Silver dollar - Metynnis hypsauchen

Scientific name: Metynnis hypsauchen

Common name: Silver dollar

Family: Characidae

Usual size in fish tanks: 15 - 20 cm (5.91 - 7.87 inch)

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Recommended pH range for the species: 6 - 7.5

Recommended water hardness (dGH): 4 - 18°N (71.43 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature: 24 - 29 °C (75.2 - 84.2°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

Tank Requirements

The Silver Dollar (Metynnis hypsauchen) is a peaceful, herbivorous fish from the Amazon and Paraguay River basins of South America. It requires a large tank due to its active nature and size, reaching 15-20 cm (5.91-7.87 inches) in length. A minimum tank size of 75 gallons (284 liters) is recommended to provide plenty of swimming space. Silver Dollars are schooling fish, so it's important to keep them in groups of at least five or more. This reduces stress and helps them feel secure in the aquarium.

Silver Dollars thrive in soft to moderately hard water with a temperature range of 24-29°C (75.2-84.2°F). The water's pH should be maintained between 6 and 7.5. Strong filtration is necessary to keep the water clean and clear, as these fish can produce significant waste. Weekly water changes of 25-30% are recommended to maintain water quality and keep your fish healthy.

Tank Setup

Due to their herbivorous nature, Silver Dollars will quickly devour most live plants. Therefore, it's best to use fake plants or hardier species like Anubias and Java Fern if you want to add greenery to the tank. These plants are more resistant to the Silver Dollar's grazing habits.

Provide plenty of hiding spots using rocks, driftwood, and caves. These timid fish appreciate shaded areas where they can retreat if they feel threatened. Ensure that the tank has open areas for swimming, as they are active fish that need space to move around.

Tankmates

Silver Dollars are generally peaceful, making them suitable for community tanks with other large, non-aggressive species. Ideal tankmates include:

Be cautious when pairing them with smaller fish, as Silver Dollars may mistake them for food. Additionally, avoid keeping them with aggressive fish that might bully these shy species.

Food and Feeding

Silver Dollars are herbivores, and their diet should consist mainly of vegetable matter. They will readily accept blanched spinach, lettuce, peas, zucchini, and cucumber. Use high-quality veggie flakes or algae wafers as their staple food, supplemented with fresh vegetables. While they may occasionally nibble on protein-rich foods like bloodworms or brine shrimp, this should be offered sparingly, as a primarily plant-based diet is essential for their health.

Feed them twice a day and remove any uneaten food after a few minutes to prevent it from decaying in the water. Silver Dollars are voracious eaters, and their teeth are adapted to shred plant matter, so ensure you provide enough greens to satisfy their appetite.

Sexing

Sexing Silver Dollars can be challenging, but males typically have a longer, red-tipped anal fin with a black stripe. Females are usually rounder in shape, especially when they are full of eggs.

Breeding

Breeding Silver Dollars is relatively straightforward once you have a compatible pair. These egg layers can spawn in large groups, laying up to 2000 eggs at a time. Provide a separate breeding tank with soft water and slightly warmer temperatures (around 27-29°C / 80.6-84.2°F) to encourage spawning.

The female will scatter her eggs, which will then sink to the substrate. Both parents should be removed after spawning to prevent them from eating the eggs. The eggs will hatch in 3-4 days, and the fry will become free-swimming a few days later. Feed the fry on a diet of newly hatched brine shrimp or crushed flake food until they are large enough to accept regular foods.

Lifespan

Silver Dollars are long-lived fish that can survive for over 10 years in captivity with proper care. Maintaining stable water conditions, providing a balanced diet, and avoiding stress are key factors in ensuring a long and healthy life for your Silver Dollar.

Short Description

The Silver Dollar (Metynnis hypsauchen) is a peaceful, herbivorous fish native to the rivers of South America. Known for their round, silver body and schooling nature, these fish make a striking addition to large community tanks. While they are easy to care for, their tendency to eat live plants requires careful consideration when setting up their tank. With the right care and a proper diet, Silver Dollars can live for over a decade, providing aquarists with years of enjoyment.