Congo Tetra

About

The Congo tetra (Phenacogrammus interruptus) is one of those fish that looks almost unremarkable at the shop but rewards patient keepers with a transformation that has to be seen to be believed. Native to the lower and middle Congo River basin in the Democratic Republic of Congo and Republic of Congo, these tetras inhabit the same river system that gives them their name. Males, once settled and maturing in good water conditions, develop flowing, layered fins and an iridescent blue-gold sheen that shifts with the light, especially under natural sunlight. Females are smaller and less flamboyant but contribute to the overall effect of a well-established group. They are an active, open-water schooling species and should always be kept in a mixed-sex group of at least five, though larger numbers genuinely make a difference. Despite their active nature, they are peaceful fish, though their size and energy can unsettle smaller, shyer tankmates. Their fins are vulnerable to nippers, so species selection matters. Congo tetras are sensitive to water quality and will visibly show it in degraded fin development and faded color if conditions slip. This makes them a better choice for keepers who already have a handle on consistent tank maintenance rather than true beginners. Omnivorous and not demanding in terms of diet, they accept most prepared and live foods readily.