Common names
Western Blue Skate

Short Description
Diagnosis after WEIGMANN, SÉRET & STEHMANN, 2021 [29465]: A medium-sized species of the genus Notoraja with disc evenly inverse heart-shaped, with broadly rounded outer corners and with body length to mid-cloaca shorter than tail length from mid-cloaca. Snout very long, direct preorbital length 15.1–16.7% TL. Orbits relatively small, horizontal diameter 0.9–1.2 times interorbital width. Dorsal surface almost completely devoid of denticles except trunk area close to pectoral axils where bands of few denticles start and continue as more pronounced rows on tail; anterior tail also with several short rows of spinules and a rather regular row of small spinules on lateral tail. Only one small preorbital thorn on each side; a regular or irregular row of about 16–25 small median tail thorns; lateral tail with two irregular rows of about 15–25 dorsolateral thorns that are much larger than the median thorns. When fresh, dorsal disc plain intense dark blue, somewhat mottled blackish-brown in orbital and snout regions, pelvic fins and claspers medium brownish blue, tail dark blackish blue. Ventral surface dark blue-grayish with indistinct bright mottling, outer disc margins and snout darker blue, gill area conspicuously dark blue, mouth, cloaca, and tips of anterior pelvic-fin lobes whitish, tail and rest of pelvic fins including claspers pale bluish brown. Bases of equal-sized and long but low dorsal fins separated by short interspace. Postdorsal tail section long, 6.1–6.8% TL, with low epichordal and rudimentary hypochordal lobes. Blackish lateral tail folds along full tail length. Upper jaw tooth rows 28–34, pectoral-fin radials 58–61. Claspers lacking dermal denticles, external pseudosiphon and shield; inner dorsal lobe with components slit, cleft, and pseudorhipidion; ventral lobe with rhipidion, projection, spike, and sentina. Terminal clasper skeleton with dorsal terminal 2 cartilage, a ventral terminal, and accessory terminal cartilage 2. Neither a dorsal terminal 1 nor an accessory terminal 1 cartilage were detected; although they might have been insufficiently calcified and present before dissection, they are not detectable on radiographs of the adult male specimens either. Neurocranium with long and slender rostral shaft, appendices are short, flattened cartilaginous wings that are fused to rostral shaft only at rostral node; anterior fontanelle very narrow and carrotshaped, posterior fontanelle gourd-shaped. Scapulocoracoid subquadrangular, with anterior bridge, rear corner sharply marked, postdorsal fenestra enlarged, four tiny to small postventral fenestrae. Pelvic girdle with massive ischiopubic bar with nearly straight anterior and deeply concave posterior contour; prepelvic processes very short, solid, conical, and nearly straight, their length 1.5–1.9 times median thickness of ischiopubic bar.

Distribution
western Indian Ocean, off southern Mozambique and off northwestern Madagascar [29465]

Size / Weight / Age
539 mm TL (types) [29465]

Habitat
marine; depth range 1230 - 1600 m [29465]

Dentition
Jaws weakly angled, with 28 (29–34) upper and 27 (27–32) lower tooth rows, medially arranged in parallel rows (in densely set quincunx pavement pattern in female paratype) and in strongly oblique parallel rows in outer thirds of jaws; individual teeth small, horizontally pointed, with triangular cusp, becoming smaller towards jaw angles (cusp low in female paratype) [29465]

Remarks
shark-references Species-ID=16126;