Silver Dollar

Metynnis argenteus

Also sold as Blackberry silver dollar · Spotted silver dollar

Silver Dollar (Metynnis argenteus) is a peaceful freshwater fish that reaches about 15 cm (5.9 in) and swims in open water. It wants 75–82°F (24–28°C) and pH 6–7, is kept in groups of 5 or more, and needs a tank of at least 260 L (69 gal).

At a glance

Type	Fish
Adult size	15 cm (5.9 in)
Minimum tank	260 L (69 gal)
Group size	5 or more
Temperature	75–82°F (24–28°C)
pH	6–7
Temperament	Peaceful
Lifespan	10 years
Eats shrimp	Yes

Before it goes in

Silver Dollar needs at least 260 L (69 gal). The smallest size in this library that clears that is the 75 Gallon.
Keep 5 or more. Below that it hides, colours down and is far more likely to be picked on.
It eats small fish and shrimp — anything under about 5 cm (2 in). In this library that means Cherry Shrimp, Rummy Nose Tetra and Crystal Red Shrimp.
It is the wrong size to share a tank with Iridescent Shark, Senegal Bichir and Black Ghost Knifefish: it ends up as food.
It holds at 75–82°F (24–28°C). That shares a window with Betta and Cherry Shrimp, but not with Goldfish and Dojo Loach.
It eats most plants. Hygrophila corymbosa 'Siamensis' and Bacopa caroliniana will not last with it; tough-leaved Anubias nana 'Petite' and Marimo Moss Ball will.
A group of 5 takes up roughly 54% of what a 75 Gallon will comfortably hold, so plan the rest of the stock around it.

What tank size does it need?

At least 260 L (69 gal). The smallest size here that clears it is the 75 Gallon.

How many should I keep?

5 or more. Fewer than that and it spends its time hiding instead of out in the open.

Will it eat shrimp?

Yes. Shrimp are food to it, so pick one or the other.

What water does it want?

75–82°F (24–28°C), pH 6–7.

How long does it live?

10 years in a tank that suits it. That is how long you are signing up for.

Good tank mates

Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Bristlenose Pleco, Celestial Pearl Danio, Molly, Otocinclus and Ramshorn Snail.
Plants that hold up with it: Anubias nana 'Petite', Marimo Moss Ball, Subwassertang and Anubias barteri.

Often compared with

	Silver Dollar	Silver Hatchetfish	Angelfish
Adult size	15 cm	4 cm	15 cm
Min tank	260 L	108 L	150 L
Group	5+	6+	1+
Temperature	75–82°F (24–28°C)	68–82°F (20–28°C)	75–84°F (24–29°C)
Eats shrimp	Yes	—	Yes

More livestock

Plan a tank with Silver Dollar →

Sources (5) · checked Sep 2026