Scolopsis vosmeri ( Bloch, 1792 )

Russell, Barry C., Hasan, Mohammad Eusuf & Durand, Jean-Dominique, 2019, Scolopsis igcarensis Mishra, Biswas, Russell, Satpathy & Selvanayagam, 2013, a junior synonym of S. vosmeri (Bloch, 1792) (Perciformes: Nemipteridae), Zootaxa 4629 (4), pp. 589-599 : 591-597

Scolopsis vosmeri ( Bloch, 1792)

English name: White-banded monocle bream

Table 1 , Figs 1 –11

Anthias vosmeri Bloch, 1792: 120 , Pl. 321 (type locality: ‘japonisches Meer’, but probably Tranquebar, India; see Remarks, below).

Scolopsis leucotaenia (non Bleeker)— Day 1875: 88, Pl. XXIII, fig. 4.

Scolopsis igcarensis Mishra, Biswas, Russell, Satpathy & Selvanayagam, 2013: 444 ( India: coasts of Tamil Nadu, Kerala, and Mumbai; Sri Lanka).

Scolopsis vosmeri — Day 1875: 87 (in part, Eastern Indian Ocean Specimens), Pl. XXIII, fig. 3; Russell 1984: NEMIP Scol 2 (in part, Eastern Arabian Sea Specimens); Russell 1990: 122, Pl. VIII, fig. g (in part, Eastern Indian Ocean specimens, from Pakistan to Malacca strait, West of Borneo); Russell 2001: 3089 (in part, Andaman Sea, Malacca Strait, and lower South China Sea); De Bruin et al. 1995: Pl. XXIII, Fig. 159 ( Sri Lanka Coast); Barman & Mishra 2009: 36, 50 ( India); Psomadakis et al. 2015: 272, Pl. XXV, fig. 199 ( Pakistan Coast).

Diagnosis. A species of Scolopsis with the following combination of characters: temporal region scaly, scales on top of head reaching forward to just in front of anterior nostrils; suborbital naked; lower margin of eye tangent to or just above a line from snout tip to upper pectoral-fin base; exposed bony ridge below eye bearing an antrorse and retrorse spine; scales on preopercle extending to posterior margin, 5–6 rows of scales behind suborbital and 3–4 rows behind eye; lower limb of preopercle usually with single row of embedded scales; 4–7 rows of scales on opercle; most body scales (except for caudal peduncle) with black spot; caudal peduncle white; a white band usually present beneath lateral line, from origin of lateral line to below posterior part of dorsal fin; a broad white bar from nape onto operculum, and suborbital with distinctive white patch, these features not present in juveniles and smaller subadults; upper limb of opercular margin narrowly brown, lower limb narrowly reddish-orange; a small dark spot on upper base of pectoral fin; pelvic and anal fins crimson or orange-red.

Description. Counts and proportional measurements as percentage of SL are provided in Table 1 . Morphometric characters given in the diagnosis above are not repeated.

Dorsal-fin rays X,9; anal-fin rays III,7; pectoral-fin rays 18–19; pelvic-fin rays I,5; lateral line scales 40–44; 3½–4½ transverse scale rows above lateral line, 13–15½ rows below; gill rakers on first gill arch 9–13 (usually 11); vertebrae 22.

Body moderately deep, laterally compressed, depth 36.9–51.1 % SL; dorsal profile of head more convex than ventral contour, head length 29.3–37.1 % SL; snout short, 24.5–33.2 % HL; eye diameter about equal to or a little more than snout length, 0.6–1.1 in snout; interorbital width 1.0– 1.9 in eye diameter; suborbital depth 1.8–4.2 in eye diameter; posterior margin of suborbital with a moderately large backwardly-directed spine at upper edge and 3 smaller spines or several serrations below this, lower edge smooth; posterior margin of preopercle serrated or denticulate on posterior margin; posterior margin of opercle mostly smooth, a short, flat, pointed or rounded spine at upper angle; teeth in jaws conical, pointed, and slightly recurved; in several bands anteriorly on upper jaw; sides of lower jaw with a single series of teeth anteriorly that forms a band of 3 or 4 rows; lateral surface of maxilla smooth; gill rakers short and stubby, 9–13 on first arch.

Dorsal-fin membranes slightly incised, fourth and/or fifth spines longest; second anal-fin spine longer, and more robust than other two spines, its length 1.4–2.5 times that of first and 1.1–1.5 times that of third; pectoral fins reaching to or just before of level of anus, 24.0–29.2 % SL; pelvic fins moderately long, reaching beyond anus, 22.4–32.1 % SL; caudal fin forked, lobes slightly rounded; lower lobe a little shorter than upper; body covered with ctenoid scales.

Life colours, juveniles (<c. 60 mm SL): reddish brown, darker on back; paling light pinkish to white on lower part of body; a narrow white band along base of dorsal fin; a distinctive white lateral band from behind upper margin of eye to upper caudal peduncle, this band bordered above and below by dark reddish brown or blackish band; body scales, particularly those on upper sides and back with darker centres; suborbital and lower part of preopercle pale whitish or silvery; fins pinkish; dorsal fin with traces of dusky medial band along its length ( Figs. 1 , 3 )

Subadults (c. 60–80 mm SL): colour as for juveniles, but dark bands bordering white lateral band becoming less distinct; white bar on nape incompletely formed, not extending onto operculum; caudal peduncle becoming uniformly pale whitish; fins reddish ( Figs. 2 , 3 , 4 , 6 ).

Adults (> c.80 mm SL):Reddish brown to dark brown, with a black spot basally on each scale except for breast and caudal peduncle, shading to white on caudal peduncle; margins of scales on side of body with greenish hue; a white or yellowish white lateral band from origin of lateral line to below posterior part of dorsal fin (this band occasionally faded or absent); head reddish brown with a curving white bar extending from nape onto operculum, broader ventrally; posterior edge of opercle above opercular spine narrowly reddish brown; opercular membrane below opercular spine narrowly orange-red; posterior edge of preopercle pale orange; suborbital broadly whitish with white adjacent area behind angle of mouth; eye red suffused, with yellow blotch present on upper part; a small black spot on upper base of pectoral fin; dorsal fin reddish brown, usually with brighter red margin; pectoral, pelvic and anal fins crimson or orange-red; anal spines whitish; caudal fin pale reddish, upper and lower edges darker, ( Fig. 5 , 7 ).

Distribution. Scolopsis vosmeri is known from the northern and eastern Indian Ocean from Pakistan, India, Sri Lanka, Bangladesh, Myanmar and Thailand (Andaman Sea), to western Indonesia and Borneo. It inhabits shallow inshore rock and coral reefs, often in turbid water, in depths to about 30 m.

Comparisons. Scolopsis vosmeri is distinguishable from all other species of Scolopsis by having a distinctive white or yellowish-white lateral band. This band extends from behind the eye to the upper caudal peduncle and is margined above and below by darker bands in juveniles and subadults; in adults, it extends from behind the upper part of the opercle to below the posterior part of dorsal fin. Underwater observations of this species in Myanmar ( Fig. 6 ) and in aquarium in Bangladesh ( Fig. 7 ) show that subadults and adults can actively ‘flash’ the white lateral band on and off while swimming, perhaps as a signal to conspecifics.

Genetics. Genetic analysis of juvenile specimens initially identifiable as Scolopsis igcarensis , collected from Bangladesh, show them to be indistinguishable from some adult specimens of S. vosmeri from Bangladesh ( MK779330 and MH 311294 ), Western Thailand (ACRSD-F174) and Myanmar ( MH235710 ) (mean within clade divergence of 0.1%).

Hung et al. (2016) recognised two genetically and geographically distinct (West Pacific vs Indian Ocean) lineages for the species assigned to Scolopsis vosmeri . These specimens, identified as S. vosmeri , uploaded from GenBank, form two sister clades that present 12.7% and 13.9% of divergence from S. vosmeri from Bangladesh, Myanmar and Thailand ( Fig. 8 ). These two cryptic sister Scolopsis species, separated by 4.2% of divergence, are provisionally named here Scolopsis sp. A and Scolopsis sp. B, form part of a species complex that has been generally referred to as S. vosmeri (Russell 1984, 1990, 2001) and will be dealt with separately in a forthcoming paper (Russell et al. in prep.).

Remarks. Bloch’s (1792: 120, Plate 321) description and figure of Anthias vosmeri ( Fig. 9 ) clearly shows the reddish body and fins, pale band extending from the nape across the opercle (incompletely shown in Bloch’s figure) and yellowish band beneath the lateral line, that are characteristic of this species. However, the type locality, “japonischen Meers”, given by Bloch is almost certainly wrong. In many cases Bloch incorrectly reported fishes from India and the East Indies as coming from Japan ( Cuvier & Valenciennes 1830; Paepke 1999, 2001), but later corrected some of his localities ( Paepke 2001), with Bloch & Schneider (1801) subsequently reporting the locality of Anthias vosmeri , as “Habitat cum antecedente”, referring to that of a previously described species, Anthias macrophthalmus Bloch [= Priacanthus hamrur (Forsskål) ], whose locality was given as Tranquebar (= Tharangambadi) in the Indian state of Tamil Nadu. Thus, it is likely that the type specimen of Scolopsis vosmeri was collected from south-eastern India, where this species also is known to occur today.

Day (1875: Plate XXIII, Fig. 1 , 2 , 3 ) provided three figures of Scolopsis vosmeri indicating three life stages: young, semi-adult, and adult respectively. The adult stage ( Fig. 10 ) shows the horizontal white band and thus conforms to S. vosmeri , while the others represent different species. Day (1875: Plate XXIII, fig. 4) also figured a specimen from Bombay (= Mumbai) as Scolopsis leucotaenia (Bleeker) ( Fig. 11 ) that closely resembles the colour pattern of juveniles of S. vosmeri described here.As pointed out by Mishra et al. (2013), the true S. leucotaenia is the juvenile form of Scolopsis margaritifera (Cuvier in Cuvier & Valenciennes) and differs in colour from S. vosmeri in having a distinct black spot anteriorly on the dorsal fin between the first three rays (absent in Day’s Plate XXIII, fig. 4), and the uppermost dark band on the body above the lateral line (versus band mostly on or below the lateral line in Day’s figure and juveniles of S. vosmeri ). Scolopsis leucotaenia (= margaritifera ) also differs from S. vosmeri in having the head scales reaching forward only to the anterior margin of the eye (versus head scales extending forward to or in front of anterior nostrils in S. vosmeri ); fewer lateral-line scales (34–39, versus 42–43); longer pelvic fins, that reach almost to or beyond the anal fin origin (versus pelvics reaching only to just beyond anus); centre of the scales on the body with pearly or whitish spots (versus body scales dark brown in middle); and the second anal spine not longer and stronger than the third spine. Day’s figured specimen (ZSI F-401), c. 57 mm SL, is damaged but has the head scaled to the front of anterior nostril, a prominent suborbital ridge beneath the eye (right side), at least 40 lateral-line scales, and 17 pectoral-fin rays—characters that are consistent with S. vosmeri . Thus, we consider Day’s record of S. leucotaenia to also represent the juvenile form of S. vosmeri .

Figures

FIGURE 1. Scolopsis vosmeri, juvenile c.45 mm SL, underwater, Myeik Archipelago, Myanmar (from video clip, B.C. Russell).

FIGURE 2. Scolopsis vosmeri, subadult, USNM 443789, 77 mm SL, Bangladesh (photo: M.E. Hasan).

FIGURE 3. Scolopsis vosmeri juvenile c.40 mm SL (above) and subadult c.80 mm SL (below) underwater, Myeik Archipelago, Myanmar (from video clip, B.C. Russell).

FIGURE 4. Paratype of Scolopsis igcarensis, ZSI F-10625/2, 79.7 mm SL, Kalpakkam, India (photo from Mishra et al. 2013).

FIGURE 5. Scolopsis vosmeri, adult, BPBM 27195, 155.1 mm SL, Hikkaduwa, Sri Lanka (photo: J.E. Randall).

FIGURE 6. Scolopsis vosmeri, subadults c.80 mm SL underwater, showing ability to ‘flash’ lateral band on (red arrow, upper left) and off (red arrow, lower right). Myeik Archipelago, Myanmar (from video clip, B.C. Russell).

FIGURE 7. Scolopsis vosmeri, adults c.150 mm SL (upper) and c. 100 mm SL (lower) showing ability to ‘flash’ lateral band on and off. Photographed in aquarium, St Martins Island, Cox’s Bazaar, Bangladesh (photo: M.E. Hasan).

FIGURE 8. Neighbour-Joining (NJ) tree showing phylogenetic relationships among Scolopsis species. The Scolopsis vosmeri complex comprises three species: S. vosmeri sensu stricto and a pair of sister species, from the NW Pacific–S. China Sea (Scolopsis sp. A) and Indian Ocean (Scolopsis sp. B) respectively.

FIGURE 9. Anthias vosmeri Bloch (from Bloch 1792: Pl. 321).

FIGURE 10. Scolopsis vosmeri, adult, figured in Day (1875: Pl. XXIII, fig. 3); note the horizontal white stripe characteristic of S. vosmeri.

FIGURE 11. Scolopsis vosmeri, juvenile, figured in Day (1875: Pl. XXIII, fig. 4, as S. leucotaenia).

Tables

TABLE 1. Selected counts and morphometric data for type series of Scolopsis igcarensis (from Mishra et al. 2013) compared with other specimens of S. vosmeri examined here.

	Scolopsis igcarensis (Type series, n=13)	Scolopsis vosmeri (n=37)
SL	67.1–148.1 mm	77.0–173.1 mm
Counts
Lateral line scales	40–44	40–44
Scales above/below lateral line	3½ /13–15½	3½–4½ /13–15½
Gill rakers (total)	10–13	9–12
Scale rows on opercle	5	4–7
Scale rows on preopercle behind eye	3–4	3–6
Pectoral fin rays	15–18	16–19
Proportions
Body depth (% SL)	36.9–50.9	39.8–51.1
Head length (% SL)	29.7–34.1	29.3–37.1
Snout length (% HL)	24.5–30.2	24.9–33.2
Eye diameter (% HL)	29.9–40.9	28.2–37.1
Eye in snout	0.6–0.9	0.8–1.1
Interorbital width in eye	1.0–1.9	1.0–1.7
Suborbital depth in eye	2.0–4.4	1.8–3.0
Caudal-peduncle depth in peduncle length	0.8–1.3	0.7–1.7
Base of dorsal fin (% SL)	54.9–62.7	56.9–62.8
Base of anal fin (% SL)	16.0–20.0	15.9–21.0
Pectoral fin length (% SL)	24.6–29.2	24.0–28.1
Pelvic fin length (% SL)	25.1–31.1	22.4–32.1
Pectoral length in pelvic length	0.8–1.1	0.8–1.2
First dorsal spine in longest dorsal spine	1.6–2.3	1.2–2.3
Longest dorsal spine in longest dorsal ray	1.0–1.3	1.0–1.2
First anal spine in second anal spine	1.7–2.5	1.4–2.3
Third anal spine in second anal spine	1.2–1.5	1.1–1.5