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Silver Dollar Fish (Metynnis Argenteus) Profile & Care

If you are looking for the best freshwater fish to add to your aquarium, the options will be plenty, so it can be confusing to find the nicest one for you.

But you can narrow it down to what you are ready for right now. Let’s say you already have an aquarium. Now what? A big or small fish? Fish that do not require high-cost maintenance. Then, you might want to have a fish that can accompany you for many years into the future.

If the latter describes you, then you will find a lot of interest in the Metynnis Argenteus or silver dollar fish.

These fish are low in maintenance and have a long lifespan. The schooling fish are peaceful and easy to handle, even though you have just started your hobby.

Here I am going to let you know all of the things about silver dollar fish, from its caring tips, tank setup, to the diet and breeding guidelines.

Species Overview

Level of CareIntermediate
AppearanceAlmost round in appearance and colored silver with a hint of green and grey. 
Life Expectancy10 years
Size6 inches
Tank Size75 gallons – 100 gallons
Tank EnvironmentDark peat, rock, and gravel with dense plants for shades and hiding
Tank MatesPeaceful fish of similar sizes

Metynnis is a freshwater fish that can improve the beauty of your aquarium. Its long life span adds more reason why you need to add this to the aquarium.

It is a schooling peaceful fish that you can easily breed and care for. The appearance of silver dollar fish is so authentic and unique. From the first time you take a look at it, you will know that this fish is a great choice for your community tank.

They are herbivores. You can give them any plant you want and they will survive for a long time in the future.

They are hardy and long-lasting. You can expect them for many years in the future, as long as you provide them with the proper environment and care they need to strive for.


There is a good reason why this fish is called the silver dollar fish. They got their name from their appearance.

They have a shiny silver body coloration just like an older silver dollar. The fish body is also round and flattened, just like a silver dollar already. There is also a little blue or green tint to their body shape.


The average size of this unique fish is around 5 to 6 inches. But in common captivities, they might not be able to grow as big as that, especially if they are more active with their friends.

If you are expecting a larger size of silver dollar fish, you will want to feed the fry well from earlier.

Behavior & Temperament

The metynnis buddies have peaceful traits and tend to be indifferent to their tank mates. However, the fish can be a bit aggressive during feeding time.

Although they are flexible in-dwelling positions, they tend to spend most of their time swimming closer to the water’s surface.

The fish can be skittish, so this behavior might terrify other fish in the same community tank.

They are school fish. So, it is not appropriate to let them be in the tank alone. The experts suggested keeping these fish in groups of at least five specimens in the same tank.

They can jump as well, although the cases are not too frequent. That’s why this kind of species is prevalent in your big tank.

Your tank must also be deep enough to handle their behavior. To be safe, you could put a tight lid on top of your tank so that they won’t escape easily.

Yellow cichlid surrounded by 3 metynnis argenteus fish


The average lifespan of metynnis friends is ten years or more. But they can achieve this achievement if you care for them well.

The poor treated silver dollar pets won’t be able to survive that long. The main causes of their short lifespan are freshwater illness and high-stress levels.

Tank Setup

The best setup and care for the silver dollar buddies is by replicating the tank conditions and environment as closely as possible to their natural habitat that is Tapajós River Basin in Brazil . Here’s what I’ve found about how to care for and maintain the particular pets inside your big tank.


You will need at least 75 gallons for a group of 5 specimens of the fish.

Peat will be the main ingredient of the substrate of the aquarium. The most ideal bottom parts should be filled with dark peat. The next things to add are rocks and gravel.

These fish can be shy and intimidated when the pairs of big eyes monitor them. Therefore, you will also want to add denser vegetation to give dimmer light and shades. They will have an adequate number of hiding spots there.

These fish usually flock to the rivers. So, they will feel a more natural ambiance with objects like driftwood, weeds, natural rocks, and some water holes.

The water flow must be moderate. Too strong will push away the fish. slow will demotivate the fish.

As long as you can get closer when mimicking their natural environment, they can get rid of their nervousness much quicker when you first add them to the tank.

They will swim from the middle to the top of the pool. They can be skittish if they don’t find enough space for swimming. Here is where you can make use of your large aquarium.

Water Conditions

The fish can be hardy and strong in captivity. One of the perks that many aquarists love is that they have a good tolerance for different water conditions. But too many fluctuations will not be good for their health.

Prepare to install a good filtration system to ensure that your fish will have a great place to live in. The oxygen levels need to be maintained. If you see your fish tend to move more sluggishly, it can be a bad sign that the oxygen level is too low.

Keep the fish tank temperature between 75and 82 ° Fahrenheit. Meanwhile, the pH level should be around 5.5 to 7.5.

The hardness is around 4 to 18 dGH. They are adaptive breeds. But you won’t risk the changes to bigger gaps since it will affect their overall wellness.


Since they are jumpy fish, you will want to cover the top part of the tank with a covered lid. Add floating plants and dense plants to make the light dimmer. Providing the shades for them will affect their behaviors positively. Also, consider installing a darker background. Too much light will make them anxious and stressed.

If you want to add decorative plants, you must be ready for the fish to eat them. Consider picking tasteless plants like Java Fern or Hornwort. Or you could use artificial plants since the metynnis do not like them.

Metynnis Argenteus Tank Mates

When it comes to silver dollars, you will have plenty of choices to tag them with their tank mates. Since their nature is peaceful and indifferent, almost all fish of the same size can be their best tank mates.

From medium to large cichlids, green terrors, as well as Oscars, are good tank mates for your metynnis.

If you build a community tank, you might want to fill it with particular dwellers. Your silver dollar pets can also live with bottom dwellers like loaches, corydoras, etc.

You could also add another controversial tankmate, like Bala sharks, for instance. But you must also look at the tank size. If the tank is too small to accommodate all of the fish, most of them could be distressed and more aggressive. So, don’t risk it if you only have limited space for your pets.

If you want to go for the safest option, you could consider adding smaller fish, such as guppies and tetras. They can also make your community tank brighter and more vibrant.

But you must take into consideration that not all silver dollars can live peacefully with the smaller fish. Some of them even harass and bully them.

Silver Dollar Fish Food & Diet

Silver dollar fish are omnivorous. They are not too picky when it comes to their diets. But most of the time, you will find out that these fish pick more herbivorous foods than meaty ones. In nature, they are surrounded by plants. So, they will take the easy path to eating veggies rather than meat.

You can even feed them with veggies only and they won’t protest. Consider easy items such as cress, lettuce, cucumbers, spring greens, and so on. If you can find veggie flakes sold in your local store, that would be great too.

You can sometimes give them meaty foods such as brine shrimp, bloodworms, etc.

Breeding Guidelines

2 silver dollar fish

To breed it, you will need to pick a mated pair. For the best results, it is better to keep them in a group since they’re still juvenile. Once they reach maturity, they are ready to spawn.

Prepare soft, warm water at around 79 to 82 ° Fahrenheit at a pH level of 6 to 7. The water hardness should be 4 to 8 dGH.

Make the lights dimmer and prepare floating plants and long plants like Java moss.

The eggs will be released by the females at the plants. These will hatch in just 3 days and the fry will be swimming in a week to ten days. Fry will reach adult size in only six to eight months.