Tetragonopterinae

Mirande, Juan Marcos, 2010, Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy, Neotropical Ichthyology 8 (3), pp. 385-568 : 500-501

Node 224: Tetragonopterinae (-9 / 69 / – / 4)

Genera Bario Myers , Brachychalcinus Boulenger , Deuterodon , Gymnocorymbus , Hasemania Ellis , Hemigrammus Gill , Hyphessobrycon Durbin , Jupiaba , Moenkhausia , Myxiops ?, Paracheirodon , Orthospinus Reis , Petitella Géry & Boutière ?, Poptella Eigenmann , Pristella Eigenmann , Probolodus , Stethaprion Cope , Stichonodon Eigenmann , Tetragonopterus , and Thayeria .

The subfamily Tetragonopterinae was the most diverse among the Characidae under the classical systematics of the family ( e. g. Géry, 1977). Reis (2003b) later restricted this subfamily to the genus Tetragonopterus due to the lack of presumably apomorphic features shared by its members. In that classification, most tetragonopterines were classified as incertae sedis within Characidae ( Lima et al., 2003). Both in the phylogeny by Mirande (2009) as in the present study Tetragonopterus argenteus is the sister group of the Stethaprioninae . In the phylogeny of Mirande (2009) the Tetragonopterinae and Stethaprioninae form a monophyletic unit which is the sister group of a large clade of characids. In that hypothesis both subfamilies were valid and Hemigrammus , along with several other genera, formed the Hemigrammus clade. In the phylogenetic hypothesis herein obtained both the Stethaprioninae and Tetragonopterinae are nested in a large clade composed additionally by the members of the Hemigrammus clade of Mirande (2009). This monophyletic assemblage is named Tetragonopterinae , which has precedence over Stethaprioninae . This clade includes also the type-species of the highly diverse genera Hemigrammus and Moenkhausia , and presumably also Hyphessobrycon . Weitzman & Palmer (1997) and Weitzman & Malabarba (1998) discussed the possible polyphyly of Hyphessobrycon , and the paraphyly of Hemigrammus . This analysis corroborates their findings that a phylogenetic classification of Hemigrammus and Hyphessobrycon would result in generic reassignments of many species currently in those genera. Probably the same statement is applicable to Moenkhausia . Petitella (not analyzed herein) shares with Hemigrammus bleheri a presumably apomorphic coloration, with an intensely red head and the presence of three conspicuous black bars in the caudal fin. Indeed, Petitella georgiae Géry & Boutière is mainly distinguished from Hemigrammus bleheri as having only one row of premaxillary teeth ( vs. two rows). Thus, Petitella is tentatively included in this node. Myxiops , as discussed below, shares several presumably apomorphic features with Deuterodon and it is also tentatively included in this clade. Most internal clades of the Characidae are poorly supported, and this node is not an exception. The monophyly and composition of the Tetragonopterinae as herein defined, thus, should be further tested.

Synapomorphy:

1. Uroneurals (306): (0> 1) two pairs. Reversal of synapomorphy 15 of node 205. Paralleled in nodes 276 and 300 and in Bryconamericus scleroparius , Galeocharax humeralis , and Markiana nigripinnis . Reversed in node 288 and in Gymnocorymbus ternetzi and Jupiaba scologaster .