Bathyraja microtrachys


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Bathyraja microtrachys
Species Authority: (Osburn & Nichols, 1916)
Common Name(s):
English Fine-spined Skate
Taxonomic Notes: This skate been misidentified as the Roughtail Skate, Bathyraja trachura, but B. microtrachys is clearly a distinct species. Although adult males have not been observed for this species, egg cases have been collected and are distinct from those of other eastern North Pacific skates (D.A. Ebert unpubl. data).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2009
Date Assessed: 2004-09-07
Needs updating
Assessor(s): Carlisle, A.B. & Ebert, D.A.
Reviewer(s): Valenti, S.V. & Fowler, S.L. (Shark Red List Authority)
The Fine-spined Skate (Bathyraja microtrachys) is a deepwater skate with a patchy distribution in the Eastern Pacific, from Washington State to southwest of San Diego, California, USA. This species occurs at depths of 1,995–2,900 m and is common below 2,000 m, beyond the range of most groundfish fisheries. The only known specimens have been collected by scientific research cruises and there is no reason to suspect that the population has declined, resulting in an assessment of Least Concern.

Geographic Range [top]

Range Description: Northeast and Eastern Central Pacific: sporadic distribution from Washington State to about 300 miles southwest of San Diego, California, USA (Ebert 2003).
United States (California, Oregon, Washington)
FAO Marine Fishing Areas:
Pacific – eastern central; Pacific – northeast
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Appears to be fairly common below 2,000 m depth (Ebert 2003). The only known specimens have come from scientific research cruises.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: Very little is known about this deepwater skate, which is found in waters between 1,995 and 2,900 m deep (Ebert 2003). Confusion with other deepwater skates such as the Deepsea Skate (Bathyraja abyssicola) and Roughtail Skate (B. trachura) has precluded a better understanding of this species. It appears to assume the ecological niche of the Roughtail Skate (Bathyraja trachura), at the great depths at which it lives. Maximum size is 74 cm (D.A. Ebert pers. obs. 2007). Females mature at 60–70 cm. The largest recorded male was an immature specimen measuring 35 cm, and size at birth is about 17 cm. Little is known about their diet other than that they feed on deep-water shrimps (Ebert 2003).
Systems: Marine

Threats [top]

Major Threat(s): This species is generally distributed in very deep waters, beyond the range of most fisheries.

Conservation Actions [top]

Conservation Actions: None in place.

Citation: Carlisle, A.B. & Ebert, D.A. 2009. Bathyraja microtrachys. The IUCN Red List of Threatened Species. Version 2015.2. <>. Downloaded on 03 September 2015.
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