Brycon insignis is
endemic to Brazil, where it was originally found in the drainages of the Paraíba do Sul,
Itabapoana and
Itapemirim rivers. Historically, the this fish was found in the
Grande River system, which drains into
Guanabara Bay,
Imbé River, which runs into
Feia Lagoon, the
Macaé River, the
São João River, and the Itabapoana River, all separate river systems close to the drainage of the Paraíba do Sul. There have been no records from the Macaé in recent years, and it is likely extinct in the Grande, not having been recorded since the early 20th century. No wild populations have been found in the sections of the Paraíba do Sul within
São Paulo. However, fish have been captured in the
Paraibuna reservoir, probably introduced in a restocking effort. In
Espírito Santo this species occurs only in the Itapemirim. This is a
benthopelagic species. ==Biology==