Jewel tetra

The jewel or serpae tetra reaches about 4 cm standard length and is best known for its semi-aggressive temperament — it nips the fins of slow-moving or long-finned tankmates, especially when kept in groups smaller than a dozen. A school of 12 or more in a tank with a base of at least 80 by 30 cm (about 72 L) spreads the aggression within the group. Temperature of 20–28 °C and pH 5.0–7.5 cover both wild and farm-raised stock, with the wild form preferring softer, more acidic conditions. Dark substrate, floating plants, and dim lighting bring out the deep red body colour. Diet is omnivorous: good-quality flake, live and frozen bloodworm, daphnia, and brine shrimp. A native of sluggish tributaries and backwaters across the Amazon and Paraguay basins, it thrives in a planted tank with open swimming space. Not suitable for shrimp tanks.