Microgenys is a small, poorly known genus of tetra-type characins (order Characiformes) from the western Amazon foothills, recorded in the atlas from Peru, Bolivia, and Guyana. Atlas species span roughly 1–3 in, putting most of the genus among the smaller characins found in that region. As with many small Andean-foothill and headwater characins, published biology is thin - body shape and fin counts are the features used to separate the species, and little has been written about their ecology or behavior in the wild.
The genus is essentially unknown to the aquarium hobby; none of its three atlas species - Microgenys lativirgata (known locally as mojarita), M. minuta, and M. weyrauchi - has an established presence in the trade, and detailed care information is not available. Two of the three species carry a Data Deficient IUCN assessment and the third has not been evaluated, reflecting how little survey work has reached this genus rather than any documented population decline.