A new species of Bryconops Kner (Characiformes: Iguanodectidae) from the Rio Maicuru, lower Amazon basin, Brazil

Abstract

A new species of Bryconops is described from the rio Maicuru, a tributary of the left margin of the lower Amazon River, Pará, Brazil. Bryconops chernoffi new species, differs from all its congeners by the presence of an elongated dark patch of pigmentation immediately after the posterodorsal margin of the opercle, running vertically from the supracleithrum to the distal margin of the cleithrum (vs. absence of a similar blotch), and by a dark dorsal fin with a narrow hyaline band at middle portion of dorsal-fin rays (vs. dorsal fin hyaline or with few scattered chromatophores). It differs further from all its congeners, except B. colanegra, by the presence of a blurred black stripe at the anal fin base. It differs from B. colanegra by possessing fewer predorsal scales (8–9 vs. 10–11) and in that the third infraorbital contacts the preopercle ventrally (vs. third infraorbital not contacting preopercle ventrally). The new species is assigned to the subgenus Creatochanes by the number of maxillary teeth, and ossification and denticulation of the gill rakers.

The true identity of Bryconops cyrtogaster (Norman), and description of a new species of BryconopsKner (Characiformes: Iguanodectidae) from the Rio Jari, lower Amazon basin

“…(1991) and Planquette et al . (1996) ( e g ., Lima et al ., 2003, Silva‐Oliveira et al ., 2015, 2018) or as a junior synonym of B. melanurus , based on Chernoff et al . (1994) ( e.g ., Koerber et al ., 2017, Wingert et al ., 2018, Fricke et al ., 2019).…”

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

“…Moreover, the moderately large number of taxa found in each of three relatively small geographic regions (central Amazon near Manaus, Xingu River near Altamira, and the coastal rivers near Belém) suggests that dispersal capability of these taxa is high and secondary contact between species is likely to result in admixture or selective reinforcement of divergent characters. Indeed, there is an estimate of at least nine species level taxa in the genus for the lower and middle Xingu River [ 11 ].…”

“…(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 ].…”

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.…”