Gymnocharacinae, Eigenmann, 1909

Mirande, Juan Marcos, 2010, Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy, Neotropical Ichthyology 8 (3), pp. 385-568 : 521

Node 281: Gymnocharacinae (37 / 91 / 9 / 4)

Genera Coptobrycon , Grundulus Valenciennes , Gymnocharacinus Steindachner , and Nematobrycon .

The subfamily Gymnocharacinae was proposed by Eigenmann (1910) as containing only Gymnocharacinus bergii . This group was maintained by Géry (1977) as the tribe Gymnocharacini ; that author ( Géry, 1977: 535) mentioned that this species could be related with some “generalized Hemibrycon -like tetragonopterine”. Miquelarena & Arámburu (1983) listed 22 characters distinguishing Gymnocharacinus bergii from the remaining Tetragonopterinae of Géry (1977). According to the present hypothesis some of those characters are synapomorphies of this clade. Miquelarena & Arámburu (1983) justified the validity of the monotypic subfamily Gymnocharacinae based on the mentioned list of characters. However, the number of synapomorphies itself is not an appropriate basis to assign a group a particular nomenclatural category. Such decision requires an underlying phylogenetic hypothesis. In the present analysis this clade also includes Coptobrycon bilineatus , Grundulus cochae , and Nematobrycon palmeri . A close relationship between these four species was not previously proposed. Mirande (2009) proposed the Gymnocharacinae to be composed of Coptobrycon , Grundulus , and Gymnocharacinus , leaving Nematobrycon in the monotypic Nematobrycon clade. The monophyly of this clade was obtained in the analyses under self-weighted optimization by Mirande (2009) and in the final hypothesis herein proposed. Although this node is relatively less stable than that of the Gymnocharacinae of Mirande (2009), it is herein preferred to redefine this subfamily to include also Nematobrycon . Among the genera included in this node, Coptobrycon and Gymnocharacinus are monotypic, while both Grundulus and Nematobrycon are composed of few species that greatly resemble each other and which are much different from the remaining Characidae . Although the monophyly of Grundulus and Nematobrycon were not proposed in terms of shared synapomorphies, these genera are treated as monophyletic in this paper. The disjunct geographic distribution of the genera included in this clade is noteworthy. The species of Grundulus and Nematobrycon inhabit northwestern South America, Coptobrycon bilineatus lives in the upper basin of the río Paraná, in eastern Brazil, and Gymnocharacinus bergii is the most austral member of the family Characidae , inhabiting the Argentine province of rio Negro in the northeastern Patagonia. Given the present state of knowledge it is premature to advance conclusions about the biogeography of this subfamily.

Synapomorphies:

1. Denticles on gill rakers (201): (0> 1) absent. Paralleled in nodes 245 and 253 and in Axelrodia lindeae and Pseudochalceus kyburzi . Some trees: Paralleled in Hyphessobrycon elachys and H. herbertaxelrodi .

2. Bony hooks on fin rays (307): (1> 0) absent. Paralleled in nodes 207, 283, 297, and 301 and in Astyanax paris , Bryconamericus mennii , Exodon paradoxus , Inpaichthys kerri , Pseudochalceus kyburzi , and Rhoadsia altipinna . Some trees: Paralleled in Hasemania nana and Hyphessobrycon elachys .

3. Adipose fin (356): (0> 1) absent. Paralleled in node 181 and in Carnegiella strigata and Phenagoniates macrolepis .