|Scientific Name:||Pristiophorus japonicus Günther, 1870|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor(s):||Wang, Y., Tanaka, S. & Nakaya, K.|
|Reviewer(s):||Valenti, S.V., Fowler, S.L. & IUCN SSG Asia Northwest Pacific Red List Workshop participants (Shark Red List Authority)|
The Japanese Sawshark (Pristiophorus japonicus) is uncommon through its range and lives in the benthic zone in sandy, muddy bottoms. There is little information available on the population size. This species is a utilized bycatch of gillnets, bottom longline and trawl fisheries, and is particularly susceptible to capture in gillnets due to the thorns on its snout. The species is rarely captured, but no information is available to determine whether it is naturally rare or may have already been depleted. Very little information is available on this species and it is not possible to assess it beyond Data Deficient at present, but mortality in fisheries and population trends should be investigated as a priority.
|Range Description:||Northwest Pacific: this species is distributed throughout Japan (Southern Hokkido to Ryukido Island), off northern China (and also Taiwan, Province of China) from the East China Sea, the Yellow Sea, Bohai Sea, and southwest of Korea (Yamada et al. 2007).|
Native:China; Japan; Korea, Republic of; Taiwan, Province of China
|FAO Marine Fishing Areas:|
Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is apparently uncommon throughout its range (Yamada et al. 2007). No other information is available.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||A sawshark of temperate waters over continental shelves and upper slopes on or near sand or mud bottom (Compagno in prep). Found at depths of 50-800 m (Yano 2000).|
Usually produces 12 pups per litter (Compagno in prep.). It grows to a maximum total length of 136-153 cm, with males maturing at 80-100 cm and females maturing at approximately 100 cm (Compagno in prep.). Size at birth is approximately 30 cm TL (Yamada et al. 2007). Feeds on small bottom dwelling organisms (Compagno in prep).
The species may make vertical migrations, according to water temperature, from shallow coastal waters to the upper continental slope (S. Tanaka pers. obs. 2007). The species can only be collected in coastal waters of the Izu Peninsula, Shizuoka, in early spring when water temperature is at its lowest (S. Tanaka pers. obs. 2007).
Probably of limited importance to fisheries, though in Japan its meat is considered of high quality and used for human consumption (Compagno in prep).
This species is captured as a utilised bycatch of gill nets, trawl nets and bottom longline fisheries. This is not a commercial species, but it is particularly susceptible to capture in gillnets because of the thorns on the snout (Yamada et al. 2007). This species is captured as bycatch in gillnet fisheries targeting spiny lobster set in less than 20 m depth. Although the fishery operates from September-April, the species only occurs as bycatch during March-April. It is thought that the species moves into deeper waters throughout the rest of the year. It is captured occasionally at depth of 200-400 m by trawl net fisheries in the East China Sea (Yamada et al. 2007). It is also an uncommon catch of trawl net fisheries operating in Suruga Bay, Japan (S. Tanaka pers. obs. 2007).
There are no specific conservation measures in place for this species.
According to the Law of Fisheries of China, bottom trawling is banned within certain areas of Chinese waters (Y. Wang pers. comm. 2007). Bottom trawling is restricted in certain zones and at different times in shallow water (Y. Wang pers. comm. 2007). Individual Provinces must apply national regulation within China. They also apply their own regulations on the basis of national regulations (Y. Wang pers. comm. 2007).
|Citation:||Wang, Y., Tanaka, S. & Nakaya, K. 2009. Pristiophorus japonicus. The IUCN Red List of Threatened Species 2009: e.T161634A5469437.Downloaded on 18 October 2017.|
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