Serranus drewesi Iwamoto, 2018

Iwamoto, Tomio & Wirtz, Peter, 2018, A Synopsis of the Eastern and Central Atlantic Combers of the Genus Serranus (Teleostei: Scorpaeniformes: Serranidae), Proceedings of the California Academy of Sciences 65 (1), pp. 1-39 : 30-31

Key to species of Serranus and Chelidoperca in the eastern Atlantic

We have included the species Chelidoperca africana Cadenat, 1960 because it is frequently called Serranus africanus in the literature and is so treated by Smith (1990:704, CLOFETA], Williams and Carpenter (2015), and Heemstra and Anderson (2016).

1a) A III,6; D X,10–11, last two soft rays longest; pelvic-fin origin well in front of pectoral-fin base; body subcylindrical................. Chelidoperca africana Cadenat, 1960 ( Fig. 25 )

1b) A III,7–8 (rarely 6); D X, 12–16 (rarely 11); middle rays of soft dorsal fin longest; pelvic-fin origin below or only slightly in front of pectoral-fin base; body laterally compressed....... 2

2a) Lateral line scales 60–90...................................................... 3

2b) Lateral line scales 40–52...................................................... 5

3a) Nape distinctly arched; prominent vermiform or reticulate markings on head; lateral line scales 62–75; scales on cheeks and thoracic region cycloid; sensory canal system does not extend onto opercle; profile of dorsal fin not indented in adults........ Serranus scriba (Linnaeus, 1758)

3b) Nape not highly arched; no reticulate markings on head; lateral line scales 69–90; scales on cheeks and thoracic region ctenoid; sensory canal system extends onto opercle; profile of dorsal fin slightly indented........................................................... 4

4a) D X,13–15 (rarely 12); A III,7–8, usually 7; circumpeduncular scales fewer than 47; caudal fin lacking black tips................................. Serranus cabrilla (Linnaeus, 1758)

4b) D X,14–16; A III,7–8, usually 8; circumpeduncular scales 47 or more; caudal fin with black tips............................................. Serranus atricauda Günther, 1874

5a) A prominent black ocellated spot at beginning of soft dorsal fin; pelvic fins mostly black, but sometimes with white spine and pale basal section; interorbital space scaly................................................................ Serranus hepatus (Linnaeus, 1766)

5b) No black ocellated spot on soft dorsal fin; pelvic fins pale to dark dusky; interorbital space naked...................................................................... 6

6a) A III,6; GR 14; scales all cycloid; a large black spot on dorsal fin between last 3 spines and first branched ray, the spot merging with black saddle on body; mandibular rami partially covered with small thin scales............................ Serranus drewesi Iwamoto , sp. nov.

6b) A III,7 or 8; GR 19–26; scales ctenoid; no black spot on dorsal fin between last 3 spines and first branched ray; mandibular rami naked......................................... 7

7a) Scales present on interopercle; anterior nostril with a short elevated posterior flap that lacks cirri at distal tip............................. Serranus sanctaehelenae Boulenger, 1895

7b) Interopercle naked; anterior nostril bearing cirri at tip of elevated posterior rim.......... 8

8a) Caudal fin lunate to shallowly forked, often with a short streamer at tip of upper lobe; two blue stripes on head, one originating on snout and passing below orbit to end on lower margin of opercle, the other from posterior margin of orbit across gill cover and ending below middle opercular spine, last three anal-fin rays usually longer than those anteriorly............................................................. Serranus accraensis ( Norman, 1931)

8b) Caudal fin truncate or emarginated, lacking streamer at tip of upper lobe; no blue stripes on sides of head, last three anal-fin rays usually shorter than those anteriorly................ 9

9a) Anteriormost body band below spinous dorsal fin descends onto belly immediately behind base of pectoral fin; a bright light blue or white crescent mark behind orbit................................................................... Serranus heterurus ( Cadenat, 1937)

9b) Anteriormost body band below spinous dorsal fin descends onto belly well removed from base of pectoral fin and separated from same by a broad white (pale) band; no prominent white (pale) crescent mark behind orbit.................................................... 10

10a) Anterior margin of spinous dorsal fin blackish or with a black blotch; pectoral-fin rays i16; gill rakers on first arch 15-18......... Serranus inexpectatus Wirtz and Iwamoto , sp. nov.

10b) Distal margin of spinous dorsal fin lacking black margin or blotch; pectoral-fin rays i14-i15; gill rakers on first arch 19-22................. Serranus pulcher Wirtz and Iwamoto, 2016

Figures

FIGURE 25. Chelidoperca africana. A specimen 15 cm TL, taken off the Ivory Coast in 150 m depth. Photograph by Oddgeir Alvheim.