Cory Melanistus (Corydoras melanistus)

Corydoras melanistus carries a bold black saddle across its dorsal fin that reads almost like a warning label, though the only thing it's actually signaling is 'more Corydoras nearby' — these fish use chemical alarm cues released from damaged skin to warn shoal-mates of danger, a defense that predates most of what's swimming above them. Those forward-facing barbels aren't just for show either; they're loaded with taste buds for sifting sand and gravel for anything edible.

Care level: Easy · Temperament: Peaceful, shoaling · Max size: ~2.5" · Min tank: 20 gal · Diet: Omnivore, sinking pellets + occasional live/frozen