Pseudochromis tonozukai, Anthony C. Gill & Gerald R. Allen, 2004

Anthony C. Gill & Gerald R. Allen, 2004, Pseudochromis lugubris and P. tonozukai, two new dottyback fish species from the Indo-Australian Archipelago (Perciformes: Pseudochromidae: Pseudochrominae)., Zootaxa 604, pp. 1-12 : 7-11

Pseudochromis tonozukai new species

Spot-stripe Dottyback

(Figures 2, 4-5; Table 1)

Pseudochromis sp.; Michael, 2004: 139-140 (colour photos; sexual dimorphism; natural history)

Holotype: NCIP 6187, 65.9 mm SL, gravid female, Indonesia, northern Sumatra, Aceh, Weh Island, near Point Seukundo (5°52'N 95°17'51"E), 36 m, spear, G.R. Allen, 27 January 1999.

Paratype: WAM P.31526-001, 62.6 mm SL, male, collected with holotype.

Diagnosis. The following combination of characters distinguishes P. tonozukai from all other pseudochromines: dorsal-fin rays III,25; anal-fin rays III,14-15; scales in lateral series 34-36; caudal fin rhomboid to trifurcate; and upper part of pectoral fin without small dark spot.

Description. Dorsal-fin rays III,25, all segmented rays branched; anal-fin rays III,14- 15 (III,15), all segmented rays branched; pectoral-fin rays 17-18 (18/18); upper procurrent caudal-fin rays 6; lower procurrent caudal-fin rays 5-6 (5); total caudal-fin rays 28-29 (28); scales in lateral series 34-36 (35/36); anterior lateral-line scales 25-27 (26/27); anterior lateral line terminating beneath segmented dorsal-fin ray 18-19 (19/18); posterior lateral-line scales 7-13 + 0-1 (7 + 0/7 + 0); scales between lateral lines 3; horizontal scale rows above anal-fin origin 11-14 + 1 + 3 (11 + 1 + 3/12 + 1 + 3); circumpeduncular scales 16; predorsal scales 21; scales behind eye 3; scales to preopercular angle 5; gill rakers 6 + 12; pseudobranch filaments 11-12 (11); circumorbital pores 24-31 (24/25); preopercular pores 12-24 (13/12); dentary pores 4; posterior interorbital pores 1.

Lower lip incomplete; dorsal and anal fins without distinct scale sheaths, though with scales intermittently overlapping fin bases; predorsal scales extending anteriorly to posterior nasal pores; opercle with 5 moderately distinct serrations; teeth of outer ceratobranchial- 1 gill rakers well developed on raker tips only; anterior dorsal-fin pterygiophore formula S/S/S + 3/1 + 1/1/1/1/1/1 + 1/1; dorsal-fin spines moderately stout and pungent; anterior anal-fin pterygiophore formula 3/1 + 1/1/1 + 1/1/1 + 1; anal-fin spines moderately stout and pungent, the second spine stouter than the third; pelvic-fin spine moderately stout and pungent; second segmented pelvic-fin ray longest; caudal fin angular with upper, lower and mid rays weakly to strongly produced to give rhomboid to trifurcate shape; vertebrae10 + 16; epineurals 13-15 (15); epurals 3.

Upper jaw with 2 pairs of curved, enlarged caniniform teeth anteriorly, medial pair smallest, and 6 or 7 (at symphysis) to 2 or 3 (on sides of jaw) inner rows of small conical teeth; lower jaw with 1 or 2 pairs of curved, enlarged caniniform teeth anteriorly, medial pair smallest, and 4 or 5 (at symphysis) to 1 (on sides of jaw) inner rows of small, conical teeth, teeth on middle of jaw larger and curved; vomer with 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 the tooth patch more-or-less contiguous with posterolateral arm of vomerine tooth patch; ectopterygoid edentate; tongue moderately pointed and edentate.

As percentage of SL: head length 23.6-24.4 (24.4); orbit diameter 8.1-8.3 (8.3); snout length 6.2-6.4 (6.4); fleshy interorbital width 5.5-5.9 (5.9); bony interorbital width 3.8- 4.6 (4.6); body width 11.5-11.7 (11.5); snout tip to posterior tip of retroarticular bone 13.8-14.1 (13.8); predorsal length 31.6-32.6 (32.6); prepelvic length 30.7-30.8 (30.8); posterior tip of retroarticular bone to pelvic-fin origin 17.9; dorsal-fin origin to pelvic-fin origin 27.6-28.2 (28.2); dorsal-fin origin to middle dorsal-fin ray 32.3-34.6 (34.6); dorsal-fin origin to anal-fin origin 41.1-41.4 (41.4); pelvic-fin origin to anal-fin origin 28.8- 30.2 (28.8); middle dorsal-fin ray to dorsal-fin termination 26.7-27.0 (27.0); middle dorsal-fin ray to anal-fin origin 24.4-25.0 (25.0); anal-fin origin to dorsal-fin termination 33.8-34.8 (33.8); anal-fin base length 27.5-28.4 (27.5); dorsal-fin termination to anal-fin termination 14.5-14.7 (14.7); dorsal-fin termination to caudal peduncle dorsal edge 12.3- 12.7 (12.7); dorsal-fin termination to caudal peduncle ventral edge 18.7-19.0 (19.0); anal-fin termination to caudal peduncle dorsal edge 19.9-20.0 (19.9); anal-fin termination to caudal peduncle ventral edge 13.5-14.1 (13.5); first dorsal-fin spine 1.8-2.4 (2.4); second dorsal-fin spine 4.5-5.6 (5.6); third dorsal-fin spine 7.3-8.0 (8.0); first segmented dorsal-fin ray 12.6-12.8 (12.6); fourth last segmented dorsal-fin ray 16.8-18.5 (16.8); first anal-fin spine 1.6-2.6 (2.6); second anal-fin spine 4.2-5.0 (5.0); third anal-fin spine 6.7- 7.3 (7.3); first segmented anal-fin ray 9.1-11.4 (11.4); fourth last segmented anal-fin ray 15.8-17.4 (15.8); third pectoral-fin ray 14.3-14.5 (14.3); pelvic-fin spine 10.5-10.9 (10.9); second segmented pelvic-fin ray 29.3-30.7 (29.3); caudal-fin length 29.2-34.7 (34.7).

Live coloration (based on underwater photographs of individuals taken at the type locality by T. Tonozuka). Females (Fig. 4): head grey, becoming pale pink ventrally; indistinct reddish to maroon stripe extending from posterior edge of eye to opercle, with scattered blue to mauve spots within stripe; lower part of stripe on operculum with fine gold vermiculations; blue to mauve curved streak extending from mid-posterior edge of orbit around outer edge of infraorbital stripe; iris yellowish grey, with bright blue suboval ring around pupil; dorsal contour of body grey, becoming yellowish grey posteriorly; edges of scales within grey to yellowish grey area dark grey, forming chequered to reticulate pattern; remainder of body white with dark reddish grey to dark grey stripe extending from maroon stripe on head to mid-lower part of caudal fin, becoming brown to black on fin; scales within stripe each with dark blue to mauve basal spot; dorsal fin yellowish grey on basal half, remainder of fin yellowish hyaline with indistinct mauve spots and mauve distal margin; anal fin hyaline, narrowly pale blue on base, with distal margin pale blue; brown to black stripe on caudal fin broadly bordered with white on dorsal edge and pale grey on ventral edge; white area bordered dorsally with dark yellowish grey stripe, this converging posteriorly with lower brown to black stripe; remainder of caudal fin yellowish hyaline dorsally and mauvish hyaline ventrally; pelvic fin pale blue to white basally, remainder of fin hyaline; pectoral fin pinkish hyaline. Males (Fig. 5): head grey, becoming pale pink ventrally; indistinct reddish to maroon stripe extending from posterior edge of eye to opercle, with scattered blue to mauve spots within stripe; lower part of stripe on operculum with fine gold vermiculations; blue to mauve curved streak extending from mid-posterior edge of orbit around outer edge of infraorbital stripe; iris yellowish grey, with turquoise suboval ring around pupil; dorsal contour of body grey, edges of scales within grey area dark grey, forming chequered to reticulate pattern; remainder of body white with broad maroon (anteriorly) to orange stripe extending from maroon stripe on head to mid-lower part of caudal fin, becoming brown to black on posterior part of caudal fin; scales within stripe each with dark blue to mauve basal spot; dorsal fin greyish hyaline on basal half, remainder of fin hyaline with indistinct mauve spots and mauve distal margin; anal fin hyaline, narrowly pale blue on base, with distal margin indistinctly mauve; orange to black stripe on caudal fin bordered with white, broadly on dorsal edge and narrowly on ventral edge; upper white area bordered dorsally with yellowish grey stripe, this converging posteriorly with lower orange to black stripe; remainder of caudal fin yellowish hyaline dorsally and mauvish hyaline ventrally; pelvic fin pale blue to white basally, remainder of fin hyaline; pectoral fin pinkish hyaline.

Preserved coloration. Pattern similar to live coloration: pale areas on head, body and fins become pale yellow to pale brown; blue to mauve spots on head and body become brown to dark grey; dorsal part of head and body become greyish brown, with dark reticulations on dorsal part of body becoming dark grey-brown; dark reddish grey to dark grey stripe on female becoming dark greyish brown to dark grey; maroon to orange stripe on male becoming dark greyish brown and distinct anteriorly, and dusky brown and indistinct posteriorly; dark stripes on caudal fin remain, becoming greyish brown to dark grey or black.

Habitat and distribution. Pseudochromis tonozukai is known only from Weh Island, off northern Sumatra, Indonesia (Fig. 2).

It was observed and collected in 36-40 m. The habitat consisted of a 45° slope with mixed sand-rubble substrate. Approximately 10 individuals were observed in the proximity of dead coral outcrops. Several of these were solitary individuals, but at least four male-female pairs were seen.

Comparisons. Pseudochromis tonozukai appears to be related to P. bitaeniatus and P. lugubris . Characters distinguishing the three species are discussed under Comparisons for P. lugubris .

Pseudochromis tonozukai might also be confused with P. reticulatus Gill and Woodland (1992) from northwestern Australia and P. pictus Gill and Randall (1998) from Alor Island, Indonesia. Both of these species have a pointed caudal fin (rounded with the middle rays produced) and are pale with dark reticulations on the upper part of the body. However, neither species has a stripe on the lower part of the body, and both have more segmented dorsal-fin rays than P. tonozukai (26-27 versus 25). Pseudochromis pictus further differs in having more circumpeduncular scales (20 versus 16).

Due largely to the unusual caudal-fin shape, specimens of P. tonozukai will not key unambiguously beyond couplet 52 of Gill’s (2004) key to Pseudochromis species. It is readily distinguished from species at or following that couplet in having the following character combination: caudal fin rhomboid to trifurcate; segmented dorsal-fin rays 25; segmented anal-fin rays 14-15; and upper part of pectoral fin without small dark spot. The live and preserved colorations also readily distinguish P. tonozukai from these and all other pseudochromid species.

Remarks. The specific epithet is for Takamasa Tonozuka, who first discovered the species and brought it to the attention of the second author.