Diagnosis |
This medium-size (413 mm TL) species is distinguished by the following set of characters: heart-shaped disc with a short projected snout tip; disc slightly wider than long, its width 51-54% of TL, and length 47-48% TL; short snout, its preorbital snout length 12-15% TL, preoral snout length 12-15% TL; interorbital width 3.6-4.1% TL; interspiracular width 6.0-6.6% TL; long and slender tail, its length from posterior margin of cloaca to tip of tail 54-58% TL; dorsal surface of disc largely free of dermal denticles; rostrum with some denticles, without thorns; a small but distinct preorbital thorn on anterior upper orbital rim; denticles present on posterior mid-dorsal trunk; tail prickly with dense, irregular and randomly arranged thorns; mid-dorsal row on tail hardly distinct from the rest of thorn pattern; naked ventral surface of disc and tail; upper jaw with 29-36 tooth rows, lower with 28-32; pectoral-fin radials 67-70; monospondylous trunk centra 23-25; predorsal caudal diplospondylous centra 70-74; total number of centra 126-134; dorsal surface rich blue, uniform, with a narrow blackish outer margin; ventral surface of disc and tail brownish black, gill slits darker, cloaca opening and mouth corners whitish (Ref. 81757). |