Most species of Pempheris have some dark markings on the dorsal fin, but this is either
restricted to a narrow anterior margin or is a distal blotch restricted to the first four or five segmented rays;
occasionally the dark margin and distal blotch occur in tandem (Table 2). Pempheris bexillon is unusual in having a
dorsal fin with a black, distal margin along its full length with the remainder of the fin yellow. Only one other
species, P. flavicycla Randall et al. 2013 from the Red Sea, northern Western Indian Ocean, and eastward to
Indonesia, has occasional specimens that have a dorsal-fin color approaching that of P. bexillon. The distal margin
of the dorsal can be black almost to the penultimate dorsal ray, but the remainder of the fin is not yellow (Randall et
al. 2013, figs. 3–4); in more typical specimens the dorsal fin has only a dark anterior margin and black distal blotch
on fin-rays 1–4 (Randall et al. 2013, figs. 5–9). In addition, when a dorsal-fin marginal band is present in P.
flavicycla, it is less sharply defined; the eye of this species also has a distinctive yellow iris ring around the pupil.
Meristic data are very similar between these two species.