Spotted Metynnis – Silver Dollar

Species Profile

• Scientific Name: Metynnis maculatus
• Common Name: Spotted Metynnis – Silver Dollar
• Adult Size: 6 inches (15 cm)
• Life Expectancy: 10 years (with proper care)
• Habitat: Slow-moving rivers and floodplain lakes in South America, particularly in the Amazon and Orinoco basins. They inhabit areas with dense vegetation.

Tank Requirements

• Minimum Tank Size: 75 gallons (for a small group; they are schooling fish)
• Ideal Temperature: 75–82°F (24–28°C)
• pH Range: 5.5–7.5
• Water Hardness: 4–18 dGH
• Temperament: Peaceful, schooling fish; best kept in groups of 5 or more. May nip fins if kept alone or with long-finned species.

Diet & Nutrition

• Omnivorous:
  Prefers a plant-based diet; enjoys blanched vegetables (spinach, lettuce, zucchini), spirulina flakes, and algae wafers. Will also accept high-quality flakes, pellets, and occasional protein sources like bloodworms or brine shrimp.

Appearance

• Color: Silver body with multiple dark spots (especially on the flanks). The body is laterally compressed and almost disc-shaped, resembling a silver dollar coin.
• Size: Adults grow to around 6 inches in length and have a deep-bodied, round profile.

Distinctive Features

• Flattened, disc-like shape similar to a silver coin.
• Dark spots across the body distinguish it from other silver dollar species.
• Fast swimmers with strong schooling instincts – prefer open swimming space and low-stress environments.