Spotted Metynnis

About

Found across the Amazon and Paraguay River basins, this silver dollar relative, Metynnis maculatus, is one of those fish that surprises people once they learn its family tree. Genetically, it sits within the piranha clade of the family Serrasalmidae, yet in practice it is a largely peaceful, plant-munching schooling fish. Its silvery body is dotted with small, roughly circular dark spots concentrated toward the belly, which is the main feature that separates it from its close look-alike relatives. In the wild it grazes heavily on fruits and plant matter, and while it may opportunistically take small invertebrates or meaty food under stress, it poses no real threat to fish too large to be swallowed. That said, it does need space and company. Kept alone or in small groups, individuals can become nervous or uncharacteristically pushy, so a group of at least six is the sensible starting point. Robust tankmates of comparable size, many cichlids, larger catfish, and other big characins, make solid companions. Aquatic plants are not a great idea unless you are prepared to lose them. Given its manageable care needs and tolerance for a reasonable range of water conditions, this species is accessible enough for a beginner who has the tank footprint to do it justice.