Pseudochromis chrysospilus, Gill, Anthony C. & Zajonz, Uwe, 2011

Gill, Anthony C. & Zajonz, Uwe, 2011, Pseudochromine and pseudoplesiopine dottyback fishes from the Socotra Archipelago, Indian Ocean, with descriptions of two new species of Pseudochromis Rüppell (Perciformes: Pseudochromidae), Zootaxa 3106, pp. 1-23 : 7-9

Pseudochromis chrysospilus sp. nov.

Gold-spotted Dottyback

Figures 4–5 ; Tables 1–2

Holotype. SMF 29234, 56.1 mm SL, Socotra Archipelago, SW coast of Socotra Island, Ras Qatanin Bay, 12o21'17"N 53o32'39"E, large boulder (biotope code S5.1.5), 8–11 m, U. Zajonz & F.N. Saeed, 9 April 2000 (ST- 726).

Paratypes. AMS I.45575-001, 1: 40.0 mm SL (cleared and stained), Socotra Archipelago, W coast of Socotra Island, Shuab Bay, Ras Asfar, 12°39’24”N 53°24’07”E, bedrock with encrusting corals and filter feeders in front of cliff (biotope code S4.2.3), 8–10 m, U. Zajonz & M. Apel, 9 March 1999 (ST-017); SMF 29207, 4: 31.1–42.6 mm SL, collected with AMS I.45575-001; SMF 33400, 3: 34.1–42.5 mm SL, collected with holotype; NHCY-P 4, 4: 38.9–51.6 mm SL, collected with holotype; SMF 33552, 1: 39.5 mm SL, Socotra Archipelago, Socotra Island, Ras Qatanin, 12°21’21”N 53°32’44’E, T. Alpermann, 11 February 2011; SMF 33553, 1: 44.9 mm SL, Socotra Archipelago, Socotra Island, Ras Shuab, 12°31’39”N 53°18’27”E, T. Alpermann, 11 February 2011; SMF 33554, 1: 50 mm SL, Socotra Archipelago, Socotra Island, Steroh, 12°19’00”N 53°52’51”E, T. Alpermann, 11 February 2011; SMF 33555, 1: 56.9 mm SL, Socotra Archipelago, Socotra Island, Ras Bidou, 12°39’15”N 53°23’51”E, H. Pulch & F.N. Saeed, 2 December 2009 (ST 09-14-20); SMF 33556, 1: 64.7 mm SL, Socotra Archipelago, Socotra Island, Ras Qatanin, 12°21’09”N 53°32’36’E, H. Pulch & F.N. Saeed, 9 December 2009 (ST 09-19-01); SMF 33557, 1: 55.6 mm SL, Socotra Archipelago, Socotra Island, Ras Qatanin, 12°20’31”N 53°32’36’E, H. Pulch & F.N. Saeed, 10 December 2009 (ST 09-20-18).

Diagnosis. A species of Pseudochromis with the following combination of characters: dorsal-fin rays III,28– 31; anal-fin rays III,18–19; scales in lateral series 47–52; scales below lateral-line 12–15, usually 13–14; scales on upper flank each with dark blue to dark purple basal spot; and scales on posterior part of body with gold basal spots.

Description (based on 19 specimens, 31.1–64.7 mm SL; data for all types followed, where variation was noted, by data for holotype in parentheses). Dorsal-fin rays III,28–31 (III,29), all or all but first 1–3 segmented rays branched (all segmented rays branched); anal-fin rays III,18–19 (III,19), all segmented rays branched; pectoral-fin rays 17–19 (19/19); upper procurrent caudal-fin rays 7–9 (8); lower procurrent caudal-fin rays 7–8 (7); total caudal-fin rays 31–34 (32); scales in lateral series 47–52 (51/49); anterior lateral-line scales 36–43 (42/40); anterior lateral line terminating beneath segmented dorsal-fin ray 21–26 (24/23); posterior lateral-line scales 5–13 + 0–2 (10 + 1/8 + 1); scales between lateral lines 3–4 (3/3); horizontal scale rows above anal-fin origin 12–15 + 1 + 2–4 = 16–19 (14 + 1 + 3/14 + 1 + 3); circumpeduncular scales 19–22 (20); predorsal scales 19–24 (20); scales behind eye 3; scales to preopercular angle 5–6 (6); gill rakers 3–5 + 10–12 = 14–17 (4 + 11); pseudobranch filaments 8–11 (11); circumorbital pores 33–76 (54/53); preopercular pores 16–42 (25/24); dentary pores 3–5 (5/5); posterior interorbital pores 1–5 (2).

Lower lip incomplete; dorsal and anal fins without distinct scale sheaths, although often with intermittent small scales overlapping fin bases; predorsal scales extending anteriorly to point ranging from posterior AIO to mid AIO pores; opercle with 3–5 relatively distinct serrations; teeth of outer ceratobranchial-1 gill rakers varying from moderately developed and running most of raker length, to mostly weakly developed with well-developed teeth confined to raker tips; anterior dorsal-fin pterygiophore formula S/S/S + 3/1 + 1/1/1/1 + 1*/1 + 1* or S/S/S + 3/1 + 1/1/ 1/1/1/1 + 1 (S/S/S + 3/1 + 1/1/1/1/1 + 1); dorsal-fin spines stout and pungent; anterior anal-fin pterygiophore formula 3/1 + 1/1, 3/1 + 1/1 + 1 or 3 + 1/1 + 1/1 (3 + 1/1 + 1/1); anal-fin spines relatively stout and pungent, second spine much stouter than third; pelvic-fin spine moderately stout and pungent; second segmented pelvic-fin ray usually longest, sometimes subequal to third; caudal fin truncate to emarginate, often with only upper lobe produced; vertebrae 10 + 16; epineurals 15–18 (17); epurals 3.

Upper jaw with 2–4 pairs of curved, enlarged caniniform teeth anteriorly, and 4–5 (at symphysis) to 1–2 (on sides of jaw) inner rows of small conical teeth, outermost of rows of conical teeth much larger and more curved than inner rows; lower jaw with 2–4 pairs of curved, enlarged caniniform teeth anteriorly, and 3–4 (at symphysis) to 1 (on sides of jaw) inner rows of small conical teeth, teeth on middle of jaw larger and curved; vomer with 1–2 rows of small conical teeth, forming chevron; palatine with 1–3 rows of small conical teeth arranged in elongate, suboval patch, anterior part of tooth patch more-or-less contiguous with posterolateral arm of vomerine tooth patch; ectopterygoid edentate; tongue moderately pointed and edentate.

As percentage of SL (based on 10 specimens, 34.1–64.7 mm SL): Head length 20.4–24.9 (21.9); orbit diameter 6.8–9.4 (7.7); snout length 4.8–5.9 (5.5); fleshy interorbital width 3.6–4.7 (3.6); bony interorbital width 2.5–3.1 (2.5); body width 19.6–11.7 (10.0); snout tip to posterior tip of retroarticular bone 10.2–13.5 (10.2); predorsal length 27.4–32.3 (29.1); prepelvic length 27.2–31.6 (28.5); posterior tip of retroarticular bone to pelvic-fin origin 16.8–20.1 (17.6); dorsal-fin origin to pelvic-fin origin 22.4–25.4 (24.4); dorsal-fin origin to middle dorsal-fin ray 32.3–37.1 (35.7); dorsal-fin origin to anal-fin origin 35.9–39.4 (37.1); pelvic-fin origin to anal-fin origin 27.0–31.4 (28.7); middle dorsal-fin ray to dorsal-fin termination 23.8–29.4 (26.7); middle dorsal-fin ray to anal-fin origin 22.1–24.2 (23.4); anal-fin origin to dorsal-fin termination 33.9–38.3 (37.4); anal-fin base length 29.0–35.2 (33.2); dorsal-fin termination to anal-fin termination 12.5–14.1 (13.4); dorsal-fin termination to caudal peduncle dorsal edge 9.5–11.8 (11.2); dorsal-fin termination to caudal peduncle ventral edge 16.3–18.0 (17.1); anal-fin termination to caudal peduncle dorsal edge 16.0–18.4 (18.0); anal-fin termination to caudal peduncle ventral edge 9.9–12.1 (11.9); first dorsal-fin spine 1.8–3.1 (2.9); second dorsal-fin spine 4.2–6.4 (4.6); third dorsal-fin spine 6.6–9.1 (7.7); first segmented dorsal-fin ray 10.2–11.5 (10.9); fourth last segmented dorsal-fin ray 13.8–15.2 (15.2); first anal-fin spine 1.8–2.7 (2.5); second anal-fin spine 4.2–6.5 (5.2); third anal-fin spine 5.1–7.3 (5.7); first segmented anal-fin ray 8.0–10.0 (8.9); fourth last segmented anal-fin ray 11.1–13.4 (13.4); third pectoral-fin ray 12.7–15.4 (13.2); pelvic-fin spine 7.4–10.0 (7.5); second segmented pelvic-fin ray 14.7–17.4 (16.2); caudal-fin length 22.1–23.8 (23.4).

Live coloration (based on field observations and colour slide of 42.5 mm SL paratype from Socotra; Figure 5 ). Head and body yellowish to orangish brown, darker dorsally, becoming purplish blue behind anal-fin origin; upper part of operculum and head with dark purplish blue spots; two or three slightly oblique, dark blue stripes on cheeks beneath eye; snout and lips dark grey; iris bright red to brown with bright blue oblique line above and below pupil; scales of nape and upper flanks (immediately behind and above pectoral-fin base) each with dark blue to dark purple basal spot; scales of remainder of body each with orange-brown to bright golden yellow basal spot; dorsal fin yellowish to reddish brown, with three to six rows of elongate dark blue to purple spots, these curving proximally posteriorly to form broken oblique lines; anal fin blue to bluish hyaline, with several rows of yellow spots, these strongest on basal part of fin; caudal fin dark purplish grey, becoming greyish hyaline posteriorly; each scale of caudal-fin base with orange-brown basal spot; pectoral fins yellowish hyaline, brown basally; pelvic fins greyish hyaline to hyaline.

Preserved coloration. Pattern similar to live coloration, head and body becoming brown, paler ventrally; dark purple to blue spots on head, nape, flanks and dorsal fin become dark brown to dark grey, these darkest on flanks; stripes on cheek become brown, though often indistinct; dark grey-brown to dark grey spot usually present on edge of opercle immediately behind upper tip of preopercle; dark grey-brown stripe extending from midside of upper lip to midanterior edge of eye; orange-brown and yellow spots on body and fins become pale brown; caudal fin brown basally and brownish hyaline distally, usually with indistinct to distinct narrow, dark grey stripe near upper border of fin, and another near lower border; border of fin above and below stripes noticeably paler; pectoral fins and pelvic fins pale brown to hyaline.

Habitat and distribution. Collected from the south-west coast of Socotra Island at Ras Qatanin Bay, around a large boulder in 8–11 m from a macroalgae dominated biotope with large sponges and very sparse encrusting hard coral on rock platform with gravelly sand, and from the west coast of Socotra Island at Shuab Bay, Ras Asfar in 8– 10 m on a sparse hard coral and filter feeder community on rock outcrops. Additional visual records were made in 2000 from a Porites dominated community on rock platform from the west coast near Ras Bidou (ST-736, biotope code 6.6.1). Recently (2009, 2011) the species has been recorded (by H. Pulch, F.N. Saeed and T. Alpermann) from Ras Qatanin, Shuab Bay and Ras Bidou again, and from the south of Socotra (off Steroh village). The species has not been collected at any of the relatively sheltered hard coral dominated biotopes at the north and north-east coast of Socotra, indicating tentatively a preference for the rather harsh, monsoon and upwelling impacted habitats in the south and west of Socotra Island. Two visual records from Hawlaf and Di Hamri at the north coast might represent misidentifications. The species has thus far only been recorded from the shallow depth range of 3– 11 m. It does also not seem to inhabit the other islands of the Archipelago. This apparent range restriction requires confirmation.

Comparisons. Pseudochromis chrysospilus belongs to a species complex (hereafter termed the “ P. caudalis - complex”) that includes P. caudalis Boulenger (1898) from the Persian Gulf to South Asia, P. m o o i i Gill (2004) from Komodo Island, Indonesia, and P. natalensis Regan (1916) from south-eastern Africa. Pseudochromis caudalis -complex species are distinguished from congeners in having relatively high numbers of segmented dorsal- and anal-fin rays (modally 27–30 and 17–19, respectively), relatively small scales (scales in lateral series usually 43– 50), and usually a large dark grey to dark greyish brown (bright blue in life) spot on the anterior part of the opercle behind the upper tip of the preopercle. Meristic characters separating the four species are summarised in Table 2. Pseudochromis chrysospilus differs from P. caudalis in having more segmented anal-fin rays (18–19, usually 19, vs. 17–19, rarely 19), more segmented dorsal-fin rays (28–31 vs. 28–29), and fewer scales below anterior lateral line (12–15, usually 13–14 vs. 15–17). It differs from P. m oo ii in having more segmented anal-fin rays (18–19, usually 19 vs. 17), more scales in lateral series (47–52 vs. 46) and fewer scales below anterior lateral line (12–15, usually 13–14 vs. 15). It differs from P. natalensis in having more segmented dorsal-fin rays (28–31 vs. 26–28, modally 27); more segmented anal-fin rays (18–19, usually 19 vs.16–18, modally 17); more total caudal-fin rays (31–34, modally 32 vs. 29–32, modally 30); and more scales in lateral series (47–52 vs. 41–50, usually 44–46). It further differs from these species in live coloration, particularly in having dark blue to dark purple basal spots on scales on the upper flanks and gold spots on the posterior part of the body.

Remarks. Research on the niche ecology and conservation genetics of P. chrysospilus is currently underway as part of a joint project of the second author with H. Pulch of the BiK-F.

Etymology. The specific epithet is from the Greek “chrysos,” gold, and “spilos,” spot, and alludes to the distinctive gold spots on the body.

Material examined. See above type material.

Figures

FIGURE 4. Pseudochromis chrysospilus, SMF 29234, 56.1 mm SL, holotype, Ras Qatanin Bay, SW coast of Socotra Island, Socotra Archipelago. (Photo by P. Hurst)

FIGURE 5. Pseudochromis chrysospilus, live, SMF 33400, 42.5 mm SL, paratype, Ras Qatanin Bay, SW coast of Socotra Island, Socotra Archipelago. (Photo by U. Zajonz)