A new species of Geophagus (Teleostei: Cichlidae): Naming a cichlid species widely known in the aquarium hobby as 'Geophagus sp. Tapajos red head'.

A new species of Geophagus sensu stricto is described from the Tapajos River basin, Brazil, elevating the number of species of the genus to 21. The new species is of commercial importance and is known in the aquarist trade as Geophagus 'red head'. The new species is diagnosed using an integrative approach, based on mitochondrial DNA analysis along with morphological evidence. The new species is distinguished from all congeners by the absence of markings on the head, the bar pattern composed by nine vertical bars on the flanks and the presence of distinct longitudinal bands in the caudal fin. Additionally, it shows a genetic distance of at least 2.0% in cytochrome b gene sequences from its closest congeners. Molecular analysis including most genera of Cichlidae from South America corroborates that the new species belongs to the group of Geophagus sensu stricto.

A new species of Bryconops (Characiformes: Iguanodectidae) from the Rio Tapajós basin, Brazil.

A new species of Bryconops is described from upper rio Juruena drainage, rio Tapajós basin, Amazon basin, state of Mato Grosso, Brazil. The new species is hypothesized as belonging to the subgenus Creatochanes by presenting the posterior extension of maxilla reaching to the junction of second and third infraorbital bones, and the ventroposterior margin of second infraorbital forming a complete border with third infraorbital, resulting in the lack of a naked area between them. The new species is easily distinguished from other species of the subgenus Creatochanes by the color pattern of the caudal fin, which consists of the dorsal lobe conspicuously dark pigmented on its distal half and the ventral lobe dark gray pigmented along its ventral portion below the horizontal through the ventral margin of the caudal peduncle.

More than meets no eyes: taxonomic status of a Liotyphlops (Serpentes: Anomalepididae) blindsnake from the atlantic rainforest

Liotyphlops Peters, 1881 is an anomalepidid blindsnake genus that encompasses 12 species, widely distributed in Central and South America. In this study, we evaluate the taxonomic status of Liotyphlops sousai Santos & Reis, 2018, a species described based on a single specimen from the Atlantic Rainforest of southern Brazil, and after analyzing evidences based upon molecular systematics, external morphology and osteology, we propose its synonymy with Liotyphlops beui (Amaral, 1924), a common and widely distributed Anomalepidid species. We also provide comments and recommendations on the taxonomy of Liotyphlops, assessing the risks associated with describing a new species based on small type series.

Review of the Odontesthes perugiae species group from Río de La Plata drainage, with the description of a new species (Atherinomorpha: Atherinopsidae).

Specimens presently identified as belonging to Odontesthes perugiae species group from rio Paraná, rio Uruguay and rio Negro in Argentina, Brazil and Uruguay are revised. Two species are recognized: Odontesthes perugiae, type species of the genus with Odontesthes orientalis as a junior synonym, and a new species described herein. Odontesthes perugiae is redescribed and its distribution restricted to the lower rio Paraná, lower rio Uruguay and rio Negro basins. The new species is endemic from the upper rio Uruguay above Salto do Yucumã (Brazil) or Saltos del Moconá (Argentina) falls. Both species share with the remaining taxa included in the O. perugiae species-group (O. bicudo, O. ledae, O. mirinensis, and O. piquava) the possession of teeth of the outer row on dentary and premaxilla shorter than those in the inner row, being distinguished from them by the number of gill rakers, body measurements and some osteological characters.

A new species of Bryconops (Teleostei: Characidae) from the rio Madeira basin, Northern Brazil

A new species of Bryconops is described from a tributary to the rio Madeira in the Amazon basin, State of Rondônia, Brazil. Bryconops piracolina belongs to the subgenus Bryconops by having no teeth or rarely one tooth in the maxilla, and a naked area on cheek between the second and third infraorbitals. The new species is distinguished from all species of this subgenus by the presence of a large black blotch on dorsal-fin base. Furthermore, it is distinguished from all congeners, except B. inpai, by possessing the adipose fin entirely black. It differs from B. inpai by the lack of humeral spots. It further differs from all species of the subgenus Bryconops, except B. caudomaculatus, by having the last scales of the longitudinal series of scales that bears the lateral line series not pored beyond the end of the hypural plate, and differs from B. caudomaculatus by the smaller number of pored lateral line scales (31-36, mean 34.6, vs. 37-43, mean = 40.6, respectively).

Uma nova espécie de Bryconops é descrita para um tributário do rio Madeira na bacia do rio Amazonas, Brasil. Bryconops piracolina pertence ao subgênero Bryconops por não possuir dentes ou raramente apresentar apenas um dente na maxila, e por possuir uma área nua na face entre o segundo e terceiro infraorbitais. A espécie nova se distingue de todas as espécies do subgênero Bryconops pela presença de uma grande mancha negra na base da nadadeira dorsal. Além disto, difere de todas as espécies do gênero, exceto B. inpai, por possuir a nadadeira adiposa inteiramente preta. Difere de B. inpai pela ausência de manchas umerais. Difere de todas as espécies de Bryconops, exceto B. caudomaculatus, por possuir as últimas escamas da série longitudinal de escamas da linha lateral sem poros além da terminação da placa hipural e difere de B. caudomaculatus pelo menor número de escamas com poros da linha lateral (31-36, média 34,6 vs. 37-43 média, 40,6; respectivamente).