The Threadfin Rainbowfish is a small fish with a long thin silvery body, black fins and some yellow and red colouration. The males have long feathery fins and grow longer than the females. Very peaceful fish, but not suitable for the general community aquarium since it's easily outcompeted for food and the long fins of mature males may be nipped at by certain common species. It's a shoaling species by nature and really should be kept in a group of at least 6 specimens, ideally 10 or more. Maintaining it in such numbers will not only make the fish less nervous but result in a more effective, natural-looking display. Males will also display their best colours and some fascinating behaviour as they compete with one other for female attention.
Best kept in a densely-planted tank and an excellent choice for the carefully-aquascaped set-up. Filtration does not need to be particularly strong as it mostly hails from sluggish waters and may struggle if there is a fast current. Do not add this fish to a biologically immature aquarium as it can be susceptible to swings in water chemistry.