Pygmy Hatchetfish

The smallest and most delicate hatchetfish, from Peru and Bolivia, at only 2.5 cm. It needs a calm tank without boisterous fish.

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 eat baby shrimp.

Fairly tolerant of different water, if it is clean and stable. Keep the temperature steady.

A tiny surface feeder that needs very small floating foods: crushed flake, baby brine shrimp and fruit flies. It rarely takes anything below the surface.

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

Not commonly bred in aquariums, and little has been recorded about how it spawns.