Are you looking for a little more bang for your buck? You won’t have to flip a coin to decide if taking on Silver Dollar Fish (Metynnis argenteus) might suit your tank community and your skill level as a hobbyist.
With shimmering good looks, these fish look like cash come to life in the form of old silver dollar coins. Coming from the same family as the Piranha, you might expect them to be a slightly terrifying or aggressive species, but they are assuredly not.
From the freshwater rivers of South America, Silver Dollars are actually primarily herbivores with the odd protein snack thrown in! Peaceful temperaments, stunning good looks, and relatively easy to care for, they make a great fit for just about any tank community with compatible parameters.
Quite a few species are sold under the common name M.argenteus, but they all have a similar appearance.
They are more often recommended for those with intermediate experience, though, so read on to find out how to best look after this species and get the best of all they have to offer.
Silver Dollar Fish Behavior
Silver Dollars love to hang around the top layers of your tank, which is less common and means that you could really have a well-positioned community when planning your tank for action in all areas.
They eat primarily plants, which means you will need to think about your live vegetation and ensure it’s heavily planted as they are known to devour them with ease.
They love to weave between the tall plant life, which is helped by their slim, flattened build. They can easily slip between the stems of dense plantings as a result.
Even though they have a slight piranha-esque look about them at their head, they are decidedly peaceful and pleasant fish.
Actively schooling with the group, they provide a lot to look at and will reward their owners with some wonderful displays. A point to note here is that they must always be kept in a group and are usually sold in groups too.
A single Silver Dollar is not a happy one and will usually be extremely stressed and even perish. Aim to have a minimum of five in your shoal, and the more, the merrier if you have the space to accommodate.
They can also be nervous and stressed if the tank is kept in a busy or high-traffic area in the home, or an area with too much bright lighting, so factor that into your planning.
As a result of their top-layer dwelling habits, they have been known to jump the tank when they get excited, so a snug-fitting lid is essential.
Silver Dollar Fish Lifespan
If you cater to the needs of your Silver Dollar Fish, you could expect them to live for around 10 years. The quality of their tank conditions will impact their lifespan, as always, so you can expect a longer life if you meet their requirements meticulously.
We will discuss more on tank requirements a little later in this article.
Silver Dollar Fish Appearance
Their name says it all. They possess tall flat bodies with a predominantly rounded or rounded diamond shape.
Covered in shiny, lustrous silver scales, they resemble an old silver dollar coin, albeit a much larger one!
They will reach 6 inches in length on average but can get up to 8 or 9 in captivity, depending on tank size.
A Silver Dollar’s dorsal fin is placed at the highest point of its body where it starts and runs to the end ‘pinch’ just before the caudal fin emerges, leaving a small gap.
Tiny pectoral fins are almost invisible, while the anal fin runs the posterior third of the body length finishing at the same pinch in body outline.
There are variations in coloring, but often the fins have transparent areas and some punches of color.
Here are some of the more popular varieties easily available in the hobby listed below.
Spotted Silver Dollar Fish
The usual silvery body but with small black dots on their sides, they grow up to 6.5 inches in length.
Tiger Silver Dollar Fish
Silvery-blue bodies and a number of large dark vertical stripe marks across their bodies. One of the most active varieties, they grow up to 6 inches in length.
Red Hook Silver Dollar Fish
Easily identified with a red anal fin and black trim, these ones can grow up to 9 inches in captivity.
Silver Dollar Fish Habitat And Tank Requirements
We ideally want to achieve optimum health for fish we keep in captivity by closely mimicking their natural habitat. Their wild origins are the blackwaters of streams and rivers and the basins of South America with slow to moderately moving currents.
Blackwater conditions are often murky, acidic, and slow-moving, filled with tannins and peat due to the amount of vegetation. Rotting wood and other debris also contribute to this type of habitat.
Let’s look at some specifics that are needed to provide these fish with a great quality of life that best suits them for optimum health.
Tank Conditions
Your Silver Dollars are not small fish, and you have to have a school of them so they will produce a fair amount of waste.
Factor in the amount of vegetation you will need to be catering to in order to keep them happy, and you should expect to be providing excellent oxygenation along with good filtration systems in place.
When it comes to your planting scheme, if you want to avoid total destruction, then go with a mix of artificial plants and things like Java Fern and Hornwort that won’t be tempting to tear into. They call Silver Dollars the Plant Piranha for a good reason!
But there are fast-growing plants you can include if you wish to provide them with a more natural food supply. Try things like Amazon Swords, Water Lettuce, Anacharis, and Water Sprite.
Dark substrates and backgrounds look best to show off these fish. Include rocks and driftwood that they can hide in and around, but there is no need to try and create caves as they don’t really bother with them.
Beyond these guidelines, remember to have a secure lid for this pelagic fish species to avoid any heartache.
Water changes need to be weekly and at least 25 – 35% changed over for optimum water quality.
Water conditions should be noted and maintained as follows:
- a pH of 5.0 – 7.0
- Water hardness between 8 – 15 dKH
- Temperature between 75 – 82ºF (24 – 28ºC)
- Lighting conditions should be low as they don’t experience much direct sunlight in the murky river water.
Tank Size
The minimum tank size for a school of five Silver Dollar Fish is 75 gallons, and for every additional specimen, you should add another 10 – 15 gallons.
However, this is the minimum, so getting something closer to 100 gallons is even better to keep a shoal of 5 happier. These fish are not only long, but they are also very tall too.
In terms of shape, you’ll want something long and rectangular that will allow them plenty of active swimming areas.
Choosing Tank Mates For Silver Dollars
When it comes to finding species appropriate for your Silver Dollar Fish, you have plenty of options since they are pelagic and close the surface swimmers.
You’ll want to keep sizes of tank mates relative, nothing too small like nannyish, or even your peaceful herbivore will try to eat them in close quarters. Keep the other species peaceful, and you shouldn’t have any problems.
Some excellent tank mate pairings that would work well include:
- Bristlenose Places
- Clown Places
- Kuhli Loaches
- Cory Catfish
- Oscar Fish
- Red Empress Cichlid
- Blue Dolphin Cichlid
- Bala Sharks
- Tetras
- Giant Gourami
- Angelfish
- Nerite Snails
- Giant Danios
- Black Ghost Knife
Basically, as long as they are peaceful and on the larger side, you can try your hand at mixing them in, and you shouldn’t have any problems.
It’s worth noting that you should keep an eye on any Cichlids in the mix around spawning periods as they can become more aggressive and may need to be separated in breeding tanks for a spell.
Notes On Feeding Silver Dollar Fish
If you are supplying your tank with live plants that have flavor appeal, expect your Silver Dollars to be munching on those regularly and factor that in as part of their diet.
You should aim to feed them 2 or 3 times a day as they are so active and expend a large amount of energy.
When it comes to their feed, ensure you use flakes and not pellets that will sink and be out of their reach or comfort zone. Algae wafers and spirulina wafers should form a large part of their diet, along with fresh veggie offerings.
Blanched greens like lettuce, watercress, spinach, peas, cucumber, and also things like carrots and squash are readily eaten. Boiled potatoes and fruit also work really well if suitably softened.
When it comes to offering snippets of proteins, bloodworms and brine shrimp will appeal if you mix them up with seaweed.
Silver Dollar Fish can get quite competitive when it comes to feeding time, so ensure everyone is getting some of the menu by spreading it around the tank.
As always, we recommend removing any uneaten food to prevent water fouling and issues with water parameters.
Silver Dollar Fish Common Health Issues
Silver Dollars are not prone to anything species-specific to be aware of, just the usual hazard of freshwater fish life.
Most freshwater fish are susceptible to Ich (White Spot Disease), which, as the name implies, is easily distinguished by white spots on the body due to a parasitic infection.
Raising the water temperature above 77ºF and/or quarantining the affected fish can help remedy this disease as well as purpose-bought medications for this affliction.
You can often avoid parasitic infections by thoroughly quarantining and washing any new decor or before introducing anything new to the tank, living or otherwise.
Normally when these health hazards happen, it’s because the water parameters and quality have dropped.
Health issues can be minimized with a strict water cleaning and change schedule along with regular checking of water parameters with a suitable testing kit.
How To Breed Silver Dollar Fish
Silver Dollar Fish will happily breed in captivity and are fairly easy to encourage.
Since most shoals are bought as a group at the same time, it should be fairly easy to spot a pair, and they reach sexual maturity at 1 year old.
You can identify when breeding is on the card as males will develop a few black spots behind their pectoral fins. Nature’s way of telling you the hobbyist to get your breeding tank ready!
The breeding tank should be shallower, a few degrees warmer, and a minimum of 40 gallons. Decorate with floating plants, employ a sponge filter, keep the lights dim, and wait for the chase.
The female will lay eggs near the floating plants, which then sink to the bottom, where the male will fertilize them. When spawning is complete, remove the parents and expect fry in about 3 days and feed them infusoria, veggie flakes, and similar fry foods.
Are Silver Dollar Fish A Good Idea For You?
What’s not to like? Peaceful, top dwelling, actively schooling fish with flashy silver good looks and an imposing size that is impossible to ignore.
Feeding these fish is a breeze, and if you can supply a breeding tank, even raising some is straightforward enough too.
Their compatibility is what sets them apart, so you can have a multi-dimensional tank and action on every level if you can support the bioload.
There is a lot to admire about these fish, and it’s easy to see why they have such a loyal fan base in the hobby.
Just don’t mistake them for a waterlogged piggy bank and throw your own coins in!
