Key to Aphredoderus

1. Dorsal spines 3 (98% of specimens), scale rows above lateral line greater than 8 (90%).............................. 2

- Dorsal spines 4 (87%), scale rows above lateral line 8 or less (89%)............................................. 4

2. Postorbital length less than 15 % SL (96%)...................................................... A. mesotrema

- Postorbital Length>= 15 % SL (96%)..................................................................... 3

3. Orbit>= 86 % of interorbit length (84%), long bar or strongly blended blotches on caudal peduncle........ A. retrodorsalis

- Orbit <86 % of interorbit length (85%), 2 caudal blotches or chevrons.................................. A. gibbosus

4 Black stripe from caudal markings to belly of fish (100%)............................................. A. ornatus

- No black stripe on caudal peduncle (100%)......................................................... A. sayanus