A new genus of armored catfish (Siluriformes: Loricariidae) from the Greater Amazon, with a review of the species and description of five new species

Abstract

A new genus of Hypopopomatinae armored catfish is described from the northern portions of South America, namely the Amazon, Orinoco and Guianan coastal drainages. The new genus is diagnosed from all remaining hypoptopomatines by having the canal cheek plate on the ventral surface of the head posteriorly elongated and contacting the cleithrum, in addition to other features that distinguish the new genus from specific genera. Five new species are described and 18 species currently allocated in Parotocinclus, Hisonotus, and Curculionichthys are transferred to the new genus and rediagnosed. Parotocinclus amazonensis and P. aripuanensis are considered junior synonyms of P. britskii. The secondary sexual dimorphism of the members of the new genus is detailed and illustrated. Morphological characters are used to delimit four phenotypic groups of species that might have phylogenetic significance, which still have to be properly tested. A key to the species is offered and diagnoses, illustrations, and distribution maps are provided for all species.

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

“…Parotocinclus includes 26 species that occupy the coastal drainages of the Brazilian Shield from Santa Catarina State of Brazil, in the south, to Piauí State, in the north, including the rio São Francisco (Fricke et al ., 2022; Reis & Lehmann, 2022). Currently, 12 species of Parotocinclus are known from the north‐eastern Mata Atlântica freshwater ecoregion (NMAF, sensu Abell et al ., 2008): P. adamanteus Pereira, Santos, de Pinna & Reis, P. arandai Sarmento‐Soares, Lehmann & Martins‐Pinheiro, P. bahiensis (Miranda Ribeiro), P. cristatus Garavello, P. doceanus (Miranda Ribeiro), P. jacumirim Silva‐Junior, Ramos & Zanata, P. jequi Lehmann, Braun, Pereira & Reis, P. jimi Garavello, P. maculicauda (Steindachner), P. minutus Garavello, P. nandae Lehmann, Camelier & Zanata, and P. planicauda Garavello & Britski.…”