Bloodfin Tetra (Aphyocharax anisitsi)

Aphyocharax anisitsi, the Bloodfin Tetra, is a distinctive and underappreciated tetra from the Paraná River basin in Argentina and neighbouring regions. Its common name perfectly describes its most striking feature: vivid blood-red colouration in the dorsal, caudal, adipose, ventral, and anal fins, contrasting with the semi-transparent silver body. In a school, the flash of red fins against silver bodies creates a beautiful, dynamic display.

The Bloodfin Tetra is notably more cold-tolerant than most tropical tetras — capable of surviving and thriving at temperatures as low as 15°C, reflecting its origin in the temperate Paraná River system of Argentina. This makes it suitable for unheated aquariums in warm seasons or setups that don't maintain fully tropical temperatures year-round, though it thrives best at 22–28°C.

One of the most noteworthy qualities of this species is its exceptional longevity for a small tetra — well-kept individuals regularly live for 10 years or more, with some reports of specimens exceeding 15 years. This makes the investment in a school of Bloodfin Tetras particularly rewarding.

Bloodfin Tetras are active, surface-oriented swimmers that appreciate open mid-water and upper swimming space. They are entirely peaceful with all non-predatory fish but are accomplished jumpers — a tight-fitting aquarium lid is essential.

Tank Setup: A minimum 60-litre tank for a school of eight. Provide open mid-to-upper water swimming space, moderate water flow, and a tightly fitting lid (excellent jumpers). Plants along the sides and background, floating plants for surface cover. Not demanding about decor.

Water Parameters: Temperature 15–28°C; pH 6.0–8.0; GH 5–20 °dH; KH 3–12 °dH. Exceptionally adaptable — tolerates cooler water than most tropical fish. Standard Belgian tap water works perfectly.

Feeding: Omnivore. Accepts virtually all aquarium foods: flake, micro pellets, frozen bloodworm, brine shrimp, Daphnia. Surface and mid-water feeder. Feed twice daily. Enthusiastic, competitive feeders.

Tank Mates: Compatible with most peaceful community species: other tetras, rasboras, barbs, corydoras, gouramis, loaches. Avoid very small nano fish that might be outcompeted at feeding. Suitable for cooler-water communities with danios and White Cloud Mountain Minnows.

Behaviour: Active, schooling fish that occupy upper and mid water. Groups of 10+ school most impressively. Males may display to each other briefly — harmless. Regular surface gulping is normal air-breathing for some individuals.

Health: Extremely hardy and long-lived. One of the most disease-resistant tetras. Tolerates a very wide range of conditions. Weekly 25% water changes maintain ideal health. Almost never ill if basic water quality is maintained.