Potamotrygon magdalenae

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The Potamotrygon magdalenae, also called Teacup Stingray, is a freshwater stingray native to the Magdalena River region of Colombia. Its flattened body, barbed venomous tail and graceful undulating movements make it a spectacular animal, but it is demanding in captivity. Despite its commercial nickname, it does not necessarily remain tiny as an adult. This bottom-dwelling ray inhabits quieter areas where it searches the substrate for small prey. Listed here with a rarity level of 2, it is less commonly available than many regularly offered freshwater fish. The specimens presented in the hobby are collected from the wild.

General species description

The Potamotrygon magdalenae is a freshwater stingray in the family Potamotrygonidae, adapted to life along the bottom of tropical rivers. It moves by undulating its broad pectoral fins, often just above the substrate, and then settles down to blend into its surroundings. Its rounded disc is usually brown to gray, with a paler underside. As in other stingrays, the tail carries one or more barbs that can inflict a painful injury; handling should therefore be avoided. The name Teacup Stingray mainly describes young specimens and does not guarantee a permanently small adult size. In an aquarium, this species requires substantial bottom area, warm water and efficient filtration because it produces considerable waste. Its behavior is generally discreet, but it becomes active while exploring the substrate or locating food.

Geographic origin and biotope

Country of reference: Colombia. The Potamotrygon magdalenae comes from the Magdalena-Cauca drainage, one of Colombia’s major river systems. It is associated with lowland areas, secondary channels and quieter habitats where the current remains moderate. The bottom is generally made of sand, silt or mud, together with plant debris and cover along the banks. Vegetation is concentrated mainly around the margins, including emergent plants, riverside grasses and tropical shrubs. In the wild, depth changes with the season and river level; the ray uses shallow areas that provide access to the bottom. For aquarium care, clean, well-oxygenated and stable water is more important than a very strong current. A soft substrate without sharp stones protects the disc and underside.

Precise location and local name

The Potamotrygon magdalenae is associated with the Magdalena River and several parts of its drainage, including habitats connected to the Cauca River. In Colombian regions where it is known, it is commonly called raya, or more specifically raya de río and raya del Magdalena. These vernacular names may also be applied to several freshwater stingrays depending on the region. The species uses quiet margins, backwaters, connected lagoons and soft-bottomed secondary channels. This geographic association directly explains the specific name magdalenae. In captivity, its wild origin must be taken seriously: gradual acclimation, minimal handling and careful transport are essential. Knowing the collection locality can also help keepers better understand its needs and avoid mixing animals from very different environments.

Appearance and physical characteristics

The body of the Potamotrygon magdalenae forms a nearly circular, flattened and flexible disc, with broad pectoral fins. The dorsal surface is brownish or grayish and may show lighter markings, while the underside is pale. The eyes sit on top of the head, a typical adaptation for an animal that rests on the bottom. The tail is long and tapering, with a venomous barb that is periodically replaced. Young specimens sold as Teacup Stingrays can look very small, but adult disc width may reach approximately 35 cm. Males can be identified by their claspers, two reproductive organs located at the base of the tail; females lack these structures. Color and body shape can vary with age and locality.

General diet

The Potamotrygon magdalenae is primarily a carnivorous ray that searches for food on or within the substrate. Its natural diet consists mainly of small bottom-dwelling invertebrates, including insect larvae, crustaceans and worms; it may also take small fish when available. It locates prey through electrical and chemical senses, then draws it in with its ventral mouth. In an aquarium, suitable meaty foods may include clean earthworms, shrimp, mussels and quality pieces of fish. Offer varied foods in reasonable portions to prevent obesity and excessive waste. Young rays may need small frequent meals, while adults do well with a consistent feeding schedule. A ray that refuses food may be stressed, newly imported or kept under unsuitable conditions.

Essential data

• Original river name: Magdalena River, Magdalena-Cauca drainage
• Local name used: Raya, raya de río, raya del Magdalena
• Origin of the scientific name: Potamotrygon combines Greek roots associated with river and ray; magdalenae refers to the Magdalena River.
• Full-name etymology: Potamo means river, trygon means ray; magdalenae means from the Magdalena.
• Common/vernacular names: Teacup Stingray, freshwater stingray, raya
• Family: Potamotrygonidae
• Subfamily: Potamotrygoninae
• Name pronunciation: po-ta-mo-TRY-gon mag-da-LEH-naï
• Discovery: Auguste Duméril, 1865
• Maximum adult size: Approximately 35 cm disc width
• Water temperature and pH: 24 to 28 °C; approximately pH 6.5 to 7.5
• Watercourse appearance and surrounding vegetation: Quiet channels, margins and backwaters; tropical riverside vegetation
• Typical tankmates: Geophagus pellegrini, Caquetaia kraussii, Hoplias malabaricus
• Temperament and behavior: Generally calm and discreet; bottom-dwelling, burrowing and sometimes active at feeding time
• Water depth: Shallow to moderately deep areas, mainly along the bottom
• Sexual dimorphism: Male with claspers at the base of the tail; female without claspers
• Bottom structure and flow: Sand, silt or mud; slow to moderate current

In your aquarium

Success depends on a very long and wide aquarium that provides extensive bottom area rather than excessive height. Use fine, soft sand, remove sharp decorations and provide oversized filtration with regular water changes. Keep the temperature stable, offer varied meaty foods and carefully monitor the disc, breathing and appetite. Because these animals are collected from the wild, careful acclimation and stress reduction are priorities. Avoid direct handling because of the caudal barb, and plan for an aquarium that can accommodate the true adult size instead of relying only on the Teacup Stingray nickname.