Portunus trituberculatus

Portunus trituberculatus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Brachyura
Family:	Portunidae
Genus:	Portunus
Species:	P. trituberculatus
Binomial name
Portunus trituberculatus (Miers, 1876)
Synonyms   [1]
Neptunus trituberculatusMiers, 1876

Portunus trituberculatus, also known as the gazami crab, Japanese swimming crab or horse crab, is a crab species commonly found off the coasts of East Asia and is closely related to Portunus armatus . It is the most widely fished species of crab in the world. ^[2]

Fishery

Global capture production of Gazami crab (Portunus trituberculatus) in thousand tonnes from 1950 to 2022, as reported by the FAO

Portunus trituberculatus is the world's most heavily fished crab species, with over 300,000  tonnes being caught annually, 98% of it off the coast of China. ^[4] The species is considered highly nutritious, especially in regard to crab cream (roe). ^[5]

Distribution

Portunus trituberculatus is found off the coasts of Korea, Japan, China, and Taiwan. ^[6]

Description

The carapace may reach 15 centimetres (5.9 in) wide, and 7 cm (2.8 in) from front to back. P. trituberculatus may be distinguished from the closely related (and also widely fished) P. armatus by the number of broad teeth on the front of the carapace (three in P. trituberculatus, four in P. armatus) and on the inner margin of the merus (four in P. trituberculatus, three in P. armatus). ^[4]

Relationship to humans

Controversy

Due to the increased farming breeding of Portunus trituberculatus, the natural habitat environment of the crab has significantly declined. It has also diminished the gazami crab's immune system which has led to the decline in its ability to fight off diseases. P. trituberculatus has suffered from many dieases most notably Decapod iridescent virus 1 (DIV1) Vibrio parahaemolyticus. ^{[7] [8]}

These diseases have ultimately reduced the overall health of the crabbing industry. ^[9]

Taxonomy

Portunus trituberculatus was first described in 1876 by Edward J. Miers, under the name Neptunus trituberculatus. ^[1] To better understand the species development, evolution and reproduction a reference genome has been sequenced, assembling to 1.0 Gb in size and anchoring to 50 chromosomes. ^[10] And demonstrating it diverged from the Chinese mitten crab around 183.5 million years ago.

Virus research

In 2019 it was discovered that gazami crab populations in China are commonly infected with the Flavivirus Wenzhou shark flavivirus ^[11] which was previously identified in all tissues of the Pacific spadenose shark, Scoliodon macrorhynchos. ^[12] While currently unknown if Wenzhou shark flavivirus causes disease in infected shark hosts, this virus moves horizontally between gazami crabs and sharks in ocean ecosystems in a manner similar to other Flavivirus infections such as Dengue virus, which cycle horizontally between arthropod (mosquito) and vertebrate hosts.

References

1. Peter Davie (2010). "Portunus (Portunus) trituberculatus (Miers, 1876)". World Register of Marine Species . Retrieved May 6, 2011.
2. Kwon, Hyeong Kyu; Kwon, Nahyeon; Cho, Yang-Ki; Hwang, Jeomshik; Choi, Yangho; Lim, Weol Ae; Lee, Soo Jeong; Lee, Jae Bong; Kim, Guebuem (2025-05-05). "Difference in nutritional status and food sources for hard- and soft-shell crabs (Portunus trituberculatus) using amino acids and isotopic tracers". Scientific Reports. 15 (1): 15694. doi:10.1038/s41598-025-99629-x. ISSN   2045-2322. PMC   12052833 .
3. "Fisheries and Aquaculture - Global Production". Food and Agriculture Organization of the United Nations (FAO). Retrieved 2024-05-06.
4. "FAO fisheries global information system" . Retrieved August 2, 2006.
5. Xiu-rong, Su; Tai-wu, Li; Ming-jin, Ding; Chien, Paul K. (1997-06-01). "Evalution[sic] on nutritive value of Portunus trituberculatus". Chinese Journal of Oceanology and Limnology. 15 (2): 168–172. doi:10.1007/BF02850688. ISSN   1993-5005. S2CID   86409328.
6. "Portunus trituberculatus". Crabs of Japan. Marine Species Identification Portal. Retrieved March 20, 2011.
7. Qiu, Liang; Chen, Xing; Gao, Wen; Guo, Xiao-Meng; Xie, Guo-Si; Gong, Miao; Yang, Bing; Li, Chen; Zhang, Qing-Li; Huang, Jie (2022-02-15). "Confirmation of susceptibility of swimming crab to infection with Decapod iridescent virus 1" . Aquaculture. 548 737607. doi:10.1016/j.aquaculture.2021.737607. ISSN   0044-8486.
8. Sun, Dongfang (2023-12-11). "Comparative Transcriptome Analysis of the Response to Vibrio parahaemolyticus and Low-Salinity Stress in the Swimming Crab Portunus trituberculatus". Biology . 12 (12): 1518.
9. Hao, Guijie (January 2016). "Biological Characteristics of Serum Agglutinin from Portunus trituberculatus". Agricultural Science & Technology. 17: 152–187.
10. Tang, Boping; Zhang, Daizhen; Li, Haorong; Jiang, Senhao; Zhang, Huabin; Xuan, Fujun; Ge, Baoming; Wang, Zhengfei; Liu, Yu; Sha, Zhongli; Cheng, Yongxu (2020-01-01). "Chromosome-level genome assembly reveals the unique genome evolution of the swimming crab (Portunus trituberculatus)". GigaScience. 9 (1). doi:10.1093/gigascience/giz161. PMC   6944217 . PMID   31904811.
11. Parry R, Asgari S (2019). "Discovery of Novel Crustacean and Cephalopod Flaviviruses: Insights into the Evolution and Circulation of Flaviviruses between Marine Invertebrate and Vertebrate Hosts". J Virol. 93 (14) e00432-19. doi:10.1128/JVI.00432-19. PMC   6600200 . PMID   31068424.
12. Shi M, Lin XD, Chen X, Tian JH, Chen LJ, Li K; et al. (2018). "The evolutionary history of vertebrate RNA viruses". Nature. 556 (7700): 197–202. Bibcode:2018Natur.556..197S. doi:10.1038/s41586-018-0012-7. PMID   29618816. S2CID   256771319.