The phylogenetic placement of Hollandichthys Eigenmann 1909 (Teleostei: Characidae) and related genera

Abstract

The phylogenetic relationships among characids are complex with many genera remaining of uncertain systematic position inside the family. The genus Hollandichthys is one of these problematic genera. It has been considered as incertae sedis inside this family until two recently published phylogenies, one morphological and one molecular, arrived at alternative hypothesizes as to the relationships of Hollandichthys with Pseudochalceus or Rachoviscus, respectively. In this paper, we infer the phylogenetic relations of these taxa based on five genes (three mitochondrial - COI, ND2 and 16S; and two nuclear - Sia and Trop), totaling up to 2719 bp. The 41 analyzed species in the Characidae include four incertae sedis characid taxa once hypothesized as related to Hollandichthys, but never analyzed in a single phylogeny (Rachoviscus, Pseudochalceus, Nematocharax and Hyphessobrycon uruguayensis). Here we propose Rachoviscus as the sister-group of Hollandichthys, grouped in the large clade C previously defined, along with the remaining incertae sedis taxa studied here. In addition, we support the evidence that insemination evolved independently at least three times in the Characidae.

A new species of the characid genus Hollandichthys Eigenmann from coastal rivers of southern Brazil (Teleostei: Characiformes) with a discussion on the diagnosis of the genus

“…It is hard to argue in favor of the old hypothesis (Schultz, 1966;Géry, 1972) of a close relationship of Hollandichthys to Pseudochalceus, reinforced by Mirande (2009Mirande ( , 2010, due to the absence of Rachoviscus species in Mirande's analyses and therefore the lack of a testable hypothesis of relationships among the three genera in those two papers. Hollandichthys is very similar to Pseudochalceus in the color pattern and in the almost fully toothed maxilla, but as pointed out by Thomaz et al (2010) this similarity seems to represent convergence or shared plesiomorphic traits.…”

“…Monophyly of Hollandichthys was demonstrated by Thomaz et al (2010: fig. 1), who found two well supported sister clades among fourteen samples of Hollandichthys in a Bayesian analysis with Sia, Trop, 16S, COI and ND2 genes.…”

“…The co-occurrence of the first pelvic-fin ray branched in Hollandichthys and some stevardiines seems to be homoplastic, since Glandulocauda and Mimagoniates are deeply nested with Clade A characids (Malabarba & Weitzman, 2003;Javonillo et al, 2010;Mirande, 2010;Oliveira et al, 2011) that excludes Hollandichthys and Rachoviscus. Although Hollandichthys possesses small scales & Weitzman, Deuterodon stigmaturus (Gomes) (Lucena & Lucena, 1992, Mimagoniates rheocharis Menezes & Weitzman, and Odontostoechus lethostigmus Gomes (Malabarba, 1998), the loricariid genus Epactionotus Reis & Schaefer (1998), and two monophyletic groups of loricariids of the genus Pareiorhaphis (Pereira & Reis, 2002 Thomaz et al, 2010), stream in Bertioga, São Paulo. UFRGS 11773, 5, 37.7-97.8 mm SL (includes the voucher TEC 897C; Thomaz et al, 2010), stream Taquarubu, São Sebastião, São Paulo.…”

“…Although Hollandichthys possesses small scales & Weitzman, Deuterodon stigmaturus (Gomes) (Lucena & Lucena, 1992, Mimagoniates rheocharis Menezes & Weitzman, and Odontostoechus lethostigmus Gomes (Malabarba, 1998), the loricariid genus Epactionotus Reis & Schaefer (1998), and two monophyletic groups of loricariids of the genus Pareiorhaphis (Pereira & Reis, 2002 Thomaz et al, 2010), stream in Bertioga, São Paulo. UFRGS 11773, 5, 37.7-97.8 mm SL (includes the voucher TEC 897C; Thomaz et al, 2010), stream Taquarubu, São Sebastião, São Paulo. UFRGS 11776, 13, 45.8-86.9 mm SL (includes the voucher TEC 909D; Thomaz et al, 2010), stream Toca do Boi, Parati, Rio de Janeiro.…”

“…However, posteriorly Mirande (2010) assigned Hollandichthys to a group named "Pseudochalceus clade" formed by Hollandichthys and Pseudochalceus and considered closely related to the Rhoadsiinae. Based on molecular data, both Javonillo et al (2010) and Thomaz et al (2010) hypothesized Hollandichthys as the sister-group of Rachoviscus Myers, instead of Pseudochalceus.…”