Moenkhausia costae, also known as the Blackline Tetra, is a peaceful schooling fish from South America. These fish need to be kept in groups (3-4 at least, more being preferable) and display their best behaviour when kept as such. These fish are tight schoolers and there are few other tetras that look as nice swimming together as a large group of these fish!

These are subadults, ranging from 1-2 long.