Nannostomus trifasciatus

Nannostomus trifasciatus (from the Greek nanos, meaning "small"; the Latin stomus, relating to the mouth; and the Latin trifasciatus, meaning "three bands"), commonly known as the three-lined or three-stripe pencilfish, is a freshwater species of fish belonging to the characin family Lebiasinidae. They are popular in the aquarium trade due to their small size, beautiful color pattern, and relative hardiness.