Arctoraja sexoculata (Misawa, Orlov, Orlova, Gordeev & Ishihara, 2020)
Simushir skate
Arctoraja sexoculata
photo by Misawa, R

Family:  Arhynchobatidae (Softnose skates)
Max. size:  35.2 cm TL (male/unsexed); 28.6 cm TL (female)
Environment:  demersal; marine; depth range - 150 m
Distribution:  Northwest Pacific: Simushir Island, Kuril Islands.
Diagnosis:  This medium-sized species (ca. max. size 80.0 cm TL, 55.0 cm DW) is distinguished by the following set of characters: dorsal ground color is 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 4 or 5 pairs of white blotches located at the tail origin, midpoint, D1 origin, and on inter-dorsal space; ventral surface is 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; the median row of thorns discontinuous, no mid-dorsal thorns; orbital thornlets along medial rim of orbit; dorsal surface of disc and tail with fine prickles; prickle band on mid-disc extending along sides of tail; prickles on pectoral fin base relatively sparse; ventral surface is 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 and moderately short, preoral length 11.1-14.1% TL, supported by slender, flexible unsegmented cartilage; snout angle 103-119ยบ; eyes rather large with 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 dorsal fin origin 3..8-4.2% tail length; predorsal caudal vertebrae 86-93 (Ref. 123274).
Biology: 
IUCN Red List Status: Data deficient (DD); Date assessed: 11 February 2021 Ref. (130435)
Threat to humans:  harmless


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