Acanthistius joanae, Heemstra, Phillip C., 2010

Heemstra, Phillip C., 2010, Taxonomic Review of the perciform fish genus Acanthistius from the east coast of southern Africa, with description of a new species and designation of a neotype for Serranus sebastoides Castelnau, 1861, Zootaxa 2352, pp. 59-68 : 61-67

Acanthistius joanae new species

Figs. 1–5

Acanthistius sp: Heemstra & Randall,1986: 511, Fig 166.2; Heemstra & Heemstra, 2004. Acanthistius sebastoides: Beckley, 1994: 232 , Fig. 109.7; King and Fraser, 2001: 32 & 33.

Type material: Holotype: SAIAB 26041, mature female, 113 mm SL; South Africa: off Umdloti, KwaZulu- Natal; depth 80 m; A. R. Thorpe, collector. Paratypes: BPBM 32784, 109 mm SL, South Africa: off KwaZulu- Natal. SAIAB 5766, male, 129 mm SL; South Africa: near Port Alfred, Eastern Cape Province; 22 Feb. 1977; SAIAB 26209, female, 119 mm SL;off Umdloti, SAIAB 28056, 3: 116 – 125 mm SL, off Kelso, KwaZulu- Natal, depth 30 m; SAIAB 29406, 66 mm SL; Landers Reef, off Park Rynie, 30° 23.2' S, 30° 50.6' E; depth 140 m; 19 August 1991. SAIAB 40259, 90 mm SL; Landers Reef; SAIAB 40459, 2 females:125 & 130 mm SL; Landers Reef; 30° 19' S, 30° 47' E; SAIAB 46440, 3: 116 –122 mm SL; Aliwal Shoal off Scottburgh, KwaZulu-Natal, 21 June 1994; SAIAB 53810, 118 mm SL, off Umdloti; 74 m, March 1987; SAIAB 59180, 125 mm SL; Aliwal Shoal. SAM 34438, 2: 107 & 130 mm SL, both male; Aliwal Shoal, depth 42 m, 23 June 1994; SAIAB 81415, 113 mm SL; Landers Reef. SAIAB 81416: 126 mm SL; Landers Reef; USNM 283001, 132 mm SL, off Umdloti, USNM 300448, 143 mm SL, off Umdloti,

Diagnosis. Interorbital, maxilla, infraorbitals, interopercle, dorsal 4 branchiostegal rays, gular area, isthmus, chest, belly and proximal two-thirds of pectoral fin covered with distinct ctenoid scales. Interorbital area slightly convex. Longest dorsal fin spine equal to or longer than peduncle depth. Caudal, anal, and pelvic fins pale (fin rays mostly reddish orange in life); most prominent dark mark on the head is a large oval, blackish brown blotch covering most of the opercle. Pectoral-fin rays 17–19

Description. (Morphometric data are given in Table 1.)

(Data from paratypes are given in parentheses.) Dorsal fin rays XII,16 (XII,14 –16); anal fin rays III,7 the rays branched; pectoral fin rays 17, 17 (17–19), the upper and lowermost rays unbranched, and the rest branched; pectoral fins reach vertical at anus; pelvic fins also reach anus; branched caudal-fin rays 8+7; principal rays 9+8; dorsal procurrent caudal rays 4–8, with last 3 segmented; ventral procurrent rays 4–7, with 2 rays segmented; no median fin rays elongated; 4th to 6th dorsal-fin spines longest, but slightly shorter than longest dorsal soft-ray or 2nd anal-fin spine. Body and most of head covered with strongly adherent, distinctly ctenoid scales, extending forward over top of head and interorbital area to a line joining front edge of anterior nostrils; maxilla, infraorbitals, operculum, dorsal branchiostegal rays and gular area with distinct ctenoid scales; snout, preorbitals and lower jaw naked, the skin perforated by numerous minute, close-set, raised pores. Proximal half of all fins are scaly. Lateral-line scales 48 (47–52); scale rows between 6th dorsal-fin spine and lateral line 16 (13–17). Gill-rakers iii,3 / 9,v (ii-iv, 2–4 / 8–9, iv-vi; total 19–21); longest gill-raker slightly longer than longest gill-filament. Pseudobranch with 34 (31–35) filaments. Body depth 2.5 (2.4 –2.6), head length 2.3 (2.2–2.6) in SL. Orbit 4.2 (3.9–4.5) in head length; interorbital flat or slightly convex, width about half orbit diameter, 7.8 (6.8–8.0) in head length. Maxilla expanded posteriorly, width including supramaxilla 2.9 (2.4–3.7) times in upper jaw length; posteroventral corner of maxilla with a low knob. Anterior nostrils oval or circular, with a low fleshy rim produced posteriorly as a broad fimbriate flap that can be laid back to cover posterior nostril; posterior nostrils circular, with fleshy fimbriate margin, equidistant from anterior nostril and edge of orbit; infraorbital scales extend forward to a vertical at front edge of eye; about 23 irregular scale series on cheek. Rear edge of opercle with 3 sharp spines, distance from middle spine to lower spine about half distance from middle spine to upper spine; posterior edge of preopercle with 21–23 (14–20) serrae, becoming progressively larger ventrally, 2 (1–3) large, curved, antrorse spines (partly hidden by skin) on lower edge of preopercle. Supratemporal bone rear edge smooth, or with 5 (1–5) small serrae. Premaxilla with a band of small cardiform teeth, the band narrowing posteriorly and widening anteriorly, and an outer series of 17 (16 –19) short, slightly curved, fixed canines becoming smaller posteriorly. Front half of lower jaw with a band of small, depressible, cardiform teeth, the band narrowing posteriorly, and a few short, stout canines on outer edge of tooth band; 2 or 3 short, stout, curved canines about one-third distance from symphysis to rear end of lower jaw; teeth on rear half of lower jaw are mainly in a single row of small, curved canines directed medially and interspersed with a few much smaller teeth. Two or 3 rows of short, conical teeth in a chevron-shaped band on vomer, and an elongate band of similar teeth on palatines. Second epibranchial with elongate tooth plate. Vertebrae 10+16; epipleural ribs on first 9 vertebrae; pleural ribs on vertebrae 3 through 10; last 12–14 dorsal-fin pterygiophores are trisegmental; last 5 anal-fin pterygiophores are trisegmental. Pyloric caeca 4–8.

Colour. In life: (125 mm SL, SAIAB 28056) Head and body pale grey, covered with irregular russet spots and blotches; conspicuous, dark, reddish brown blotch covering most of opercle; series of 5 irregular, white blotches along base of dorsal fin and a vertical white streak at base of caudal fin (white markings very noticeable underwater); spinous dorsal fin pale grey, with orange spots on membranes and distal parts of spines; median fin rays orange, inter-radial membranes pale; anal-fin base and rays white, the membranes reddish; pectoral-fin rays orange; first pelvic-fin ray pinkish, remainder white; isthmus, chest and belly white. In alcohol: head and body buff, with faint brown areas and close-set pale spots; dark blotches on head still visible.

Comparisons. Acanthistius joanae is most similar to its South African cognate, A. sebastoides . Acanthistius joanae usually has 17 or 18 pectoral fin rays (19-21 in sebastoides ). The maxilla of A. sebastoides is apparently naked (scales minute and embedded or absent), but that of A. joanae is covered with distinct, adherent, ctenoid scales that are visible to the naked eye and discernible with the touch of a finger; A. joanae also has conspicuous ctenoid scales on the infraorbitals, interopercles, dorsal 4 branchiostegal rays, gular area, isthmus and chest; but on these areas of A. sebastoides , the scales are absent or minute and embedded. The lateral-line scale tubes of A. joanae have 2 branches, but those of A. sebastoides have 3–5 branches ( Figure 5 ).The apparent rarity of A. joanae may be attributed to its smaller size and its living in deeper water. The specimens from KwaZulu-Natal were caught in depths of 23, 30, 73 and 140 metres; whereas, Acanthistius sebastoides is common from the intertidal region out to depths of 30 m.

Etymology. Acanthistius joanae is named to honour Joan Wright, able and conscientious former research assistant of the author.

Serranus cuvieri (non Smith): Castelnau, 1861: 2.

Serranus sebastoides Castelnau, 1861: 3 (Algoa Bay and Simonstown)

Acanthistius sebastoides: Barnard,1927 : Boulenger, 1895: 141; Smith and Smith, 1966: 8; Randall & Heemstra, 1986: 510, Pl. 32, Fig. 166.1; Bianchi, et al. 1999: 165; Heemstra & Heemstra, 2004: 159.

Perciform species 1: Brownell, 1979: 24, figs. 162-168.

Neotype here designated for 175 mm SL female from Algoa Bay (33°58'54" S, 25°41'42" E) SAIAB 85233.

Diagnosis. (Characters of the genus given above are not repeated.) Maxilla, infraorbitals, interopercle, branchiostegal rays, gular area, isthmus, chest and proximal two-thirds of pectoral fin naked, or with small, inconspicuous, embedded cycloid scales. Head and body buff, covered with small red spots and a few larger dark brown blotches; most prominent dark mark on the head is a large, oval, blackish brown blotch close behind eye. Caudal and anal fin dark bluish grey; pelvic fins pale yellowish; Pectoral-fin rays 19–21.

Description. Morphometric data are given in Table 1; data from the neotype are given first, with data from the other specimens examined in parentheses.

Dorsal-fin rays XII, 15 (XI–XIII,15–17); anal-fin rays III,7 (2 specimens with 8 anal rays); pectoral-fin rays 19 and 20 (19–21), upper and lowermost rays unbranched and the rest branched; pectoral fins reach vertical at anus; pelvic fins also reach anus; branched caudal-fin rays 8+7; principal rays 9+8; dorsal procurrent caudal rays 6 (4–8), with last 3 segmented; ventral procurrent rays 5 (4–7), with 2 rays segmented; no median fin rays elongated; 4th (4th to 6th) dorsal-fin spines longest, but slightly shorter than longest dorsal soft-ray or 2nd anal-fin spine. Body and most of head covered with strongly adherent, distinctly ctenoid scales, extending forward over top of head and interorbital area to a line joining front edge of anterior nostrils; cheek and operculum with ctenoid scales; snout, preorbitals and lower jaw naked, the skin perforated by numerous minute, close-set, raised pores. Proximal two-thirds of all median fins are scaly; pelvic fin rays with scales extending along proximal two-thirds of rays. Lateral-line scales 52 (47–52); lateral-line scale tubes with 3 (3 – 5) branches; scale rows between 6th dorsal-fin spine and lateral line 15 (13–17). Gill-rakers ii,2 / 8,ii (ii-iv, 2– 4 / 8–9, ii; total 19–2); longest gill-raker slightly longer than longest gill-filament. Pseudobranch with 30 (32– 35) filaments. Body depth 2.5 (2.4–2.6), head length 2.3 (2.2–2.6) in SL. Orbit 3.9 (3.9–4.5) in head length; interorbital flat or slightly convex, width about half orbit diameter, 6.8 – 8.0 in head length. Maxilla expanded posteriorly, width 3.1 (2.4–3.7) times in upper jaw length; postero-ventral corner of maxilla with a low knob; supramaxilla well developed, autogenous, hidden by skin and scales. Anterior nostrils oval or circular, with a low fleshy rim produced posteriorly as a broad fimbriate flap reaching to posterior nostril; posterior nostrils circular, with fleshy fimbriate margin, equidistant from anterior nostril and edge of orbit; infraorbital scales extend forward to a vertical at front edge of eye; about 20 irregular scale series on cheek. Rear edge of opercle with 3 sharp spines, distance from middle spine to lower spine equals half distance from middle spine to upper spine; dorsal edge of preopercle with 20 (18–22) serrae, becoming progressively larger ventrally, 2 (1–3) large, exposed, antrorse spines on lower edge of preopercle. Supratemporal bone rear edge smooth, or with 4 (2–4 small serrae. Premaxilla with a band of small, cardiform teeth, the band narrowing posteriorly and widening anteriorly, and an outer series of 4 (3 or 4) larger, slightly curved, fixed canines at symphysis; some inner teeth near symphysis also enlarged. Lower jaw with a band of small, depressible, cardiform teeth, the band narrowing posteriorly, and a few short, stout canines on outer edge of tooth band; 3 (2 or 3) short, stout, curved canines about one-third distance from symphysis to rear end of jaw; teeth on rear half of lower jaw teeth similar but with 3 (3 or 4) stout canines at middle of each side of lower jaw. Vomer with a chevron patch of 3 (3 or 4) rows of short slender teeth and a long band of similar teeth on palatines. Second epibranchial with elongate tooth plate. Vertebrae 10+16; 3 supraneural bones: 0/0/0+2/1+1/1/1/1/; epineural bones on first 9 vertebrae; ribs on vertebrae 3 through 10; last 12 (12–14) dorsal-fin pterygiophores are trisegmental; last 5 anal-fin pterygiophores are trisegmental. Pyloric caeca (7 or 8).

Colour. In life: Head, body and dorsal fin buff, covered with small reddish orange spots; caudal fin and rear half of peduncle blackish, the rear edge white; pectoral fins reddish orange distally, the proximal half buff with orange spots; anal fin dusky orange with white edge.

In alcohol, head and body buff, covered with small pale spots; and irregular dark brown blotches, the largest and most prominent dark blotch on the head is that immediately behind the eye; nape and top of head blackish, with numerous small pale spots caudal fin and rear part of peduncle dark brownish grey; pelvic and anal fins also dark grey. Attains 28 cm SL.

Distribution. Endemic to southern Africa from False Bay, Western Cape Province to Durban. Also reported from Namibia ( Bianchi et al. 1999).

Discussion: Although the count of 4 anal fin spines for the juvenile reared by Brownell (1979) has not been found in any of the other 60 specimens that have been examined, his specimen is likely to be A. sebastoides . All of the other counts and features (including the colour pattern) agree with the other juveniles of this species that were seen. Acanthistius sebastoides is a sedentary species known from depths of 1– 30 m.

Comparisons. Acanthistius sebastoides was compared with A. joanae in the account above. A. sebastoides differs from both South American species ( A. brasilianus and A. patachonicus ) in its color pattern, 19–21 pectoral fin rays (15–17 pectoral rays in South American species) and 50–55 lateral-line scales (lateral line scales 56–70 in South American species) The Australian species of Acanthistius ( cinctus , ocellatus , pardalotus , paxtoni , and serratus ) all differ in color patterns, and various meristic and morphometric characters (See Hutchins, 1981, Hutchins and Kuiter, 1982 and Kuiter, 1994),

Remarks. In the original description of Serranus sebastoides, Castelnau (1861, p. 3 mentioned two fish: one from Algoa Bay and one from False Bay [Simons Town] These syntypes are apparently lost. ( Bauchot et al. 1984). In view of the considerable similarity between the two South African species of Acanthistius , it will clarify the taxonomic status of these species to designate a neotype for Serranus sebastoides , and this neotype will also provide an objective definition of this species.

Acanthistius sebastoides material examined. SAIAB 15280, 9: 55–184 mm SL, Tsitsikamma; SAIAB 78910, 2, 43–188 mm SL, Port Alfred; SAIAB 32150, 3, 122- 132 mm SL, Port Elizabeth; SAIAB 10953, 163 mm SL, East London; SAIAB 59894, 3,150– 173 mm SL, Pressley’s Bay, Eastern Cape Province; USNM 246689, 173 mm SL, Tsitsikamma; SAM 28499, 24.2 mm SL, specimen reared from egg by Charles Brownell False Bay; Western Cape Province; SAIAB ( RUSI) 74-71, 122 mm SL, Algoa Bay; SAIAB ( RUSI) 7891, 2, 43– 188 mm SL, Port Alfred.

Figures

FIGURE 1. Acanthistius joanae: 129 mm SL paratype, SAIAB 5766 (South Africa; from Heemstra & Randall, 1986; drawn by D. P. Voorvelt).

FIGURE 2. Acanthistius joanae: enlarged view of head of the 113 mm SL holotype, SAIAB 26041, to show the spination of head bones and scalation (South Africa; drawn by D. P. Voorvelt).

FIGURE 3. Acanthistius joanae: 113 mm SL SL holotype, SAIAB 26041 (South Africa; painted by D. P. Voorvelt).

FIGURE 4. Acanthistius joanae, 124 mm SL, SAIAB 62993, Aliwal Shoal, KwaZulu-Natal. Photograph, P. C. Heemstra.

FIGURE 5. lateral-line scales to show 2 branches for Acanthistius joanae (left) and 3 branches for A. sebastoides (right).