Description: Characterized by male having bluish grey to black body color, back with pale blue vermiculations, broad black stripe containing pair of light blue or white lines at upper side and remainder of side blue with black-edged white spots; female yellowish brown on side with reticulum of broad black lines and spots, maze of fine black lines on back; carapace quadrangular in cross section, nearly flat on top and slightly convex at bottom; straight to slightly convex dorsal profile of snout, lacking bony protuberance above upper lip; rounded caudal fin (Ref. 90102).