| Diagnosis: |
This species is distinguished by the following set of characters: rhomboidal disc with its axis of greatest width well forward, snout tip to maximum disc width 37% (35-39%) DW; short preorbital snout with small apical lobe, rather obtuse, snout angle 121-127°; pectoral-fin apices are narrowly rounded, angle 86-92°; orbits are moderately small, protruding slightly; mouth relatively narrow, its width 6.2-7.0% DW; small pelvic fins, length 17-19% DW, width across base 13-14% DW; preoral snout length is 2.8-3.1 times internasal width, 19-21% DW, interorbital distance 2.0-2.2 times orbit length, prenasal length 2.2-2.4 times internasal width; subcircular tail with longitudinal ventral groove is behind caudal sting; tail weakly depressed posteriorly, with longitudinal lateral ridge on each side in subadults; an enlarged, seed-shaped, suprascapular thorn usually followed by up to 5 much smaller primary denticles in adults (suprascapular thorn may be preceded by a few much smaller primary denticles in early juveniles); a band of secondary denticles suboval (in subadults), very broad (its width across scapulocoracoid much narrower than its width at spiracles), with sharply-defined lateral margins, broad and semi-truncate near tail base; band fully developed and covering entire dorsal surface of tail by 49 cm DW; colour of dorsal surface mainly uniformly brownish, disc margin paler brown dorsally and ventral disc uniformly whitish, not obviously black edged; in subadults, darker dorsal surface of tail is sharply demarcated from slightly paler ventral surface (median furrow dark and contrasted with skin adjacent); in juveniles, the dorsal post-sting tail has conspicuous, alternating, black-and-white saddles that persist nearly to tail tip, ventral tail uniformly greyish; pectoral-fin radials 130-135; total vertebral count (excluding first synarcual centra) 108-116, monospondylous centra 44-46, pre-sting diplospondylous centra 64-67 (Ref. 111065). |