Bathyraja trachouros 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Rajiformes Arhynchobatidae

Scientific Name: Bathyraja trachouros (Ishiyama, 1958)
Common Name(s):
English Eremo Skate, File Skate
Breviraja trachouros (Ishiyama, 1958)
Taxonomic Notes: Dolganov and Tuponogov (1999) suggest that B. trachouros may be synonymous with B. violacea (Ishihara pers. obs.), however, B. trachouros is treated as a valid species here (clasper structure is distinct) and was recognized as valid by Compagno (2005).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2009
Date Assessed: 2004-09-09
Needs updating
Assessor(s): Ishihara, H., Huveneers, C. & Orlov, A.
Reviewer(s): Valenti, S.V. & Musick, J.A. (Shark Red List Authority)
The Eremo Skate (Bathyraja trachouros) is a rare, medium-sized (102 cm TL) deepwater skate, endemic to Japan, from northern Honshu to southern Hokkaido, at depths of 100-800 m. Its biology is virtually unknown. The species is caught as bycatch and kept by the bottom trawl fishery targeting cod and rockfish. However this fishery impacts the species over the shallow part of its depth range only. Its deeper range provides Eremo Skate with a refuge, as this depth is not fished in the area of occurrence. As the majority of the population is thought to occur beyond the range of current fisheries, this species is assessed as Least Concern. However, given that it is apparently rare, with a relatively restricted geographic distribution, careful monitoring of fisheries within the species' range is required. If fisheries expand further throughout the species' range in the future this assessment should be revisited.

Geographic Range [top]

Range Description:Northwest Pacific: Eremo Skate (Bathyraja trachouros) is endemic to northern Japan, from Sendai, northern Honshu to southern Hokkaido (Ishihara 1990).
Countries occurrence:
Japan (Hokkaido, Honshu)
FAO Marine Fishing Areas:
Pacific – northwest
Additional data:
Lower depth limit (metres):800
Upper depth limit (metres):100
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:An apparently rare species. No data on population status or abundance are available.
Current Population Trend:Stable
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:A medium sized deepwater skate, B. trachouros can be found at depths of 100-800 m and attains 102 cm total length (TL). The species is mature at ~88 cm TL (Ishiyama 1958, Ishihara 1990), but its biology is virtually unknown.

Use and Trade [top]

Use and Trade: Flesh used for human consumption and sold at about US$2/kg.

Threats [top]

Major Threat(s): This species is caught as bycatch and retained by the bottom trawl fishery targeting cod and rockfish. However this fishery impacts the species over the shallow part of its bathymetric range only. The deeper extent of its range provides the Eremo Skate with a refuge as this depth is not fished in the area of occurrence. No data are available on catch levels of trends over time.

Conservation Actions [top]

Conservation Actions: There are no conservation measures in place for this species. Careful monitoring of fishing effort in the area of occurrence is needed to ensure that the current population is not detrimentally affected.

Citation: Ishihara, H., Huveneers, C. & Orlov, A. 2009. Bathyraja trachouros. The IUCN Red List of Threatened Species 2009: e.T161701A5484194. . Downloaded on 16 October 2018.
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