Megalamphodinae Carvalho, Lima & Melo

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 : 21-22

Megalamphodinae Carvalho, Lima & Melo , new subfamilp

ZooBank: urn:lsid:zoobank.org:act:5366C168-9D5A-4C10-83BC-1CC92D99A05A .

Type genus: Megalamphodus Eigenmann, 1915 .

Included genera: Axelrodia, Britanichthys Géry, 1965, Hemigrammus (in part), Makunaima Terán et al., 2020,

Megalamphodus , Paracheirodon Géry, 1960 , and Petitella Géry and Boutière, 1964.

Definition: The least inclusive crown clade that contains Megalamphodus megalopterus and Hemigrammus stictus (Durbin, 1909) . This is a minimum-crown-clade definition. See Figure 5 for a reference phylogeny of Megalamphodinae.

Etymology: From the ancient Greek μεγαλάμϕοδος (mˌɛɡəlɐmfˈo͡ʊdo͡ʊz) meaning with spacious ways.

Remarks: Megalamphodinae are presented as a new subfamily that includes three major clades: a lineage comprising Axelrodia stigmatias Fowler, 1913 (type species of the genus), Petitella georgiae Géry and Boutière, 1964 (type species of the genus), P. bleheri Géry and Mahnert, 1986 , Hemigrammus stictus (Durbin, 1909) , Britanichthys axelrodi Géry, 1965 , three species of Paracheirodon , species of Makunaima , and species of Megalamphodus ( Fig. 5 ). Hemigrammus stictus is a new and undescribed genus from Amazon–Orinoco–Guianas (Melo et al. in prep.). The genus Makunaima was described to include the species M. guaporensis (Eigenmann, 1911) , M. guianensis (Eigenmann, 1909) , and M. multidens (Eigenmann, 1908) ( Terán et al. 2020) . The UCE phylogeny supports Makunaima as monophyletic and includes two additional species, Makunaima pitieri (Eigenmann, 1920) new combination, and probably an undescribed species from the Tapajós ( Fig. 5 ; Table 1).

Megalamphodus was described by Eigenmann (1915) and classified in Cheirodontinae , based on the presence of a single tooth row in the premaxilla. Species subsequently added to Megalamphodus include M. uruguayensis Fowler, 1943 , M. roseus Géry, 1960 , and M. sweglesi Géry, 1961 . Géry (1977) considered Megalamphodus as belonging to the ‘ Pristella- group’, together with Pristella Eigenmann, 1908 . However, Weitzman and Palmer (1997) noticed that large specimens of Megalamphodus megalopterus , the type species of Megalamphodus , possess two premaxillary tooth rows, and considered Megalamphodus a junior synonym of Hyphessobrycon .

The present phylogeny supports part of the monophyletic group of rosy tetras (sensu Weitzman and Palmer 1997); thus, we revalidate Megalamphodus to accommodate these species (Table 1), namely: M. bentosi (Durbin, 1908) (former Hyphessobrycon bentosi ), M. copelandi (Durbin in Eigenmann, 1908) (former Hyphessobrycon copelandi ), M. epicharis (Weitzman and Palmer, 1997) (former Hyphessobrycon epicharis ), M.eques (Steindachner, 1882) (former Hyphessobrycon eques ), M. erythrostigma (Fowler, 1943) (former Hyphessobrycon erythrostigma ), M. haraldschultzi (Travassos, 1960) (former Hyphessobrycon haraldschultzi ), M. khardinae (Zarske, 2008) (former Hyphessobrycon khardinae ), M. megalopterus (former Hyphessobrycon megalopterus , type species), M. micropterus Eigenmann, 1915 (former Hyphessobrycon micropterus ), M. socolofi (Weitzman, 1977) (former Hyphessobrycon socolofi ), M. sweglesi (former Hyphessobrycon sweglesi ), and two possibly new species: Megalamphodus cf. rosaceus and Megalamphodus sp. Leticia ( Fig. 5 ; Table 1).

Species of Megalamphodus have been included in molecular and morphological phylogenetic analyses and the resolution of M. megalopterus in the ‘rosy tetra clade’ justifies the resurrection of Megalamphodus as a valid genus (Javonillo et al. 2010, Oliveira et al. 2011, Mirande 2019).

The relationships among lineages of

Megalamphodinae have been investigated with morphological and phylogenomic datasets ( Terán et al. 2020, Melo et al. 2022a). A feature shared by the majority of species of Megalamphodinae is the presence of red, reddish, or reddish brown pigmentation over most or entire bodies. Megalamphodus can be diagnosed by the presence of a conspicuous black blotch on the dorsal fin. Most species of Megalamphodinae are distributed in cis-Andean northern South America ( Fig. 5 ), and many are popular in the ornamental fish trade as, for example, Axelrodia stigmatias , M. bentosi , M. eques , M. erythrostigma , M. sweglesi , Paracheirodon , and Petitella .

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.