Distinguishing this large group of small serranid fishes from other serranid subfamilies can be subtle and dorsal-fin spine and anal-fin soft-ray counts are often necessary. All of the regional serranines have ten dorsal-fin spines while, serendipitously, the other regional serranids have nine or fewer or eleven or more (except E. nigritus). In addition, the serranines (except for the deep-water anthiines) have seven anal-fin soft rays and non-serrated fin spines, while the remaining subfamilies of Serranidae have eight or more anal-fin soft rays and sometimes serrated fin spines. Some larval snappers (Lutjanidae) have a similar general appearance but have eight or more anal-fin soft rays (and a prominent preopercular spine). The larval grunts (Haemulidae) have twelve or more dorsal-fin spines, are generally narrower-bodied, and their third anal-fin spine is a segmented ray in the larval and early juvenile stages. There is certainly some overlap in body shape between the narrower-bodied serranines (such as Diplectrum) and the haemulids, in which case fin-ray characters are useful.
The deep-water anthiine serranines are sometimes raised to their own subfamily (Anthiinae) and they are the only serranines to have some species with a mode of eight anal-fin soft rays.
Dorsal-fin soft-ray counts separate the genera: There are several reef-associated Caribbean serranine genera, generally separating into two groups by dorsal-fin soft-ray counts: the numerous hamlets of Hypoplectrus with D-X,15 and the large genus of basslets of Serranus, typically with D-X,12. The deep-water serranines have 10 or 11 or 13-16.
Shallow-water Serranus species separate out slightly by modal pectoral fin-ray counts (but the ranges overlap extensively): a group with 14 comprising S. baldwini (13-15), S. tigrinus (14), and S. tortugarum (13-15); then S. tabacarius with 15 (sometimes 14); S. subligarius with 16 (14-17, a northern species), and S. flaviventris with 16 (or 17, a southern species). There are a number of deeper-water species as well that broadly overlap these counts: S. annularis with 13 (or 14), S. chionaraia with 14 (or 13), S. luciopercanus with 14, S. maytagi with 15-16, S. notospilus and S. phoebe with 15-16 (14-17) and S. atrobranchus with 16 (15-17).
The remaining shallow-water serranine genera have sometimes overlapping fin-ray counts with the Serranus- three Diplectrum species: D. bivittatum (X,12 Pect-15-16, occ. 14), D. formosum (X,12 Pect-16-17, up to 18), and D. radiale (X,12 Pect-16-18, mode 17, from the S. Caribbean); Paralabrax dewegeri (X,13-14 Pect-17); Serraniculus pumilio (X,10-11, Pect-14-15); and Schultzea beta (X,11-12 Pect-16).
Two deep-water serranines have fewer dorsal-fin soft rays than the others: Parasphyraenops atrimanus (X,10 III,6 Pect-17) and P. incisus (X,10 III,7 Pect-17). The Centropristis species, from more temperate US waters only, also can have fewer, with 11 (one with 12) dorsal-fin soft rays and A-III,7 and comprise C. fuscula (with D-X,12), C. ocyurus (Pect-17), C. philadelphica (Pect-18), and C. striata (Pect 16-19).
The remaining deep-water taxa tend to have 13 or more dorsal-fin soft rays and include Bullsichthys caribbaeus (X,13-14 III,7 Pect-14-15) and the anthiines. Anthiines comprise four Anthias species, all with D-X,14-15 Pect-18-21: i.e. Anthias tenuis (III,8), A. nicholsi (III,7), A. woodsi (X,14, III,7), and A. asperilinguis (X,15, III,7); Hemanthias vivanus (X,14, III,8 Pect-18-19), H. aureorubens (X,13-16,usually 15, III,8 Pect-16-17), and H. leptus (X,14 III,8); Pronotogrammus martinicensis (X,15 (13-16) III,7-8, Pect-16-18), and, finally, Plectranthias garrupellus with the unusual fin-ray count of X,16 III,7 and Pect-13. Note that some of these latter species with eight anal-fin rays have identical fin-ray counts to some lutjanid snappers.
