Sebastes nudus Matsubara 1943
Creators: name: Kai, Yoshiaki
name: Nakabo, Tetsuji
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Scorpaeniformes
Sebastidae
Sebastes
Sebastes nudus

description: Sebastes nudus Matsubara 1943
[Japanese name: Ohgon-murasoi] (Figs. 2 B, 3B, 5, 6; Tables 1–2)
Sebastes (Murasoius) pachycephalus, form. nudus Matsubara 1943: 239, pl. II-2 (type locality: Hakodate, Hokkaido, Japan and Busan, Korea).
Sebastes (Murasoius) pachycephalus, form. chalcogrammus Matsubara 1943: 244, pl. III-2 (type locality, Shimonoseki, Japan).
Sebastes pachycephalus (not of Temminck & Schlegel): Jordan & Starks 1904: 117 (in part, Wakanoura, Kobe, Hiroshima and Shimonoseki, Japan); Okada et al. 1935: 206 (in part, Hokkaido southward to Kyushu, Japan and southern Korean Peninsula; plate based on S. pachycephalus); Amaoka 1984: 312, pl. 278-F and G (in part, southern Hokkaido southward to Kyushu, Japan and southern Korean Peninsula); Cheng 1997: 408, fig. 301 [after Li (1955)] (Qingdao, Weihai and Yantai, China); Kim et al. 2004: 100, unnumbered fig. (in part, Hokkaido southward to Kyushu, Japan and southern Korean Peninsula); Kim et al. 2005a: 117 (in part, Hokkaido southward to Kyushu, Japan and southern Korean Peninsula; figure identifiable as S. pachycephalus); Kim et al. 2005b: 222, unnumbered fig. (in part, Hokkaido southward to Kyushu, Japan, all coast of Korea, and China); Amaoka et al. 2011: 187, unnumbered figs (Hokkaido, Japan).
Sebastes pachycephalus complex "Species Nu-C": Kai et al. 2011: (Hiroshima, Kyoto, Ishikawa, Miyagi, Iwate, and Hokkaido, Japan).
Sebastes pachycephalus pachycephalus: Hiyama & Yasuda 1961: 112 (in part, Hokkaido southward to Kyushu, Japan and southern Korea; plate identifiable as S. pachycephalus).
Sebastes pachycephalus nudus: Matsubara 1955: 1077, fig. 376 [after Matsubara (1943)], key (Hakodate, Hokkaido, Japan and Busan, Korea); Matsubara 1965: 427, unnumbered fig. [after Matsubara (1943)] (Hokkaido and Aomori, Japan and Busan, South Korea); Nakabo 1993: 518, key (Hakodate, Hokkaido, Japan and Busan, Korea); Masuda & Kobayashi 1994: 85, figs. 5 (Shakotan Peninsula, Hokkaido, Japan); Nakabo 1995: 177, color photos (Iwate and Fukui, Japan); Nakabo 2000: 595, key (Hakodate, Hokkaido, Japan and Busan, Korea); Nakabo 2002a: 595, key (Hakodate, Hokkaido, Japan and Busan, Korea).
Sebastes pachycephalus chalcogrammus: Matsubara 1955: 1077, fig. 379 [after Matsubara (1943)], key (Chiba, Kanagawa, Kobe, and Shimonoseki, Japan and Busan, Korea); Matsubara 1965: 426, unnumbered fig. [after Matsubara (1943)] (Chiba southward to Kyushu, Japan); Kanayama & Kitagawa 1982: 43, unnumbered fig. (Miyako, Iwate, Japan); Lindberg & Krasyukova 1987: 77, fig. 34 [after Matsubara (1943)]; Nakabo 1993: 518, key (Chiba, Kanagawa, Kobe, and Shimonoseki, Japan and Busan, Korea); Masuda & Kobayashi 1994: 85, fig. 6 (Shakotan Peninsula, Hokkaido, Japan); Nakabo 2000: 595, key (Chiba, Kanagawa, Kobe, and Shimonoseki, Japan and Busan, Korea); Shimizu 2001: 25, fig. 36 (Ehime, Japan); Nakabo 2002a: 595, key (Chiba, Misaki of Kanagawa, Kobe, Shimonoseki, Japan and Busan, Korea); Kitagawa et al. 2008: 60, unnumbered fig. [after Kanayama & Kitagawa (1982)] (Pacific coast of northern Honshu Is., Chiba, Kanagawa, Kobe, and Shimonoseki, Japan and Busan, Korea).
Sebastes nudus: Lindberg & Krasyukova 1987: 77, fig. 34 [after Matsubara (1943)] (Hakodate, Hokkaido, Japan and Qingdao, China).
Sebastes (Sebastodes) nudus: Barsukov 2003: 191, fig.82 (Qingdao, China).
Sebastichthys pachycephalus: Jordan & Starks 1904: (in part, Wakanoura, Kobe, Hiroshima, and Shimonoseki, Japan); Okada et al. 1935: 206 (in part, Hokkaido southward to Kyushu, Japan and Korean Peninsula; plate based on S. pachycephalus); Okada & Matsubara 1938: 306 (in part, Hokkaido southward to Kyushu, Japan and Korean Peninsula); Li 1955: 236, fig. 150 (Qingdao and Yantai, China).
Materials examined. 88 specimens, 23.2–212.8 mm SL. Japan: FAKU 352 (holotype of S. p. nudus), 198.5 mm SL, Hakodate, Hokkaido; FAKU 6317 (holotype of S. p. chalcogrammus), 261.8 mm SL, Shimonoseki, Yamaguchi; FAKU 6325, 115.0 mm SL, Kominato, Chiba; FAKU 6529, 130.3 mm SL, Kobe, Hyogo; FAKU 41969, 142.0 mm SL, Maizuru, Kyoto; FAKU 50141–50145, 50146–50150, 50153–50155, 84093, 84094, 96286, 133427–133430, 133433, 133434, 151.3– 195.8 mm SL (21), Miyako, Iwate; FAKU 50151–50152, 50167, 118.8– 125.2 mm SL (3), Yawatahama, Ehime; FAKU 70827, 135.0 mm SL, Tai, Maizuru, Kyoto, coll. R. Doiuchi; FAKU 82522, 82523, 84106, 84111, 84112, 85919, 85921, 97.1–167.3 mm SL (7), Ushitsu, Noto, Ishikawa, coll. Y. Kai and K. Sakai; FAKU 84036–84040, 131.1– 181.7 mm SL (5), Otaru, Hokkaido; FAKU 84087, 84088, 84092, 149.1– 174.8 mm SL (3), Kesennuma, Miyagi, coll. Y. Kai; FAKU 84089–84091, 156.0– 169.3 mm SL (3), Kamaishi, Iwate, coll. Y. Kai; FAKU 84095–84099, 136.4– 154.4 mm SL (5), coll. Y. Kai; FAKU 85917, 99.2 mm SL, Aki, Hiroshima, coll. K. Nozaki; FAKU 87653, 86.3 mm SL, Yatsuka, Shimane, coll. T. Morihisa; FAKU 130187, 138.8 mm SL, coll. K. Takatsu; FAKU 130486, 130487, 92.0– 106.6 mm SL, Hakodate, Hokkaido, coll. Y. Kai; KAUM–I. 26561, 165.7 mm SL, Tobi-shima, Yamagata, coll. H. Motomura; NMCI–P. 1528, 1529, 102.2– 124.6 mm SL (2), Ushitsu, Noto, Ishikawa; OMNH–P 3111, 23.2 mm SL, Kasumi, Hyogo, coll. Kasumi High School; OMNH–P 5859, 109.0 mm SL, Hamasaka, Hyogo, coll. A. Uno; OMNH–P 8586–8587, 108.9– 114.4 mm SL (2), Misaki, Osaka, coll. Osaka Fisheries Experimental Station; OMNH–P 13889, 133.2 mm SL, Himi, Toyama, coll. K. Hatooka; OMNH–P 14496–14497, 149.3– 167.8 mm SL (2), Higashi-Tarumi, Kobe, Hyogo, coll. Y. Shibata. South Korea: FAKU 6337, 103094, 133289–133294, 133297, 133310, 126.2– 212.8 mm SL (10), Busan. Locality unknown: FAKU 102295, 102297, 102298, 102300 – 102302, 102305, 104150, 133296, 133298, 63.3–174.7 mm SL (10).
Diagnosis. A species of Sebastes with the following characters: cranium armed dorsally with robust preocular, supraocular, postocular, and parietal spines; interorbital space concave; lower jaw without scales, shorter than upper jaw; base of dorsal fin lacking minute scales from below first to fifth or variously to posteriormost spine; body with two indistinct, darkish brown saddles; yellow or brownish-red markings on dorsum when fresh.
Description. Measurements as percentages of SL of the specimens examined are given in Table 1. Selected counts are given in Table 2.
Body relatively deep, moderately compressed anteriorly, progressively more compressed posteriorly. Nape and anterior body moderately convex. Tentacles absent on head and body, except for nostril tentacle. Head completely covered with ctenoid scales, except for tip of snout, maxillary, lacrimal, lower jaw, interopercle, and branchiostegal rays. Posterior part of maxillary sometimes with minute embedded scales. Body covered with ctenoid scales usually with some accessory scales in posterior field, except for pectoral fin base, prepelvic region and ventral abdominal surface. Embedded cycloid scales covering pectoral fin base and prepelvic region; remaining ventral abdominal surface covered with minute cycloid scales, usually with narrow naked area anteriorly. Base of entire spinous portion of dorsal fin typically naked, sometimes with minute scales below first to fifth or variously to posteriormost spine (Fig. 2 B). Bases of soft-rayed portion of dorsal and anal fins covered with minute scales, usually extending onto basal membranes.
Mouth large, slightly oblique; posterior margin of maxilla reaching or nearly reaching (reaching in holotype) level with posterior margin of orbit. Maxilla covered with thick skin. Lower jaw shorter than upper jaw, without distinct symphysial knob. Upper and lower jaws with band of villiform teeth. Palatines and vomer with villiform teeth, latter forming V-shaped patch.
Nasal spine simple, sharp, directed dorsally. Preocular spine robust, well developed, directed dorsoposteriorly; tip of spine reaching or extending slightly beyond (reaching in holotype) level with anterior margin of pupil. Supraocular spine robust, well developed, directed posteriorly; tip of spine reaching or extending beyond (reaching in holotype) level with posterior margin of orbit. Postocular spines simple, directed dorsoposteriorly. Interorbital space concave without ridge, its width about half of orbit diameter. Parietal spine well developed, somewhat divergent posteriorly in dorsal view. Supracleithral spine simple, directed posteriorly. Upper posttemporal spines flattened, with embedded base, lower posttemporal spine absent. Sphenotic, tympanic, and pterotic spines absent. Sphenotic, tympanic, and pterotic spines absent. Lacrimal with round lobe anteriorly and one spine posteriorly; spine flattened, blunt, directed ventroposteriorly, its tip below level of anterior margin of pupil. Suborbital without spine or ridge. Preopercle with five spines; two uppermost spines large, directed posteriorly; third moderate, directed posteriorly; forth and fifth small, blunt, directed ventroposteriorly. Opercle with two simple flattened spines directed posteriorly; upper spine somewhat larger than lower spine.
Dorsal fin with 13 spines (rarely 12 or 14; 13 in holotype) and 10–13 (usually 12 including holotype) soft rays; all soft rays branched (first ray weakly branched). Dorsal-fin origin above anterodorsal portion of gill slit. Dorsal fin gradually increasing in height to fifth spine, decreasing thereafter to 12th spine; 13th spine somewhat larger than 12th, forming anterior support of soft-rayed portion of dorsal fin. Soft-rayed portion of dorsal fin with entire margin rounded; anterior rays longer (usually third or forth ray longest; third in holotype), posterior rays gradually shortening. Anal fin with three spines and six (rarely five or seven; five in holotype) soft rays; all soft rays branched. First anal-fin spine slightly posterior to last dorsal-fin spine; second spine robust, longest. Anterior rays on soft-rayed portion of anal fin longest; posterior margin rounded. Posterior margin of caudal fin rounded. Pectoral fin rounded; its tip not reaching posteriorly to level with anus; ventral 9–12 (usually 10 including holotype) rays unbranched and thickened. Posterior tip of depressed pelvic fin below tip of pectoral fin, rarely reaching anus.
Gill rakers short, blunt, longest raker in joint between cerato- and hypobranchial, length of preceding and succeeding rakers progressively shorter; ceratobranchial rakers usually seven, including holotype (rarely six), hypobranchial rakers 14–17 (14 in holotype), often rudimentary and united, being difficult to distinguish individually.
Color when fresh (Fig. 5). Head and body brown or beige dorsally and laterally, somewhat paler ventrally. Head with three dark brown irregular bands radiating from eye, sometimes with small yellow spots. Body usually with two indistinct faintly brown saddles; anteriormost positioned under fifth to 11th dorsal-fin spines, posterior saddle under soft-rayed portion of dorsal fin; irregular yellow or brownish-red markings often extending onto ventral part of body, and dorsal and anal fins (Figs. 5 A, B); but sometimes small and indistinct (Figs. 5 C–E), occasionally absent (Fig. 5 F). Lower jaw, pectoral fin base, and prepelvic region without dark brown spots. Dorsal and anal fins brown or pale brown, sometimes with dark brown blotches; membranes of soft-rayed portion darker. Caudal fin brown or light brown, sometimes with yellow or brownish-red markings basally; membranes somewhat darker. Pectoral fin brown or pale brown with irregular brown markings basally; dorsoposterior portion dark; ventral half somewhat paler. Pelvic fin light brown; membranes somewhat darker.
Color in preserved specimens (Fig. 2 B). Head and body dark or gray dorsally and laterally, somewhat paler ventrally. Head with three irregular dark bands radiating from eye. Body with two indistinct dark saddles, extending onto dorsal fin. Yellow and brownish-red markings when fresh represented by pale or white markings when preserved.
Distribution (Fig. 3 B). Sebastes nudus is presently known from southern Hokkaido southward along the Pacific coast of Japan to Kanagawa and along the Sea of Japan coast of Japan to northern Kyushu Is. and the Seto Inland Sea, in addition to the southern Korean Peninsula, and the Bohai and Yellow Seas. This species is solitary, inhabiting rocky reefs in shallow coastal waters.
Remarks. The present description of S. nudus is based on specimens genetically identified as “Species Nu-C” in Kai et al. (2011), plus additional specimens not genetically examined here, but considered as conspecific with the former, due to their lacking scales below the dorsal-fin spines and having yellow or brownish-red markings on the dorsum (when fresh).
The names “ nudus ” and “ chalcogrammus ” first appeared in Matsubara (1943) as forms of S. pachycephalus, subsequently being recognized as subspecies of S. pachycephalus (see “Remarks” above under S. pachycephalus). The holotype of S. pachycephalus nudus (Fig. 6 A) was characterized by a lack of minute scales below the entire spinous dorsal-fin base, and had 17 pectoral-fin rays (ventral 10 rays unbranched and thickened) on both sides, whereas the holotype of S. p. chalcogrammus (Fig. 6 B) lacked minute scales below first to fifth dorsal-fin spine, and had 18 pectoral-fin rays (ventral 11 rays unbranched) on the left side and 17 (10) rays on the right side. The non-type specimens examined in this study all lacked minute scales below the dorsal-fin spine base (although sometimes with minute scales posteriorly from below the fifth spine) and usually had 17 pectoral-fin rays (ventral 10 rays unbranched) (Table 2), therefore considered as conspecific with the holotypes of S. p. nudus and S. p. chalcogrammus. In addition, the described above holotypes when fresh had yellow and brownish-red markings respectively (Matsubara 1943), similar to the present non-type specimens. Because all of these specimens represent a single taxon specifically distinct from S. pachycephalus, it is necessary to establish which of S. p. nudus and S. p. chalcogrammus has priority, both names having been newly proposed on the same date in the same publication (Matsubara 1943). However, Barsukov (2003) considered S. (Sebastodes) nudus as a valid species, having priority over S. chalcogrammus. Thus, we considered his action as a “determination by the first reviser” of ICZN (1999: Art. 24), and identified the present specimens as S. nudus. Although a detailed description of the species was not given in Barsukov (2003), a figure (based on a specimen collected from Qingdao) clearly showed pale markings on the dorsum, confirming its identity as S. nudus. As stated in “Remarks” under S. pachycephalus, the figures and descriptions of S. pachycephalus nudus and S. p. chalcogrammus given by Matsubara (1955, 1965) generally followed those of Matsubara (1943).
Lindberg & Krasyukova (1987) reported Sebastes nudus on the basis of two specimens collected from Hakodate, Japan and Qingdao, China. Except for the counts of the dorsal, anal and pectoral fins, and pored lateral line scales, their description followed Matsubara (1943). Judging from the pectoral fin count (17), those specimens were most likely to have been S. nudus as recognized here. In addition, the description of S. pachycephalus chalcogrammus given by Lindberg & Krasyukova (1987) followed that of Matsubara (1943).
Nakabo’s (1993, 2000, 2002a) descriptions of four subspecies of S. pachycephalus (S. p. pachycephalus, S. p. nigricans, S. p. nudus, and S. p. chalcogrammus) generally followed Matsubara (1943). Although his description of S. p. nudus was based on FAKU W461 and that of S. p. chalcogrammus on FAKU 102296, FAKU 102299, and FAKU 102303, none of these specimens were available here. Judging from the descriptions given, both S. p. nudus and S. p. chalcogrammus of Nakabo (1993, 2000, 2002a) corresponded to S. nudus as recognized here, due to their lacking minute scales below the dorsal-fin spines. Nakabo (1993, 2000, 2002a) further distinguished S. p. nudus from S. p. calcogrammus on the basis of the former having yellow markings on the dorsum (vs. brownish-red markings in the latter), but such a difference has been shown by genetic analysis to represent intraspecific variation (Kai et al. 2011).
Descriptions and figures of S. pachycephalus given by Li (1955) and Cheng (1977) are undoubtedly attributable to S. nudus because of the yellow body markings. Similarly, the photos of S. p.chalcogrammus in Kanayama & Kitagawa (1982) and Kitagawa et al. (2008), apparently of the same specimen, are clearly S. nudus, owing to the reddish-yellow markings on the dorsum and dorsal, anal and caudal fins. Shimizu’s (2001) description of S. pachycephalus chalcogrammus as having a broad naked area below the dorsal-fin spines, 17 pectoral-fin rays, and brownish-red markings on the dorsum is also indicative of S. nudus. Although the descriptions of S. pachycephalus in Kim et al. (2004) and Kim et al. (2005b) were clearly based on both S. pachycephalus and S. nudus, the photos are identifiable as S. nudus because of the yellow markings on the dorsum. Although Amaoka et al. (2011) mentioned the color variations of S. pachycephalus, their figures were clearly of S. nudus, also because of the yellow and brownish-red markings on the dorsum.
The Japanese name “Ohgon-murasoi”, first applied to the subspecies S. p. nudus by Matsubara (1955), is herein recognized as the standard Japanese name of S. nudus.
*: specimens genetically identified as hybrids in Kai et al. (2011).
description: Published as part of Kai, Yoshiaki & Nakabo, Tetsuji, 2013, Taxonomic review of the Sebastes pachycephalus complex (Scorpaeniformes: Scorpaenidae), pp. 541-560 in Zootaxa 3637 (5) on pages 551-555, DOI: 10.11646/zootaxa.3637.5.3, http://zenodo.org/record/223192