Lacustris (Turquoise) Rainbowfish (Melanotaenia lacustris)

Melanotaenia lacustris is a lake endemic out of Papua New Guinea's Lake Kutubu, one of several rainbowfish species restricted to a single body of water, and that isolation is part of why the turquoise coloring reads so distinctly compared to river-dwelling relatives spread across broader ranges. Like the rest of the family, that shimmer comes from reflective guanine platelets rather than pigment, and it looks best in a tight school under decent lighting. Peaceful, active, and a great centerpiece for a larger community tank.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~4" · Min tank: 30 gal · Diet: Omnivore, flake/pellet