Acestrorhamphidae, Eigenmann, 1907, 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 : 16-17

Acestrorhamphidae Eigenmann, 1907

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

Includedsubfamilies: Acestrorhamphinae , Grundulinae , Hyphessobryconinae , Jupiabinae , Megalamphodinae, Oxybryconinae, Pristellinae, Rhoadsiinae , Stethaprioninae, Stichonodontinae, Stygichthyinae, Thayeriinae, Trochilocharacinae, Tyttobryconinae , and an unnamed subfamily.

Definition: The least inclusive crown clade that contains Oligosarcus argenteus Günther, 1864 , Grundulus bogotensis (Humboldt, 1821) , Rhoadsia altipinna Fowler, 1911 , Ŋayeria obliqua Eigenmann, 1908 , Hyphessobrycon compressus (Meek, 1904) , Tytobrycon xeruini Géry, 1973 , Jupiaba poranga Zanata, 1997 , Pristella maxillaris (Ulrey, 1894) , Stethaprion erythrops Cope, 1870 , Stichonodon insignis ( Steindachner, 1876) , Megalamphodus megalopterus Eigenmann, 1915 , Stygichthys typhlops Brittan and Böhlke, 1965 , Trochilocharax ornatus Zarske, 2010 , and Oxybrycon paroulus Géry, 1964 . This is a minimum-crown-clade definition. See Figures 5–7 for a reference phylogeny of Acestrorhamphidae .

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

Remarks: The presence of a very large metacentric pair of chromosomes, at least two times bigger than the second chromosome pair, is a putative synapomorphy for Acestrorhamphidae (Sánchez-Romero et al. 2015). Studying Rhoadsia altipinna, Sánchez-Romero et al. (2015) discovered 2n = 50 chromosomes with the first pair being very large metacentric chromosomes that are at least twice as large as the second pair. The authors concluded, based on all available cytogenetic information for characids, that this large pair 1 is present in all karyotyped Clade C species but not in any other karyotyped characid species. The large metacentric pair is present in more than 100 species of Acestrorhamphidae and absent in more than 50 species of Stevardiidae and Characidae s.s. (Sánchez-Romero et al. 2015). We hypothesize that this large first chromosome pair represents a derived condition and is, therefore, synapomorphic for Acestrorhamphidae.

Three additional synapomorphies of Acestrorhamphidae include: interrupted lateral line, three or fewer maxillary teeth, and three or four unbranched rays articulating with first dorsal fin pterygiophore ( Mirande 2019). Additionally, the majority of species of Acestrorhamphidae have two rows of premaxillary teeth with typically five teeth in the inner row, nine branched dorsal-fin rays, and anterior branch of laterosensory canal of sixth infraorbital absent, but recognized that ‘the huge diversity of this clade precludes any diagnosis based on exclusive characters, but the combination of these three characters with the listed synapomorphies should be useful to recognize a species of this subfamily’ ( Mirande 2019).

Phylogenetic studies using Sanger-sequenced mitochondrial and nuclear genes (Javonillo et al. 2010, Oliveira et al. 2011, Mariguela et al. 2013, Melo et al. 2016), total evidence analyses ( Mirande 2019), and analysis of phylogenomic datasets ( Arcila et al. 2017, Betancur-R et al. 2019, Melo et al. 2022a; present study) resolve Acestrorhamphidae as a monophyletic group. Acestrorhamphidae has been labelled as ‘clade C’ or ‘Stethaprioninae’ in previous phylogenetic studies (Javonillo et al. 2010, Oliveira et al. 2011, Mirande 2019). The name Stethaprioninae was proposed by Eigenmann (1907) in a paper published in December of that year,while Eigenmann et al.(1907) published the name Acestrorhamphinae in July of 1907 ( Van der Laan et al. 2014). Thus, we recognize Acestrorhamphidae as a valid family-group name, with Acestrorhamphus Eigenmann and Kennedy (1903) (= Oligosarcus ) as the type genus.

Given the species-richness and the phylogenetic relationships presented in Figures 5–7 , we classify species of Acestrorhamphidae among 15 subfamilies. Several genera, including Astyanax , Hemigrammus , Hyphessobrycon , Jupiaba , and Moenkhausia , have long been resolved as polyphyletic ( Oliveira et al. 2011, Mirande 2019, Melo et al. 2022a), a result corroborated in the UCE phylogeny ( Figs 5–7 ). Future revisionary work on the taxonomy of Acestrorhamphidae will require the study of a higher number of species to establish monophyletic genera, which is beyond the scope of this study.

Figures

Figure 5. Phylogeny of Acestrorhamphidae and subfamilies Oxybryconinae, Trochilocharacinae, Stygichthyinae, Megalamphodinae, and Stichonodontinae based on 1348 nuclear loci of ultraconserved elements (538 472 bp). Numbers near nodes represent bootstrap support.

Figure 6. Phylogeny of Acestrorhamphidae and subfamilies Stethaprioninae, Pristellinae, Jupiabinae, Tyưobryconinae, and Hyphessobryconinae based on 1348 nuclear loci of ultraconserved elements (538 472 bp). Numbers near nodes represent bootstrap support.

Figure 7. Phylogeny of Acestrorhamphidae and subfamilies Thayeriinae, Rhoadsiinae, Grundulinae, and Acestrorhamphinae based on 1348 nuclear loci of ultraconserved elements (538 472 bp). Numbers near nodes represent bootstrap support.