Silver Dollar Fish - Metynnis hypsauchen
Updated May 13, 2020
Author: Mike - FishLore Admin
The Silver Dollar fish comes from South America and has been a favorite among tropical fish hobbyists for many years. They get to be about 6 inches or about the size of a saucer. They are a brilliant silver in color and in some varieties, the male will have a small amount of red on its anal fin.
They do best in schools of 6 or more and can become scared easily if not in a school. However, even in small schools they can still be very skittish, especially if you approach the tank too quickly. If you come up too fast or if you make quick movements they may start darting around the tank and could possibly injure themselves. For this reason, make sure that there are no sharp tank decorations in the aquarium.
They are mostly peaceful but can be extremely aggressive eaters. Watching them eat can be fun. Drop an algae wafer into your tank and watch the other silvers chase the one that gets it around the tank. For the plant keepers out there, they are herbivores and notorious for the serious damage that they can do to your live plants.
For food, they will accept most foods including flakes, pellets, frozen, freeze dried and live foods.
The Silver Dollar Fish can be fairly hardy once acclimated, but avoid fluctuating water parameters. When you are doing your water changes try to put in water that is as close to the same temperature as possible and don't let those nitrates get too high!
Silver Dollar Fish Care Details
Scientific Name : Metynnis hypsauchen
Common Names : Silver Dollar Fish
Size : 6 - 7 inches (15 - 18 cm)
pH : 6 - 7.5
Temperature : 75°F - 82°F (24°C - 28°C)
Water Hardness : 8° to 15° dH,
Life span : 10 plus years
Origin / Habitat : South America
Temperament / Behavior : They are generally peaceful. It is best to keep them in small schools of 4 or more. They may become scared easily if not kept in schools. Silver Dollars have been frequently studied over the years for their maneuverability.
Breeding : Breeding them is not very difficult. Silver Dollars are an egg laying type of fish and prefer broad leaves to lay their eggs on. The Female can lay up to 2000 eggs and the male will fertilize them. During the breeding process, the male will constantly chase the female around until the female lets the male come beside her. Sometimes the male will wrap his body against the females and once the females disperse the eggs the male also disperses his sperm cells. After 3 days the eggs will hatch and the Fry will start swimming around the tank. Since they are herbivores the it is safe to keep the eggs in the same tank as the adults but make sure to keep an eye on them.
The newly hatched Fry should be fed crushed spiralina flakes, bribe shrimp or food made for Fry. (Crushed flake food can be also used). Any Fry that are not fed adequately during the first few days might suffer from stunted growth and may never achieve full maturity.
Aquarium Size : 55 gallons but preferably much larger since they should be kept in schools. The common silver dollar is usually in the range of 6-8 inches. Juveniles should be kept in tank size of minimum 55 gallons. However, adults should be kept in a 6 foot tank because of there tendency to zoom around.
Tank Mates : Many, due to their peaceful nature. They can be housed with Medium to Large sized American Cichlids such as Severums, Green Terrors and Oscars. They can be also housed with a number of bottom feeders like Corydoras, YoYo loaches and Clown Loaches. Keeping them with Clown loaches means you will need a large tank!
Fish Disease : Freshwater Fish Disease - Diagnose, Symptoms and Treatment
Diet / Foods : Herbivore primarily, but will go after most anything you put in the tank. Give them a varied diet of fish food including algae wafers, flake, freeze dried and live foods for optimum health. The will eat live plants.
Tank Region : Mostly in the middle
Gender : The male's anal fin will have a small amount of red on it.
Photo Credit : Photos copyright JJPhoto.dk
Fish Lore Forum : Silver Dollar ForumForum Avatar :
Silver Dollar Comments and Tips
Depending on the size of your tank, they can grow to be quite big. I've seen them grow to almost 10 inches. They are quite placid and very peaceful toward other species in community tanks.
2 weeks ago, I purchased 6, 1" tetras and put them in my 55 gallon tank with 6 silver dollars fish and 1 angel fish, all 5". The angel is 9 years old. The silver dollrs are 1 year old. Within 24 hours, tetras were dead and old fish had cloud eye and some had white, wounded lips. Treated tank with Melafix for several days - then two four-day treatments of Tripple Sulfur. All fish look OK but lips of two look pink, like new skin. Should I stop or do something else?
It can be very dangerous for your fish if you are mixing medications. I've not used tripple sulfur before but I have used melafix successfully to treat bacterial infections. I would recommend performing a water change (30%) and then running fresh activated carbon through your filter system to remove the medication. Keep up the 30% water changes for a couple of days and keep a close eye on your water parameters (ammonia, nitrite, nitrate and pH) because sometimes medicines can destroy the good bacteria along with the bad. Make sure your remaining fish have optimum water quality for the next few weeks by performing those frequent water changes and hopefully they can pull trough this stressful time. Check out how to setup a quarantine tank so you can avoid introducing diseases into your main tank in the future. Good luck with your fish.
I would certainly have to disagree that anything but the smallest be kept in a 10 gallon aquarium. I have 7, and kept them in a tank this size when they were young out of desperation, and their disposition changed considerably for the better when they were in a 33 gallon (this is now too small, and I'm moving up to a 48 long). They are a magnificent fish, but make sure they have good hiding spots to get away from the action, or they'll certainly injure themselves when they "freak out" if startled.
I find mine to be reltively slow swimmers and very peaceful. However, there can be "bad apples" among the group, which can go after smaller fish. I recommend just keeping 3 if mixed with other smaller fish. I think they tend to get less timid and more bullyish in larger schools. They are definitely a larger tank fish, especially if you're keeping them with little tetras such as neon tetras (like me). The silver dollars are currently in a 55 gallon tank and are starting to become awakward/clumsy amongst the plants and decorations as they grow bigger and have a harder time squeezing into their usual hiding spots.
I have 3 of them in a 46g tank. They are very active and always stay together. They are the first ones to the food and come to the top to get it. They get the fins nipped a little by thier neighboring tiger barbs, but all is well for over 5 months.
I have 3 of them in a 75 gallon tank. They are very peaceful towards other fishes, though my largest (saucer-size) will chase the smaller Dollars around the tank. I've always read how they will eat anything you put in the tank. Not so with mine, they will only eat algae discs. I've even put some lettuce in there and none of them would touch it. Seems to be very good, hardy fish. The largest one is over 6 years old and still going strong. Would highly disagree with keeping this fish in a tank smaller than 50 gallons. We had to move ours to a 20 gallon hospital tank while we did extensive cleaning of the 75 gallon and our big fish almost broke the little tank when he flipped out. Definitely a skittish fish, we have to make sure they see us coming by the tank before we walk past, otherwise they get scared and start panicking. Would definitely recommend no sharp objects in tank. Ours have injured themselves merely by smashing into the side of the tank, its just good we don't have sharp objects in there. They don't like the tank light, whenever its on they go and hide... as soon as its turned off they come out and start swimming around.
I have a pair and they are very silent. But while feeding they are more aggressive than the other fish. One question I have is that I found a few spots on their fins and near the gills when they both come near each other. Why is this?
Some silver dollar species have different markings and may develop different markings, colors, spots or patterns when ready to mate.
I have several silvers in a 40 gallon tank along with 2 extremely large black shark/cats. They coexist very well. During feeding they change coloring and fin markings brighten up vividly... 8 years and getting to be around 8 inches, great fish.
My 3" silver dollar is driving my new 4" oscar fish crazy. It just won't leave him alone and my oscar spends the day at the bottom of the tank. They are in a 55g tank. I think my oscar needs to toughen up.
Be warned they are not as timid and peaceful as you think. I have 4 in my aquarium and several Tetras and Danios have fallen prey to them. Initially I thought the culprit was my Pleco, so I decided to take him back to my Pet Store. But once he was gone the predation continued. After consultion with my local Pet Shop, we concluded the Silver Dollars where indeed the culprits. But I still love my Dollars, incredibly beautiful and graceful, and easy to keep... just choose their tank mates carefully!
I had a silver dollar that was about 4cm when I bought it and now is triple that within 4 months - "fast growers". I have now just picked up another three after reading some of the comments on this site, I didn't have any problems as he was happy swimming along with the tiger barbs and Angelfish but I thought I would give him some friends of his own type. I feed mine a variety of frozen blood worm and beef heart which he loves. Its great watching him run off with the cube and the barbs wrestling it off him.
I have 3 silver dollars. They're about 4 inches. I love the way they look. I've had them for about a year now. They don't bother any of my other fish and eat almost anything I feed them. They get scared easily, though and one seems to be more dominant to the other 2. I think it's because their group is small. But I mostly think it's because he might be a mix with a silver dollar and something else. He doesn't look completely like a silver dollar. He's somewhat aggressive towards the biggest silver dollar and is a pig. When I feed them frozen cubes of brine shrimp he gets the whole cube. Its annoying.
I have four Silver Dollars that I have had for at least 18 years! They got to be about 3" in diameter; two years ago we moved and put them in a new tank same capacity (70 gallons) but taller and not as long. They started growing again - some more than others - but the biggest is now about 4.5 inches. Their behavior matches the descriptions perfectly - they go berserk if my wife approaches the tank; also sometimes if I approach too suddenly. They clearly know me - line up at the wall giving me the evil eye if I sit down in the room without feeding them.
My silver dollar ate my plecostomus. What happened to peaceful, gentle, and graceful?
Silver dollars are herbivores primarily and it's highly unlikely that they ate your pleco. More likely your plecostomus died of other causes and the silver dollars were just nipping at the carcass.
More Tetra Fish Profiles
Black Neon Tetra
A nice little tetra that can be quite hardy and looks really good in a planted tank or aquariums with darker substrates.
Black Phantom Tetra
A medium sized tetra that does well with similarly sized fish species.
Black Skirt Tetra
A tetra with larger fins so use caution if you plan on stocking them with known nippers.