Trochilocharacinae Zarske, 2010

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 : 17

Trochilocharacinae Zarske, 2010 , new usage

Type genus: Trochilocharax Zarske, 2010 .

Included genus: Trochilocharax .

Etymology: From the ancient Greek τΡοΧιλία (tɹo͡ʊkˈɪliə) meaning a pulley and ΧάΡαξ (kˈɑː͡ɹɹaeks) as a name for species of Sparidae that exhibit teeth on the oral jaws ( Thompson 1947: 284–5).

Remarks: The genus and species Trochilocharax ornatus were described based on aquarium specimens from Peru (Zarske 2010). Trochilocharax ornatus is a very distinctive characid due to its small size (maximum reported length: 17 mm standard lenght), absence of body scales (except for a pouch scale in the caudal fin of males), and highly pronounced sexual dimorphism, which includes the presence of numerous extraoral conical teeth on the premaxillary and dentary in males (Zarske 2010). Morphological comparisons between Trochilocharax and several genera of Stevardiinae (Tytocharax, Argopleura , Xenurobrycon , Iotabrycon , Scopaeocharax , Ptychocharax , and Chrysobrycon ) led to the classification of Trochilocharax ornatus as the only species in the tribe Trochilocharacini within Stevardiinae (Zarske 2010) . Among characiforms, the presence of a pouch scale is unique to some genera of Stevardiidae , and the presence of extraoral conical teeth in mature males is unique to species of Tytocharax. The UCE phylogeny demonstrates that Trochilocharax is a deeply branching monotypic lineage that is resolved as the sister-group of a clade that contains Stygichthyinae, Megalamphodinae, Stichonodontinae, an unnamed subfamily, Stethaprioninae, Pristellinae, Jupiabinae, Tyttobryconinae, Hyphessobryconinae, Thayeriinae , Rhoadsiinae , Grundulinae, and Acestrorhamphinae ( Figs 5–7). Based on the resolution of the UCE phylogeny, we elevate Trochilocharacini to the subfamily-level Trochilocharacinae to include Trochilocharax ( Fig. 5). Trochilocharax ornatus and Oxybrycon paroulus are both endemic to the Amazon basin ( Fig. 5), suggesting that Amazonia might have been the location of the initial diversification of the species and lineages that comprise Acestrorhamphidae .