Rudd (Scardinius erythrophthalmus)

The Rudd (Scardinius erythrophthalmus) is a popular aquarium fish. This profile covers habitat, appearance, tank setup, water parameters, diet, compatibility, breeding, and health — focused on rudd care at home.

For related reading, see European Bitterling.

Rudd in aquarium Rudd (Scardinius erythrophthalmus). Photo: Pmau / Wikimedia Commons (CC BY-SA 4.0)

Natural Habitat and Origin

Rudds come from

Appearance and Size

Adults reach about 10–16 inches (25–40 cm). Look for clear eyes, intact fins, and active swimming when selecting stock.

Tank Size and Setup

Plan for pond or very large coldwater system. Use plants, driftwood, and open swimming lanes. Gentle filtration suits most community species.

Water Conditions

  • Temperature: 50–72°F (10–22°C)
  • pH: 6.5–8.5
  • Ammonia / nitrite: always 0 ppm

Diet and Feeding

Natural diet: omnivore. Offer quality flakes or micro pellets plus frozen or live foods several times weekly.

Compatibility

Keep in groups of groups in ponds when schooling applies. Avoid aggressive or predatory tank mates that outcompete or harass them.

Breeding

Condition with live foods, provide spawning sites or plants, and protect eggs or fry from adults. Species-specific details vary — observe pairs in a dedicated breeding setup when possible.

Health and Care Level

Overall care: advanced (space). Quarantine new fish, maintain weekly water changes, and address water quality before medicating.

Conclusion

With appropriate tank size, stable parameters, and compatible neighbors, Scardinius erythrophthalmus makes a rewarding display species for attentive keepers.