Abstract
Hyphessobryconcarusp. nov.is described based on five different and independent methods of species delimitation, making the hypothesis of this new species supported by an integrative taxonomy perspective. This new species has a restricted distribution, occurring just in the upper Pindaré river drainage, Mearim river basin, Brazil. It is a member of the rosy tetra clade, which is characterized mainly by the presence of a dark brown or black blotch on dorsal fin and absence of a midlateral stripe on the body.Hyphessobryconcarusp. nov.is distinguished from the members of this clade mainly by the shape of its humeral spot, possessing few irregular inconspicuous vertically arranged chromatophores in the humeral region, or sometimes a very thin and inconspicuous humeral spot, and other characters related to teeth count, and color pattern. The phylogenetic position of the new species within the rosy tetra clade was based on molecular phylogenetic analysis using sequences of the mitochondrial gene cytochrome oxidase subunit 1. In addition, a new clade (here termedHyphessobryconmicropterusclade) within the rosy tetra clade is proposed based on molecular data, comprisingH.carusp. nov.,H.micropterus,H.piorskii, andH.simulatus, and withH.carusp. nov.andH.piorskiirecovered as sister species. Our results suggest cryptic speciation in the rosy tetra clade and, more specifically, in theH.micropterusclade. We recommend the use of integrative taxonomy for future taxonomic revisions and species descriptions when dealing with species complexes and groups containing possible cryptic species.
Highlights
Hyphessobrycon Durbin, 1908 is a species-rich characid genus comprising about 160 valid species (Fricke et al 2019)
Several genetic studies focusing on characoid fishes, such as Astyanax Baird & Girard, 1854 (e.g. Ornelas-Garcia et al 2008), Caenotropus Günther, 1864 (e.g. Melo et al 2014), Chilodus Müller & Troschel, 1844 (e.g. Melo et al 2014), Curimatopsis Steindachner, 1876 (e.g. Melo et al 2016a), Gymnocorymbus Eigenmann, 1908 (e.g. Benine et al 2015), Hyphessobrycon (e.g. Castro-Paz et al 2014, Guimarães et al 2018), Piabina Reinhardt, 1867 (e.g. Pereira et al 2011), Prochilodus Agassiz, 1829 (e.g. Melo et al 2016b), Nannostomus Günther, 1872 (e.g. Benzaquem et al 2015) and Tetragonopterus Bleeker, 1863 (e.g Melo et al 2016c) have evidenced that some species may exhibit large discontinuities in their geographic distribution patterns, with high genetic divergences, but little morphological variability among geographically isolated lineages. These results suggest that these groups may represent species complexes or cryptic species, that is, they might even including morphologically quite similar or undistinguishable species that are hidden and erroneously classified (Brown et al 1995; Bickford et al 2006; Adams et al 2014; Souza et al 2018)
Molecular techniques are frequently useful for solve species complexes and discover cryptic species (e.g. Bickford et al 2006; Costa and Amorim 2011; Pereira et al 2011; Adams et al 2014; Costa-Silva 2015; Costa et al 2012, 2014, 2017; Amorim 2018; Guimarães et al 2018; Ottoni et al 2019) and could be an excellent complement for traditional taxonomy (Kekkonen and Hebert 2014)
Summary
Hyphessobrycon Durbin, 1908 is a species-rich characid genus comprising about 160 valid species (Fricke et al 2019). Integrative studies, using more than one criteria, such as character-based, tree-based, genetic distance and coalescent-based approaches, especially including molecular data, are useful and powerful for the recognition of hidden and/or possible new species in such species complexes (Sytsma and Schaal 1985; Bickford et al 2006; Goldstein and Desalle 2010; Padial et al 2010; Adams et al 2014; Costa-Silva et al 2015; Souza et al 2018; Ottoni et al 2019) In this context of integrative taxonomy, the present study aims to investigate the diversity within the rosy tetra clade sensu Weitzman and Palmer (1997a). A new clade, within the rosy tetra clade, is proposed based on the phylogenetic tree topology presented
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
