Acestrorhamphinae Eigenmann 1907

Melo, Bruno F, Ota, Rafaela P, Benine, Ricardo C, Carvalho, Fernando R, Lima, Flavio C T, Mattox, George M T, Souza, Camila S, Faria, Tiago C, Reia, Lais, Roxo, Fabio F, Valdez-Moreno, Martha, Near, Thomas J & Oliveira, Claudio, 2024, Phylogenomics of Characidae, a hyper-diverse Neotropical freshwater fish lineage, with a phylogenetic classification including four families (Teleostei: Characiformes), Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 202 (1), pp. 1-37 : 29-30

Acestrorhamphinae Eigenmann 1907 , new usage

Type genus: Acestrorhamphus Eigenmann and Kennedy 1903 , junior synonym of Oligosarcus Günther 1864 .

Included genera: Andromakhe Terán et al., 2020 , Astyanax (in part), Ctenobrycon , Hyphessobrycon (in part), Oligosarcus , and Psalidodon (in part).

Definition: The least inclusive crown clade that contains Oligosarcus argenteus , Ctenobrycon olioerai Benine et al., 2010 and Psalidodon fasciatus (Cuvier, 1819) . This is a minimum-crown-clade definition. See Figure 7 for a reference phylogeny of Acestrorhamphinae .

Etymology: From the ancient Greek ἄκεστΡα (ˈɑːkɛstɹə) meaning a darning needle and ῥάμϕος (ɹˈaemfo͡ʊz) meaning curved beak.

Remarks: The subfamily Acestrorhamphinae is resolved as monophyletic in the UCE phylogeny and comprises four major lineages ( Fig. 7): Ctenobrycon , Astyanax , a clade containing Hyphessobrycon and Oligosarcus , and Psalidodon . There are modifications to the taxonomy for each of these lineages that are outlined below.

Ctenobrycon includes four species C. spilurus (Valenciennes, 1850) , C. olioerai , and two species transferred here: Ctenobrycon kennedyi (Eigenmann, 1903) (former Psellogrammus kennedyi ) and C. magdalenae (Eigenmann and Henn, 1916) (former Astyanax magdalenae ) ( Fig. 7). The taxonomic history starts with the description of Ctenobrycon with Tetragonopterus hauxwellianus Cope, 1870 as the type species based on the presence of ctenoid (= spinoid) scales in the pre-ventral region (Eigenmann 1908). The monotypic genus Psellogrammus , with Hemigrammus kennedyi Eigenmann, 1903 as type species, was described in the same study (Eigenmann 1908). Tetragonopterus spilurus Valenciennes, 1848 was transferred to Ctenobrycon (Eigenmann 1910) . A close relationship between Psellogrammus and Ctenobrycon was suggested based on shared

characteristics such as elongated anal fin, ctenoid scales, high body depth, maxilla not extending to the orbit, and absence of scales on the caudal fin (Eigenmann 1927). The hypothesized relationship between Psellogrammus and Ctenobrycon in pre-cladistic taxonomic studies was corroborated by molecular and combined molecular and morphological phylogenetic studies ( Oliveira et al. 2011, Betancur-R et al. 2019, Mirande 2019, Melo et al. 2022a). A phylogenetic analysis identified a ‘ Ctenobrycon clade’ supported by three morphological synapomorphies that included Ctenobrycon , Psellogrammus , Astyanax magdalenae , A. stilbe (Cope, 1870) , and A. atratoensis Eigenmann, 1907 ( Terán et al. 2020). In light of the present phylogenetic evidence and morphological similarities ( Oliveira et al. 2011, Betancur-R et al. 2019, Mirande 2019, Terán et al. 2020, Melo et al. 2022a), we transfer all species in the ‘ Ctenobrycon clade’ to Ctenobrycon , resulting in the new combinations Ctenobrycon magdalenae and Ctenobrycon kennedyi ( Table 1 ).

Astyanax as defined by Terán et al. (2020: 9) resolves as a lineage of Acestrorhamphinae in the UCE phylogeny ( Fig. 7). In addition, Moenkhausia pirauba Zanata et al., 2010 and Genycharax tarpon Eigenmann, 1912 resolve within Astyanax , thus resulting in Astyanax pirauba and Astyanax tarpon , new combinations ( Fig. 7; Table 1 ). The clade Astyanax is supported by two morphological synapomorphies, but A. tarpon and A. pirauba were not included in the morphological analysis ( Terán et al. 2020). This clade also contains A. metae Eigenmann, 1914 and A. oenezuelae Schultz, 1944 from the Orinoco, and a clade with widespread species such as A. bimaculatus (Linnaeus, 1758) and A. lacustris (Lütken, 1875) ( Fig. 7).

A monophyletic Oligosarcus is resolved as the sister-lineage of a clade containing two species of Hyphessobrycon : H. bifasciatus Ellis,1911 and H.igneus Miquelarena et al., 1980 in the UCE phylogeny ( Fig. 7), corroborating results from phylogenetic analyses of morphological and combined molecular and morphological datasets ( Ribeiro and Menezes 2015, Mirande 2019, Terán et al. 2020). The UCE phylogeny results show Hyphessobrycon bifasciatus and H. igneus as the sister-lineage of Oligosarcus ( Fig. 7). The two Hyphessobrycon species need reallocation to a different genus considering the morphological evidence supporting Oligosarcus ( Ribeiro and Menezes 2015) . Because the purpose of this study is not to describe new genera or species, we currently consider that the best decision is maintaining it in Hyphessobrycon until a further generic description and reallocation are published.

In the phylogeny inferred from the UCE loci, a monophyletic Psalidodon (sensu Terán et al. 2020) is resolved as a sister-lineage to the clade containing Hyphessobrycon and Oligosarcus ( Fig. 7). Psalidodon includes species previously classified in the genera Astyanax , Hasemania , Hyphessobrycon , and Moenkhausia ( Fig. 7). Terán et al. (2020) transferred many species of Astyanax to the genus Psalidodon , a clade supported with two morphological synapomorphies, and found monophyly of Andromakhe supported by 17 molecular synapomorphies. Andromakhe saguazu (Cascioưa et al., 2003) is resolved inside Psalidodon in our phylogeny ( Fig. 7). However, we treat Andromakhe as valid as the type species of the genus, A. latens (Mirande et al., 2004) , was not included in our UCE dataset. However, considering the phylogenetic position of A. saguazu, we transfer this species to

Psalidodon, as Psalidodon saguazu, new combination (Table 1). Other species are herein transferred to Psalidodon under the new combinations Psalidodon alleni (Eigenmann and McAtee, 1907) , Psalidodon balbus ( Myers, 1927) , Psalidodon biotae (Castro and Vari, 2004) , Psalidodon cremnobates (Bertaco and Malabarba, 2001) , Psalidodon dissimilis (Garavello and Sampaio, 2010) , Psalidodon goyacensis (Eigenmann, 1908) , Psalidodon hamatus (Bertaco and Malabarba, 2005) , Psalidodon henseli (de Melo and Buckup, 2006) , Psalidodon kalunga (Bertaco and Carvalho, 2010) , Psalidodon laticeps (Cope, 1894) , Psalidodon minor (Garavello and Sampaio, 2010) , Psalidodon scabripinnis (Jenyns, 1842) , Psalidodon serratus (Garavello and Sampaio, 2010) , Psalidodon togoi (Miquelarena and López, 2006) , Psalidodon oarzeae (Abilhoa and Duboc, 2007) , Psalidodon oermilion (Zanata and Camelier, 2009) , Psalidodon uaiso (Carvalho and Langeani, 2013) , and Psalidodon uberaba (Serra and Langeani, 2015) ( Fig. 7; Table 1 ). Some of these species were originally assigned to other genera based on morphological features, such as the lack of an adipose fin (e.g. Hasemania kalunga and H. uberaba ) or incomplete lateral line (e.g. Hyphessobrycon balbus and H. uaiso ). However, based on the resolution of these species in the UCE phylogeny ( Fig. 7), we hypothesize that these features are homoplastic.