Threadfin Rainbowfish

A tiny rainbowfish in which males have long, thread-like fins. It is widely sold but delicate, it needs tiny food and calm tankmates, and long fins attract nippers.

Check the scientific name when buying, as common names vary between sellers and countries.

Mature females are usually rounder in the belly, and males are usually slimmer and often brighter.

A long tank with open swimming water, plants around the edges and steady filtration suits this fish. A darker substrate and some floating plants usually bring out its colour.

Active and social, and most settled when kept with its own kind.

Keep a group of at least 6, and more if you can. Larger groups are calmer and show better colour and behaviour.

Not territorial, although males may spar and display.

Suits a community of similar-sized, peaceful fish that like the same water. Avoid large predators, which will treat it as food. It may nip the fins of slow or long-finned fish, and a larger group usually reduces this. It may eat baby shrimp. Long fins attract nippers, so avoid fin-nipping fish.

Fairly tolerant of different water, if it is clean and stable.

A delicate rainbowfish with a tiny mouth. Feed fine foods such as baby brine shrimp and crushed flake, several times a day.

Feed small amounts, and remove anything left after a few minutes.

An egg scatterer with no parental care. Adults eat eggs and fry, so use a separate tank with fine plants, moss or mesh on the bottom, and remove the adults after spawning. The fry need very small foods at first.