Potamotrygon marquesi, a new species of neotropical freshwater stingray (Potamotrygonidae) from the Brazilian Amazon Basin

Abstract

Potamotrygon marquesi, sp. nov., is described and compared with other species of Potamotrygon occurring in the Amazon Basin. The identity of this new species is supported by an extensive external and internal morphological study including coloration pattern, squamation, skeleton and ventral lateral‐line canals. Morphometrics and meristics were used to further distinguish P. marquesi from congeners. Potamotrygon marquesi was first considered to fall within the range of variation found in P. motoro. However, even with an extensive variation in coloration observed in P. motoro, this new species presents a series of autapomorphies that confidently distinguishes it from what is understood as the morphological variation found in P. motoro. Additional morphological characters that diagnose P. marquesi include three angular cartilages, asymmetrical star‐shaped denticles, a single regular row of spines on tail dorsum, lateral row of caudal spines near the sting insertion, dorsal disc background in beige and grey mixed with shades of grey and bearing open and closed bicolored rings, among others. Although presenting a gap of distribution along the west–east extension of the Amazon Basin, its diagnostic charactistics are consistent in both recorded regions. Our study supports the need for many morphological characters to robustly distinguish members of Potamotrygoninae considering their extremely variable dorsal disc color pattern.

Injuries Caused by Freshwater Stingrays in the Western Amazon: Folk Medicine and Beliefs

“…They have approximately 38 species occurring in the major river systems of South America (Carvalho et al 2016;Cruz 2009;Fricke et al 2020;Garrone Neto and Haddad 2010). Three Potamotrygonidae species inhabit the Juruá River Basin, an important waterway in state of Acre: Paratrygon aiereba, Potamotrygon motoro, and Potamotrygon marquesi (Lasso et al 2013;Silva and Loboda 2019) (Figure 1).…”

Morphology and phylogenetic significance of the pelvic articular region in elasmobranchs (Chondrichthyes)

“…The pelvic girdle is clearly an underexplored morphological complex in a phylogenetic context, especially the pelvic articular region and the arrangement and number of foramina present, even though multiple studies involving its morphological and functional aspects (Daniel, 1934; Gilbert and Heath, 1972; Compagno, 1988, 1999; Shirai and Okamura, 1992; Goto et al., 1999; Lucifora and Vassalo, 2002; Macesic and Kajiura, 2010; Macesic and Summers, 2012; Maia et al., 2012; Macesic et al., 2013; Ekstrom and Kajiura, 2014; Shibuya et al., 2015; Trinajstic et al., 2015; Silva and Casas, 2020; Silva and Vaz, 2021) or its origin (Thatcher, 1877; Gegenbaur, 1878; Mivart, 1879; Balfour, 1881; Freitas et al., 2006; Cole and Currie, 2007; Dahn et al., 2007; Johanson, 2010; Nakamura et al., 2015; Onimaru et al., 2015; Gillis and Hall, 2016; Tulenko et al., 2016, 2017; Sleight and Gillis, 2020) are available across literature. Detailed descriptions of the pelvic girdle, when present, are often in conjunction with taxonomic works that do not propose morphological characters in a broader phylogenetic context (McEachran and Compagno, 1979; Dingerkus and Defino, 1983; Stehmann and Séret, 1983; Miyake, 1988; Séret, 1989; Compagno and Heemstra, 2007; Silva and Carvalho, 2011; Vaz and Carvalho, 2013; Fontenelle et al., 2014; Silva and Carvalho, 2015a; Vaz, 2015; Viana et al., 2016; Petean and Carvalho, 2018; Silva and Loboda, 2019).…”

Karyotypic variation of two populations of the small freshwater stingray Potamotrygon wallacei Carvalho, Rosa & Araújo 2016: A classical and molecular approach

“…The subfamily Potamotrygoninae is a group of South American stingray lineages of marine origin that comprises over 40 species restricted to freshwater environments [1][2][3][4][5][6][7]. Currently, four genera, Heliotrygon, Plesiotrygon, Paratrygon, and Potamotrygon are recognized for this subfamily [8,9], occurring in different South America river basins that flow into the Caribbean and Atlantic Sea [2,10].…”