Beringraja rhina

Beringraja rhina, commonly known as the longnose skate, is a species of skate in the family Rajidae from the northeast Pacific. It is found from the eastern Bering Sea and Alaska to Baja California and the Gulf of California. The longnose skate is found at depths of 9–1,069 m (30–3,507 ft) and often deeper than the big skate.[2][3] The longnose skate has only recently been associated with the genus Beringraja, having been previously included in Raja until genetic evidence supported reclassification.[4][5] This issue has not be completely resolved and the scientific name "Raja rhina" is still in widespread use.[2][1]

Small longnose skate

Beringraja rhina
A longnose skate near Santa Cruz Island in 2011
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Rajiformes
Family: Rajidae
Genus: Beringraja
Species:
B. rhina
Binomial name
Beringraja rhina
(Jordan & Gilbert, 1880)
Synonyms
  • Raja rhina

Description

The longnose skate has an elongated snout and deeply notched pelvic fins. Maximum size has been reported as 1.8 m (5.9 ft) in length.[6] Maximum age has been estimated as 25 years in Gulf of Alaska[7] and 26 years in British Columbia.[8] The age estimates are based on counting growth bands in vertebrae, a method which has been validated using bomb radiocarbon.[9]

Distribution and habitat

In a recent study published in August 2019, researchers found that this nearshore species tends to dwell in the upper continental slope in highly sedimented areas, and also in association with rock out crops, authigenic carbonate crust, and mixed substrate areas in depths between 200-929 m. Longnoses inhabited areas with 3–6 °C temperatures. This research came from the first long-scale, long-term assessment of skates in deepwater of the eastern North Pacific.[10]

Reproduction

The longnose skates egg case is large and smooth, and has large webbed keels on its posterior and anterior margins. The egg case's maximum size is 15 cm (5.9 in) long and 12 cm (4.7 in) wide.

References
  1. "Raja rhina (Longnose Skate)". IUCN Red List of Threatened Species. Retrieved 2018-08-16.
  2. "Raja rhina, Longnose skate : fisheries". Fishbase.org. 2016-07-20. Retrieved 2018-08-16.
  3. Stevenson, Duane E.; Orr, James W.; Hoff, Gerald R.; McEachran, John D. (2007). Field Guide to Sharks, Skates, and Ratfish of Alaska (PDF). Alaska Sea Grant College Program, University of Alaska Fairbanks. ISBN 1-56612-113-2.
  4. Last, P. R., S. Weigmann and L. Yang 2016. Changes to the nomenclature of the skates (Chondrichthyes: Rajiformes). In: Last and Yearsley (eds.). Rays of the World: Supplementary Information. CSIRO Special Publication. 11-34.
  5. "Chondrichthyan Tree of Life". Retrieved 16 August 2018.
  6. Stevenson, D. E. (2004). "Identification of Skates, Sculpins, and Smelts by Observers in North Pacific Groundfish Fisheries (2002-2003)" (PDF). NOAA Technical Memorandum. NMFS-AFSC-142.
  7. Gburski, Christopher M.; Gaichas, Sarah K.; Kimura, Daniel K. (2007-10-01). "Age and growth of big skate (Raja binoculata) and longnose skate (R. rhina) in the Gulf of Alaska". Environmental Biology of Fishes. 80 (2): 337–349. doi:10.1007/s10641-007-9231-8. ISSN 1573-5133.
  8. McFarlane, G. A.; King, J. R. (2006-05-01). "Age and growth of big skate (Raja binoculata) and longnose skate (Raja rhina) in British Columbia waters". Fisheries Research. 78 (2): 169–178. doi:10.1016/j.fishres.2006.01.009. ISSN 0165-7836.
  9. King, J. R.; Helser, T.; Gburski, C.; Ebert, D. A.; Cailliet, G.; Kastelle, C. R. (2017-09-01). "Bomb radiocarbon analyses validate and inform age determination of longnose skate (Raja rhina) and big skate (Beringraja binoculata) in the north Pacific Ocean". Fisheries Research. 193: 195–206. doi:10.1016/j.fishres.2017.04.004. ISSN 0165-7836.
  10. Kuhnz, L.A.; Bizzarro, J.J.; Ebert, D.A. (September 2019). "In situ observations of deep-living skates in the eastern North Pacific". Deep Sea Research Part I: Oceanographic Research Papers: 103104. doi:10.1016/j.dsr.2019.103104.
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