Phylogenomic analyses in the complex Neotropical subfamily Corydoradinae (Siluriformes: Callichthyidae) with a new classification based on morphological and molecular data
Angelica C Dias, Luiz F C Tencatt, Fabio F Roxo, Gabriel de Souza da Costa Silva, Sérgio A Santos, Marcelo R Britto, Martin I Taylor, Claudio Oliveira
Zoological Journal of the Linnean Society, zlae053, https://doi.org/10.1093/zoolinnean/zlae053
Published: 11 June 2024
The family Callichthyidae, which comprises the subfamilies Corydoradinae and Callichthyinae, represents one of the largest families within the Siluriformes. Corydoradinae, the largest subfamily of Callichthyidae, alone accounts for >200 valid species, with new species being described frequently. This subfamily holds significant popularity among catfish enthusiasts worldwide, mainly because Corydoras are small, peaceful, and colourful fishes. Recognizing the existence of polyphyletic groups within Corydoradinae, the aim of this study was to construct a new phylogenetic hypothesis using genomic data (ultraconserved elements) and to re-evaluate the synonymized genera using the most recent morphological data. Our results supported the monophyly of Corydoradinae and identified seven distinct groups of species, each one with an associated pre-available generic name. These genera, namely Corydoras, Aspidoras, Scleromystax, Gastrodermus (resurrected), Osteogaster (resurrected), Brochis (resurrected), and Hoplisoma (resurrected), were all validated based on evidence derived from molecular and morphological analyses. A taxonomic key for the Corydoradinae genera is provided.
Classification breakdown supplied by "Fish in the news"
From the paper - "Our results corroborate the hypothesis of monophyly of 𝑆𝑐𝑙𝑒𝑟𝑜𝑚𝑦𝑠𝑡𝑎𝑥 proposed by Brito (2003) and Alexandrou et al. (2011), who named this assemblage lineage 3. All topologies demonstrate that 𝐶. 𝑙𝑎𝑐𝑒𝑟𝑑𝑎𝑖 belongs to this group and is the sister of all species in this genus. Specimens of 𝐶𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠 𝑙𝑎𝑐𝑒𝑟𝑑𝑎𝑖 were known only from its type series at the time of the studies by Reis (1998) and Brito (2003), and were not available in the original collections in the same period (Hieronimus 1995). Sampling efforts by some authors of the present paper (C.O. and M.R.B.) at the putative type locality resulted in a relatively large number of specimens that allowed examination of characters that recovered 𝐶𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠 𝑙𝑎𝑐𝑒𝑟𝑑𝑎𝑖 in 𝑆𝑐𝑙𝑒𝑟𝑜𝑚𝑦𝑠𝑡𝑎𝑥, and herein we propose them combination 𝑆𝑐𝑙𝑒𝑟𝑜𝑚𝑦𝑠𝑡𝑎𝑥 𝑙𝑎𝑐𝑒𝑟𝑑𝑎𝑖. This combination appeared for the first time in the study by Fuller and Evers (2005: 272), although without any information to justify it."
From the paper - "𝑀𝑖𝑐𝑟𝑜𝑐𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠 was proposed by Myers (1953) as a subgenus of 𝐶𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠, having 𝐺. ℎ𝑎𝑠𝑡𝑎𝑡𝑢𝑠 as its type species. Despite our results showing that 𝐺. ℎ𝑎𝑠𝑡𝑎𝑡𝑢𝑠 and 𝐺. 𝑝𝑦𝑔𝑚𝑎𝑒𝑢𝑠 form a clade sister group to the remaining 𝐺𝑎𝑠𝑡𝑟𝑜𝑑𝑒𝑟𝑚𝑢𝑠, we opted to keep 𝑀𝑖𝑐𝑟𝑜𝑐𝑜𝑟𝑦𝑑𝑜𝑟𝑎𝑠 in the synonymy of 𝐺𝑎𝑠𝑡𝑟𝑜𝑑𝑒𝑟𝑚𝑢𝑠 because the only putative diagnostic feature between these two genera would be the serration pattern on the posterior margin of the pectoral-fin spine."
From the paper - "Our results revealed the putative existence of two species of 𝐵𝑟𝑜𝑐ℎ𝑖𝑠 𝑠𝑝𝑙𝑒𝑛𝑑𝑒𝑛𝑠 (Castelnau, 1855): one from Peru (𝐵. 𝑠𝑝𝑙𝑒𝑛𝑑𝑒𝑛𝑠, voucher 87580, LBP 22528) and other from Paraguay River Basin (𝐵. 𝑎𝑓𝑓. 𝑠𝑝𝑙𝑒𝑛𝑑𝑒𝑛𝑠, voucher 41751, LBP 8503). 𝐵𝑟𝑜𝑐ℎ𝑖𝑠 𝑠𝑝𝑙𝑒𝑛𝑑𝑒𝑛𝑠 is described originally from Tocantins River, and there is an available name for species from Peru currently synonymized to 𝐵. 𝑠𝑝𝑙𝑒𝑛𝑑𝑒𝑛𝑠, 𝐵𝑟𝑜𝑐ℎ𝑖𝑠 𝑐𝑜𝑒𝑟𝑢𝑙𝑒𝑢𝑠 (Cope, 1872), described from Ampiyacu river, the same river where the sample that we have in our analysis was collected."
