Scolopsis igcarensis, Mishra, Biswas, Russell, Satpathy & Selvanayagam, 2013

Mishra, S. S., Biswas, Sudeepta, Russell, Barry C., Satpathy, K. K. & Selvanayagam, M., 2013, A new species of the genus Scolopsis Cuvier, 1830 (Perciformes: Nemipteridae) from southern India and Sri Lanka, Zootaxa 3609 (4), pp. 443-449 : 444-448

Scolopsis igcarensis sp. nov.

Proposed name: Igcar monocle bream

Figure 1,2; Table 1 .

Scolopsis leucotaenia (non Bleeker 1853) – Day, 1875: 88, Pl. XXIII, fig. 4 ( Bombay = Mumbai)

Holotype. ZSI F-10623/ 2, 118.2 mm SL, Kalpakkam (12°33´N, 80°11´E), Tamil Nadu, India, September 2010, Sudeepta Biswas.

Paratypes. BPBM 18765 , 74.0 mm SL, Negombo Reef (7°13ʹN, 79°50ʹE), Sri Lanka, adjacent sand and rubble bottom, 8 m depth, speared, 30 March 1975, John E. Randall ; BPBM 19054 , 75.4 mm SL, Negombo Reef , Sri Lanka, sand bottom next to reef, 8 m depth, speared, 27 March 1975, John E. Randall ; BPBM 27712 , 74.0 mm SL, off Mulloor Point , Vizhinjam (8°23ʹ N, 76°59ʹ E), Kerala, India, rocky bottom in 4 m, dynamite collection by fisherman, 14 February 1980, John E. Randall ; CMFRI GB.31.98.5.6 , 148.1 mm SL, Tuticorin Fishing Harbour (8°47ʹ N, 78°09ʹ E), 21 March 2012, K.K. Bineesh ; ZSI F-10624/2 , 5: 75.9–115.6 mm SL, Kalpakkam, Tamil Nadu, India, September 2010, Sudeepta Biswas ; ZSI F- 10625/2 , 3: 67.1–82.4 mm SL, Kalpakkam, Tamil Nadu, India, July 2008, Sudeepta Biswas.

Diagnosis. A species of Scolopsis with the following combination of characters: scales on top of head reaching forward to between anterior nostril and snout tip; lower margin of eye tangent to a line from snout tip to upper pectoral fin base; an exposed bony ridge below eye; second anal spine larger and more robust than first or second anal spines; a white band from behind eye to level of end of dorsal fin base.

Description. Counts and proportional measurements of the type series are provided in Table 1 .

Dorsal-fin rays X, 9; Anal-fin rays III, 7; Pectoral-fin rays ii, 17 (16–18); Ventral-fin rays I, 5.

Body moderately deep, laterally compressed, depth 2.3 (2.0–2.7) in SL. Dorsal profile of head more convex than ventral contour, head length 3.2 (2.9–3.4) in SL. Snout short, 3.9 (3.2–4.1) in HL. Eye moderately large, 3.3 (2.5–3.3) in HL, eye diameter about equal to or a little more than snout length 0.9 (0.6–1.0) in snout length. Interorbital width 1.2 (1.1–1.9); Suborbital depth 2.0 (2.0–4.4) in eye diameter; a moderately large backwardlydirected spine and with 3 smaller spines below this on posterior margin of suborbital. An exposed bony ridge present beneath eye immediately behind suborbital, this ridge pointed at each end, sometimes spinous in larger specimens. Posterior margin of opercle coarsely denticulate; posterior margin of preopercle denticulate. Canine teeth absent. Teeth conical, pointed; 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. Maxilla smooth. Gill rakers short and stubby, 11 (10–11) on first arch. Lower margin of eye tangent to a line from snout tip to upper pectoral fin base.

Second anal spine larger and more robust than other two spines, its length 2.2 (1.9–2.5) times that of first and 1.5 (1.2–1.5) times that of third. Caudal fin forked, lobes pointed; lower lobe a little shorter than upper. Pelvic fins moderately long, reaching beyond anus, 1.1 (1.1–1.2) in HL. Pectoral fins reaching to or just short of level of anus, 1.2 (1.1–1.4) in HL. Body covered with ctenoid scales. Temporal region scaled, scales on top of head reaching forward to in front of anterior nostril. Preopercle scales in 4 (3–5) rows behind eye; sub-orbital naked; lower limb of preopercle with single row of embedded scales. Opercle with 5 rows of scales; upper margin of opercle with a small, flat embedded spine. Lateral line with 42 (41–44) pored scales, 3½ transverse scale rows above lateral line, 14 (13–15) rows below. Vertebrae 22.

Colour. Body reddish brown, with a distinct whitish band from behind upper edge of eye to almost end of dorsal fin running mostly below the lateral line. Scales usually dark brown at middle. Pectoral fin light pink; dorsal and anal fin darker brown, caudal fin lighter.

Distribution. India - coasts of Tamil Nadu and Kerala, Mumbai, and Sri Lanka.

Etymology. The species name is derived from the acronym of the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, where it was first collected and in recognition of the contribution of IGCAR to marine environmental studies and support for ongoing ichthyological research on the Tamil Nadu coast of India. The common name Igcar monocle bream is proposed for this species.

Discussion. Among the known species of the genus, Scolopsis igcarensis sp. nov. most resembles S. vosmeri ( Bloch 1792) ( Fig. 3 ). Scolopsis vosmeri , however, differs from S. igcarensis in having a more robust suborbital spine; bony ridge beneath eye less prominent, covered with skin; and pectoral fins not reaching to level of anus. Scolopsis vosmeri also differs in colour pattern, described as having “a white cheek band and sometimes a whitish horizontal stripe below lateral line from edge of opercle to below soft part of dorsal fin ( Day 1875; Russell 1990). The stripe in S. vosmeri is more usually yellowish-white and only found in large specimens ( Fig. 3 ). Small specimens do not possess this stripe but the typical white vertical cheek band is always present in S. vosmeri . This cheek band is lacking in all of our specimens of Scolopsis igcarensis and together with the characters above, clearly distinguishes it from S vosmeri .

Day (1875: Plate XXIII, fig. 4) figured a specimen from Bombay (= Mumbai) as Scolopsis leucotaenia (Bleeker) ( Fig. 4 ) that closely resembles S. igcarensis . The true Scolopsis leucotaenia ( Fig. 5 ), however, is the juvenile colour form of Scolopsis margaritifer (Cuvier 1830) ( Russell, 1990) , and differs from S. igcarensis 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 S. igcarensis ), and the uppermost dark band on the body above the lateral line (this band is mostly on or below the lateral line in Day’s figure and S. igcarensis ).

Scolopsis . leucotaenia (= margaritifer ) also differs from S. igcarensis 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. igcarensis ); fewer lateral-line scales (34 to 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); center 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. igcarensis . Thus, we feel confident in concluding that Day’s record of Scolopsis leucotaenia represents S. igcarensis .

Comparative material. Scolopsis igcarensis : ZSI F-401, c. 57 mm SL, Bombay (= Mumbai), India (specimen figured as S. leucotaenia in Day 1875). Scolopsis margaritifer : NTM S.10822-005, 3: 58–70 mm SL, Halmahera, Indonesia; NTM S.11968-015, 47 mm SL, NE West Islet, Ashmore Reef, Timor Sea, Australia; NTM S.13686-025, 85 mm SL, reef off Riwo Village, Madang, Papua New Guinea. Scolopsis vosmeri : AMS I.21013-009, 112.1 mm SL, Madras (=Chennai), India; BPBM 27713, 65.0 mm SL, Vizhinjam, Kerala, India; ZSI F-331-333, 3: 69–153 mm SL, Madras (=Chennai), (specimens figured in Day 1875); ZSI F-2475 & 2476, 2: 124–129 mm SL, Madras (=Chennai), India; ZSI F-10626/2, 1 ex., 137 mm SL, Tharuvaikullam, Tamil Nadu, India; ZSI F-10627/2, 5: 56.1–133.8 mm SL, Kalpakkam, Tamil Nadu, India.

Figures

FIGURE 3. Scolopsis vosmeri (Bloch), 159 mm SL, Sri Lanka, Hikkaduwa. (photo: J. E. Randall)

FIGURE 4. Scolopsis leucotaenia as figured in Day (1875).

FIGURE 5. Scolopsis leucotaenia (Bleeker 1853), juvenile of Scolopsis margaritifer (Cuvier 1830), from Bleeker (1875 – 76).

Tables

TABLE 1. Counts and proportional measurements of the holotype and 12 paratypes of Scolopsis igcarensis sp. nov.

	Holotype ZSI F-10623/2, 118.2 mm SL	Paratypes 12 specimens: 67.1–148.1 mm SL
Counts
Dorsal spines	10	10–10
Dorsal rays	9	9–9
Anal spines	3	3–3
Anal rays	7	7–7
Pectoral branched rays (left)	17	16–18
Pectoral branched rays (right)	17	16–17
Lateral line (Llat) scales	42	41–44
Transverse scale rows above Llat	3.5	3.5–3.5
Transverse scale rows below Llat	14	13–15
Gill rakers (upper limb)	6	5–6
Gill rakers (lower limb)	5	5–5
Gill rakers (total)	11	10–11
Preopercle scale rows (behind eye)	4	3–5
Preopercle scale rows (below eye)	6	5–7
Proportional measurements
Depth in SL	2.3	2.0–2.7
Head length (HL) in SL	3.2	2.9–3.4
Depth in HL	0.7	0.6–0.9
Snout length in HL	3.9	3.2–4.1
Eye diameter in HL	3.3	2.5 –3.3
Eye in snout length	0.9	0.6–1.0
Intorbital width in eye	1.2	1.0–1.9
Suborbital depth in eye	2.0	2.0–4.4
Peduncle depth in peduncle length	0.9	0.8–1.3
Dorsal fin length in SL	1.6	1.6–1.8
Anal fin length in SL	5.7	4.5–6.0
Pectoral fin length in HL	1.2	1.1–1.4
Pelvic fin length in HL	1.1	1.1–1.2
Pectoral fin length in pelvic fin length	1.0	0.9–1.2
1st dorsal spine length in longest dorsal spine	1.8	1.6–2.3
longest dorsal spine length in longest dorsal dray	1.3	1.0–1.3
1st anal spine length in 2nd anal spine	2.2	1.9–2.5
2nd anal spine length in 3rd anal spine	0.7	0.7–0.8