Key to all known species of Luciobrotula Smith & Radcliffe, 1913

(modified from Nielsen 2009)

1. Precaudal vertebrae 13; total vertebrae 50 or 51............................................................................... 2

– Precaudal vertebrae 15 or 16; total vertebrae 52–57......................................................................... 3

2. Lateral line ending at 2 ^nd dorsal-fin ray; total gill rakers 13–14...................................................................................................................................................... L. brasiliensis Nielsen, 2009 (off Brazil)

– Lateral line ending at 33 ^rd dorsal-fin ray; total gill rakers 17................................................................................................................................................... L. polylepis sp. nov. (off Papua New Guinea)

3. Lateral line short and distinct, ending at 2 ^nd dorsal-fin ray.... L. lineata (Gosline, 1954) (off Hawaii)

– Lateral line long, usually indistinct, ending at 19 ^th –37 ^th dorsal-fin ray.............................................. 4

4. Dorsal-fin rays 81–89;anal-fin rays59–65;first gill arch with3developed rakers and 18–23dentigerous plates; longest filaments on first gill arch 2.8–3.6% SL......... L. coheni Nielsen, 2009 (East Pacific)

– Dorsal-fin rays 86–96; anal-fin rays 66–75; first gill arch with 3–4 developed rakers and 12–18 dentigerous plates; longest filaments on fist gill arch 1.3–2.7% SL.................................................. 5

5. Four occipital pores, one interorbital pore; first anal-fin ray below 18 ^th –24 ^th dorsal-fin rays; dorsal rim of otolith without concavity (large specimens)................................................................................................................................................ L. bartschi Smith & Radcliffe, 1913 (Indo-West Pacific)

– Pores absent on occipital and interorbital region; first anal-fin ray below 24 ^th –28 ^th dorsal-fin rays; dorsal rim of otolith with or without concavity................................................................................. 6

6. Head brown; otolith with a distinct concavity in dorsal rim in specimens larger than 300 mm SL; total vertebrae 56–57; longest pelvic-fin ray 7.9–9.6% SL..................................................................................................................... L. corethromycter Cohen, 1964 (Gulf of Mexico, Caribbean Sea)

– Head pale; otolith without a distinct concavity in dorsal rim in specimens larger than 300 mm SL; total vertebrae 53–55; longest pelvic-fin ray 11.0–12.5% SL.................................................................................................................................................... L. nolfi Cohen, 1981 (tropical East Atlantic)