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Quick Stats

  • Family: Characidae
  • Scientific Name: Metynnis argenteus
  • Care level: Beginner
  • Temperament: Peaceful, social
  • Diet: Herbivorous
  • Water conditions: 24 – 27 degrees Celcius (75 – 81F), pH 6.5 – 7.5, 4 – 18 dGH
  • Max Size: 20 centimeters (8 inches)
  • Minimum tank size (as an adult): 200 Liters (55 gallons)

Brief Overview: Silver Dollar Fish Care

The Silver Dollar Fish is native to South American river systems but has long been popular among fish keepers. They are relatively easy to keep and can thrive in a variety of water conditions.

Silver Dollars swim at all water levels, though most often in the middle and top of the tank, and require a tank in which they can swim freely. They have a nervous nature that results in fast-paced maneuvers through the tank. This species is characterized by its round, laterally-flattened body shape and brilliant silver coloration. Their size and coloring as a juvenile resemble the large silver $1 coin used in the United States in the 19th century. This resemblance is the origin of the species’ name common name. Their scientific name also takes note of their bright coloration; Argenteus translates from Latin to “covered in silver.”

This fish typically grows to be between 6 and 8 inches long and prefers to live in schools, so the minimum tank size depends on how many fish you decide to include. Even in groups, this fish is flighty and has been known to dart around the tank and injure themselves at the approach of a human or when otherwise spooked.

Silver Dollar Fish are known to be relatively peaceful and get along well with many other species of fish in a community tank setting, though they are extremely aggressive eaters and will voraciously attack food items. Silver Dollars are herbivorous and can easily damage and outright consume live plants in their tanks.

Silver Dollar Fish is easy to care for and hardy, healthy individuals once they are established. Avoid water fluctuations in temperature and nitrate levels and your fish will be happy and healthy for 10 years or more.

Silver Dollar Fish Lifespan

How Long Do Silver Dollar Fish Live For?

Silver Dollar Fish have a life expectancy of 10 years or more in an aquarium with proper care and conditions.

How fast/slow should you expect your Silver Dollar Fish to grow?

Silver Dollar Fish are categorized by a slow growth rate but eventually reach their large adult size. Silver Dollars should be able to easily swim, turn around, and hide in their tank.

What’s Silver Dollar Fish max size?

Silver Dollar Fish can grow to a respectable size, usually around 20 centimeters in length.

Different types of Silver Dollar Fish

Metynnis argenteus or Common Silver Dollar Fish is the most common type kept by aquarists. Here are some other popular species.

Metynnis fasciatus: This species is known as the Striped Silver Dollar and is categorized by the vertical black stripes running the length of their bodies.

Metynnis hypsauchen: The species most often confused with M. argenteus, it also goes by the name Silver Dollar Fish. This species is typically a darker silver color, with black spots behind the eyes, and does not grow as large with a maximum size of 15 centimeters.

Metynnis lippincottianus: Also known as the Spotted Silver Dollar, this species grows up to 13 centimeters and has darker silver to black spots on their silver bodies. They are found in Brazil and French Guayana.

Myloplus rubripinnis: More commonly known as the Red Hook Silver Dollar Fish, this species has more distinctive coloring than its close cousins. The anal fin is red with black trim and the body may have bright orange-colored spots along its length. This species can reach up to 55 centimeters in the wild.

Silver Dollar Fish Diet & Feeding

Silver Dollar Fish are herbivorous but will eat protein on occasion.

What do Silver Dollar Fish eat in the wild?

In the wild, Silver Dollars lean more towards a plant-based diet but have been known to prey upon sources of protein as well. They feed on a variety of plants along the banks of the rivers they inhabit but have been known to consume worms and small insects on occasion.

What foods are recommended for Silver Dollar Fish?

In an aquarium setting, Silver Dollars should be fed a combination of a flake food made specifically for tropical herbivores and fresh veggies such as lettuce, spinach, cucumber, and zucchini. They may also enjoy seaweed and algae wafers as well as the occasional brine shrimp. Adding krill or shrimp will help the males present a brighter orange color. We recommend Fluval Vegetarian Flakes fish food for your Silver Dollar fish.

Silver Dollar Fish Feeding habits

Silver Dollar Fish do just fine on standard fish flakes, but variety can be added to their diet in the form of algae wafers, freeze-dried and live foods.

Silver Dollar Fish should be fed several times each day, with extra care taken not to overfeed or leave leftover food in the tank. Feed only as much as your Silver Dollars can consume in 2 or 3 minutes.

Silver Dollars are voracious and aggressive eaters. Do not be surprised if they chase one another around the tank during feeding times.

Silver Dollar Fish Tank Setup

Like all fish, Silver Dollars thrive in a tank that resembles their natural habitat and suits their needs. Silver Dollars need a tank set-up that mirrors their home in the Amazon River.

A brief overview of natural habitat

Silver Dollar Fish are native to the river systems of South America, though their similarity in appearance to Metynnis hypsauchen makes pinpointing their range difficult. Most sources indicate the Common Silver Dollar is found in Guyana, the Amazon River east of Rio Negro to Paraguay.

Silver Dollars prefer to live in large schools among heavily vegetated riverbanks with a moderate current. Heavy vegetation gives them plenty of places to hide as well as surfaces on which to lay their eggs.

Silver Dollar Fish Tank size

Silver Dollars’ maximum size is not overly large, but due to their preference to live in schools and their nervous nature, a large tank (300 liters or more) is highly recommended. This gives the fish plenty of room to grow and swim without crashing into walls and tank decor when they become spooked. Consider a tank 6 feet in length or more to accommodate their flighty tendencies. Silver Dollars have even been known to jump when scared, so a securely-fitting lid should be taken into account as well.

Silver Dollar Fish Water conditions

Silver Dollars are generally very hardy and can adapt well to a variety of water parameters, though quick changes in conditions may negatively affect them. Silver Dollar Fish are a freshwater species. Water should be kept at an ideal temperature between 24 and 27 degrees Celcius (75 – 81 degrees Fahrenheit) and their ideal pH is slightly acidic, between 6.5 and 7.5. Silver Dollars can handle a hardness of up to 18 dGH.

Water filtration is important due to the numerous fish inhabiting one tank as this leads to higher ammonia and nitrite levels. Internal or external filtration can be used, but external filtration leaves more room for your fish to move around in the tank, especially when they spook and dart away. 25 – 50% water changes should be performed bi-weekly.


Silver Dollar Fish are flighty and nervous by nature, so they require plenty of places to hide. Silver Dollars prefer low light and heavy vegetation in the wild, but they will consume live plants in a tank setting. Consider a thick-leafed plant like an Anubias or artificial plants to create the thick vegetation Silver Dollars prefer. Be sure that any rocks, logs, and other tank decor have no sharp edges and leave plenty of open water for your Silver Dollars to zoom around in without injuring themselves.

Silver Dollar Fish

Silver Dollar Fish Tank Mates

Silver Dollars are peaceful and social. They should be kept in a school of at least 5 individuals but preferably more. This species gets along well with most other fish as long as neither species fits in the other’s mouth.

Some possible tank mates for the Silver Dollar are:

Silver Dollar General Behavior

Though known for their flighty nature and aggressive eating habits, Silver Dollars are generally peaceful and social, making great additions to any community tank. They spend most of their time swimming in schools in open water in the middle and top of the tank, but dart into hiding as soon as someone walks by or turns on a light.

How to Keep Silver Dollar Fish Healthy

Silver Dollars are generally hardy but susceptible to typical ailments that affect freshwater fish.

Common diseases to look out for

Like most aquarium fish, Silver Dollars are susceptible to ich. Symptoms of ich include twitching, rubbing their bodies on various surfaces in the tank, and the appearance of white spots on the body and gills. They usually respond well to medication and heal quickly. Ich can be treated by elevating the tank water temperature to 30 degrees Celcius for 3 days. If that does not work, treat with copper-based medication.

Silver Dollars can be affected by skin flukes and other parasites, fungal infections, and bacterial infections. Know the signs and treatments of common freshwater fish diseases to catch problems early and keep your Silver Dollars happy and healthy.

Tips on keeping the Silver Dollar Fish in good health

Silver Dollars are usually relatively easy to keep healthy as long as you monitor your water composition. Perform water changes and test water quality semi-regularly to keep ammonium and nitrite levels in check, and do not overfeed as food waste will cause these levels to spike.

Keep in mind that parasites and bacteria can be introduced by new tank mates as well as live food, plants, and tank decorations.

Breeding Silver Dollar Fish

In the wild, this species spawns in groups in shallow waters with heavy vegetation. Silver Dollars are relatively easy to breed in a large tank with well-maintained, high-quality water conditions. For an aquarium setting, keep the water soft and slightly acidic, use low lighting, and provide clumps of spawning moss for eggs to fall on. Males court females by chasing and “shimmying” up next to them. The female will release her eggs in or near floating plants and the male will follow and fertilize them. The eggs do not adhere to the plants but fall to the bottom and are slightly transparent and yellow in color.

Interesting Facts About Silver Dollar Fish

  • Silver Dollar Fish are closely related to the Piranha
  • Males are distinguishable by their red anal fins
  • Silver Dollar Fish is named after the U.S. $1 silver coin
  • Females can release up to 2000 eggs in one spawning

Is a Silver Dollar Fish right for you?

Silver Dollars are flighty and nervous, needing to be kept in schools, but their social and peaceful nature also makes them ideal additions to a large community freshwater tank. Despite their sensitivity, they are easy to care for, tolerating a wide variety of freshwater conditions which make them a suitable choice for beginners.


Hi, my name is Jordan. I've been in the fishkeeping hobby since my childhood. Welcome to my blog where I help fishkeepers enjoy the hobby by offering free guides, advice, & product reviews. Read more...