The tetra (Hyphessobrycon bentosi) exhibits two phenotypes associated with shoulder spotting. Fish possess ei-ther a prominent black vertical spot located directly behind the operculum (H. b. bentosi, bentosi white tip tetra) or lack this spot (H. b. rosaceus, rosy tetra). Segregation patterns observed from the progenies of ten different crosses suggest that the inheritance of these phenotypes is controlled by two autosomal loci acting in a complementary fashion, with domi-nance at both loci required for the expression of the spotted phenotype.
Frankel, Jack, "Inheritance of Shoulder Spotting in the Tetra, Hyphessobrycon bentosi Characidae" (2009). Department of Biology Faculty Publications. 135.