A new species of Parotocinclus (Loricariidae: Hypoptopomatinae) from the rio Pardo basin, Bahia State, Brazil, with comments on the sexually dimorphic traits of the nares and olfactory lamellae

A new species of Parotocinclus is described from lower rio Pardo basin, Bahia, Brazil. The new species differs from the majority of its congeners by the presence of a rudimentary or vestigial adipose fin, restricted to one to three small unpaired plates on the typical location of the fin. The new species differs from congeners that lack a well-developed adipose fin, and also from various other congeners, by a series of features including the absence of unicuspid accessory teeth and abdomen completely covered by plates similar in size. Additionally, mature males of the new species possess hypertrophied and a higher number of olfactory lamellae, when compared to similar-sized or even larger females. Hypertrophied and higher number of olfactory lamellae in males is shared with the congeners from the north-eastern Mata Atlantica freshwater ecoregion examined to the feature.

Automated summary

A new species of Parotocinclus is discovered in the lower Rio Pardo basin, Bahia, Brazil. This species is distinguished from its congeners by its unique adipose fin structure and body features, and mature males have more olfactory lamellae.