Head to head
Silver Dollar Fish vs Piranha
The silver dollar fish and the piranha belong to the same broader family, Serrasalmidae, but they have taken very different evolutionary paths: one is a peaceful, coin-shaped plant-eater, the other carries a fearsome reputation built on interlocking razor teeth and a powerful bite.
| Silver Dollar Fish | Piranha | |
|---|---|---|
| Scientific name / family | Metynnis argenteus | Serrasalmidae (around 60 species) |
| Diet | Herbivore, mainly aquatic and overhanging plant matter | Varied, including fish, fins, insects, carrion, fruit, and seeds |
| Teeth | Not specialised for cutting flesh | Single row of interlocking triangular razor-edged teeth |
| Temperament | Peaceful, non-aggressive | A few species notably predatory and capable of biting |
| Bite force | Not notably powerful | Black piranha bites with around 320 newtons, roughly 30 times its body weight |
| Social behaviour | Schools peacefully | Shoals mainly for defence against predators |
| Body shape | Flat, round, coin-shaped body | Deep-bodied |
| Conservation status | Least Concern | Not Evaluated |
Silver Dollar Fish vs Piranha: common questions
Are silver dollar fish related to piranhas?
Yes, both belong to the family Serrasalmidae, though the silver dollar fish feeds mainly on plant matter while the piranha's diet is far more varied and, in a handful of species, genuinely predatory.
Which is more dangerous to keep in a home aquarium?
The piranha, particularly species like the red-bellied or black piranha, carries far more risk due to its sharp interlocking teeth and strong bite, while the silver dollar fish is considered a peaceful, low-risk community fish.
Can silver dollar fish and piranhas be kept in the same tank?
This is generally not recommended, since a predatory piranha species may treat a silver dollar fish as potential prey, despite the two being fairly close relatives within the same family.