Parotocinclus nandae, a new distinctive colored catfish (Loricariidae: Hypoptopomatinae) from the upper Rio Paraguaçu, Bahia State, northeastern Brazil

Pablo Lehmann A,Angela Zanata,Priscila Camelier,Roberto E Reis

doi:10.1371/journal.pone.0236690

Abstract

A new species of Parotocinclus from the upper Rio Paraguaçu, Bahia, Brazil, is described. The new species is distinguished from all congeners by its unique color pattern, with irregular dark blotches resulting in a somewhat marble-spotted pattern on head and trunk of most specimens and dorsum of head with a conspicuous V-shaped light mark from tip of snout to nares. The new species is also distinguished from congeners by having the lower lip elongated posteriorly and reaching or surpassing the anterior margin of cleithrum on the pectoral girdle, the canal cheek plate on the ventral surface of the head reduced and with a slightly concave margin, and abdomen covered by small embedded platelets, without contact with each other and not arranged in a line between the pectoral-fin axilla and pelvic-fin origin. The presence of a thick and rough skin in the interradial membrane of pelvic fin exclusively in the females of P. nandae is reported by the first time to occurs in Siluriformes.

Highlights

The loricariid fishes of the subfamily Hypoptopomatinae, or small armored catfishes known as “cascudinhos” in Brazil, includes 32 valid genera and 247 species distributed throughout most of lowland tropical South America and generally found in shallow streams and typically associated with emergent and marginal macrophytes [1, 2]
The polyphyletic nature of Parotocinclus has been demonstrated by morphology- and DNA-based phylogenetic studies (e.g., Gauger & Buckup [8]; Lehmann [9]; Cramer et al [10]; Roxo et al [11]; Pereira & Reis [12], and Reis et al [13]), but the persistent recognition of this genus in spite of its polyphyletic nature is maintained by the possession of an adipose fin, which is unique among the genera of the subfamily [4]
Extensive ichthyological surveys throughout coastal rivers of northeastern Brazil failed to record the new species outside the upper Rio Paraguacu basin, rendering the species apparently endemic to this drainage

Summary

Introduction

The loricariid fishes of the subfamily Hypoptopomatinae, or small armored catfishes known as “cascudinhos” in Brazil, includes 32 valid genera and 247 species distributed throughout most of lowland tropical South America and generally found in shallow streams and typically associated with emergent and marginal macrophytes [1, 2]. A new species of Parotocinclus from Northeastern Mata Atlantica freshwater ecoregion (Abell et al [24]), the seventh species of loricariid known from the Rio Paraguacu basin, is described . Extensive ichthyological surveys throughout coastal rivers of northeastern Brazil failed to record the new species outside the upper Rio Paraguacu basin, rendering the species apparently endemic to this drainage

Material and methods

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Discussion