🐾 Pets Alpha
🐠 Fish Species Guide

Silver Dollar Fish

The vegetarian piranha cousin — a shimmering, disc-shaped schooling fish that will devour every plant in your aquarium. That metallic silver body, that flat disc shape, those tiny scales that catch the light. Complete guide: why Silver Dollars are plant-eating machines, the 280L+ tank requirement, and their surprising Piranha family connection.

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📋 Species Overview

Name
Metynnis argenteus
Family
Serrasalmidae (Piranha!)
Size
15 – 20 cm
Min. Tank
280 L / 75 gal
Diet
HERBIVORE
Group
5+ minimum

🌿 Plant-Eating Machines — NO Live Plants!

Silver Dollars are in the same family as Piranhas (Serrasalmidae) — but instead of meat, they eat plants. And they eat A LOT of plants. They will devour every live plant in your tank within days. Java fern, Anubias, everything — gone. If you want a planted tank, Silver Dollars are absolutely the wrong fish. Use silk/plastic plants or hardscape (rocks, driftwood) only. Feed: high-quality veggie flakes/pellets (Spirulina-based), blanched vegetables (zucchini, spinach, romaine lettuce), and occasional protein treats.

🐟 Skittish Schoolers — Need Open Swimming Space

Silver Dollars are extremely skittish — they need a group of 5+ to feel secure, and a long tank with plenty of open swimming space. Without a group, they panic at shadows, crash into tank walls, and injure themselves. They're peaceful community fish despite their Piranha family tree — excellent tank mates for similarly-sized peaceful fish (larger Tetras, peaceful Cichlids, Bala Sharks). 280L/75gal minimum for a group — they reach 20 cm and are active swimmers.

💰 Cost

CategoryCost (USD)
🐟 $8-$15 each | 🐟 Group of 5 $40-$75 | 🏠 280L Setup $500-$1,200