Blue Tetra

About

Found in clear coastal streams running from southern Bahia down to northern Rio Grande do Sul in Brazil, Mimagoniates microlepis is one of those quietly interesting small tetras that rewards patient observation. It belongs to a group known as internally inseminating characins. Females can store live sperm in their ovaries after mating during the dry season, then use that stored sperm to fertilize eggs when the rains arrive and survival odds for offspring improve. That alone makes it more biologically fascinating than most small tetras you'll encounter in the hobby. It occasionally turns up for sale under the name "blue tetra", but should not be confused with Knodus borki, which shares that common name and is actually much more widely available. This species is gentler and less prone to fin-nipping than that look-alike. In the aquarium it's a peaceful, active shoaler that genuinely needs company. A group of at least six is the minimum, and ten or more is much better. It won't hold its own against boisterous or aggressive tankmates, so choose companions carefully. Smaller South American tetras, pencilfish, Corydoras, Apistogramma, and cool-water cichlids like Gymnogeophagus all make compatible neighbors. It also does well in a biotope setup reflecting its native stream habitat. Breeding is achievable for intermediate keepers willing to set up a dedicated spawning tank.