This species is distinguished from most of its congeners by the intense dark blue-grayish coloration and large dorsolateral tail thorns. It is further distinct with the following characters: disc evenly inverse heart-shaped, with broadly rounded outer corners; body length to mid-cloaca is shorter than tail length from mid-cloaca; snout very long direct preorbital length 15.1-16.7% TL.; orbits are relatively small, horizontal diameter 0.9-1.2 times interorbital width; dorsal surface nearly completely devoid of denticles except the trunk area close to pectoral axils where bands of few denticles start and continue as more pronounced rows on tail; anterior tail with several short rows of spinules and a rather regular row of small spinules on lateral tail; one small preorbital thorn on each side; a regular or irregular row of about 16-25 small median tail thorns; lateral tail with 2 irregular rows of about 15-25 dorsolateral thorns that are much larger than the median thorns. Colouration when fresh, the dorsal disc plain intense dark blue, somewhat mottled blackish-brown in the orbital and snout regions, pelvic fins and claspers medium brownish blue, tail dark blackish blue; the ventral surface dark (Ref. 123885).