Australian Rainbowfish

About

The Australian rainbowfish (Melanotaenia fluviatilis) goes by a few other names in the hobby, Murray River rainbowfish and crimson-spotted rainbowfish among them, and it's one of those species you don't see as often as you'd expect given how rewarding it is to keep. It's endemic to Australia and ranges further south than any other rainbowfish, which means it's genuinely adapted to cooler conditions that would stress most of its relatives. In the wild it turns up in a wide variety of habitats: slow-moving streams, drainage ditches, backwaters, overflow ponds, and reservoirs, usually hanging around submerged vegetation and woody debris near the banks. It can be confused with the closely related M. duboulayi, the two were once considered the same species, but differences in patterning and fin ray counts separate them. Males develop noticeably orange throats and reddish caudal fins when in breeding condition, which is when they look their best. Like other rainbowfish it's a shoaling species that does significantly better in groups of six or more. It's peaceful enough in terms of aggression, but it's a fast, active swimmer and can unsettle smaller or more timid tankmates. Characins, danios, barbs, and Corydoras all make sensible companions. Breeding is achievable for intermediate keepers, though raising the fry takes a bit of patience.