Red Eye Tetra (Moenkhausia sanctaefilomenae)

Moenkhausia sanctaefilomenae ranges across Brazil, Paraguay, and Argentina, and grows a fair bit larger and hardier than the delicate nano tetras it gets shelved next to, with a bold red eye ring and a dark spot at the tail base that stays visible even in a dim tank. It's an unfussy fish that tolerates a wider temperature and hardness range than most Amazon tetras, making it a solid bridge species between beginner setups and more demanding blackwater builds. A proper school of these reads as genuinely striking without needing much finesse to keep.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~2.5" · Min tank: 20 gal · Diet: Omnivore, flake/pellet