Home » Aquarium inhabitants » Predatory fish » Reticulated Stingray

Reticulated Stingray

Overview

The reticulated stingray, Potamotrygon orbignyi, is a freshwater stingray species from the family Potamotrygonidae. In older literature it may appear under the synonym Potamotrygon reticulatus. This large freshwater stingray has become one of the most popular river stingrays kept by experienced aquarists. Its distinctive net-like pattern, active behavior and relatively peaceful temperament make it a fascinating but demanding aquarium inhabitant.

In nature reticulated stingrays are top predators within their ecosystem, feeding on small fish and invertebrates. In captivity they require very large tanks, powerful filtration and frequent feeding with high-quality meaty foods. Because of their size and sensitivity, this species is recommended only for aquarists already familiar with large fish and advanced husbandry.

Habitat

The species is native to South America. Its natural range covers wide areas of the Amazon and Orinoco river basins and also river systems in Suriname, Guyana and French Guiana. Reticulated stingrays inhabit a variety of biotopes, but are most often found in shallow, swampy sections of rivers with sandy or silty bottoms. Here the fish spend much of their time resting or partially buried in the substrate while waiting for prey.

Description

Like other river stingrays, the reticulated stingray has a classic disc-shaped body. The disc can reach about 35 cm in diameter, while the long, thin tail can extend the total length of the fish to more than twice the disc size. On the tail there is a sharp but fragile spine connected to venom glands, which the stingray uses primarily for self-defense. Proper handling and respect for the fish will prevent accidents, but aquarists should always be cautious when working in the tank.

The body pattern consists of a net-like or reticulated design made up of several shades of brown. This unique coloration gives the species its common name and helps to camouflage the ray against sandy and muddy riverbeds. Adult fish are impressive, truly a large freshwater stingray that becomes the center of attention in any aquarium.

Unique features and physiology

In comparison with some related Potamotrygon species, the reticulated stingray has a relatively small stomach in proportion to its body mass. This means it cannot take in large meals at once and instead needs to be fed frequently with small portions throughout the day. This physiological feature becomes especially important during transportation and acclimation, when feeding schedules are often disrupted. Young stingrays are particularly sensitive to irregular feeding and may arrive at the store already weakened.

Another critical aspect is the very long tail. During transport the tail can be strongly bent in cramped containers or even stay above the water surface for long periods if the bag or box is kept vertically. Such damage is the main cause of many health problems in this species. Because of these factors, choosing a healthy specimen at the time of purchase is essential for long-term success.

Behavior and compatibility

In the wild reticulated stingrays are active predators, so they pose a direct threat to most small fish and freshwater shrimp. Anything that can fit into their mouth is treated as potential food. At the same time, this freshwater stingray is not aggressive toward fish that are too large to be swallowed. With suitable tank mates it usually behaves calmly and focuses on searching the bottom for food.

Good companions include robust cichlids such as Geophagus species and Severum cichlids, as well as large Pimelodus catfish. In very spacious aquariums, reticulated stingrays can also be kept together with South American arowanas and large predatory fish similar in size and temperament. Delicate or slow-moving fish, as well as very small species, should be avoided.

Care and aquarium setup

For a single adult reticulated stingray, the recommended freshwater stingray tank size starts from 600 l. For this bottom-dwelling species the footprint of the tank is more important than its height; the ray needs a large open area to move and rest. The design of the aquarium can be simple, but the bottom must remain as free as possible from obstructions.

The substrate is a key element. Fine river sand or very small, smooth gravel is ideal, as the fish regularly buries itself partially in the ground. Sharp or coarse materials can damage the disc and underside. Decor may include a few large driftwood pieces, smooth rocks and heavy boulders, but they must be stable enough that the stingray cannot move or overturn them while digging.

Because the fish frequently disturbs the bottom, rooted plants are unlikely to survive; they are usually uprooted sooner or later. As an alternative, aquarists can use plants attached to driftwood or rocks, such as Anubias, many aquatic ferns and mosses. These add visual interest without occupying precious bottom space.

Filtration is one of the most important aspects of long-term care. As a carnivorous bottom feeder, this species produces a significant amount of organic waste. Efficient external filters, often more than one, are strongly recommended. Models with built-in heaters and aeration are especially convenient, as they reduce the number of devices inside the tank and free up swimming space. A good rule of thumb is that the filtration system should be able to move a volume of water equal to at least four times the capacity of the aquarium per hour. Water movement should be weak to moderate, avoiding strong currents near the bottom where the stingray rests.

Water quality depends not only on filtration but also on regular maintenance. Perform weekly water changes of about 50 % while siphoning uneaten food, feces and other organic waste from the substrate. Recommended parameters for this freshwater stingray species are a temperature of 24–26 °C, pH between 6.5 and 7.5 and soft water up to 10 dGH. The species does not require brackish conditions and should be kept in pure freshwater. Lighting is best kept subdued, which corresponds to its natural environment and helps the fish feel secure.

Feeding

In nature the reticulated stingray feeds mainly on small fish, freshwater shrimp and large invertebrates such as worms. In the aquarium its diet should be based on similar live or fresh foods. Suitable items include pieces of fish, shrimp, earthworms and other large worms. Juveniles readily accept bloodworms, tubifex, Artemia and similar small prey. Dry foods are generally not used for this species; it rarely accepts them and they do not satisfy its nutritional needs.

Because of the relatively small stomach capacity, food should be available frequently in small portions rather than in one or two large meals. Ideally, there should always be a small amount of food accessible on the bottom, without allowing excess to decompose. Special attention must be paid to young rays, which are much more vulnerable to starvation and can lose weight quickly if feeding is irregular. A well-fed fish will have a full, smooth body without visible protrusions at the base of the tail and without sunken areas under the eyes.

Choosing a healthy reticulated stingray

These rays are commonly offered for sale and may come either directly from South America or from breeding facilities in Europe and Asia. Regardless of origin, there is always a risk of buying a sick or emaciated specimen due to the difficulties of transportation and feeding. Before purchasing, try to observe the fish during feeding. Healthy individuals eagerly accept food and actively search for it on the bottom.

Inspect the animal carefully. There should be no visible kinks or injuries on the tail, as these often lead to infections. The area at the base of the tail should look full, not bony or sharply outlined. Under the eyes there should be no deep hollows. All these signs indicate exhaustion and poor condition, which can be hard to reverse even in excellent aquarium conditions. Choosing a strong, well-fed specimen at the beginning greatly increases the chances of success with this demanding large freshwater stingray.

Breeding

The reticulated stingray is a viviparous species. The young develop inside the female’s body and are born fully formed. Gestation lasts several months, and during a single season the female may produce only 1–8 pups. Observations suggest that in aquariums the gestation period can be somewhat shorter than in the wild, probably due to constant temperature and abundant food.

These rays are very selective when choosing mates. Simply placing a male and a female together rarely results in successful reproduction. In captivity, experienced keepers usually acquire a group of young rays and allow them to grow together, letting them form compatible pairs naturally. This process may take several years, which makes breeding unsuitable for the average hobbyist. For this reason, regular home aquariums rarely see deliberate breeding projects with this species, and most specimens available in shops are still collected from the wild or bred in specialized facilities.

Conclusion

The reticulated stingray is a striking and fascinating freshwater stingray species that can become a true centerpiece of a large aquarium. However, it is also a demanding fish that requires a very spacious tank, powerful filtration, stable soft water and frequent feeding with high-quality meaty foods. Careful selection of a healthy specimen and attention to water quality are essential for long-term success.

For aquarists ready to meet these requirements, this species offers the unique opportunity to observe the behavior of a river stingray in a well-planned home aquarium and to enjoy the beauty of its intricate net-like pattern and graceful movements along the sandy bottom.