GYMNOCRANIUS EUANUS - (GUNTHER, 1879)
Actinopterygii (Gigaclass) > Actinopteri (Class) > Teleostei (Subclass) > Acanthuriformes (Order) > Lethrinidae (Family) > Monotaxinae (Subfamily) > Gymnocranius (Genus)
Bossu blanc à points noirs, Iodine bream, Japan sea bream, Japanese large eye bream, Japanese sea bream, Paddletail seabream, Pearl-eyed snapper, Speckled emperor, Shirodai, シロダイ, 日本白鱲, 真裸頂鯛,
Synonymes
Gymnocranius japonicus (Akazaki, 1961)
Monotaxis affinis (Whitley, 1943)
Sphaerodon euanus (Günther, 1879)
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Description
Dorsal spines (total): 10; Dorsal soft rays (total): 9-10; Anal spines: 3; Anal soft rays: 9-10; Pectoral fin rays: 14; Body oblong, its depth 2.4-2.5 times in standard length. Dorsal profile of head sloping steeply; Lower edge of eye well above a line from tip of snout to middle of caudal-fin fork; Eye relatively large, although its diameter less than interorbital space and width of preorbital width (at least in adults); Mouth relatively small, posterior part of jaws reaching to about level of nostril openings; outer surface of maxilla smooth; 2-3 pairs of small, slender canines at front of each jaw, other teeth villiform, but well developed molars on lateral sections of jaws. Caudal fin moderately forked, inner edge of fork slightly convex, with blunt tips, the median rays slightly longer than eye diameter. Lateral-line scales: 48-49 plus 3-4 tubed scales extending onto base of caudal fin; Cheek with 4-5 transverse scale rows; 4 ½ scale rows between lateral line and base of middle dorsal-fin spines; Inner surface of pectoral-fin axil scaleless. Max. length: 45.0 cm TL, common length: 35.0 cm TL. Depth range: 15 - 50 m.
Color
Overall silvery white to greyish; scales of back and sides with a small brownish basal spot; Scattered prominent black blotches mainly on anterior half of body; A very faint bar sometimes present below eye to lower edge of cheek; Fins mainly clear to reddish, caudal fin sometimes dusky reddish brown; Faint spots may be evident on dorsal, caudal, and anal fins.
Etymology
Gymnocranius: from Greek, gymnos = naked + from Greek, kranion = skull. Proposed as a subgenus of Dentex (Sparidae) lacking scales on top of head.
euanus: from type locality, Eua + from Latin suffix, -anus = from.
Original description: Sphaerodon euanus Günther, 1879 - Type locality: Eua, Friendly Islands - Tonga.
Distribution
Western Pacific: eastern Malaya (Malaysia) and Gulf of Thailand east to Philippines, Papua New Guinea and Tonga, north to Amami Islands (Kagoshima Prefecture, southern Japan), south to eastern Australia, New Caledonia and Solomon Islands.
Biology
Occurs over sand and rubble areas adjacent to rock and coral reefs in lagoons and outer slopes. Feeds on bottom-dwelling gastropods. Also caught with bottom longlines and handlines. Marketed fresh.
Synonymes
Gymnocranius japonicus (Akazaki, 1961)
Monotaxis affinis (Whitley, 1943)
Sphaerodon euanus (Günther, 1879)
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Description
Dorsal spines (total): 10; Dorsal soft rays (total): 9-10; Anal spines: 3; Anal soft rays: 9-10; Pectoral fin rays: 14; Body oblong, its depth 2.4-2.5 times in standard length. Dorsal profile of head sloping steeply; Lower edge of eye well above a line from tip of snout to middle of caudal-fin fork; Eye relatively large, although its diameter less than interorbital space and width of preorbital width (at least in adults); Mouth relatively small, posterior part of jaws reaching to about level of nostril openings; outer surface of maxilla smooth; 2-3 pairs of small, slender canines at front of each jaw, other teeth villiform, but well developed molars on lateral sections of jaws. Caudal fin moderately forked, inner edge of fork slightly convex, with blunt tips, the median rays slightly longer than eye diameter. Lateral-line scales: 48-49 plus 3-4 tubed scales extending onto base of caudal fin; Cheek with 4-5 transverse scale rows; 4 ½ scale rows between lateral line and base of middle dorsal-fin spines; Inner surface of pectoral-fin axil scaleless. Max. length: 45.0 cm TL, common length: 35.0 cm TL. Depth range: 15 - 50 m.
Color
Overall silvery white to greyish; scales of back and sides with a small brownish basal spot; Scattered prominent black blotches mainly on anterior half of body; A very faint bar sometimes present below eye to lower edge of cheek; Fins mainly clear to reddish, caudal fin sometimes dusky reddish brown; Faint spots may be evident on dorsal, caudal, and anal fins.
Etymology
Gymnocranius: from Greek, gymnos = naked + from Greek, kranion = skull. Proposed as a subgenus of Dentex (Sparidae) lacking scales on top of head.
euanus: from type locality, Eua + from Latin suffix, -anus = from.
Original description: Sphaerodon euanus Günther, 1879 - Type locality: Eua, Friendly Islands - Tonga.
Distribution
Western Pacific: eastern Malaya (Malaysia) and Gulf of Thailand east to Philippines, Papua New Guinea and Tonga, north to Amami Islands (Kagoshima Prefecture, southern Japan), south to eastern Australia, New Caledonia and Solomon Islands.
Biology
Occurs over sand and rubble areas adjacent to rock and coral reefs in lagoons and outer slopes. Feeds on bottom-dwelling gastropods. Also caught with bottom longlines and handlines. Marketed fresh.
Last update: 20, March 2023