Potamotrygon amandae

Loboda, Thiago S., 2016, New records of two ocellated species of the genus Potamotrygon Garman, 1877 (Chondrichthyes: Myliobatiformes: Potamotrygonidae) for Paraguay and Bolivia., Ichthyological Contributions of PecesCriollos 45, pp. 1-8 : 5

Potamotrygon amandae . Morphometric data are given in Table 1 (except for NMW 50219).

According to Loboda & Carvalho (2013) and the specimens described here, P. amandae is distinguished from its congeners by the dorsal background predominantly dark gray or dark brown, ocelli, when present, composed of two colors with a whitish center surrounded by a gray, dark gray or black ring, ventral disc coloration predominantly gray or dark gray, greater spiracular length with mean around 10% DW, tail relatively long (mean of distance between cloaca and tip around 82% DW) and slender (width in basis around 11% DW), tail rows of pointed spines generally double.

As reported for P. motoro ( Loboda, 2010) , some specimens of P. amandae from the Amazon basin ( fig. 3 ) possess tubercles (pointed spines modified, see Brito & Deynat, 2004) in the rows of pointed spines on the tail and also on the margins of the disc.

Figures

fig. 3. Potamotrygon amandae AMNH 59876, 263 mm DW (disc width), from Guaporé river, Bolivia, in dorsal (A) and ventral (B) views