Parapercis moki, Ho, Hsuan-Ching & Johnson, Jeffrey W., 2013

Ho, Hsuan-Ching & Johnson, Jeffrey W., 2013, Redescription of Parapercis macrophthalma (Pietschmann, 1911) and description of a new species of Parapercis (Pisces: Pinguipedidae) from Taiwan, Zootaxa 3620 (2), pp. 273-282 : 279-281

Parapercis moki n. sp.

New English name: Mok’s sandperch Figs. 2 A–B, Table 1

Holotype. NMMB-P0892 (104.4 mm), Chong-Chou, Kaohsiung, southwestern Taiwan, northern South China Sea, 29 Nov. 1984, coll. M. Mok et al. (originally catalogued NSYU 1943).

Diagnosis. A species of Parapercis with relatively slender body; six transverse bars on upper body; numerous small pores with canals forming about 9–10 vertical rows on cheek, opercle and subopercle; scales on nape extending anteriorly to level of posterior margin of eyes; large spine on posteroventral corner of subopercle; interorbital space very narrow (1.6% SL); and combination of the following characters: 4 dorsal-fin spines, each spine progressively longer posteriorly, with last spine entirely connected by membrane to first dorsal-fin ray; 23 dorsal-fin soft rays; anal-fin with 1 spine and 19 soft rays; pectoral-fin rays 18 or 19; four pairs of canine teeth anteriorly in lower jaw; palatine teeth present, in two rows; vomerine teeth stout, in two rows; scales on sides, belly and prepectoral region ctenoid, becoming cycloid on nape and prepelvic areas; margin of preopercle smooth with some small indentations on posterior margin; appressed pelvic fin not reaching origin of anal fin.

Description. Morphometric data based on the holotype are provided in Table 1. Dorsal-fin rays IV, 23; anal-fin rays I, 19; all dorsal and anal soft rays branched, the last to base; pectoral-fin rays 18 (left side) and 19 (right side), branched except uppermost; pelvic-fin rays I, 5; principal caudal-fin rays 9 (upper) + 8 (lower) =17; upper procurrent caudal-fin rays 9; lower procurrent caudal-fin rays 7; pored lateral-line scales 56 (not including 2 pored scales on base of caudal fin); scales above first lateral-line scale to origin of dorsal fin 4; scales above highest part of lateral line to base of dorsal fin 3; scales below lateral line posteroventrally to origin of anal fin about 17; median predorsal scales 12 (counted to level of posterior margin of eye); circumpeduncular scales 26; gill rakers of outer first gill arch 5 + 9 = 14; pseudobranchial filaments 16; branchiostegal rays 6; vertebrae 10 + 23 = 33.

Body relatively slender, its depth 5.6 times in SL, 1.6 in HL; body subcylindrical anteriorly, the width 5.3 in SL, 1.5 in HL, strongly compressed posteriorly; head relatively short, its length 3.5 in SL; ventral part of head, chest, and abdomen slightly convex; snout relatively short, its length 3.3 in HL; eye relatively large, orbit diameter 3.1 in HL; interorbital space very narrow and flat, the least fleshy width 17.5 in HL; caudal-peduncle depth 3.5 in HL; caudal-peduncle length 3.7 in HL.

Mouth large, the maxilla not quite reaching a vertical through center of eye, upper jaw relatively short, its length 2.5 in HL; mouth slightly oblique, forming an angle of about 20° to horizontal axis of body, lower jaw projecting; front of lower jaw with 4 pairs of recurved canine teeth, the middle one on each side twice as large as the rest; side of upper jaw with row of about 24 slender conical teeth that curve medially and posteriorly, anterior 8 increasingly larger and more strongly recurved; remaining teeth in outer row on side of jaw decreasing in length; broad band of villiform teeth medial to canines in about 7 rows at front of upper jaw, gradually narrowing posteriorly to a narrow band in about 3 irregular rows; front of lower jaw with 4 pairs of incurved canine teeth, increasing in length laterally, 4th twice as large as 1st and strongly curving laterally as well as posteriorly; band of about 5 rows of villiform teeth medial to canines at front of lower jaw, medial row continuing laterally in jaw posterior to last canine as row of 7 increasingly larger and more strongly recurved teeth, followed by a single row of small teeth, with an additional inner row of 3 teeth at posterior part, to end of jaw; vomer with a triangular patch of stout conical teeth, 7 on anterior margin largest, lateral and posterior ones progressively smaller; palatine with two rows of stout teeth, those on outer row larger than those on inner row; lips smooth, their inner surface with large fleshy papillae that interdigitate with anterior teeth; tongue broadly rounded, reaching forward to posterior vomerine teeth.

Gill membranes free from isthmus, with a broad transverse free fold. Gill rakers short and spinous, longest about half length of longest gill filament. Nostrils small, anterior nostril in front of center of eye (viewed from side), a little less than half way to groove at margin of upper lip, with high anterior rim and pointed posterior flap that reaches nearly anterior margin of posterior nostril when laid back; posterior nostril dorsoposterior to anterior nostril, its aperture ovate, with slight anterior rim.

Pores of cephalic sensory system as shown in Fig. 2 . Row of 3 large pores above maxilla; 3 pores near nostrils, one above, one between and one below; row of 3 pores on either side anteriorly in interorbital space; irregular series of small pores medially on posterior half of interorbital space; numerous small pores with subcutaneous canals posteriorly on occiput, pores divided into several irregular double series, from anterior end of lateral line on body, continuing to ventral margin of eye, opercle and subopercle; cheek with 8–9 irregular double series; series of 10 small pores along the margin of preopercle; a series of 4 large pores on mandible; two medial pore at front of chin.

Opercle with single sharp spine level with ventral edge of pupil (when viewed from side); subopercle with a single sharp spine at posteroventral corner; preopercle broadly rounded, its free edge smooth except for slight indentations at each pore site, extending from level of ventral edge of orbit downward and forward to slightly in front of a vertical at posterior edge of orbit.

Scales finely ctenoid on body, becoming cycloid anterior to a line from base of third dorsal spine to anterior end of lateral line, extending forward to a vertical from posterior margin of eye; scales on base of pectoral fin ctenoid, those on area anterior to pelvic–fin base, opercle and subopercle cycloid; cheek scales cycloid, in about 9 irregular horizontal rows, relatively large and nonimbricate, extending anteriorly to a vertical from anterior 1/3 of eye; progressively smaller scales extending out on basal portion of caudal fin for at least 2/3 length of fin; base of pectoral fin with up to 4 rows of small cycloid scales; lateral line broadly arched over pectoral fin, then gradually slanting to straight midlateral portion on about posterior fourth of lateral body.

Origin of dorsal fin over third lateral-line scale, predorsal length 3.3 in SL, equal to head length; 4 dorsal-fin spines, all relatively slender, progressively longer posteriorly; 1st dorsal-fin spine 5.4 in HL; 2nd dorsal-fin spine 4.2 in HL; 3rd dorsal-fin spine 3.8 in HL; 4th dorsal-fin spine longest 3.3 in HL, full length of spine likely attached to 1st soft ray by membrane (membrane damaged in holotype); last dorsal soft ray longest, 2.0 in HL; origin of anal fin below base of 4th dorsal soft ray, preanal length 2.1 in SL; anal-fin spine 7.1 in HL; last anal soft ray longest, 2.4 in HL; caudal fin rounded, without prolonged upper lobe; total fin length 5.6 in SL, 1.6 in HL; pectoral fins broadly rounded when spread, tenth ray longest, 4.6 in SL, 1.3 in HL; origin of pelvic fins anterior to pectoral-fin origin, below base of exposed part of opercular spine, prepelvic length 3.7 in SL, 1.0 in HL; pelvic-fin spine slender, 4.1 in HL; pelvic fins extending to genital papilla, but not reaching origin of anal fin; fourth soft pelvic ray longest, 4.6 in SL, 1.3 in HL.

Color when fresh. Currently unknown.

Color in alcohol ( Fig. 2 A). Uniformly light brown with six slightly oblique narrow bars laterally on upper body, each bar of about the same width, extending from base of dorsal fin to slightly below midbody; first bar at front of spinous dorsal fin and posterior base of pectoral fin; second at base of 2nd–3rd dorsal-fin rays; third at 6th–7th rays; fourth at 11th–12th rays; fifth at 16th–17th rays; and sixth at 21st–22nd rays. A prominent black spot at upper corner of caudal fin base, from the last procurrent to 7th ray of upper lobe, slightly larger than pupil of eye, appearing non-ocellate. About 5 narrow oblique bars on caudal fin.

Distribution. Known only from the holotype collected from off Chong-Chou, Kaohsiung, southwestern Taiwan.

Etymology. Named after Professor Hin-Kiu Mok, National Sun Ye-San University, in recognition of his numerous contributions to fish studies and for providing the holotype for this study.

Comparison. Parapercis moki is unique within the genus in having many vertical rows of lateral-line pores on the cheek. It is most similar to Parapercis sexlorata Johnson, 2006 , these two being the only Parapercis species with 6 narrow oblique black bars on the upper body. Parapercis moki can readily be distinguished from P. s e x l o r a t a in having 4 pairs of conical teeth anteriorly in the outer row of the lower jaw (vs. three pairs) and a strong spine on posteroventral corner of subopercle (vs. some feeble spinules). Parapercis moki is also similar to P. muronis and P. macrophthalma in general appearance. It can be distinguished from both of the latter in having 4 dorsal-fin spines (vs. 5); 6 narrow oblique black bars on upper body (vs. 5 vertical bars in P. macrophthalma and 5 oblique bars in P. muronis ); a prominent spot slightly larger than the pupil of the eye on the anterodorsal corner of caudal fin base (vs. an relatively inconspicuous spot smaller than the pupil of the eye). Other Parapercis species with 4 dorsal fin spines are easily distinguished by colouration.

Figures

FIGURE 2. Parapercis moki n. sp., holotype, preserved condition, NMMB-P 0892, 104.4 mm SL, Kaohsiung, southwestern Taiwan. A. lateral view of the fish. B. dorso-lateral view of head pore pattern and squamation (upper) and pores on lower jaw (lower).