This species has been traded as ‘six-eyed tetra’ in reference to its colour pattern comprising two dark spots on each flank plus the eye.

Based on the extensive review of the genus by Lucena and Malabarba (2010), in which nine new species were described, P. tegatus can be told apart from congeners by the following combination of characters: lateral line incomplete with 8-13 perforated scales; laterally elongate humera…

This species is sometimes confused with unidentified fishes such as A. sp. ‘L352’.

It can be told apart from closely-related congeners by possession of relatively long maxillary barbels which are free from the lower lip, and a colour pattern consisting of small spots on the head and vermiform lines on the body in males, and small spots all over the head and body in females.