Characidium grajahuense is a fish in the family Crenuchidae. It is native to South America and is found in the coastal streams between Guanabara Bay and the Mangaratiba, in Rio de Janeiro, Brazil.

Size

This species reaches a length of 8.8 cm (3.5 in).

Etymology

The fish's name denotes a place: Grajaú, Rio de Janeiro, Brazil, which is the type locality.