Key to species of Thorogobius

1a Nape and predorsal area completely or only laterally scaled.................................................... 2

1b Nape and predorsal area naked........................................................................... 3

2a Nape and predorsal area completely scaled and two dark patches at the bases of both dorsal fins; eastern Atlantic from Senegal to Angola .......................................................................... Thorogobius angolensis

2b Predorsal area scaled at sides, otherwise naked and no dark patches at the bases of both dorsal fins; eastern Atlantic from São Tomé and Príncipe to Angola .................................................... Thorogobius laureatus nov. sp.

3a Scales in transversal series ≥ 11 and brown blotches present all over the body................... Thorogobius ephippiatus

3b Scales in transversal series ≤ 10 and no brown blotches all over the body.......................................... 4

4a Pectoral fin rays ≥ 19, no pale brown spots and blotches on the body and head; spots, if present, pale fawn and only on nape and predorsal area; eastern Atlantic from Ghana, Equatorial Guinea (Gulf of Guinea) and Angola ...................... 5

4b Pectoral fin rays ≤ 18, pale brown spots and blotches all over the body and head; endemic to the Mediterranean Sea......................................................................................... Thorogobius macrolepis

5a Scales in longitudinal series ≥ 30 and no blotches or spots on body and head; distinct dark vertical stripes on caudal fin; Equatorial Guinea (Gulf of Guinea) and southern Angola; head neuromast rows tr and trp absent........... Thorogobius rofeni

5b Scales in longitudinal series ≤ 29 and pale fawn spots irregularly scattered over nape and predorsal area; no vertical stripes on caudal fin; eastern Atlantic from Ghana and Angola; head neuromast rows tr and trp present...................................................................................................... Thorogobius alvheimi nov. sp.