A new species of Bryconops (Ostariophysi: Characiformes: Characidae) from the upper rio Tocantins drainage, Brazil

Abstract

A new species of the genus Bryconops, subgenus Bryconops, is described from the rio Conceição, a tributary to the rio Palma, upper rio Tocantins drainage, Tocantins State, Brazil. The new species is distinguished from all its congeners, except B. humeralis and B. vibex by the color pattern in vivo (dorsal, adipose, and caudal fins entirely orange). The new species is easily distinguished from B. humeralis and B. vibex by the absence of a humeral spot and by the lack of maxillary teeth (vs. presence of a single humeral spot and presence of 1-3 maxillary teeth on both sides). Furthermore, the new species is distinguished from B. vibex by the number of perforated lateral line scales (38-41 vs. 44-46).Uma nova espécie do gênero Bryconops, subgênero Bryconops, é descrita do rio Conceição, um afluente do rio Palma, bacia do rio Tocantins, Estado do Tocantins, Brasil. A nova espécie distingue-se de suas congêneres, exceto B. humeralis e B. vibex pelo padrão de coloração in vivo (nadadeiras dorsal, adiposa e caudal inteiramente laranjas). A nova espécie distinguese de B. humeralis e B. vibex pela ausência de mancha umeral e pela ausência de dentes maxilares (vs. presença de uma mancha umeral e presença de 1 a 3 dentes maxilares em ambos os lados). Além disso, a nova espécie distingue-se de B. vibex pelo número de escamas com poros na linha lateral (38-41 vs. 44-46).

Convergent and environmentally associated chromatic polymorphism in Bryconops Kner, 1858 (Ostariophysi: Characiformes: Iguanodectidae)

“…The subgenus Bryconops includes the species Bryconops alburnoides Kner, 1858, B . caudomaculatus (Günther, 1864), Bryconops collettei Chernoff & Machado-Allison, 2005, Bryconops disruptus Machado-Allison & Chernoff 1997, Bryconops durbinae (Eigenmann, 1908) Bryconops gracilis (Eigenmann, 1908), Bryconops hexalepis Guedes et al, 2019 [ 18 ], Bryconops magoi Chernoff & Machado Allison, 2005, Bryconops piracolina Wingert & Malabarba, 2011, Bryconops rheorubrum Silva-Oliveira et al, 2019, and Bryconops tocantinensis Guedes et al, 2016 [ 18 ]. The subgenus Creatochanes includes Bryconops allisoni Silva-Oliveira et al, 2019, Bryconops affinis (Günther, 1864), Bryconops chernoffi Silva-Oliveira et al, 2015, Bryconops colanegra Chernoff & Machado-Allison, 1999, Bryconops colaroja Chernoff & Machado-Allison, 1999, Bryconops cyrtogaster (Norman, 1926), Bryconops giacopinii (Fernández-Yépez, 1950), Bryconops humeralis Machado-Allison et al, 1996, Bryconops imitator Chernoff & Machado-Allison, 2002), Bryconops inpai Knöppel et al, 1968, Bryconops melanurus (Bloch, 1794), Bryconops sapezal Wingert & Malabarta, 2011, Bryconops vibex Machado-Allison et al, 1996 and Bryconops marabaixo Silva-Oliveira et al, 2019.…”

“…(C . ) marabaixo— where the distal point of the maxilla does not reach the articulation with the quadrate), indicating a need for a revision of the genus and reevaluation of those characters in a phylogenetic framework [ 11 , 16 , 18 ].…”

“…In addition to morphology, identification of Bryconops species has been proposed to incorporate information on the pigmentation of the caudal-fin [ 17 , 18 ]. However, considering the wide distribution of some taxa (especially B .…”

Body Shape Variation in the Bryconops Melanurus Complex (Characiformes: Iguanodectidae) Using Traditional and Geometric Morphometrics

“…Inhabits freshwater habitats with rocky, fast waters. (Guedes et al, 2016;Mol, 2007;Silva-Oliveira et al, 2018, 2019aWingert et al, 2018). The species-group typically lives in either open waters or shore habitats (Mol, 2007).…”

“…Introduction Currently, the genus Bryconops (Kner, 1858) has 27 described species (Table 1 and 2), making it the most species-rich genus in the characiform family Iguanodectidae (Chernoff & Machado-Allison, 1999Silva-Oliveira et al, 2020, 2021. It is comprised of small-sized tetras (Guedes et al, 2016;Silva-Oliveira et al, 2018, 2019aWingert et al, 2018) from the cis-Andean freshwater river basins of South America (including Orinoco, Amazon, and Paraguay), as well as small Atlantic coastal drainages ranging from Venezuela to the Parnaíba River in Brazil (Fricke et al, 2022;Silva-Oliveira et al, 2020, 2021van der Sleen & Moreira, 2018). Species of Bryconops are typically found in lotic habitats with acidic water, whether transparent or black water.…”