Aphyocharax rathbuni – Green Fire Tetra

The Green Fire Tetra, also known as Rathbun’s Bloodfin or Aphyocharax rathbuni, is a true gem of the small toy fish world that can be often overlooked.

Aphyocharax rathbuni – Green Fire Tetra

The Green Fire Tetra, also known as Rathbun’s Bloodfin, is a true gem of the small toy fish world that can be often overlooked. Indeed, I walked past this fish in the aquarium shop tanks, but my wife, Sandy, recognized it for the special species that it is. In the dealer’s tank, it was a small green-gray fish showing a little bit of red towards the tail. In a planted tank, it can only be described as a living jewel.



This fish is small with a maximum size of 5 centimeters (2 inches). Its special fascination is that the fish’s color changes and evolves with time. The body of the male is a metallic blue green, and the anal fin and lower rear of the body is red. As the male matures the tips of his pelvic and anal fins turn a brilliant white. As he matures further, the edges of the lobes of his tail turn white. The base of the tail is red and spreads over the remainder of the tail as he ages. When the male displays for spawning or dominance, the base of his anal and dorsal fins turn a deep black green color.

The female has a more heavy body, and she is more of a metallic greenish blue in color. She has a hi-light of blue along her lateral line. She also has the red that the male has, but her fins are clear.


Eigenmann first described the Green Fire Tetra in 1907. It comes from the Rio Paraguay in South America. The habitat of this fish is very varied depending on the season of the year. Because of the varied habitat, this species does very well in average-type conditions. A temperature of 23 degrees Celsius (73F), neutral pH, and medium hardness. It will readily eat any good fish food. By personal experience it does not like extremes of conditions and unlike most tetras it does not do well at low pH. It can be kept in a community tank with other peaceful fishes, and it greatly appreciates floating plants in the tank where it can swim in and out of these plants.

Breeding Aphyocharax rathbuni – Green Fire Tetra

I keep about a dozen in a school with a few more females than males. Oddly when schooling the males and females tend to keep within their own sex within the school. This species is a group spawner.

I place three pairs in a ten-gallon tank with floating plants and a wad of Java moss onto which they will lay their eggs. I cover the bottom of the tank with marbles so when the eggs fall through the java moss, they also fall through the marbles, and the parents cannot get at them. The breeding temperature is 25.5 degrees Celsius (78F), neutral pH, and hardness of about GH4 (60 ppm). Although all of the fish spawn in this set up, the largest female, along with the most dominant male, lays most of the eggs. After spawning, remove the adults. You will see fry in about five days. Feeding liquid food for a few days along with baby brine shrimp easily raises them.

The only negative thing I can say about this species is that they mature very slowly. It takes about five months for the males to develop their white fins, and fully mature colors may take sixteen months. Please believe me when I say that to see this beautiful fish at maturity is really worth the wait. All good things come to those who wait!



Aquarticles.com (original website no longer online)


Joe Kaznica – The Gravel Gossip, Diamond State Aquarium Society



Copyright images


Bijgewerkt op 12 August 2023 door John

Additional information






Aphyocharax stramineus, Piabarchus stramineus

Common name

Green Fire Tetra, Redflank Bloodfin


Social behaviour


Breeding behaviour

Egg scatterer



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