Blonde ray

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Blonde ray
Raielisse.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Rajiformes
Family: Rajidae
Genus: Raja
Species:
R. brachyura
Binomial name
Raja brachyura
Lafont, 1871
Synonyms [2]
  • Raia blandaHolt, 1894
  • Raia brachyuraLafont, 1871
  • Raja blandaHolt, 1894

The blonde ray or blonde skate (Raja brachyura) is a species of cartilaginous fish in the skate family Rajidae. [2] [3] It is found in the Eastern Atlantic and the Mediterranean.

Contents

1873 sketch by the describer, A. Lafont Raia brachyura 1871.jpg
1873 sketch by the describer, A. Lafont
Scientist releasing a tagged blonde ray during fieldwork Releasing tagged blonde ray.JPG
Scientist releasing a tagged blonde ray during fieldwork

Description

Like all rays, the blonde ray has a flattened body with broad, wing-like pectoral fins. The body is kite-shaped with a short tail (hence the specific name brachyura, which is derived from Ancient Greek and means "short tail"). In terms of coloration, it is brown with a few creamy-white blotches and dense dark spots which extend to the edges of the pectoral fins and to the tail. [5] The maximum published length is 120 cm (47 in). [6]

Distribution

The blonde ray is found in the Eastern Atlantic (from Scotland to Morocco) at depths of 10–380 m (33–1,247 ft); it is also found occasionally in the Mediterranean. [7]

Habitat

The blonde ray is demersal, preferring areas with sandy and muddy bottoms. Like many other elasmobranch species, the blonde ray uses shallow coastal wasters as nursery areas, leading to a greater number of blonde rays found near shore being juveniles. [8]

Life cycle

The blonde ray is oviparous, with embryos feeding only on yolk. It reaches sexual maturity at 85–92 cm (33–36 in) in length, which corresponds to 8–10 years of age. [9] The clutch size is around 40–140 eggs, and the female tends to her eggs after laying them. [10] [11] The average lifespan of a blonde ray is around 15 years. [11]

Blonde ray in the wild, swimming near the bottom of shallow water Blonde Ray (Raja brachyura), Tenerife, Canary Islands, Spain - panoramio.jpg
Blonde ray in the wild, swimming near the bottom of shallow water

Diet

The diet of the blonde ray (both as juvenile and adult) consists of cephalopods, small bony fish and crustaceans (such as shrimp, especially the species Crangon crangon ). [8]

Genetic disorders

Genetic disorders like leucism and albinism are found to affect the blonde ray. Leucism tends to cause this ray to go from their normal brownish appearance with darker spots to white with black spots, and leucitic individuals tend to be smaller. In albinism, we see a predominately white dorsal side with little to no spots and eye color change. No physical damages or disease was shown to be increased in blonde rays with these genetic disorders. [12]

Relationship with humans

The blonde ray is fished for human consumption (for example in the UK) and for sport, with a record weight of 17 kg (37 lb) recorded in Cobh, Ireland in 2008. [13] [14] Skates in general are often considered vulnerable to overfishing because they are long-lived, slow-growing, late to mature and produce few young, which, coupled with their generally large size, morphology, and aggregating nature, renders them susceptible to capture in many fisheries. [15] The aggregated landings of rays, although variable, have remained relatively stable over the past 60 years. [16] [17] [18] However, human impact still affects the blonde ray. Due to them being commonly found in shallower water, it is easier for them to be caught. As a result, juveniles can be fished before having a chance to breed. [19]

See also

References

  1. ↑ Ellis, J.; Ungaro, N.; Serena, F.; Dulvy, N.K.; Tinti, F.; Bertozzi, M.; Pasolini, P.; Mancusi, C.; Noarbartolo di Sciara, G. (2009). "Raja brachyura". IUCN Red List of Threatened Species . 2009 e.T161691A5481210. doi: 10.2305/IUCN.UK.2009-2.RLTS.T161691A5481210.en . Retrieved 20 November 2021.
  2. 1 2 "Raja brachyura". WoRMS. World Register of Marine Species . Retrieved 26 June 2021.
  3. ↑ Museum, British Columbia Provincial (26 June 1953). "Report of the Provincial Museum of Natural History" – via Google Books.
  4. ↑ Lafont, A. (1873). "Raja brachyura". shark-references.com. Retrieved 26 June 2021.
  5. ↑ C., Wheeler, Alwyne (1978). Key to the fishes of northern Europe: a guide to the identification of more than 350 species. Warne. ISBN   0-7232-2097-2. OCLC   803026975.{{cite book}}: CS1 maint: multiple names: authors list (link)
  6. ↑ Serena, Fabrizio (26 June 2005). Field Identification Guide to the Sharks and Rays of the Mediterranean and Black Sea. Food & Agriculture Org. ISBN   978-92-5-105291-4 – via Google Books.
  7. ↑ Guide of Mediterranean Skates and Rays (Raja brachyura). October 2022. Mendez L., Bacquet A. and F. Briand. https://ciesm.org/marine/programs/skatesandrays/raja-brachyura/
  8. 1 2 Farias, I; Figueiredo, I; Serra-Pereira, B; Bordalo-Machado, P; Moura, T; Serrano Gordo, L (2005). "Diet comparison of four ray species [Raja clavata Linnaeus, 1758; Raja brachyura Lafont, 1873; Leucoraja naevus (Müller & Henle, 1841) and Raja montagui Fowler, 1910] caught along the Portuguese continental coast". ICES CM 2005 / N:28 Elasmobranch Fisheries Science.
  9. ↑ Gallagher, M. J; C.P, Nolan; F, Jeal (2005). "Age, Growth and Maturity of the Commercial Ray Species from the Irish Sea". Journal of Northwest Atlantic Fishery Science. 35: 47–66.
  10. ↑ "Great Eggcase Hunt". The Shark Trust. Retrieved 7 May 2023.
  11. 1 2 Walker, P (June 1998). "Sensitive skates or resilient rays? Spatial and temporal shifts in ray species composition in the central and north-western North Sea between 1930 and the present day". ICES Journal of Marine Science. 55 (3): 392–402. doi: 10.1006/jmsc.1997.0325 . ISSN   1054-3139.
  12. ↑ Quigley, Declan T. G.; Carlos, Alejandro de; Barros-Garcia, David; MacGabhann, Declan (2018). "Albinism and leucism in Blonde Rays (Raja brachyura Lafont, 1871) (Elasmobranchii: Batoidea) from the Irish Sea". Bulletin- European Association of Fish Pathologists. 38– via JOUR.
  13. ↑ "Sport Fishery Abstracts". Department of the Interior, U.S. Fish and Wildlife Service. 26 June 1978 – via Google Books.
  14. ↑ "Ray – Blonde (Raja brachyura)". specimenfish.ie. Irish Specimen Fish Committee. Retrieved 26 June 2021.
  15. ↑ Ellis, J.R; Silva, J.F; McCully, S.R; Evans, M; Catchpole, T (2010). "UK Fisheries for Skates (Rajidae): History and Devel- opment of the Fishery, Recent Management Actions and Survi- vorship of Discards" (PDF). ICES: 38.
  16. ↑ Brander, K. (March 1981). "Disappearance of common skate Raia batis from Irish Sea". Nature. 290 (5801): 48–49. doi:10.1038/290048a0. ISSN   0028-0836.
  17. ↑ Fahy, E (1989). "Fisheries for Ray (Batoidei) in western statisti- cal area VIIa, investigated through the commercial catches I". Department of Maine, Dublin. Irish Fish. Investigations, See. B (Marine), 34: 14p.
  18. ↑ Dulvy, Nicholas K.; Metcalfe, Julian D.; Glanville, Jamie; Pawson, Mike G.; Reynolds, John D. (February 2000). "Fishery Stability, Local Extinctions, and Shifts in Community Structure in Skates". Conservation Biology. 14 (1): 283–293. doi:10.1046/j.1523-1739.2000.98540.x. ISSN   0888-8892.
  19. ↑ Gibson, C; Valenti, S.V; Fowler, S.L; Fordham, S.V (2006). "The Conservation Status of Northeast Atlantic Chondrichthyans; Report of the IUCN Shark Specialist Group Northeast Atlantic Regional Red List Workshop". IUCN SSC Shark Specialist Group. 3: 76.
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