Genetic evidence for a species complex within the piranha Serrasalmus maculatus (Characiformes, Serrasalmidae) from three Neotropical river basins based on mitochondrial DNA sequences

Abstract

Mitochondrial molecular markers (DNA sequences of D-loop, cytochrome b and cytochrome c oxidase I) were employed to characterize populations of the piranha Serrasalmus maculatus from Upper Paraná, Upper Paraguay and Tocantins River basins. D-loop sequences of S. maculatus population from Paraná-Paraguay River basin exhibited tandem repeats of short motifs (12 base pairs) and variable numbers depending on specimens, accounting for length variation. Concatenated mitochondrial sequences suggested that S. maculatus encompasses different mitochondrial DNA lineages. Although sampling was restricted to three river basins, phylogenetic analysis clearly indicated that the species currently recognized as S. maculatus presents high genetic variability. Maximum likelihood and Bayesian analysis clustered S. maculatus populations according to their locations. However, the highest genetic differentiation was identified between populations from Paraná-Paraguay system and Tocantins River basin. Three species delimitation analyses (PTP, GMYC, and ABGD) suggested that there are at least two species among the analyzed populations. The analysis of the mitochondrial sequences evidenced genetic differentiation among populations corresponding to related, but different species, suggesting that at least S. maculatus from the Tocantins River and Paraná-Paraguay River basins are most likely different species. Therefore, S. maculatus should be considered a species complex with morphologically cryptic diversity. An integrative revision is suggested.

Comparative cytogenetics of Serrasalmidae (Teleostei: Characiformes): The relationship between chromosomal evolution and molecular phylogenies

“…Two new species were recently described using the same marker, Catoprion absconditus Mateussi, Melo & Oliveira 2020 and Myloplus nigrolineatus Ota, Machado, Andrade, Collins, Farias & Hrbek 2020 [ 6 , 7 ]. In the basins of the Paraná-Paraguay and Tocantins rivers, a species complex was detected in Serrasalmus maculatus Kner 1858 [ 22 ] and five lineages were recognized in Pygocentrus nattereri Kner 1858 in different river basins [ 23 ]. This underestimation of diversity is a consequence of the difficulty in identifying many species and their intra- and interspecific limits, due to the variation in body shape, sexual dimorphism, ontogeny [ 1 , 4 , 7 , 24 ], and water color in Amazon basin [ 7 , 25 ].…”

Acoustic homogeneity in the piranha Serrasalmus maculatus

“…Within the taxa, Serrasalmus and Pygocentrus species produce low‐frequency harmonic sounds (Kastberger, 1981; Markl, 1971; Mélotte et al ., 2016, 2019; Raick et al ., 2020; Rountree & Juanes, 2020) that are thought to be species‐specific (Mélotte et al ., 2016; Raick et al ., 2020; Rountree & Juanes, 2020). Serrasalmus maculatus Kner, 1858 is found in the Amazon, Paraná‐Paraguay‐Uruguay and Tocantins Rivers basins (Bignotto et al ., 2020; Jégu, 2003; Zaniboni et al ., 2004). The watersheds of the Amazon and Paraná Rivers are separated by the Azimuth 125° lineament (Ribeiro et al ., 2018).…”

“…However, sporadic contacts between both basins may occur, for example in Mato Grosso where the Aguapehy River (Paraná‐Paraguay‐Uruguay basin) and the Alegre River (Amazon basin) are separated by a distance of only 1 km (Soldano, 1947). The wide geographic distribution for a single species probably explains why it is a species with a high intraspecific genetic variability (Bignotto et al ., 2019, 2020). In addition, this species has been confused in the past with Serrasalmus spilopleura Kner, 1858 (Jégu & Dos Santos, 2001).…”