奥氏江魟 · Smooth-back Stingray

Overview

Often sold under the vague “teacup ray” label, Potamotrygon orbignyi can be difficult to identify as a juvenile. Its relatively manageable usual size does not describe every population: Amazon females may grow appreciably larger. Plan housing around the fish itself rather than a sales label.

Distribution & habitat

It is native to northern South America, including Venezuela, Guyana, Suriname, French Guiana, Brazil, and Bolivia. Records include the Amazon, Orinoco, Paraná, and smaller rivers. Habitat accounts for related rays cover sandy shallows, muddy tributaries, flooded forest, and floodplain pools.

Aquarium setup

For one adult, 180 by 60 by 60 cm is the suggested starting size. Larger populations, pairs, or groups need greater length and width. Keep an open floor, secure heavy decor, and provide restrained lighting. Sand allows burial; bare floors simplify cleaning but remove cover. Plants may not survive.

Heavy feeding requires efficient biological filtration and regular upkeep. A sump keeps heaters and fragile equipment away from the disc; sufficiently large canisters are another option. Guidance suggests roughly four turnovers per hour, oxygenating surface movement, and weekly changes around half the volume. A secure cover is essential.

Diet & feeding

General ray-feeding guidance recommends varied animal foods at least twice daily. Small worms, Artemia, and krill suit juveniles; larger fish can receive suitable shellfish, shrimp, squid, fish, and earthworms.

Thin imports need prompt feeding. If frozen foods are refused, establish intake with live prey and transition after condition improves. Avoid routine mammalian or avian meat and feeder fish.

Behaviour & compatibility

Peaceful fish too large to swallow are the most suitable companions, especially if they use upper water. Territorial species create stress, while suckermouth catfish can attach to and injure the disc. Different river rays may hybridize, so confirm identities before assembling breeding groups.

Sexual dimorphism

The paired claspers projecting backward from the inner pelvic fins identify males. They remain visible, though smaller, in juveniles.

Breeding

Genus-level experience describes internal fertilization followed by maternal nourishment of live young. Mate choice is selective; a larger, well-conditioned female is preferable. Courtship bites require close monitoring and the ability to separate fish before prolonged injury occurs.

Related-ray practice includes generous feeding during pregnancy, separate care for newborns, frequent suitable meals after yolk absorption, and regular water changes. Repeated litters are demanding, so females need recovery intervals.

Notes

A noticeably smooth skin texture is an identification clue, but direct touching is unsafe. Barbed spines can injure even after shedding. Transfer rays in a suitable solid container or large fish bag, never a net, and obtain medical care following a sting. Before buying, check feeding and watch for sunken areas, protruding pelvic structures, or curled disc margins.