Serpae Tetra (Hyphessobrycon eques)

The Serpae Tetra (Hyphessobrycon eques), also known as the Jewel Tetra or Blood Tetra, is one of the most vividly colored and widely available tetras in the hobby. Native to the Amazon basin in Brazil, Colombia, and neighboring countries, its deep blood-red to orange-red body, black shoulder spot, and elegant black dorsal fin with a white tip make it immediately recognizable.

Serpae Tetras are active, bold schooling fish that are hardy and adaptable to a range of water conditions, making them accessible to beginners. However, they have a reputation for fin-nipping — a behavior that is significantly reduced when kept in large schools of 10 or more. In small groups of 3–5, the subdominant fish become stressed and fin-nipping toward slow-moving, long-finned tankmates becomes problematic.

In a large school in a well-planted aquarium, Serpae Tetras display their natural behavior: tight, coordinated schooling with vivid color flashes as the group turns in the light. They are excellent community fish when properly matched with similarly-active, short-finned species.

As omnivores, they accept a wide range of foods readily. Their combination of intense coloration, hardiness, and availability has made them a staple of the hobby for decades. Long-fin varieties have been selectively bred and are also available.

Water Parameters: pH 5.5–7.5, temperature 22–28°C, GH 4–15. Adaptable to a range of conditions, though soft, slightly acidic water is preferred. Avoid extremes. Regular water changes maintain the clean conditions needed for their best coloration.

Tank Setup: Minimum 80 liters for a school of 10. Planted aquarium with open swimming space in the center and planted borders. Dark substrate enhances their red coloration. Moderate lighting and good filtration with gentle current. Provide some surface cover (floating plants) for security.

Feeding: Omnivores that accept quality flake food, micro pellets, and small frozen or live foods including bloodworm, daphnia, and brine shrimp. Feed twice daily. Varied diet enhances their vivid red coloration.

Tankmates: Best with similarly-sized, active, short-finned fish: other tetras, barbs, danios, Corydoras, and small plecos. AVOID long-finned fish (bettas, fancy guppies, angels) as fin-nipping is highly likely, especially in small groups. Keep 10+ to reduce this behavior.

Health: Hardy and rarely sick in good conditions. Watch for ich and bacterial infections. Maintain stable water with regular water changes of 25–30% weekly. Overcrowding increases aggression and fin-nipping.