Tinfoil barb

The tinfoil barb is a big, fast-moving schooling cyprinid from the rivers and flooded forests of Southeast Asia, where it ranges across the Mekong and Chao Phraya basins. It is built like a living mirror: a deep silver body with red-and-black markings on the fins and a forked tail. Small juveniles in shop tanks give little hint of the adult, which can reach around 35 cm and live well over a decade, sometimes fifteen years.

This is a shoaling fish that should be kept in a group of at least six. Singly or in pairs they become nervous and skittish, and a startled adult is powerful enough to injure itself against the glass or lid. They are not aggressive, but they are constantly active and will eat anything bite-sized, so small fish and shrimp are not safe with them. The right tankmates are robust, similarly sized species that can handle the bustle, such as larger barbs, peaceful cichlids, loricariid catfish and bigger characins.

The catch with tinfoil barbs is simply scale. A full-grown school needs a tank measured in hundreds of litres with strong filtration and open swimming space, which puts them out of reach for most living rooms. They are unfussy omnivores that lean herbivorous in the wild, so a mix of quality dried food and vegetable matter keeps them in good color. Hardy and adaptable across roughly 22 to 28°C, they are almost never bred at home; the fish in shops come from commercial farm ponds in Asia.