Unlike most Corydoras species but similar to the other "saddlenoses", C. narcissus tend to occur in small groups (not larger groups) and especially during the breeding period mature males are quite aggressive towards each other.
In contrast to many Corydoras species, yet sharing similarities with other "saddlenose" species, C. narcissus often gathers in smaller groups, particularly during the breeding cycle, where dominant males display aggressive behavior towards one another.