キンメダイ科 Berycidae Alfonsinos
14 ナンヨウキンメ
Beryx decadactylus
Cuvier, 1829 Alfonsino
Specimens
examined: 6 (
Counts:
D IV, 19; A IV, 26–28; P1 14–16; P2 I, 9–10; GR 6–7+16–19=23–26;
LLS 58–62; V 10+14=24. Measurements: head length 32.4–34.5% SL; body depth 47.9–49.2% SL;
eye diameter 38.5–41.3% HL; interorbital width 20.3–23.9%
HL; snout length 20.3–23.3% HL; upper-jaw length 51.6–54.6% HL; lower-jaw
length 60.5–63.5% HL; caudal-peduncle length 39.4–46.3% HL; caudal-peduncle
depth 31.3–35.1% HL; pectoral-fin length 86.9–92.1% HL; pelvic-fin
length 68.1–80.4% HL.
計数形質：背鰭4棘，19軟条；臀鰭4棘，26–28軟条；胸鰭14–16軟条；腹鰭1棘，9–10軟条；鰓耙数6–7 + 16–19=23–26；側線鱗数58–62；脊椎骨数10
+ 14 = 24．計測形質：頭長32.4–34.5% SL；体高47.9–49.2% SL；眼径38.5–41.3% HL；両眼間隔20.3–23.9% HL；吻長20.3–23.3% HL；上顎長51.6–54.6%HL；下顎長60.5–63.5% HL；尾柄長39.4–46.3% SL；尾柄高31.3–35.1% HL；胸鰭長86.9–92.1% HL；腹鰭長68.1–80.4% HL.
特 徴 体は側扁し，卵円形で後部は細い．体高は頭長よりかなり大きい．眼は大きく，眼径は頭長の約40%．吻は短く，眼径の約半分．後鼻孔は楕円形．口は大きく，傾斜する．上顎後端は瞳孔の後縁直下に達する．下顎は突出する．眼の前方側面に1棘がある（290
mm SLより大きい個体では弱い）．上顎歯は小さく，円錐形で湾曲し，広い歯帯をなす．下顎歯は上顎歯とほぼ同形同大で，狭い歯帯をなす．鋤骨歯および口蓋骨歯は両顎歯とほぼ同形同大．鰓耙は細長い．鱗は強い櫛鱗で，内側に卵形の軟骨質の突起がある．側線は前部でわずかに湾曲し，後部では直線状で尾鰭上に延びる．背鰭は1基で，基底長は臀鰭基底長より短い．臀鰭基底長は頭長よりやや長い．胸鰭は斜めで尖り，基部はほぼ水平．尾鰭は強く二叉し，上葉および下葉の先端は尖る．背鰭，臀鰭および腹鰭の棘条は強く，溝が密に刻まれる．頭部，背部および鰭は鮮紅色．腹部は銀白色．腹膜は黒い．
分 布 北東太平洋および極域を除く全世界 (Paxton, 1999)．
備 考 本種は，同属のキンメダイBeryx splendens
Lowe, 1834およびフウセンキンメBeryx mollis
Abe, 1958とは，体高が高いこと (46–53
vs. 35–41%SL)，背鰭軟条数が多いこと (16–20
vs. 12–15) で容易に識別できる (Yoshino
et al., 1999; 林,
2013; 本研究)．Busakhin (1982) は本種を同属の2種と識別する形質として，鼻骨，眼の上方，および主上顎骨の下方に棘があることを挙げたが，観察標本では認められなかった．これらの棘は成長に伴い小さくなるとされる (Busakhin, 1982) ことから，大型の個体では消失すると考えられる．
(星野)
Description Body
laterally compressed, oval, posteriorly tapering.
Body depth significantly larger than head length. Eye large, its diameter about
40% of HL. Snout short, its length about half of eye diameter. Posterior
nostril elliptical. Mouth large, oblique. Upper jaw extending to below
posterior margin of pupil. Lower jaw produced. One lateral spine in front of
eye (weak in the specimens larger than 290 mm SL). Teeth on upper jaw small,
conical and curved, in wide band; teeth on lower jaw similar to upper jaw teeth
in size and shape, in narrow band. Vomerine and
palatine teeth about equal in size and shape to teeth on jaws. Gill rakers slender. Scales strongly ctenoid,
with an oval-shaped cartilaginous growth medially. Lateral line slightly curved
anteriorly, straight posteriorly,
extending onto caudal fin. Dorsal fin single, its base shorter than anal-fin
base. Anal-fin base slightly longer than head length. Pectoral fin oblique and
pointed, its base nearly horizontal. Caudal fin strongly forked, its lobes
pointed. Spines of dorsal, anal, and pelvic fins strong, densely striated.
Head, dorsum and fins bright red; abdomen silvery white; peritoneum black.
Distribution Circumglobal,
except Northeast Pacific and polar seas (Busakhin,
1982; Paxton, 1999).
Remarks This species is easily distinguished
from its congeners, Beryx splendens
Lowe, 1834 and Beryx mollis Abe,
1959, by the deeper body (46–53 vs. 35–41% SL), and more dorsal-fin soft rays
(16–20 vs. 12–15) (Yoshino et al.,
1999, 2001; Hayashi, 2013; present study). Busakhin
(1982) noted that this species is distinguished from congeners in having nasal,
supraorbital, and submaxillary
spines, but these spines were not observed in the examined specimens. This
might be due to the size of the examined specimens; Busakhin
(1982) reported that the spines decrease in size with growth.
(K.
Hoshino)