小鳞长臀脂鲤 · Blue Tetra

Overview

Mimagoniates microlepis is a blue tetra suited to relatively cool, clean, well-oxygenated water. Much of its activity takes place near the surface. Its temperature needs deserve as much attention as temperament when choosing companions.

Distribution & habitat

Native populations occur in southeastern Brazil, from southern Bahia to the northern end of Rio Grande do Sul. Clear, flowing streams, small rivers, and tributaries across coastal floodplains are typical habitats.

Aquarium setup

A footprint around 60 × 38 cm is a useful starting point. Combine dense plant stands with open swimming space, dark substrate, and wood roots. Floating vegetation supplies overhead shade. A stream-style alternative uses sand, smooth rounded stones, and woody branches.

Place a filter outlet or spray bar at one end to create circulation and disturb the surface. Good oxygenation matters. A temperature around 18–23 °C suits this fish; heating the aquarium continuously to meet the needs of warm-water species is inappropriate.

Diet & feeding

Its natural feeding is almost entirely insect-based, with terrestrial insects forming the main prey. Captive fish are generally eager feeders and accept prepared foods. Regular live or frozen Daphnia, Artemia, and bloodworms alongside dry foods provide variety.

Behaviour & compatibility

Choose peaceful companions and avoid large, overbearing, or excessively active fishes. Maintain at least six blue tetras, preferably ten or more. Cool-water companions such as Scleromystax barbatus are worth considering, whereas discus and other fishes requiring consistently high temperatures are unsuitable.

Sexual dimorphism

Adult females have rounder abdomens and usually show slightly less intense color than males.

Breeding

A separate dim aquarium can contain fine-leaved plants, spawning mops, or mesh to protect the eggs. Use soft, acidic water and gentle aeration. A group of roughly six males and six females is one option. Alternatively, condition the sexes separately and introduce a full-bodied female and a well-conditioned male in the evening; spawning commonly follows the next morning.

Remove the adults after spawning because they eat eggs. Hatching generally takes 48–72 hours, with free swimming beginning a few days later. Provide infusoria initially, then introduce microworms and newly hatched Artemia as the fry grow.

Notes

The trade name “blue tetra” is also applied to Knodus borki, so scientific identification is useful when buying. M. microlepis is less often available and is usually less boisterous and less inclined to nip fins than that other fish.