Key to the species of Barathronus

1a Peritoneum dark...................................................................................... 2

1b Peritoneum transparent................................................................................. 7

2a Dark-brown pigmentation along lateral line and between head and dorsal fin...................................... 3

2b No brown pigmentation................................................................................ 4

3a Anal-fin rays 54–66; total vertebrae 74–79; heavily pigmented on sides of body...................................................................................... maculatus (from South Africa to Japan and Southeast Australia)

3b Anal fin rays 73; total vertebrae 86; slightly pigmented on sides of body................ bruuni (Southwest Indian Ocean)

4a Anal fin rays 48–61; vertebrae 66–75..................................................................... 5

4b Anal fin rays 60–66; vertebrae 74–82..................................................................... 6

5a Fresh specimens brownish; ripe males with long and slender penis, thickness at basis of penis 13% of length of penis ( Fig. 7B)......................................................................... bicolor (West Atlantic Ocean)

5b Fresh specimens bright red; ripe males with less slender penis, thickness at basis of penis 31% of length of penis ( Fig. 11).................................................................. diaphanus (From Madagascar to Tonga Isls.)

6a Mouth cleft almost vertical; body of fresh specimen brown-yellowish; vertebrae 82....... roulei (Northeast Atlantic Ocean)

6b Mouth cleft oblique; body of fresh specimen bright red; vertebrae 74–76... algrahami (From Southeast Australia to Taiwan)

7a Males with pair of bulbs at base of penis ( Fig. 20)............................. pacificus (Atlantic and Pacific Oceans)

7b Pair of bulbs absent (male only known of B. multidens)....................................................... 8

8a Ventral flexure of anteriormost vertebrae................................................................... 9

8b No ventral flexure.................................................................................... 10

9a Fangs on vomer 8; long rakers on anterior gill arch 25....................................... linsi (Northeast Brazil)

9b Fangs on vomer 2; long rakers on anterior gill arch 20................................. affinis (Central Indian Ocean)

10a Precaudal vertebrae 37; vomer with 1+ fang(s); long gill rakers 29................... parfaiti (Northeast Atlantic Ocean)

10b Precaudal vertebrae 32–34; vomer with 7–11 fangs; long gill rakers 23–25.............. multidens (North Atlantic Ocean)