Smooth-back river stingray

Potamotrygon orbignyi

Variable fine reticulation and a dark mark behind the spiracle invite closer inspection.

Brown-grey rays assigned to P. orbignyi range from strongly reticulated to almost plain, even among captive offspring, so each pattern is not an extra species. A dark mark behind the spiracle is a useful cue.

Water temperature: 24–26 °C
pH: 6.8–7.5

Natural habitat: Inhabits river sandbanks, shallows and slow tributaries over mud or sand, also entering flooded forest and flood-recession lakes and ponds.

Teacup describes a small sale fish, not a small adult. Adults can be larger than the 35–37.5 cm DW sometimes quoted. Sting and predation risks apply.

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Appearance and identification

Compare the fine netlike pattern with the broad central vermiculations and pale kidney-like patches of P. wallacei. Reticulated rays are not one species: P. siponinmorok was described in 2026 from a former orbignyi-like concept. Mantilla or teacup trade labels do not identify this species.

Floor and movement space

Plan 180 × 60 × 60 cm for one adult. Preserve open floor space, turning room and separation options.

Aquarium environment

Maintain clear routes for the disc. Rooted plants may be disturbed. Dense decor needs a space check.

Diet and feeding

Eats fishes and aquatic invertebrates. Offer suitable varied foods and confirm feeding; bottom feeding is not waste disposal or a substitute for deliberate nutrition.

Compatibility limits

Small fish and shrimp may become prey. Disc-attaching or strongly territorial companions may cause harm. Consider size, floor space and behaviour.

Same-species behaviour

Track individuals and breeding separately when keeping multiple rays; hybrids do not keep this species name.

Sources