Parapercis okamurai Kamohara, 1960

Ho, Hsuan-Ching, 2014, Redescription of Parapercis okamurai Kamohara, 1960 (Perciformes: Pinguipedidae), based on specimens newly collected from Taiwan and Japan, Zootaxa 3857 (4), pp. 581-590 : 582-588

Parapercis okamurai Kamohara, 1960

New English name: Yellow Sandperch

Figures 1A–E , 3A–B; Tables 1–2

Materials. Holotype. BSKU 8872 (103.8), Mimase fishin port, Kochi Prefecture, Japan . Paratypes. BSKU 8917 (91.8), same as holotype. Non-types . NMMB-P11430 (102.7 mm) , NMMB-P11440 (1, 104.2 mm), Nan-fang-ao fish market, Yilan, NE Taiwan, NW Pacific Ocean , ca. 200 m, 16 Jul. 2010, coll. H.-C. Ho. NMMB-P17673 (7, 96.1–121.0 mm; 1, cleared & stained, 121.4 mm) , HUMZ 220768 (2, 103.4– 108.7 mm) , NSMT-P 115455 (1, 113.8 mm) , QM I.39132 (1, 124.4 mm), near Diao-yu-tai Islands (Senkaku Islands), ca. 200 m, NE Taiwan, collected from Da-xi fish market by Ho, H.-C., 12 Nov. 2012 . NSMT-P 101545 (1, 104.0 mm), 34°40.95'N, 139°17.92 E, off Izu-oshima I., Izu Is. , Tokyo Prefecture, Japan, 220–277 m, 14 May 2004 .

Diagnosis. A species of Parapercis that differs from congeners in having cycloid scales on the parietal region and most parts of the opercle and subopercle; dorsal surface uniformly yellowish, lateral body with 10 faint yellow bands, paler ventrally; membranes between first and third dorsal-fin spines black; an irregular black spot on the inner portion of the upper pectoral-fin base; a prominent ocellus on the upper part of the caudal-fin base, and a combination of characters.

Description. Morphometric data are provide in Table 1 . The following data are provided for the holotype, followed by the range of all measured/counted others in parentheses, except as otherwise noted.

Dorsal-fin rays V, 23 (IV, 24 in paratype and V, 22 in 1 non-type); anal-fin rays I, 19; all dorsal and anal soft rays branched, the last at base; pectoral-fin rays 18 or 19, branched, except for uppermost ray; pelvic-fin rays I, 5; principal caudal-fin rays 9 (upper) + 8 (lower) =17 (15 branched); pored lateral-line scales 61 (59–64, not including 3 or 4 pored scales on base of caudal fin); scales above first lateral-line scale to origin of dorsal fin 4.5 (4.5 or 5.5); scales below lateral line posteroventrally to origin of anal fin 15 (13–16); medial predorsal scales 9–10; circumpeduncular scales 20–21; gill rakers of first gill arch 4+10=14 (4–5+9–11=13–16); pseudobranchial filaments 12–17 (broken in holotype, 13 in paratype); branchiostegal rays 6; vertebrae 10 + 22 = 32 (6 specimens examined) .

Body relatively slender, body depth at pectoral-fin base 15.4% (13.5–17.2%) of SL; body slightly depressed anteriorly, body width at pectoral fin base 18.2% (15.6–20.0%) of SL, cylindrical medially and strongly compressed posteriorly. Head short, its length 26.7% (25.8–28.9%) of SL; ventral part of head, chest, and abdomen flat; snout short, its length 7.8% (6.9–8.6%) of SL; eye large, orbit diameter 9.0% (8.1–10.2%) of SL; interorbital space very narrow and flat, the least fleshy width 2.1% (1.5–2.4%) of SL.

Mouth large, the maxilla reaches a vertical through anterior 1/4 of eye, upper jaw short, its length 9.5% (8.9–10.5%) of SL. Mouth slightly oblique, forming an angle of about 15° to horizontal axis of body, lower jaw projecting. Front of each lower jaw with 4 (4–5, sometime with 1 or 2 missing teeth) recurved canine teeth, the third (third or fourth) one on each side twice as large as the rest; side of lower jaw with a row of 22 (20–23) stout, conical teeth that curve medially, anterior 8 (7–8) increasingly larger and more strongly recurved; remaining teeth in outer row on side of jaw subequal in length; broad band of villiform teeth median to canines in about 5 (5–6) rows at front of lower jaw, gradually tapering posteriorly to a narrow band ending before midpoint of the jaw. Front of each upper jaw with 4 (4–5) recurved canine teeth, increasing in length laterally, third about twice as large as 1st and slightly curving laterally as well as posteriorly; side of upper jaw with row of 20 (18–21) stout and conical teeth slightly curve medially, gradually smaller posteriorly; band of about 6 (5–6) rows of villiform teeth medial to canines at front of lower jaw, gradually tapering posteriorly to a single row extending to end of jaw. Vomer with a triangular patch of 2 (2–4) rows of stout, conical teeth, those on anterior margin largest, posterior ones progressively smaller; palatine with two rows of stout teeth, each row with 7 (6–7) smaller teeth. Lips smooth, their inner surface with large fleshy papillae that interdigitate with anterior teeth. Tongue broadly rounded, reaching forward to slightly beyond anterior margin of vomerine teeth.

Gill membranes free from isthmus, forming a broad transverse free fold, the middle part narrowly attached to body dorsally, only free at posterior one-fifth. Gill rakers short and spinous, longest about 1/3 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 nearly reaches to anterior margin of posterior nostril when laid back; posterior nostril dorsoposterior to anteriornostril, its aperture ovate, with low anterior rim.

Pores of cephalic sensory system with row of 4 large pores above maxilla; 2 pores near nostrils, one between nostril and one below; row of 3 pores on either side on anterior half of interorbital space (1 pairs of extra pores between posterior nostrils in paratype); 2 irregular series of small pores medially on posterior half of interorbital space; many 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 and upper part of opercle; cheek with 9 (8–10) irregular double series of pores; series of 6 large pores along the margin of preopercle; a series of 4 large pores on mandible; 2 medial pores 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 upper end of gill opening; scales extending forward to a vertical line through upper end of preopercle; scales on pectoral-fin base weakly cetnoid anteriorly and cycloid posteiroly; those on area anterior to pectoral-fin base weakly ctenoid dorsally and cycloid ventrally; those on opercle cycloid, except for 1 or 2 large ctenoid scale covering opercular spine; those on subopercle cycloid, a small naked area on lower one-fourth of subopercle; interopercle naked; cheek scales cycloid, in about 9 irregular horizontal rows below the eye, all relatively large and imbricate, extending anteriorly to a vertical through anterior one-fourth of eye (some non-type with weakly cetnoid scales posteriorly); progressively smaller ctenoid scales extending out onto basal portion of caudal fin for at least onethird height of fin; lateral line broadly arched over pectoral fin, then gradually descending to become horizontal midlaterally on posterior fourth or so of body.

Origin of dorsal fin over 6th (5th or 6th) lateral-line scale, predorsal length 28.0% (28.0–31.6%) of SL, slightly longer than head length; 5 dorsal-fin spines, all relatively slender, progressively longer posteriorly; 1st dorsal-fin spine 1.8% (1.8–3.2%) of SL (broken in paratype); 2nd dorsal-fin spine 2.8% (3.2–5.0%) of SL; 3rd dorsal-finspine 4.0% (5.2–6.4%) of SL; 4th dorsal-fin spine 6.0% (6.0–7.6%) of SL; 5th spine longest, 6.5% (6.5–8.0 %) of SL (not available in paratype), fully connected by membrane to 1st soft ray; soft dorsal fin higher than spinous one, penultimate dorsal-fin ray longest, 12.7% (11.0–14.1%) of SL; origin of anal fin below base of 5th (5th or 6th) dorsal-fin ray, preanal length 46.9% (44.3–48.0%) of SL; anal-fin spine short, 4.9% (2.0–4.0%) of SL; penultimate anal-fin ray longest, 12.1% (10.4–12.8%) of SL; caudal fin rounded, without prolonged upper lobe, the fin length 19.6% (16.5–20.3%) of SL; pectoral fins broadly rounded when spread, tenth ray longest, total fin length 21.2% (17.7–21.1%) of SL; origin of pelvic fins anterior to pectoral-fin origin, below base of exposed part of opercular spine (slightly forward in smaller non-types), prepelvic length 24.7% (22.8–25.9%) of SL, shorter than head length; pelvic-fin spine slender, 6.5% (4.4–6.6%) of SL; pelvic fins just reaches anus (slightly beyond the anus in paratype and smaller non-type and not reaching in larger non-types),total fin length 18.7% (17.7–21.5%) of SL, fourth pelvic-fin ray longest.

Coloration. When fresh ( Figs. 1A, 1C–E ), dorsal surface of head and cheek and dorsal half of body yellowish; ventral surface of head and ventral half of body pale; about 10-12 faint yellowish bars extending from lateral axis to near ventrum of body; pectoral-fin base and chest bright white; some irregular dark brown spots on shoulder, a larger irregular black spot at inner side of pectoral-fin base dorsally; scales on lateral line more yellow than other parts; pectoral fin, pelvic fin and lower half of anal fin yellowish; a black patch on anterior portion of spinous dorsal fin; soft dorsal fin pale with many oblique yellow bars; a prominent ocellus on upper portion of caudal-fin base; caudal fin pale with five yellowish narrow bars on upper 2/3 of the fin.

When preserved ( Figs. 1B , 3A–B), body uniformly pale brownish; a few small spots on shoulder region; anterior portion of spinous dorsal fin with a black patch; an irregular spot on inner side of upper pectoral-fin base; soft dorsal fin, pectoral and anal fins pale; pelvic fin slightly blackish on dorsal surface, pale elsewhere; a prominentblack spot on upper portion of caudal-fin base; caudal fin pale with 5 vertical bar on upper two-thirds of the fin.

Distribution. Known from southern Japan off Kochi Prefecture and Izu Island, northeastern Taiwan off Nanfang-ao, and Diao-yu-tai Islands (Pinnacle Islands or Senkaku Islands). A single available data was trawled from off Izu Island at depth 220–277 m, whereas other specimens were evidently collected from around 200 m.

Remarks. Although Okamura et al. (1982) mentioned that there are 10 reddish bars on lateral side of body of P. okamurai , the original description provided 10 yellowish bars.

Of all known species, P. okamurai is most similar to P. striolata ( Figs. 2A–B , 3C–D ). It differs from P. striolata in having cycloid scales on the parietal region and most parts of the opercle and subopercle, the anterior few rows of the nape, and on the chest (vs. cetnoid or weakly ctenoid in these areas in P. striolata ); some faint yellow stripes on upper half of body when fresh, but faded in preserved specimens (vs. prominent stripes in both fresh and preserved specimens);13–15 transverse scale rows below the lateral line (vs. 17–18 transverse scale rows); about 10 faint yellow bars on lateral axis of body when fresh (vs. uniformly yellowish in same area); a black spot at inner side of upper pectoral-fin base (vs. absent); a prominent ocellus on upper portion of caudal-fin base (vs. a fuzzy ocellus in same location); a uniform yellow pectoral fins (pale in preservation) and slightly blackish pelvic fins (vs. lower part of pectoral fins and dorsal side of pelvic fins usually black); and about 5 narrow bars on upper two-thirds of caudal fin (vs. up to 11 bars at same location).

It is also similar to Parapercis moki Ho & Johnson, 2013 but differs by having 5 dorsal-fin spines (vs. 4 spines), upper body uniform yellowish with some faint narrow strips (vs. 6 oblique bars), a black spot on inner, dorsal part of pectoral-fin base (vs. absent), 59–63 pored lateral-line scales (vs. 56), 9–10 medial predorsal scales (vs. 12), 20–21 circumpeduncular scales (vs. 26), a relatively short upper jaw (8.9–10.5%, vs. 11.6% of SL) and a shorter prepelvic length (22.8–25.9%, vs. 27.3% of SL).

Figures

FIGURE 1. Parapercis okamurai Kamohara, 1960. A. Original drawing of holotype, BSKU 8872, after Kamohara, 1960, fig. 2. B–C. NMMB-P11430, non-type, 102.7 mm SL. B. fresh condition. C. preserved condition.

FIGURE 3. Parapercis striolata (Weber, 1913), HUMZ 199842, 154.8, lateral view, Mimase fish market, Tosa bay. A. fresh, photo by HUMZ. B. preserved.