Buenos Aires Tetra

Looks how to spot one

Medium-sized, robust scaled characin

A sturdy, silvery tetra with a metallic shine, red-tinted fins and a dark mark on the dorsal fin. Its signature feature is a bold black cross-shaped marking where the body meets the tail. Males are slimmer and more brightly coloured than females.31

Personality what they are like

Busy and sociable, with males constantly sorting out their rank within the group. It is happiest in a good-sized shoal and with sturdy, quick tankmates rather than slow, long-finned fish.13

Daily activity how busy a day looks

Very active swimmer that needs a roomy tank with plenty of open water.12

Grooming and care the hands-on bits

Low-maintenance and forgiving of different water conditions. It grazes on soft plants, so choose tough or artificial plants, and keep up regular partial water changes.213

Home where they are happiest

Tank with a base of at least about 80 to 90 cm (around 81 litres or more). Subtropical fish: temperature about 16 to 28 °C (avoid long periods at the top end), pH about 5.5 to 8.5, hardness 1 to 20 dGH.12

Food basics what goes in the bowl

Omnivore that eats worms, insects, small crustaceans and plant matter. Offer flakes with plant or algae content, small live and frozen foods such as bloodworm, Daphnia and brine shrimp, plus some vegetables.123

Company who they like around

Keep a group of at least 8 to 10; a bigger group keeps the energy spread within the shoal. Best with robust, similar-sized tankmates.13

The story where it all began

Carl H. Eigenmann described it in 1907 as Hemigrammus anisitsi, with Villarrica in Paraguay as the type locality. It has since passed through several genera and is now placed in Psalidodon. Despite its name, it is found well beyond Buenos Aires Province.312

Recognised by the official bits

IUCN Red List

Least Concern (assessed 4 March 2021)2

FishBase

Highly commercial aquarium species; described as one of the hardiest tropical aquarium fishes2