Metynnis Hypsauchen

Datasheet

General Description

The Silver Dollar, scientifically known as Metynnis Hypsauchen, is often mistaken for its close relation, Metynnis Argenteus, due to their almost identical appearance and care requirements. With a distinguishable black blotch located above and behind each eye, Silver Dollars are a common and popular fish in the hobby, related to piranhas but peaceful in nature. They belong to the Serrasalmidae family and can grow up to 15.0cm in size.

Aquarium Setup

In captivity, Silver Dollars thrive in a tank setup mimicking their natural habitat of densely planted river tributaries. However, being avid plant-eaters, artificial plants may be a better alternative. To accommodate their behavior and boost confidence, provide dim lighting, areas of refuge, and tankmates that occupy the bottom of the tank for contrast, such as larger peaceful catfish like plecos and doradids. The minimum tank size required is 265 litres, with water conditions ideally at a pH of 6.0-7.0, hardness of 0-10 dH, and a temperature range of 24-28°C.

Behaviour

Silver Dollars are best kept in groups of at least five fish and are generally peaceful community members. While they can coexist with larger peaceful species, smaller fish may be viewed as prey. These fish predominantly occupy the middle and top areas of the aquarium, showcasing a schooling behavior that is fascinating to observe.

Feeding and Diet

Their diet should consist of a large amount of vegetable matter like courgette, cucumber, peas, and green vegetables, supplemented with commercial foods such as algae wafers, spirulina, and vegetable flakes. Silver Dollars also enjoy treats like bloodworms and brine shrimp, accepting most aquarium foods readily.

Reproduction & Dimorphism

Reproduction for Silver Dollars is moderately difficult as they are group spawners. A large breeding tank with soft, acidic water conditions is necessary, with males exhibiting colorful fin displays during courtship. Around 2000 eggs can be laid per spawning pair, with a high mortality rate expected. Males can be distinguished by their more elongated and colorful anal fin.

Habitat and Distribution

The Silver Dollar's patchy distribution covers parts of Guyana, Brazil, Peru, and Bolivia, with habitats in densely planted tributaries within the Amazon and Rio Paraguay drainages, as well as some rivers in the Guyana Shield region.