Serranus (Paracentropristis) inexpectatus Wirtz and 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 : 18-22

Serranus (Paracentropristis) inexpectatus Wirtz and Iwamoto , sp. nov.

Figures 13–15

Paracentropristis heterurus : Poll 1954:72–73, fig. 20 (in part, descr. and fig. of S. inexpectatus ; nw of Mayumba, Gabon). Heemstra and Anderson 2016:2411 (in part, descr. and fig. from Poll 1954, of S. inexpectatus ).

DIAGNOSIS.— D X,12; P 17; A III,7; gill rakers 5–7+10–11 (15–18 total); pseudobranchial filaments about 22; pored lateral-line scales 46; circumpeduncular scales 21; scales below origin of first dorsal fin 4, below first segmented dorsal ray 3–3.5. Caudal fin truncate, the upper lobe slightly pointed, lower lobe somewhat rounded. Dorsal, anal, and pectoral fins scaly near base. Anterior nostril tubelike, rim low anteriorly but rising to a high narrow flap posteriorly, with 4–6 long cirri at distal tip; posterior nostril a simple opening lacking a raised rim. Prominent black blotch distally between dorsal fin spines 1 and 4. Five broad bands on body and another over nape; the band under 5 th to 10 th spines descends to belly well removed from pectoral-fin base and to front of anal fin; band below anterior rays of soft dorsal fin descends to middle of anal-fin base.

DESCRIPTION.— Body relatively slender, width over pectoral bases about half of HL, 18–20% SL, greatest body depth below fifth or sixth dorsal spine about 2.9– 3.1 in SL and less than HL, which is about 2.6 in SL. Dorsal profile (excluding eye) rising in a relatively straight line to origin of dorsal fin, then leveling off to about fifth or sixth spine before descending in a gentle curve to base of caudal fin; ventral profile gently curved from lower jaw to caudal fin; orbit diameter about 4 into HL, longer than snout length, both substantially more than interorbital width. Lower jaw projecting slightly beyond upper jaw; maxilla extending to below posterior half of pupil. Anterior nostril tubular, the rim posteriorly elevated into a high narrow flap with 4–6 long slender cirri at distal tip; posterior nostril lacking raised rim. Opercular spines three, the uppermost small and obscure, middle spine longest. Preopercle margin serrated with flattened spines, those at angle largest; vertical portion of margin slightly inflected to form shallow lobe at angle.

Premaxillary teeth in narrow band, the outer series spaced and slightly enlarged; one or more large canines at anterior end. Dentary with a band of small teeth flanked by a series of slightly enlarged outer teeth that become larger posteriorly. Vomerine tooth band broadly V-shaped, teeth along posterior edge of bone slightly larger; each arm of vomerine teeth followed by narrow band of small palatine teeth.

First four spines of dorsal fin graduated, the middle 4 th to 6 th spines longest, the spines following subequal; the soft rays slightly higher than longest spines, the 3 rd to 5 th soft ray longest; a slight notch in fin profile. Anal fin relatively high, spines shorter than soft rays, the first spine more than half length of second and third spines, the second spine longer and stouter than the others. Pectoral fin broad-based, its origin about on same vertical as that of dorsal and pelvic fins; middle of fin (7 th to 8 th rays) longest, extending to base of first or second anal spine; pelvic fin falls short of anus. Caudal fin emarginate; dorsal lobe weakly pointed, ventral lobe somewhat rounded at tip.

Scales ctenoid, body fully covered; head naked over snout, interorbital, suborbital region, outer margin of preopercle and over subopercle. Small scales on interradial membranes of dorsal fin, mostly confined to basal one-fourth to one-half of soft rays, but a few on membrane between spines. Anal and caudal fins also with small scales at base, but on caudal fin, scales extending more distally. Scales on pectoral fin limited to immediate base of fin.

Pigmentation pattern ( Figs. 13 , 14 ) of preserved type specimens from Angolan and Gabon: Six or seven vertical bands on body from nape to base of caudal fin. Bands originate along dorsal outline of body and descend ventrally before fading on abdomen or near ventral outline; pigmentation of bands under dorsal fin extend onto base of dorsal fin rays. Anteriormost band faint, beginning over nape and extending posteriorly to below 3 rd or 4 th dorsal spine; ventrally, band descends onto opercle and subopercle. Second band below 5 th to 10 th spines descending to behind posterior half of pectoral fin, gradually fading over abdomen. That band, as in S. pulcher , does not abut against the pectoral-fin base. Third band below 1 st to 6 th soft dorsal rays, descending to ventral outline over anterior anal soft rays. Fourth band below last four or five soft dorsal rays and extending slightly onto caudal peduncle. A fifth band at middle of caudal peduncle, followed by a sixth band over end of peduncle and partly onto base of caudal fin. Angolan specimens have characteristic dark spots on snout and suborbital, and a faint dark crescent mark on hind border of orbit; tiny, irregular (in shape, size and distribution) black speckles on posterior one-half of interorbital space—these absent on Gabon specimen, which is faded. However , a small dark dot present on both sides of head just behind upper margin of orbit in all three specimens. Dorsal, anal and lower half of caudal fins dusky with faint diagonal streaks. Anal fin overall dark dusky but faintly whitish PW’s surprising find of two specimens of an undescribed species in the collection of the Zoologische Staatssammlung, when looking at comparative material for the description of Serranus pulcher .

REMARKS AND COMPARISONS.— PW initially examined the two Angolan specimens of this species and noted the slight shape differences between them and specimens of S. heterurus . However, almost all other morphological, meristic, and pigmentation characters appeared to fall within the range of variation we found in S. heterurus , lending doubt as to the distinctness of the two specimens. Poll’s (1954: 72–73, fig. 20) description and accurate illustration of his single specimen from Gabon, which he called Paracentropristis heterurus , appeared to be exactly the same as the Angolan specimens, adding to the confusion. Ultimately, we are confident that Poll’s specimen and our two Angolan specimens are the same undescribed species. Examination of many other specimens that agreed closely with Cadenat’s (1937) original description and illustration of S. heterurus brought to light several key features that distinguish S. inexpectatus from S. heterurus . Most notable are the counts of pectoral-fin rays, gill rakers, and scale rows below the origin of dorsal fin (see Table 2). A one-ray difference in the count of pectoral-fin rays may seem rather insignificant, but the count of 17 rays (including the splintlike uppermost ray) in S. inexpectatus is consistent in the type specimens and not found in any of the 12 specimens of S. heterurus we examined. Meisler (1987: fig. 3) did record a count of 17 rays in 4 fins (of 22 fins total) in 11 specimens of S. heterurus he examined (see Table 2). We were not able to examine his material. Some proportional measurements ( Table 3) appear to show differences between the two species, but with data from only three specimens of the new species, the significance of these differences must be substantiated with measurements of many more specimens. A distinct black blotch between the anteriormost three or four dorsal-fin spines in S. inexpectatus contrasts with the lack of such blotch in S. heterurus (although the distal margin of the spines may be blackish in some individuals of that species). In S. inexpectatus the broad band below the last four or five spines falls well behind the base of the pectoral fin and leaves a broad pale (or white) band or gap between the fin base and the dark band. In contrast, in S. heterurus the dark band below the middle of the spinous dorsal falls immediately behind the pelvic-fin base without a pale gap.

TYPE SPECIMENS.— Angola. Holotype : ZSM 45041 (75 mm SL) and paratype : ZSM 32516 (79 mm SL); 10°49ʹS, 13°43ʹE; 35–36 m ; R / V Dr Fridtjof Nansen sta. 30147; 9 March 2003; coll. Reinhold Hanel. Gabon. Paratype: RBINS 9534 (73.8 mm TL), 30 miles NW of Mayumba, 3°11ʹS, 10°14ʹE; 25-30 m; Expédition Océanographique Belge sta. 164; collected with a small trawl over rocky bottom (catch included skates); 17 March 1940 .

Figures

FIGURE 13. Serranus inexpectatus Wirtz & Iwamoto, new species. (a) Holotype, ZSM 45041 (72.4 mm SL) from Angola, 35-36 m; (b) Paratype, ZSM 32516 (75.1 mm SL), same data as for holotype. Photographs by Peter Wirtz.

FIGURE14. Serranus inexpectatus Wirtz & Iwamoto, new species. Lateral view of holotype (ZSM 45041) showing markings on fins, body, and head. Markings have been slightly exaggerated.Drawing by Tomio Iwamoto.

FIGURE 15. Serranus inexpectatus Wirtz & Iwamoto, new species. A freshly collected specimen from Senegal. Photo- graph by Pascal Pépé Sjamajee Rommelaere.