Serrapinnus aster Malabarba & Jerep 2014

Serrapinnus aster can be distinguished from all congeners except S. potiguar, by having scimitar-shaped ventral procurrent caudal-fin rays in mature males, almost all of which form a semicircle, resulting in a portion of the ventral procurrent caudal-fin rays having a multi-pointed partial star-shaped margin (vs. ventral procurrent caudal-fin rays rod-shaped or spatulate, usually parallel to each other, except for the anteriormost procurrent rays being inclined forward in some species). It differs from S. potiguar and congeners by having 7-9 cusps on the premaxillary teeth (vs. 5 cusps in S. microdon and S. potiguar, 9 -11 in S. lucindai, S. sterbai and S. tocantinensis and 10-12 in S. gracilis and S. littoris), incomplete lateral line (vs. complete in S. heterodon), dorsal fin hyaline (vs. with a proximal black blotch in S. notomelas), and the absence of a black spot on the posteroventral region of the abdomen (vs. presence in S. kriegi) (Ref. 96959).

Dorsal soft rays (total): 10 - 11; Analsoft rays: 19 - 22