Origin: The ancestors of this Red Hook Silver Dollar lived in wide area of the Rainforests of South America, but now they live in aquariums all over the world.

Maximum Size: In aquariums they can to grow to be about 10" long, including their tails, which is bigger than other Silver Dollars and too big for most aquariums.

Females tend to remain a little smaller than males.

Behaviors: Silver Dollars are usually not aggressive, but they can eat very small tankmates, like Guppies and Neon Tetras, so be careful when choosing tankmates.

Compatibility: Some recommended tank mates include Angels that are about the same size as the Silver Dollars, plus Swordtails and Mollies.

Also White Tip Shark Cats, when they're small. Plecostomus Catfish, and Pictus Catfish are also good tank mates for Silver Dollars.

Silver Dollars are often seen in aquariums with Gouramis, Giant Danios, Rainbows, a group of Bala Sharks, and a group of Clown Loaches.

Click here to read more about compatible groups of pet fish.

Temperature: Silver Dollars live best from about 75 to 80-degrees F. with 78 being perhaps ideal.

Click here to learn about aquarium temperature, aquarium thermometers, and aquarium heaters.

Feeding: Premium Fish Food Flakes and Pellets are the best food for these fish to eat.

Feed them flakes and very small pellets, when they're young, and then gradually increase the size of the pellets as they grow larger.

In their natural habitat they eat fruits and vegetation, so it might be fun to feed them a smallish piece of, oh say, watermelon.

Click here to learn more about and shop online for premium fish foods.

Water Conditions: These fish can adapt to most types of water. So as usual it's best not to try to change the pH or alkalinity of your aquarium water for them.

Click here for a lot more information about aquarium water conditions.

Aquarium Size: When small a few of these Red Hook Silver Dollars should live in at least a 30-gallon aquarium, but as they grow, they'll eventually need to live in a deep aquarium with at least 200-gallons of water and bigger is better.

Decor: Silver Dollars only need a thin layer of gravel. Gravel more than 1/4" thick will usually fill with bits of uneaten food that will contaminate the water.

Click here for more about aquarium gravel.

Live plants are beautiful and improve the water quality. Silver Dollars seem to enjoy live plants. Floating plants are necessary for breeding.

Aquarium Filter: Bio-Wheel Filters are highly recommended.

Use one Penguin 350B Filter in a 30-gallon aquarium.

Most 120-gallon aquariums have room across the back for several Penguin 350B Filters, and this is sort of the minimum set up for Red Hook Silver Dollars.

Better is a 150, 200, or 250-gallon aquarium with several Penguin 350B Filters across the back.

Click here to learn more about aquarium filters.

The addition of Lava Rocks will keep nitrates in the ideal range. Click here to learn more about using Lava Rocks in aquariums.

Life Span: Silver Dollars can live for several years. Keep the water conditions excellent and feed them premium foods, and they'll most likely live for many years.

Gender: It's very difficult to determine the gender of these fish. Eventually most males are bigger than most females.

Just before spawning the females fill with eggs and may be plumper than males.

Breeding: Silver Dollars are egg layers, but it isn't easy to breed these fish in captivity.

Click here for a lot more about breeding various tropical fish in aquariums.

Popularity: The Silver Dollar has been a popular aquarium fish for many years.

Names: Their scientific name is now Myloplus rubripinnis but formerly in the genus Myleus.

Variations: There are no variations of this species that are known to us.

But it occurs across a wide area of South America, so there are most likely variations.

Click here for a lot more information about keeping and caring for Silver Dollars including a picture gallery.

We hope you've enjoyed reading these comments.

DrTom - 12/23/2014