Pareiorhaphis mutuca

Pareiorhaphis mutuca has 7 soft rays in its dorsal fin and 6 in its anal fin. This species can be told from the other species of Pareioraphis by the shape and size of the cleithrum and the pattern of hypertrophied odontodes on the side of the head which are longer to teh rear and point backwards. This catfish has an elongated body and it reaches a standard length of 10.2 cm (4.0 in).

Pareiorhaphis mutuca was formerly known only from its type locality but the population there hase becomne locally extinct. However, new populations were recorded in the municipality of Caeté, in the Prata stream, a tributary of the right bank of the Velhas River, and in the Maquine stream, a tributary of the right bank of the Prata stream, both belonging to the Velhas River basin, both being in the São Francisco drainage system. This catfish is found in rocky and stony reaches of rivers, hding under stones and in crevices during the day but it is active throughout the day.

Pareiorhaphis mutuca is a species in the genus Pareiorhaphis, the name of which is a combination pareio, derived from pareiá, which means "cheek" in Greek, and rhaphis, meaning "needle". This is a reference to the needle like hypertrophied odontodes on the cheeks of the males when they are in breeding condition. The specific name, mutuca, refers to the type locality of this species, the Mutuca stream.