ a b Manh, Quang Vu (2022). "Species Status of Ragworm Populations (Nereididae: Tylorrhynchus Sp.) Exploited as a Human Specialty Based on Their Molecular Analyses in the Northern Coast of Vietnam". Comptes rendus de l'Académie bulgare des Sciences. 24 (4).
- ^ Zhu, Qian (2022-01-10). River-Sand Mining: An Ethnography of Resource Conflict in China. BRILL. ISBN 978-90-04-50591-9.
- ^ Yang, Ziqing; Sunil, Christudas; Jayachandran, Muthukumaran; Zheng, Xuchu; Cui, Kuopeng; Su, Yuepeng; Xu, Baojun (2020-01-01). "Anti-fatigue effect of aqueous extract of Hechong (Tylorrhynchus heterochaetus) via AMPK linked pathway". Food and Chemical Toxicology. 135: 111043. doi:10.1016/j.fct.2019.111043. ISSN 0278-6915. PMID 31836553. S2CID 209358186.
- ^ Dean, Harlan K. (December 2008). "The use of polychaetes (Annelida) as indicator species of marine pollution: a review" (PDF). Revista de Biología Tropical. 56 (4).