How to Identify Giant Freshwater Stingray

To identify Giant Freshwater Stingray (Urogymnus polylepis), look at these key features.

Physical Characteristics

Body shape

flat

Coloration

Dorsal surface typically uniform grey to brownish-grey, sometimes with darker mottling or spots. Ventral surface is white to off-white. Juveniles may exhibit more distinct patterning.

Scale type

placoid

Mouth position

inferior

Distinctive features

Extremely large, flattened, circular to oval disc., Long, whip-like tail, often twice the length of the disc, bearing one or more large, venomous serrated spines near the base., Small, widely spaced eyes., Absence of dorsal fins., Skin covered in small, granular denticles (placoid scales), giving it a sandpaper-like texture. Larger, conical tubercles may be present on the disc and tail in some individuals.

Dorsal fin

Absent

Tail fin

Long, slender, whip-like, without caudal fin folds, but with one or more venomous spines.

Pectoral fin

Broad, forming the main disc of the body.

Distinctive fins

Pelvic fins are small and located at the base of the tail.

Identification Tips

1. 1

   Size

   Its immense size (disc width up to 2.4 meters, total length over 5 meters) immediately distinguishes it from most other freshwater stingrays.

2. 2

   Tail

   The extremely long, whip-like tail, often twice the disc length, with prominent venomous spines near the base, is a key identifier.

3. 3

   Coloration and Texture

   Uniform grey to brownish-grey dorsal coloration and a rough, denticle-covered skin surface.

4. 4

   Absence of Dorsal Fins

   Unlike some other ray species, U. polylepis lacks dorsal fins on its tail.

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