Parapercis fuscolineata Fourmanoir, 1985

Nakayama, Naohide, Ohkawa, Toshiyuki & Endo, Hiromitsu, 2016, First Record of a Rare Sandperch, Parapercis fuscolineata, from Southern Japan (Actinopterygii: Perciformes: Pinguipedidae), Species Diversity 21, pp. 85-90 : 85-89

Parapercis fuscolineata Fourmanoir, 1985

[New standard Japanese name: Kuroobi-toragisu] ( Figs 1–2 , Table 1)

Parapercis fuscolineata Fourmanoir, 1985: 36 , fig. 1 (original description; 4 specimens; type locality: South China Sea off Lubang Islands, Philippines, 170–187 m depth; holotype lost; 2 extant paratypes: MNHN 1984-430 and BPBM 29668); Randall 2001: 3505 (in key); Ho 2015: 265 , fig. 4 (redescription; 3 additional specimens; southwestern Pacific, 180–355 m depth).

Material examined. BSKU 119364 , 1 specimen, 36.8 mm SL, Tosa Bay off mouth of Niyodo River, Kochi Prefecture, Shikoku Island, Japan, 33.2424ºN, 133.6312ºE, 200–203 m depth, bottom temperature 13.4ºC, R / V Tosa-kaiyo-maru, otter trawl, collected by T . Ohkawa, time 11:52–12:07, 11 August 2015.

Diagnosis. [Modified from Ho (2015).] Species of Parapercis with dark continuous stripe extending from hind rim of orbit to caudal peduncle, ending with large, black ocellus on upper caudal-fin base; spinous portion of dorsal fin uniformly dark; about 12 diagonal yellowish bars on lower half of body; dorsum above dark horizontal stripe uniformly dusky yellow; HL 25.8–30.4% SL; snout length 5.9–7.8% SL; orbit diameter 9.5–13.2% SL; interorbital width 1.4–1.9% SL; four pairs of enlarged canines at tip of lower jaw; vomerine teeth in 1–2 rows, forming broadly Vshaped patch; palatine teeth in 1–2 rows on each side; dorsal-fin rays IV–V, 23; dorsal-fin spines gradually increasing in height posteriorly; anal-fin rays I, 19; pectoral-fin rays 17–19; pored lateral-line scales 61–63; transverse scale rows between dorsal-fin origin and lateral line 3.5–4.5; total gill rakers on first arch 12–20.

Description of Japanese specimen. General features shown in Figs 1 and 2 . Counts and measurements given in Table 1.

Dorsal fin long-based, origin slightly behind vertical drawn through pectoral-fin base; first spine short, thin; height of spines progressively increasing posteriorly (membrane between spinous and soft portions broken); intact soft rays branched, 18th longest (most rays heavily damaged). Anal fin long-based, origin below base of fifth dorsal-fin soft ray; intact soft rays branched, 17th longest. Pectoral fin well developed; all rays branched except for uppermost and lowermost few rays; tip of pectoral fin extending posteriorly to below base of sixth dorsal-fin soft ray. Pelvic fin inserted below opercle, its tip extending slightly beyond anus when laid back. Caudal fin truncate.

Body elongate, almost uniformly shallow, depth at pec- toral-fin base 88% of width over pectoral-fin bases; body cylindrical anteriorly, progressively compressed posteriorly. Head small, rounded, HL 28% of SL. Snout short, moderately pointed in lateral view but broadly rounded in dorsal view; snout length 23% of HL. Orbit large, oval, its horizontal diameter 37% of HL. Interorbital space very narrow, 7% of HL. Mouth small, terminal; upper jaw length 34% of HL; maxilla oblique, forming angle of about 30º to horizontal axis of head and body; posterior end of maxilla reaching about to vertical drawn through anterior margin of pupil; tips of upper and lower jaws about on same vertical; lips thick, fleshy. Opercle with long, stout, horizontal spine on its dorsal margin; subopercle with similar strong spine at posteroventral corner; preopercle broadly rounded posteroventrally, its free margin extending from level of opercular spine to below hind margin of pupil; preopercle and interopercle smooth along their free margins. Gill membranes broadly united, with broad posterior free fold, not attached to isthmus. Branchiostegal rays six. Gill rakers short, ridgelike; pseudobranchial filaments broken (at least eight on left side). Caudal peduncle short, its length and depth 29% of HL.

Teeth small, conical, slender, slightly incurved, in broad tapered band in both jaws. Three pairs of prominent canines at tip of premaxillary, followed laterally by single row of 18 much smaller teeth, these decreasing in height posteriorly (16 on right side); broad inner band of small, villiform teeth anteriorly, this band gradually tapering posteriorly with about 4–5 tooth rows at widest point near symphysis. Four pairs of prominent canines at tip of dentary, followed laterally by single row of 13 conical teeth, these gradually increasing in height posteriorly (11 on right side), this row followed posteriorly by single row of nine uniformly small teeth; broad inner band of small, villiform teeth anteriorly, this band abruptly narrowing posteriorly, with about 3–4 tooth rows near symphysis. Vomer with single row of small, stout, conical teeth forming broadly V-shaped tooth patch. Palatine teeth similar to those on vomer, arranged in one distinct row on each side.

Anterior nostril modified into long tube, slightly shorter than first spine of dorsal fin, with its base situated on horizontal drawn through midorbit when viewed laterally. Posterior nostril small, oval, located dorsoposteriorly to anterior nostril, simple with no fleshy fringe along its edge. Internarial width about twice length of anterior nostril tube.

Cephalic lateralis system with many open pores along sensory canals. Supraorbital canal with seven pores: one behind snout tip, one lateral to anterior nostril, one above posterior nostril, one between both nostrils, and three along upper rim of orbit. Infraorbital canal well developed, with about nine lower branches; three pores serially arranged above upper jaw; 10 pores along posteroventral rim of orbit (12 on right side); several pores scattered over cheek. Mandibular canal with five pores along lower jaw; pair of small pores on chin. Preopercular canal with about eight anterodorsal branches; six pores along main canal; each branch with single pore terminally. Nape and postorbital region heavily damaged; at least six pores along otic canal.

Scales totally missing from head and body surfaces, except for a few remaining behind paired fins, beneath gill covers, and along lateral line and anal-fin base. Most of these scales small, thin, highly deciduous, covered with short, reclined, needle-like spinules along their hind margin; scales beneath gill covers lacking spinules. Predorsal scaled area extending to slightly behind line connecting posterior margins of preopercles. Head naked, except for cheek behind lateral corner of mouth. Postorbital area narrowly scaled above dark horizontal stripe on head. All fins naked, but caudal fin heavily scaled basally.

Lateral line broadly arched over pectoral fin, then gradually descending to become straight posterior to vertical drawn through anal-fin origin.

Color when fresh ( Fig. 1 ). Prominent dark stripe about two scales deep extending from hind rim of orbit to caudal peduncle, ending with large, black ocellus on upper caudalfin base. Dorsum above dark stripe uniformly dark yellow. Ground color of lower 2/3 of body white. About 12 diagonal, dusky yellowish bars below mid-lateral axis of body: first and second on trunk behind pectoral fin, third at vertical drawn through anal-fin origin, 4th–11th above analfin base, and last on caudal peduncle; these diagonal bands not reaching dark horizontal stripe dorsally. Narrow yellow stripe about one scale deep extending mid-laterally from vertical drawn through anal-fin origin to caudal peduncle. Spinous portion of dorsal fin uniformly dark, soft portion yellowish (but heavily damaged). Pectoral fin translucent pale yellow; small dusky spot present on lower half of pectoral-fin base. Pelvic fin generally white, but soft portion with slightly yellowish tinge. Anal fin bright yellow, paler basally. Lower half of caudal-fin base white; about three faint yellowish bars on upper half of caudal fin, lower half uniformly yellow. Snout bright yellow, especially anteriorly. Small black spot on posterior portion of eye; pupil surrounded by yellow-gold iris; dorsal surface of eyes dark green. Nape pinkish orange. Upper jaw slightly yellow, lower jaw much paler. Opercle and pectoral girdle with slightly pinkish tinge. Underside of head generally white.

Color in 70% ethanol ( Fig. 2 ). Ground color of head and body white, with prominent dark stripe extending from hind rim of orbit to caudal peduncle, followed by large, black ocellus on upper caudal-fin base. Dorsum above dark stripe uniformly dusky. About 12 diagonal dark stripes on lower 2/3 of body. Iris black, but narrowly pale along pupil; dorsal surface of eyes blackish. Oral and gill cavities uniformly white. Gill rakers, arches, and filaments cream. Fins uniformly paler, except for dark spinous portion of dorsal fin; caudal ocellus narrowly outlined in black posteriorly; pectoral-fin base somewhat dusky.

Distribution. Known from the Western Pacific from Japan to New Caledonia, including the South China Sea off the Philippines (type locality), Solomon Islands, and Vanuatu ( Ho 2015; this study; Fig. 3 ). Depth range 170– 355 m.

Remarks. Parapercis fuscolineata was originally described by Fourmanoir (1985) based on four specimens (54–78 mm SL) collected from the South China Sea off the Philippines. The holotype and a 54 mm SL paratype are now believed to be lost ( Ho 2015).

The Japanese specimen agrees well with the original description of P. fuscolineata and a redescription given by Ho (2015), including the presence of a dark continuous stripe dorsally along the body, a large, black ocellus on the upper caudal-fin base, and about 12 diagonal yellowish bars below the mid-lateral axis of the body ( Fig. 1 ). The combination of these prominent markings is unique to P. fuscolineata , and readily distinguishes this species from all its congeners. In addition, the spinous portion of the dorsal fin is uniformly dark in all known specimens, and this consistent feature appears to further characterize the species ( Ho 2015; this study).

Although the original description of P. fuscolineata is brief, it includes an excellent drawing of a 78 mm SL paratype, with an adequate description of the fresh coloration ( Fourmanoir 1985: 36, fig. 1). The color pattern of the Japanese specimen agrees well with that described by Fourmanoir (1985), except that the dark stripe on the body originates at the hind rim of the orbit (vs “origin of opercle”). However, Fourmanoir’s description is not accurate; Ho (2015) confirmed that the dark stripe of the type specimens actually originates behind the orbit. According to Fourmanoir (1985), a narrow white stripe runs dorsally along the dark stripe. However, the dorsum above the dark stripe is uniformly dusky in the Japanese specimen. This discrepancy is likely due to the specimens’ size difference (SL 54–78 mm in the types vs 36.8 mm in the Japanese specimen).

Counts and measurements of the Japanese specimen generally lie within (or only slightly outside) the range of variation of P. fuscolineata given by Ho (2015), except for the relatively much shorter dorsal-fin spines (third spine 4.0% SL in the Japanese specimen vs 4.8–7.9%; fourth spine 4.2% vs 6.1–8.5%; fifth spine 5.4% SL vs 6.4–6.9%; Table 1). The Japanese specimen differs slightly from Ho’s (2015) redescription in that the tips of both jaws extend forward to the same vertical (vs the lower jaw protruding slightly beyond the upper jaw). Further differences are obvious in the dentition, with the Japanese specimen having much narrower inner bands, viz., inner premaxillary teeth in about 4–5 series at the widest point near the symphysis (vs ca. eight series), and those of the dentary in about 3–4 series anteriorly (vs 7–8 series). The Japanese specimen also differs from Ho’s (2015) redescription in that the vomer and palatines are each covered with a single tooth row (vs two rows). Unfortunately, P. fuscolineata is poorly represented in museum collections, and there is little knowledge of its morphological variation. The differences highlighted here could be attributed to ontogenetic variation, but it should be noted that Ho (2015) examined a juvenile (NMHN 2000-5541, 34.9 mm SL) that is almost equal in size to the Japanese specimen.

Ho (2015) indicated several differences in the counts and coloration between the types and the tropical southwest Pacific specimens of P. fuscolineata , and suggested that the latter may represent an undescribed species. According to Ho (2015), these specimens differ from the two paratypes he examined in having higher counts of dorsal-fin spines (five vs four) and circumpeduncular scales (21–22 vs 18) and lower counts of gill rakers (total 12–14 vs 15–20). The Japanese specimen agrees with the paratypes in having 18 circumpeduncular scales whereas it matches the tropical southwest Pacific specimens in having five dorsal-fin spines and 13 gill rakers. Ho (2015) also noted that the body stripe of a juvenile from New Caledonia (NMHN 2000-5541, 34.9 mm SL) did not fade after a long time in preservative, although Fourmanoir (1985: 37) wrote that “the dark stripe is indistinct in a juvenile specimen and it disappears quickly in alcohol”. The body stripe of the Japanese specimen is prominently dark in both fresh and preserved conditions ( Figs 1–2 ). Due to the paucity of available material, it is impossible to provide a definitive conclusion on their conspecificity. A further in-depth study is necessary to confirm whether the species is widely distributed in the Western Pacific.

The occurrence of P. fuscolineata in Tosa Bay extends its known range approximately 2,600 km northward from the Philippines ( Fig. 3 ). It brings the total number of Japanese sandperch species to 30 ( Ogihara and Endo 2011; Hibino et al. 2013; Shimada 2013; this study). This species is not likely to be confused with other Japanese congeners due to its unique coloration. A new standard Japanese name, “Kuroobi-toragisu”, is proposed here for P. fuscolineata based on the specimen BSKU 119364. This name is derived from the characteristic dark stripe of this species (= kuroobi) and the Japanese name for sandperches (= toragisu).

Figures

Fig. 1. Fresh coloration of Parapercis fuscolineata. BSKU 119364, 36.8mm SL, Tosa Bay off mouth of Niyodo River, Kochi Prefecture, Shikoku Island, Japan, 200–203m depth. A, lateral view; B, dorsal view.

Fig. 2. Preserved specimen of Parapercis fuscolineata. BSKU 119364, 36.8mm SL, Tosa Bay off mouth of Niyodo River, Kochi Prefecture, Shikoku Island, Japan, 200–203m depth. A, lateral view; B, dorsal view.

Fig. 3. Map showing the known distribution of Parapercis fuscolineata. The star indicates the type locality.