Epigonus, Rafinesque, 1810

Okamoto, Makoto & Gon, Ofer, 2018, A review of the deepwater cardinalfish genus Epigonus (Perciformes: Epigonidae) of the Western Indian Ocean, with description of two new species, Zootaxa 4382 (2), pp. 261-291 : 263

Key to Epigonus species of the Western Indian Ocean

1a Anteriorly projecting teeth present on symphysis of lower jaw; pored lateral-line scales 35–37................. E. exodon

1b Anteriorly projecting teeth absent on symphysis of lower jaw, but small bony projections or spines may be present; pored lat- eral-line scales 45–51.................................................................................. 2

2a Gill rakers 18–20; ventral luminous organ present mid-ventrally between anterior pelvic fins.................. E. macrops

2b Gill rakers 22–36; ventral luminous organ absent............................................................. 3

3a Opercle with pungent, conspicuous bony spine.............................................................. 4 3b Operculer spine weak or absent......................................................................... 10 4a Tooth patch present on tongue; maxillary mustache-like processes large and pointed........................ E. pectinifer 4b Tongue toothless; maxillary mustache-like processes blunt or absent............................................. 5 5a Four or five tiny projections present on symphysis of lower jaw; scales strongly ctenoid.................... E. idai n. sp. 5b Two spines or two nub-like structures on symphysis of lower jaw present or absent; scales weakly ctenoid............... 6 6a Second dorsal-fin rays I, 10; pyloric caeca 11–14............................................................ 7 6b Second dorsal-fin rays I, 9; pyloric caeca 6–9............................................................... 8 7a Two spines present on symphysis of lower jaw; pectoral-fin rays 16; ribs present on last abdominal vertebra...............