Two new catfish species from central Brazil comprising a new clade supported by molecular phylogeny and comparative osteology (Siluriformes: Trichomycteridae)

Phylogenetic position of Trichomycterus astromycterus (Siluriformes: Trichomycteridae), an enigmatic trichomycterid from eastern Brazil, inferred from molecular data

“…The phylogenetic analysis comprised taxa and sequences used by Costa et al . (2021a), with the addition of sequences for T. astromycterus (GenBank accession numbers: OK652453, OK652448 and OK652451) and T. alternatus (GenBank accession numbers: OK652452, OK652449 and OK652450). The phylogenetic analysis thus comprised 64 species of all trichomycterine lineages, including B. maldonadoi and close relatives, and 5 outgroups ( Nematogenys inermis Guichenot 1848; Trichogenes longipinnis Britiski & Ortega, 1983; Copionodon pecten de Pinna, 1992; Microcambeva ribeirae Costa, Lima & Bizerril, 2004; Listrura tetraradiata Landim & Costa, 2002) (Figure 1).…”

“…The Trichomycterinae is the most diverse subfamily of the Neotropical catfish family Trichomycteridae, comprising over 250 valid species that occur in most freshwater habitats of South America (Costa et al ., 2021a). Nonetheless, monophyly and intra‐subfamilial relationships have been established only in recent years, after the inclusion of molecular data in phylogenetic analyses (Costa et al ., 2021a; Fernandez et al ., 2021; Katz et al ., 2018; Ochoa et al ., 2017, 2020). On the contrary, numerous trichomycterine taxa still have their phylogenetic position uncertain, and some others have been incorrectly placed due to a weak classification at the genus level and uncertainty of generic boundaries (Costa et al ., 2021b).…”

“…The Trichomycterinae is the most diverse subfamily of the Neotropical catfish family Trichomycteridae, comprising over 250 valid species that occur in most freshwater habitats of South America (Costa et al ., 2021a). Nonetheless, monophyly and intra‐subfamilial relationships have been established only in recent years, after the inclusion of molecular data in phylogenetic analyses (Costa et al ., 2021a; Fernandez et al ., 2021; Katz et al ., 2018; Ochoa et al ., 2017, 2020).…”

“…DNA extraction, amplification and sequencing followed Costa et al . (2021a). The analyses included a set of partial sequences of two nuclear genes, recombination activating 2 (RAG2) and myosin heavy chain 6 (MYH6), and partial sequences of two mitochondrial encoded genes: cytochrome b (CYTB) and cytochrome oxidase subunit I (COI).…”

“…alternatus, but also present in T. astromycterus comprised a long autopalatine posterolateral process, its length nearly equal to or slightly longer than the autopalatine longitudinal length excluding the postero-lateral process, a slightly folded maxilla and the anterior cranial fontanel represented by a minute aperture. Among these three character states, a long postero-lateral process of the autopalatine was independently acquired in the genera Bullockia and Hatcheria (Costa et al, 2021a(Costa et al, , 2021b. In addition, Costa (2021) noted that some species of this group also have protruding eyes and have psammophilic habits, found deeply buried in or over sand banks, like those reported for T. astromycterus by Reis et al Copionodon pecten de Pinna, 1992; Microcambeva ribeirae Costa, Lima & Bizerril, 2004;Listrura tetraradiata Landim & Costa, 2002) (Figure 1).…”