Blue Peru tetra

Knodus borki

Blue iridescence and a short dark mark in the central tail

A lively silver-blue tetra with largely clear fins. Its blue sheen changes with lighting.

Adult length: Up to 5 cm
Water temperature: 22–26 °C
pH: 5.5–7
Hardness: 5–12 dGH

Natural habitat: Inhabits rivers, streams and tributaries.

Fin nipping is reported during crowding or feeding, so quiet, slow or long-finned companions may be disadvantaged.

View comparison →

Appearance and identification

Knodus borki was long confused in trade with Boehlkea fredcochui. The central tail marking differs from the latter's transverse tail-base mark. The blue emperor has a more conspicuous dark lateral band. Mature females generally have rounder bellies and males slightly stronger coloration.