The red stingray can grow to 2 m (6.6 ft) long and 0.66 m (2.2 ft) across, though most do not exceed 1 m (3.3 ft) in length.
The maximum recorded weight is 10.7 kg (24 lb).
It has a diamond-shaped pectoral fin disc wider than long, with nearly straight front margins converging to a triangular snout.
The small eyes are slightly elevated, and followed by spiracles that are almost twice as large.
There is a thick flap of skin between the large nares.
The teeth are arranged with a quincunx pattern into a pavement-like surface.
Females and juveniles have blunt teeth, while adult males have pointed, recurved teeth.
There is a row of 3 papillae across the floor of the mouth, sometimes with up to 2 pairs of accessory papillae alongside.

The tail is whip-like and measures 1–1.5 times as long as the disc is wide.
A long, serrated spine originates in the first third of the tail, and is followed by a low dorsal keel and a ventral fin fold.
Young rays have smooth skin, while adults have a patch of small dermal denticles between and behind the eyes, and a row of thorns along the midline of the back.
There are 1–6 tubercles in front of the tail spine, and numerous small denticles behind.
This species is plain brown above, often with yellow or orange coloring before the eyes, behind the spiracles, around the disc margin, and laterally on the tail in front of the spine.
The tail darkens to nearly black towards the tip and on the ventral fin fold.
The underside is white with bright orange-red patches.
The Mekong freshwater stingray (D. laosensis) is also characterized by orange ventral coloration and has some similar meristic counts to this species, but differs in disc shape, denticle coverage, and dorsal coloration.
The red stingray can grow to 2 m (6.6 ft) long and 0.66 m (2.2 ft) across, though most do not exceed 1 m (3.3 ft) in length. The maximum recorded weight is 10.7 kg (24 lb). It has a diamond-shaped pectoral fin disc wider than long, with nearly straight front margins converging to a triangular snout. The small eyes are slightly elevated, and followed by spiracles that are almost twice as large. There is a thick flap of skin between the large nares. The teeth are arranged with a quincunx pattern into a pavement-like surface. Females and juveniles have blunt teeth, while adult males have pointed, recurved teeth. There is a row of 3 papillae across the floor of the mouth, sometimes with up to 2 pairs of accessory papillae alongside.
The tail is whip-like and measures 1–1.5 times as long as the disc is wide. A long, serrated spine originates in the first third of the tail, and is followed by a low dorsal keel and a ventral fin fold. Young rays have smooth skin, while adults have a patch of small dermal denticles between and behind the eyes, and a row of thorns along the midline of the back. There are 1–6 tubercles in front of the tail spine, and numerous small denticles behind. This species is plain brown above, often with yellow or orange coloring before the eyes, behind the spiracles, around the disc margin, and laterally on the tail in front of the spine. The tail darkens to nearly black towards the tip and on the ventral fin fold. The underside is white with bright orange-red patches. The Mekong freshwater stingray (D. laosensis) is also characterized by orange ventral coloration and has some similar meristic counts to this species, but differs in disc shape, denticle coverage, and dorsal coloration.
Red stingray