Arctoraja sexoculata

(Misawa, Orlov, Orlova, Gordeev & Ishihara, 2020)



Classification: Elasmobranchii Rajiformes Rajidae

Reference of the original description
Misawa, R. & Orlov, A.M. & Orlova, S.Y. & Gordeev, I.I. & Ishihara, H. & Hamatsu, T. & Ueda, Y. & Fujiwara, K. & Endo, H. & Kai, Y. (2020)
Bathyraja (Arctoraja) sexoculata sp. nov., a new softnose skate (Rajiformes: Arhynchobatidae) from Simushir Island, Kuril Islands (western North Pacific), with special reference to geographic variations in Bathyraja (Arctoraja) smirnovi. Zootaxa, 4861(4), 515–543

Synonyms / new combinations and misspellings
Bathyraja sexoculata, Bathyraja (Arctoraja) sexoculata

Types
Arctoraja sexoculata

Bathyraja (Arctoraja) sexoculata
Holotype: ZMMU: P 24098; Paratype: ZMMU: P 24095; ZMMU: P 24096; ZMMU: P 24097; ZMMU: P 24099;

Images of types

Description :


Citation: Arctoraja sexoculata (Misawa, Orlov, Orlova, Gordeev & Ishihara, 2020): In: Database of modern sharks, rays and chimaeras, www.shark-references.com, World Wide Web electronic publication, Version 03/2024

Please send your images of "Arctoraja sexoculata" to info@shark-references.com

Bathyraja (Arctoraja) sexoculata (Misawa, Orlov, Orlova, Gordeev & Ishihara, 2020), ZMMU-P 24098, holotype, 346 mm TL, immature male, preserved © MISAWA, ORLOV, ORLOVA, GORDEEV & ISHIHARA
Common names
eng Simushir skate, Cимуширский скат (russian)

Short Description
Diagnosis after MISAWA, ORLOV, ORLOVA, GORDEEV & ISHIHARA, 2020 [29011]: A medium-sized species (approximate maximum size 800 mm TL, 550 mm DW) of Bathyraja (Arctoraja) with the following combination of characters: dorsal ground color reddish-brown or greenish-brown, with three pairs of white blotches on disc located beside eyes, and on shoulders and posterior half of disc; lateral margin of tail with four or five pairs of white blotches located at tail origin, midpoint, D1 origin, and on inter-dorsal space; ventral surface almost entirely white; dark blotch around cloaca, dark bands along mid ventral line of tail; dorsal surface of disc with a single scapular thorn, 3–4 nuchal thorns; tail with 20–24 regularly arranged thorns; median row of thorns discontinuous, viz., mid-dorsal thorns absent; orbital thornlets present along medial rim of orbit; fine prickles on dorsal surface of disc and tail; prickle band on mid-disc extending along sides of tail; prickles on pectoral fin base relatively sparse; ventral surface uniformly smooth; disc width 63.1–65.6% TL, length 50.6–53.5% TL; anterior projection (snout to maximum width) 29.7–32.2% TL; head length (dorsal aspect) 18.9–20.6% TL; snout broad, moderately short, preoral length 11.1–14.1% TL, supported by slender, flexible unsegmented cartilage; snout angle 103–119º; eyes rather large, eye diameter 0.22–0.24 times head length, 1.00–1.11 times between orbits; tail relatively long (but shorter than disc width), length 51.5–54.1% TL and 0.79–0.86 times DW, width at first dorsalfin origin 3.8–4.2% tail length; 86–93 predorsal caudal vertebrae.

Distribution
east coast of Simushir Island, Kuril Islands, North Western Pacific [29011]

Size / Weight / Age
TL (max, types): 286–352 mm TL, 187–226 mm DW, uncatalogued specimens: adult male: ca. 810 mm TL, ca. 550 mm DW; immature female: ca. 630 mm TL, ca. 450 mm DW [29011]

Habitat
demersal; marine; depth range: +/- 150 m [29011]

Dentition
Teeth unicuspid, with slightly elevated subcircular bases; arranged regularly in parallel longitudinal rows; cusps weakly pointed, conical, directed obliquely posteriorly in upper jaw; cusps more flattened in lower jaw. [29011]

Remarks
shark-references Species-ID=16029;

Parasites (arranged by Jürgen Pollerspöck)
Cestoda
  • Onchobothrium malakhovi Gordeev & Polyakova, 2023 [31438]
  • Onchobothrium sp. [30483]