A new species of Pareiorhaphis (Siluriformes: Loricariidae) from the headwaters of the Arroio Garapiá, coastal drainage of Rio Grande do Sul state, Brazil.

Pareiorhaphis garapia, new species, is described based on specimens collected in the headwaters of the Arroio Garapiá, Rio Maquiné basin, a coastal drainage of Rio Grande do Sul State, southern Brazil. The new species is distinguished from all other Pareiorhaphis species in having the nuchal plate covered by thick skin, the exposed posterior process of the cleithrum comparatively narrow, and the last segment of the preopercular ramus of the latero-sensory canal reduced to an ossified tubule. The absence of a dorsal-fin spinelet, the reduced number of plates in the dorsal and mid-dorsal series of lateral plates, and morphometric traits also distinguish the new species from its congeners. The restricted geographic distribution of P. garapia, endemic to a headwater stream of the Rio Maquiné basin, and the syntopic occurrence of P. nudulus are discussed.

A new species of the armored catfish Parotocinclus (Loricariidae: Hypoptopomatinae), from the Amazon basin in Colombia

A new species of hypoptopomatine cascudinho is described from a creek tributary to the Amazon River in Leticia, Amazonas Departament, Colombia. The new species of Parotocinclus is distinguished from congeners from northeastern to southeastern Brazilian rivers in having the cheek canal plate elongated posteriorly on the ventral surface of head and contacting the cleithrum. It is diagnosed from P. collinsae (Essequibo River basin, Guiana) and P. halbothi (rio Trombetas basin, Brazil and Marowijne River, Suriname), by having a triangular patch of dark pigmentation on the anterior portion of the dorsal-fin membrane, by the absence of unicuspid accessory teeth on both the premaxilla and dentary, and by having a Y-shaped light mark on the snout. The new species of Parotocinclus is distinguished from all remaining congeners by having a pigmentation pattern consisting of conspicuous dark dots smaller than a pupil diameter, broadly distributed dorsally and ventrally.

Uma espécie nova de cascudinho hypoptopomatíneo é descrita de um igarapé afluente do rio Amazonas em Leticia, Departamento Amazonas, Colômbia. A espécie nova de Parotocinclus é diagnosticada de suas congêneres do nordeste e sudeste do Brasil por ter a placa com canal da bochecha alongada posteriormente na superfície ventral da cabeça e em contato com o cleitro. A espécie nova é diagnosticada de P. collinsae (bacia do rio Essequibo, Guiana) e P. halbothi (bacia do rio Trombetas, Brasil e rio Marowijne, Suriname), por possuir uma mancha de pigmentação escura triangular na porção anterior da membrana da nadadeira dorsal, pela falta de dentes acessórios unicúspides na pré-maxila e no dentário, e por possuir uma mancha clara em forma de Y no focinho. A espécie nova de Parotocinclus se distingue das demais congêneres por possuir um padrão de pigmentação do corpo consistindo de conspícuos pontos escuros menores do que um diâmetro da pupila, amplamente distribuídos dorsal e ventralmente.