Threadfin Rainbowfish Iriatherina werneri

The Threadfin Rainbowfish, the only species in its genus, is native to swamps and streams with thick vegetation in tropical northern Australia and New Guinea. (It may be that populations in Queensland, Northern Territory and New Guinea are 3 different species.)

It is distinguished by long, flowing fins. Males have longer fins and are more brightly coloured than females and can vary their colour intensity to display to females or rivals, or just to indicate good or poor health/mood. They also spread their fins and flick their spines when displaying. They grow to 5cm long.