river stingray

Ocellated stingray or South American river stingray, scientific name Potamotrygon motoro, belongs to the family Potamotrygonidae (River stingrays). A predatory and dangerous fish for the aquarist due to its spike at the tip of the tail. Requires large expenses for its maintenance, including the maintenance of equipment and the purchase of large volumes of fresh or live food. Rarely seen in the hobby aquarium.

Habitat

It comes from South America, is found in almost the entire basin of the Amazon River and other major rivers of the continent. The freshwater stingray is found in various biotopes, the main thing that unites them is the sandy or silty substrates in which it can burrow. During the rainy season, it often swims into flooded areas of tropical forests.

Brief information:

• The volume of the aquarium – from 1700 liters.
• Temperature – 24-26°C
• Value pH — 6.0–7.0
• Water hardness – soft (1-12 dGH)
• Substrate type – sandy
• Lighting – subdued, dim
• Brackish water – no
• Water movement – light or moderate
• The size of the fish is 60 cm.
• Nutrition – fresh or live food
• Temperament – aggressive
• Content alone or in a group

Description

Depending on the region of origin, the sizes of adults differ. In aquariums, they usually grow up to 60 cm. Sexual dimorphism is weakly expressed, the differences lie in the presence of special appendages in males near the anal fins, through which they secrete the seed. The coloration is gray or brown with evenly spaced light spots with a dark border. The presence of such spots is reflected in the name of this species – “ocular”.

The tail has a sharp spike for protection. In case of danger, the stingray can strike with its tail and stick its “tool”. If mishandled, there is a high risk of injury.

Food

A carnivorous species, in the wild it feeds on other fish and aquatic invertebrates, including crustaceans and worms. In a home aquarium, the diet should be appropriate. The basis of the diet should be fresh or live fish, of a suitable size, shrimp, mussels, earthworms, etc. Feed a couple of times a day in small portions.

Do not serve the meat of mammals and birds. The substances contained in them are poorly absorbed and can harm the health of river rays.

Maintenance and care, arrangement of the aquarium

The optimal size of the aquarium for a pair of fish starts from 1700 liters. The most acceptable tank shape is round without sharp edges. The design is simple and is chosen at the discretion of the aquarist. The main conditions are sandy soil and large open spaces at the bottom. When choosing a decor, it is worth abandoning rooted plants, as they will be quickly dug up and damaged. As an alternative, mosses and ferns that can grow on snags and stones are suitable. In addition, they are perfectly adapted to growth in low light. This is exactly what should be provided in the aquarium.

The filtration system is the most important element in keeping the Ocellated Stingray. The filter is designed to cope with a large amount of organic waste and provide full circulation of water at least 4 times per hour, i.e. with a tank volume of 1700 liters, its performance should be about 7000 liters per hour. In addition, half of the water should be replaced weekly with fresh water.

Such requirements imply serious costs for the purchase, installation of equipment and its subsequent maintenance, therefore, such work is usually carried out by individual specialists or professional aquarists with extensive experience.

Behavior and Compatibility

In its natural habitat, the South American river stingray is one of the top predators. Accordingly, the choice of aquarium neighbors is extremely limited. In a capacious tank, compatibility with large fish living in the middle and upper layers of the water, such as Pacu, Brazilian Geophagus, peaceful Cichlazoma, is possible.

They can live alone or in a group.

Breeding / breeding

Ocellated stingrays use the strategy of intrauterine reproduction, when already fully formed rays are born. The fry develop inside the body of the female. When they eat their yolk sacs, they begin to feed on a special substance through special threads – a primitive version of the placenta. In total, there are up to 8 fry in a brood.

River stingrays are picky about the choice of a partner, therefore, in order to obtain offspring, it is not enough to place a male and a female in the same aquarium. A pair can form naturally if you purchase several young fish that will grow together for several years. But such a breeding strategy is beyond the capabilities of most aquarists.

In the presence of a suitable pair during the spawning period, the male will begin to demonstrate mating behavior. He pursues the female until she is ready to mate. Then the stingrays are pressed against each other by the abdomen and the male injects the seed into the body of the female with the help of special processes.

The incubation period lasts from 9 to 12 weeks. However, in an aquarium, the time is reduced. Apparently, due to more comfortable conditions and regular access to food.

Fish diseases

Hardy and unpretentious fish. In favorable conditions, health problems do not arise. The main cause of most diseases is a sharp and significant deterioration in water quality. Read more about symptoms and treatments in the Aquarium Fish Diseases section.