Parapercis bicoloripes Prokofiev, 2010

Matsunuma, Mizuki, Mazlan, Abd Ghaffar, Arshad, Aziz, Seah, Ying Giat, K., Siti Tafzilmeriam S. A., Ramasamy, Azwarina Azmi, Babaran, Ricard P., Fukui, Yoshino & Motomura, Hiroyuki, 2016, Distribution Range Extensions of Parapercis bicoloripes and P. diplospilus (Perciformes: Pinguipedidae) in the South China Sea and the Adjacent Waters, with Notes on Ontogenetic Changes in P. bicoloripes, Species Diversity 21, pp. 187-196 : 188-192

Parapercis bicoloripes Prokofiev, 2010

( Figs 1–3 ; Tables 1–2)

Material examined. Twenty-seven specimens, 66.1– 136.0 mm SL . Thailand: KAUM –I . 23099, 100.2 mm SL, KAUM –I. 23124, 110.9 mm SL, KAUM –I. 23128, 100.5 mm SL, KAUM –I. 23158, 100.9 mm SL, KAUM –I. 24153, 128.4 mm SL, northern Gulf of Thailand, bottom trawl (obtained at fish market in Mahachai) . Malaysia (Terengganu State, east coast of Malay Peninsula): KAUM –I . 16935, 120.4 mm SL, off Kuala Terengganu , bottom trawl, 11 December 2008 (obtained at Chendering fishing port, Kuala Terengganu); KAUM –I . 41715, 119.1 mm SL, KAUM –I. 41716, 102.7 mm SL, 48 km off Chendering, Kuala Terengganu , 05°16′N, 103°11′E, 70–90 m depth, bottom trawl, 10 September 2011; KAUM –I . 79750, 123.3 mm SL, KAUM –I. 79751, 108.1 mm SL, KAUM –I. 79752, 104.9 mm SL, KAUM –I. 79753, 126.2 mm SL, KAUM –I. 79754, 136.0 mm SL, KAUM –I. 79755, 123.1 mm SL, KAUM –I. 79756, 126.0 mm SL, KAUM –I. 79757, 118.4 mm SL, KAUM –I. 79758, 115.3 mm SL, KAUM –I. 79759, 119.8 mm SL, KAUM –I. 79760, 107.9 mm SL, KAUM –I. 79761, 132.7 mm SL, UMTF 6569, 129.1 mm SL, UMTF 6570, 109.9 mm SL, UMTF 6571 , 79.0 mm SL, UMTF 6572, 102.4 mm SL ,

UMTF 6573, 123.9 mm SL, off Kuala Terengganu, bottom trawl . Malaysia (Sabah State, Borneo): KAUM –I. 12491, 96.2 mm SL, off Kota Kinabalu, bottom trawl (obtained at fish market in Kota Kinabalu) . Philippines: KAUM –I. 69435, 66.1 mm SL, off Miagao, Iloilo, Panay Island , 24 February 2015 .

Description. Morphometrics, expressed as percentages of SL, and frequency distribution of selected meristics are shown in Tables 1 and 2. Dorsal-fin rays V, 21; anal-fin rays I, 17; pectoral-fin rays all branched except for uppermost ray; pelvic-fin rays I, 5; branched caudal-fin rays 15 (8 and 7 in dorsal and ventral series, respectively); pseudobranchial filaments 14–20 (18); branchiostegal rays 6.

Body subcylindrical, moderately elongate; moderately deep, depth at anal-fin origin 4.8–5.8 in SL; width at pectoral-fin base 5.7–7.3 in SL. Caudal peduncle short, deep, its depth 0.9–1.1 in length. Head moderately large, length 3.5–3.9 in SL; snout blunt, length slightly longer than orbit diameter; eye relatively large, fleshy orbit diameter 3.5–4.3 in HL; interorbital space moderately wide, least bony width 10.2–15.6 in HL.

Mouth small, slightly oblique, forming angle of about 20° to horizontal axis of head; lower jaw slightly protruding beyond tip of upper jaw; posterior margin of upper jaw reaching vertical drawn through anterior margin of pupil. Upper jaw with outer row of 22–29 incurved caniniform teeth on each side, anterior pair greatly enlarged, about 3 times larger than adjacent teeth in size, other teeth increasingly smaller posteriorly; inner band of villiform conical teeth behind outer caniniform row of upper jaw, broadest anteriorly with 4 or 5 rows maximum, gradually narrowing posteriorly to 1 row at rear of jaw. Front of lower jaw with usually 3 pairs of incurved, enlarged caniniform teeth in distinctly separated outer row (irregular row of 5 pairs of variously sized caniniform teeth in KAUM–I. 79753 regarded as abnormal condition), outermost tooth largest, strongly canted posteriorly, about 3 times size of innermost tooth; inner band of villiform conical teeth medial to caniniform teeth at front of lower jaw, about 4–6 tooth rows in broadest portion, followed by row of small, incurved conical teeth, 2–4 teeth in middle of tooth row moderately enlarged; vomer with single crescentic row of 6–8 moderately large conical teeth, all subequal in size; palatine teeth absent.

Gill membranes free from isthmus, with broad free fold; developed gill rakers short, spinous, longest raker about one-third length of longest gill filament. Nostrils small, anterior nostril with short membranous tube, its tip not reaching posterior nostril when laid back; posterior nostril pore ovate with low fleshy rim.

Pores of cephalic sensory system connected by canals under skin. Three pores in row above maxilla; 3 pores near nostrils, including 1 pore above and 1 below posterior nostril, 1 between nostrils; 2 pores on anterior margin of snout; row of 7–11 pores in infraorbital series, with several branches in posterior portion; 6–8 pores in row on posterior margin of preopercle; interorbital space with 2 pairs of pores in anterior half, irregular medial row of several small pores in posterior half; occiput with numerous small pores; ventral surface of lower jaw with 5 pores on each side, anteriormost pore behind chin.

Opercle bearing short, posteriorly-directed, flattened spine approximately at level of ventral edge of orbit in lateral view; posterior margin of subopercle slightly expanded posteriorly, with 8–10 large serrae; posterior edge of interopercle with 2 or 3 weakly developed serrae; preopercle rounded with 11–20 serrae in all; posttemporal area with small exposed bony cleft, its posterior margin smooth.

Lateral line continuous, 3–5 pored lateral-line scales extending onto caudal fin; body entirely covered with developed ctenoid scales, scales on dorsolateral portion with ca. 35–50 short cteni; opercle, nape, and dorsal-postorbital region with developed ctenoid scales; cheek covered entirely with weakly developed ctenoid scales, possessing ca. 25–30 short cteni; subopercle, interopercle, snout, interorbital space, occipital area and both jaws naked; small, elongate ctenoid basal scales extending onto pectoral and caudal fins; dorsal, anal, and pelvic fins without basal scales.

Origin of dorsal fin approximately above upper pectoral fin base; dorsal-fin spines relatively short; 4th dorsal-fin spine longest; membrane between 5th spine and 1st soft ray attached near tip of 5th spine, moderately incised; all soft rays subequal in length, 19th ray (sometimes 18th or 20th, rarely 10th or 11th) longest. Origin of anal fin below base of 5th or 6th dorsal-fin soft ray; anal-fin spine weak, slender; 15th or 16th (rarely 14th) soft ray longest. Caudal fin round- ed, upper edge slightly pointed posteriorly. Pectoral fin elongate, with rounded posterior contour, 9th or 10th ray longest, its tip almost reaching vertical drawn through anal-fin origin. Pelvic fin origin slightly anterior to level of pectoralfin base, pelvic-fin spine under skin closely attached to 1st soft ray; 4th soft ray longest, its tip not reaching anus when depressed in specimens of> 79 mm SL, just reaching anus in 66.1 mm SL specimen (KAUM–I. 69435).

Fresh coloration. Body pale red, whitish ventrally ( Fig. 1 ); scales on reddish portion of body tinged centrally with yellow; ca. 7 large, indistinct, dark Y- or V-shaped markings laterally on body, from behind pectoral fin to caudal peduncle; indistinct rounded red blotch (blackish in smallest specimen, KAUM–I. 69435) on upper part of caudal-fin base, its size subequal to pupil. Head pale red; cheek with 6 or 7 radial rows of reddish or yellow spots (each cheek scale tinged with reddish or yellow); straight, narrow yellow line from anteroventral edge of orbit to dorsal margin of upper jaw; eye yellow or pink, tinged with dark red dorsally. Dorsal fin semi-translucent, membrane of soft-rayed portion with ca. 5–8 narrow, wavy, yellow longitudinal stripes, these becoming irregular and conjoined posteriorly. Anal fin pale white, tinged with yellow basally; distal part broadly tinged with red. Pectoral fin pale yellow. Pelvic fin pale red (white in KAUM–I. 69435), basal part broadly blackish, ray tips whitish. Caudal fin semi-translucent, with 5–9 radial yellow bands (or radial rows of small yellow spots), number increasing and width narrowing with growth; ventral edge tinged with red.

Distribution. Parapercis bicoloripes has heretofore been recorded only from the Gulf of Thailand, the South China Sea, and the Sulu Sea, including Nha Trang and Phan Thiet bays, Vietnam ( Prokofiev 2008, 2010); the northern Gulf of Thailand; off the east coast of the Malay Peninsula and off northern Borneo; and at Panay Island, the Philippines (this study, Fig. 2 ). Although Mohsin and Ambak (1996: 537, 737, figs 413, 860) recorded Ryukyupercis gushikeni (Yoshino, 1975) as “ Parapercis gushikeni (Yoshino) ” from Malaysia and adjacent waters, a photograph of their R. gushikeni had the diagnostic coloration of P. bicoloripes (see below). Similarly, P. diplospilus and R. gushikeni recorded from Malaysia by Ambak et al. (2010: 230, 231, unnumbered figs) can be identified as P. bicoloripes .

Remarks. The original diagnosis of Parapercis bicoloripes by Prokofiev (2010) included: dorsal-fin rays V, 20 or 21; anal-fin rays I, 17 [18 soft rays in Prokofiev (2010)]; pectoral-fin rays 17; pored lateral-line scales 55–57; scale rows above lateral line to first dorsal-fin spine base 3.5; frontal ca- nines in lower jaw 6; total gill rakers 12–14; head and body entirely covered with ctenoid scales; fifth dorsal-fin spine connected with first soft ray by membrane along most of its length; upper lobe of caudal fin slightly elongate, pointed; no dark markings on head, body, and median fins; pelvic fin bicolored. The present specimens are largely consistent with this diagnosis, with the following exceptions: pectoralfin rays [16–18 vs. 17 in Prokofiev (2010)], scale rows above the lateral line (3.5 or 4.5 vs. 3.5), pored lateral-line scales (52–55 vs. 55–57), and total gill rakers (12–19 vs. 12–14). The pored lateral-line scale count differences may have arisen from differing counting methods between the two studies. Prokofiev (2010) probably including several pored scales extending onto the caudal fin. The other minor differences in counts most likely represent intraspecific variation.

More notably, the present specimens differ from Prokofiev (2010) in most proportional measurements, including head length (25.7–28.7% SL in the former vs. 25.2–26.4% SL in the latter); pre-dorsal-fin length (26.2–30.6% SL vs. 23.9–28.4% SL); pre-anal-fin length (43.4–49.9% SL vs. 42.5–45.5% SL); pre-pelvic-fin length (23.1–25.7% SL vs. 20.9–23.2% SL); caudal-fin length (18.1–21.4% SL vs. 15.8– 18.1% SL); pectoral-fin length (19.2–22.0% SL vs. 16.9– 18.4% SL); pelvic-fin length (20.6–25.7% SL vs. 19.4–23.9% SL); caudal-peduncle length (9.0–11.1% SL vs. 11.4–14.6% SL); and caudal-peduncle depth (8.5–10.2% SL vs. 8.2–9.7% SL). Of these, the minor differences in lengths of the head and pelvic fin, and in caudal-peduncle depth, very likely represent individual variation within the species. Differences in pre-dorsal- and pre-anal-fin lengths may be explained by ontogenetic morphological changes (see below) in as much as the material used in the two studies ranged from 66.1 to 136.0 mm SL (present study) and from 88 to 155 mm SL ( Prokofiev 2010). The remaining differences between the present specimens and Prokofiev (2010) (lengths of the caudal peduncle, pre-pelvic-fin portion, and caudal and pectoral fins) possibly resulted from different measuring techniques, details of which were not provided by Prokofiev (2010).

Notwithstanding the above-mentioned discrepancies, the present specimens are identified here as P. bicoloripes , based on their color pattern. Although 13 additional species of Parapercis were newly described subsequent to Prokofiev (2010), P. bicoloripes can be distinguished easily from all the congeners by its unique coloration ( Ho and Shao 2010; Liao et al. 2011; Allen and Erdmann 2012; Ho et al. 2012, 2014; Johnson and White 2012; Sparks and Baldwin 2012; Ho and Johnson 2013; Chen et al. 2014; Johnson et al. 2014; Ho 2015).

Parapercis bicoloripes , having been previously reported from Vietnam as Parapercis sp. 1 by Prokofiev (2008), was described by Prokofiev (2010) on the basis of 20 specimens from Nha Trang and Phan Thiet bays, Vietnam. The species had also been recorded by Mohsin and Ambak (1996) and Ambak et al. (2010) from Malaysia and adjacent waters, but was misidentified by them as P. diplospilus or R. gushikeni . The present specimens, therefore, represent the first confirmed records of P. bicoloripes from Thailand, Malaysia, and the Philippines, indicating a widespread distribution of the species in the Gulf of Thailand, the South China Sea, and the Sulu Sea ( Fig. 2 ).

Morphological changes with growth. Analysis of the 26 examined specimens (66.1–136.0 mm SL) indicated that several body proportions change with growth in P. bicoloripes . Relative lengths of the snout, bony interorbital space, and upper jaw tend to become greater with growth; in contrast, relative lengths of the fleshy orbit diameter, pre-dorsalfin portion, pre-anal-fin portion, second dorsal-fin spine, anal-fin spine, and pelvic fin become shorter with growth ( Fig. 3 ). No other significant growth-related proportional changes were apparent.

The blotch on the upper part of the caudal-fin base appeared to become paler and more indistinct with growth. The smallest examined specimen (KAUM–I. 69435, 66.1 mm SL) had a distinct blackish-red blotch on the base ( Fig. 1C ), in contrast to larger specimens, which had a poorly defined red blotch ( Fig. 1A–B ). Moreover, the number and width of the yellow bands on the caudal fin become greater and narrower, respectively, with growth. Specimens of <80 mm SL (KAUM–I. 69435 and 79764) possessed about five caudal-fin bands, whereas six to nine bands were present in specimens of> 96 mm SL. The bands were relatively wide in the smallest examined specimen, about twice as wide as the spaces between them ( Fig. 1C ). In contrast, the bands of large specimens were relatively narrow, with a maximum width subequal to or clearly narrower than the spaces between them ( Fig. 1A–B ).

Although gill raker numbers varied considerably in P. bicoloripes (12–19; Table 2), no significant relationship was recognized between their number and either standard length or capture locality, the range in number apparently being as aspect of individual variation.

Figures

Fig. 1. Fresh specimens of Parapercis bicoloripes from Malaysia (A–B) and the Philippines (C). A, KAUM–I. 79754, 136.0mm SL, off Kuala Terengganu; B, KAUM–I. 16935, 120.4mm SL, off Kuala Terengganu; C, KAUM–I. 69435, 66.1mm SL, off Miagao, Iloilo, Panay Island.

Fig. 2. Distribution of Parapercis bicoloripes (triangles) and P. diplospilus (circles). Closed and open symbols indicate previously known and new records, respectively.

Fig. 3. Ontogenetic changes in relationship of snout length (circles) and fleshy orbit diameter (triangles) as percentage of standard length to standard length (mm) in Parapercis bicoloripes.