Caliraja 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 was briefly associated with the genus Beringraja, having been previously included in Raja until genetic evidence supported reclassification.[4][5] It was then reclassified into the new Caliraja genus after an analysis of egg case morphology and the number of embryos per egg case.[6] This issue has not be completely resolved and the scientific names "Raja rhina" and "Beringraja rhina" are still in widespread use.[2][1]

Caliraja rhina
A longnose skate near Santa Cruz Island in 2011
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Rajiformes
Family: Rajidae
Genus: Caliraja
Species:
C. rhina
Binomial name
Caliraja rhina
(Jordan & Gilbert, 1880)
Synonyms
  • Beringraja rhina (Jordan & Gilbert, 1880)
  • Raja rhina Jordan & Gilbert, 1880
Small longnose skate

Description

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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.[7] Maximum age has been estimated as 25 years in Gulf of Alaska[8] and 26 years in British Columbia.[9] The age estimates are based on counting growth bands in vertebrae, a method which has been validated using bomb radiocarbon.[10]

Distribution and habitat

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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 and 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.[11]

Reproduction

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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. There is a single embryo per egg case, unlike members of the Beringraja genus which average 3-5 per egg case.[6]

References

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  1. ^ a b Bizzarro, J.J.; Ebert, D.A.; Herman, K. & Kyne, P.M. (2020). "Beringraja rhina". IUCN Red List of Threatened Species. 2020: e.T161595A80677015. doi:10.2305/IUCN.UK.2020-3.RLTS.T161595A80677015.en. Retrieved 12 November 2021.
  2. ^ a b "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 978-1-56612-113-2.
  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. ^ a b Ebert, David A. (2022-10-04). "Caliraja gen. nov., a new skate genus (Rajiformes: Rajidae) from the eastern North Pacific: Caliraja gen. nov., un nuevo género de rayas (Rajiformes: Rajidae) del este del Pacífico Norte". Revista de Biología Marina y Oceanografía. 57 (Especial). doi:10.22370/rbmo.2022.57.Especial.3209. ISSN 0718-1957.
  7. ^ 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.
  8. ^ 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. S2CID 25457468.
  9. ^ 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.
  10. ^ 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.
  11. ^ 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. 152: 103104. doi:10.1016/j.dsr.2019.103104.