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The species is distinguished from all its congeners by its remarkably long and acutely angled
snout, with horizontal preorbital length 17.2-–22.6% TL (vs. 8.5-11.9% TL) and 4.2-6.1 (vs. 1.7-3.5) times orbit length, snout angle 65-85? (vs. 90-150?); with plain dorsal coloration; with an external clasper component dike; with four dorsal terminal (dt) cartilages (Ref. 131089).
Description: This medium-sized species with disc rhombic to (in adult male) evenly inverse heart-shaped, with broadly rounded outer corners and with body length to mid-vent about equal to tail length from mid-vent; preorbital snout length 17.2-22.3% TL. distance between first gill slits 11.6-12.9% of TL; orbits are moderately large, horizontal diameter 1.0-1.2 times interorbital width; dorsal disc is largely devoid of denticles, ventrally spinules at least on snout tip; thorn pattern is pronounced with 5-20 rostral thorns, a half ring of 3-5 thorns on each orbital rim, 1 supraspiracular and 1 interspiracular thorn per side, 3-5 median nuchal thorns, 0-3 lateral nuchal thorns per side, 1-2 suprascapular thorns, 0-2 lateral scapular thorns, 2-3 scapular thorns per side, a median row of 34-41 thorns from behind the shoulder girdle to just before the origin of the first dorsal fin, no interdorsal thorns, and 2-4 parallel rows of thorns on tail; bases of nearly equal-sized and long but low dorsal fins confluent or with short interspace of maximally 0.8% TL; postdorsal tail section short, 2.5-3.8% TL, with low epichordal caudal lobe, which is confluent with the second dorsal fin; brownish lateral tail folds along posterior 58.1-72.0% of tail; upper jaw tooth rows 41-49, pectoral-fin radials 69-73, pelvic-fin radials 3 + 15–3 + 18; clasper lacking external pseudosiphon; inner dorsal lobe with components roll, promontory, slit, and two clefts; inner ventral lobe with components shield, rhipidion, pent, sentinel, spike, and dike; terminal clasper skeleton with four dorsalterminal cartilages, a ventral terminal, and two accessory terminal cartilages, plus a tiny separate spindle-shaped fibrocartilage between distal tips of dorsal terminal 1 and ventral terminal; anterior cranial fontanelle with clear-cut contour all around and extending only about one fifth into rostral shaft length; scapulocoracoid subquadratic, rear corner poorly developed, large oval anterior fenestra without anterior bridge, one moderately large, oval postdorsal and postventral fenestra, respectively; pelvic girdle with massive ischiopubicbar with nearly straight anterior and deeply concave posterior contour; prepelvic processes short, solid, conical, and somewhat inclined outwards, their length 1.7–2.9 times median thickness of ischiopubic bar; differs from all congeners in the remarkably long and acutely angled snout, horizontal preorbital length 17.2-22.6% TL (vs. 8.5-11.9% TL) and 4.2-6.1 (vs. 1.7–3.5) times orbit length, snout angle 65-85? (vs. 90-150?); with external clasper component dike and with four dorsal terminal cartilages; the shape of the accessory terminal 1 cartilage with four tips is also unique within the genus. Colouration: when fresh, dorsal surface plain medium-brown, with grayish mucus coverage; ventral side plain grayish on disc and pelvic fins, snout dusky grayish, sensory pores not marked dark (Ref. 131089). |
