Expanded description of Dolops bidentata (Bouvier, 1899) (Branchiura: Argulidae) based on specimens collected on Pygocentrus nattereri Kner, 1858 (Characiformes) from Poconé Wetland, MT, Brazil

Abstract

The current information on the branchiuran Dolops bidentata, a species described more one hundred years ago, is valid but incomplete; hence, an expanded description is given herein. Additional morphological information was obtained by light and scanning electron microscopy from specimens collected on Pygocentrus nattereri from the Poconé Wetland, MT, Brazil. Description of the appendages and other structures such as respiratory area, mouth, details and ornamentation of antennules and maxillae are provided for the first time.

Phylogenetic position of Dolops bidentata (Ichthyostraca: Argulidae) based on molecular data: first record of the genus in Mexico

“…Morphologically, the material collected in Mexico resembles the original description of the species by Bouvier (1899a, b), whereas major differences were found in comparison with the specimens described by Silva-Souza et al (2011). Based on this, we assign our specimens to D. bidentata, whereas the material from Brazil probably corresponds to a different species.…”

“…(Bouvier, 1899a); Astronotus ocellatus, Prochilodus nigricans, Rhytiodus microlepis, and Piaractus brachypomus (Malta, 1982(Malta, . 1984; Pygocentrus nattereri (Silva-Souza et al, 2011); Schizodon fasciatus, Serrasalmus maculatus, and Serrasalmus marginatus (Fontana et al, 2012); Centropomus undecimalis (present study).…”

“…The presence of 2 teeth at the base of second maxillae is the distinctive feature of D. bidentata and is clearly described in the original description (Bouvier, 1899a), as well as in the expanded description of the species (Bouvier, 1899b). This feature is also present in the specimens studied here collected in Mexico as well as in the specimens collected in the state of Mato Grosso, Brazil, parasitizing the red piranha that were used for the redescription of the species by Silva-Souza et al (2011). Interestingly, other than this conspicuous feature, specimens form Mato Grosso display morphological characters clearly divergent from those described in the original description and those found on the specimens from Mexico.…”

“…One of the main differences between the specimens from Mato Grosso described by Silva-Souza et al (2011) in comparison with the specimens from Mexico is the shape, size, and arrangement of the respiratory areas. In the specimens from Mato Grosso, internal respiratory areas are small and oval and external respiratory areas large and fusiform with an indentation on the internal side in the posterior part; internal and external areas are well separated from each other.…”