Pyrrhulina australis is part of the family of pencilfishes (Lebiasinidae) and not often for sale at the fishshops. Their first description was made in 1903 by Eigenmann and Kennedy.
They can grow to a maximum total length of around 7 centimetres, lack bright colours but this species shows interesting behaviour making it an attractive companion for your aquarium.
Synonyms: Pyrrhulina australe, Pyrrhulina macrolepis.
Origin and Habitat
Pyrrhulina australis can be found in the Rio Parana and Rio Paraguay drainages. They inhabit the smaller rivers, streams, tributaries and floodplains. They inhabit both clear- and blackwater.
They live above substrate consisting of fine sand and depending on location, rocks, wood, leafs or just bare sand. In these water live none or limited numbers of plants, except in the floodplains that will have grass, reeds, trees and bushes. Many locations do have overhanging plants that will provide shade and shelter.
Behaviour and Compatibility
Being a fish that lives in groups, we advice to keep them in groups of at least six, but preferably more for larger aquariums. They will mainly inhabit the upper layers of your aquarium. Pyrrhulina Australis will show no aggression towards other species, only males can sometimes try to intimidate other males for small territories.
Pyrrhulina australis can be combined with other sub-tropical species that are not overly active and inhabit other parts of the aquarium, species that will occaissionaly use the upper layers usually are no problem as long as they won’t stress out when being chased away from time to time. Species that exclusively use the upper water layers and very active species are better avoided. Also keep in mind that Pyrrhulina australis is a sub-tropical species that requires lower temperatures than many other fish species.
You will require an aquarium with a minimum length of 100 centimetres to accommodate a group of Pyrrhulina australis as the males will create small territories which they defend against other males. You can decorate your tank with some floating plants to dimm the lights and add some wood or plants that reach the surface to create some hiding places. The water they live in is very soft to soft and has a pH that is neutral to slightly accidic and has a low conductivity. In winter temperature may drop to 17 degrees celsius en rise in summer up to 25/26 degrees. Dont hold them too long on these high temperatures as this shortens their lifespan.
The main diet for Pyrrhulina australis in the wild consists of flies and insects at the surface of the water. In the aquarium they will accept all living and most dried foods. Keep in mind they will need some living or frozen foods as they are a carnivorious species.
Sexing Pyrrhulina australis can be a bit difficult, even if you look at adults. Males are a little bigger than females who are also a bit more plumb but sometimes it is just hard to tell the difference. With some populations the adult males have a black margin on their anal- and pelvicfins. If you still can’t see the difference you can have a close look at the shape of their pelvic fins, females pelvic fins are more rounded and males more square shaped.
If the fish are happy and feel at home in their tank, they will occasionally lay some eggs on a large leaf. The male will defend the eggs for a short time but thats all parenting they will provide. In a community tank it is obvious hardly any fry will survive. If you want to breed with Pyrrhulina australis it is better to start a breeding tank voor one male and one or two females. Feed them with plenty of high quality living foods. Add floating plants to create hiding spots for the fry. You can feed them with infusoria for the first week, after that they are big enough to feed them newly hatched brine shrimp.