Pareiorhaphis cameroni, photo by K.S. Cummings
Pareiorhaphis nudulus, from Reis and Pereira 1999
Pareiorhaphis are small- to medium-sized loricariids.
Color pattern is usually dark brown and mottled with the abdomen white
(there is mottling on the lower surface of the caudal peduncle in some
species). Abdomen naked. Caudal fin straight, angled posteroventrally
to slightly emarginate. Four or more predorsal plates. At least
a single column of plates on the caudal peduncle where there are only three
rows of plates. Canal plate large with the ventral border deflected under
the head. Eyes typically small. Dorsal fin short, never reaching
the adipose fin. In one species, P. vestigipinnis, the adipose
fin is nearly absent.
Pareiorhaphis can be distinguished from all but Isbrueckerichthys, Delturus, Pogonopoma, Pseudorinelepis, and Hemipsilichthys and some Loricariinae by a combination
of a lack of evertible cheek plates and elongated odontodes along the snout
margin in breeding males. Pareiorhaphis differs from Isbrueckerichthys by having a large, ventrally deflected canal plate, having a well-developed posterior process of the cleithrum, and lacking some small, embedded plates on the abdomen; from Delturus
by lacking a postdorsal ridge, from
Pogonopoma and Pseudorinelepis by lacking plates on the abdomen and having three (vs. five or more) rows of plates in at least one column on the caudal peduncle, and from the Loricariinae by having an adipose fin and lacking an elongate, flattened caudal peduncle that is rectangular in cross-section. Non-breeding males, females, and juveniles can be separated from Pareiorhina by the presence
of an adipose fin, from Hemipsilichthys, Corymbophanes, and Delturus
by a lack of a postdorsal ridge, from Kronichthys by having a wider
body (vs. cigar-shaped) and by having the sphenotic in contact with the
sixth infraorbital externally, from Neoplecostomus and the Rhinelepini, by a lack of plates on the abdomen, from most of the Rhinelepini, Pterygoplichthyini, and Hypostomini by having more than three predorsal plates and a rectangular (vs. triangular) dorsal fin spinelet, and from the Pterygoplichthyini and the Ancistrini by a lack of evertible odontodes on the cheek.