• IMAGE DU MONDE
    • ACCUEIL
    • IMAGES AQUATIQUES
    • IMAGES TERRESTRES
    • IMAGES AERIENNES
    • VIDEO
Gymnocranius oblongus Nouvelle-Calédonie bossu blanc

GYMNOCRANIUS OBLONGUS - (BORSA, BEAREZ & CHEN, 2010)

Picture courtesy of: Gloup Noumea

Actinopterygii (Gigaclass) > Actinopteri (Class) > Teleostei (Subclass) > Spariformes (Order) > Lethrinidae (Family) > Monotaxinae (Subfamily) > Gymnocranius (Genus)

Bossu blanc oblong,

Description
Rayons mous dorsaux (Total) : 10; Rayons mous anaux : 10. Poisson au corps oblong et fusiforme, un museau légèrement arrondi, une queue allongée aux extrémités arrondies, des lignes ou des tirets bleus sub-horizontaux et sinueux sur le museau et les joues. Rapport entre la longueur standard et la hauteur du corps : 2.6-2.8, augmentant avec la taille. Taille maximum : 35.8 cm SL. Profondeur : 10 - 35 m.

Etymologie
Gymnocranius : du Grec, gymnos = nu + du Grec, kranion = crane.
oblongus : du préfixe Latin, ob- = vers, contre + du Latin, longus = long (ici oblong, de forme allongée, plus long que large). En référence à sa forme oblongue.
Description originale : Gymnocranius oblongus Borsa, Bearez & Chen, 2010 - Localité type : Lagon Sud, Nouvelle-Calédonie, profondeur : 8 - 15 m.

Distribution
Mer de corail : Nouvelle-Calédonie.

Biologie
Poisson solitaire, nageant à proximité du fond. Il est présent dans les parties sablonneuses du lagon prochent des passes. Il se nourri de coquillage et de crevettes qu'il trouve en fouillant le sable.

Espèces ressemblantes
Gymnocranius grandoculis (Valenciennes, 1830) - Présent en Nouvelle-Calédonie.
Gymnocranius griseus (Temminck & Schlegel, 1843) - Présent dans l'Est de l'Océan Indien et l'Ouest du Pacifique : de l'Est de l'Inde aux Philippines, au Nord, Sud du Japon.
Gymnocranius obesus (Chen, Miki & Borsa, 2017) - Présent des îles Ryukyu jusqu'à Bali en passant par Taïwan et la mer de Flores.

--------------------------------------------

Description
Dorsal soft rays (total): 10; Anal soft rays: 10. Four rows of scales on cheek; body oblong and fusiform, ratio of standard length to body depth between 2.6 and 2.8, increasing with size; dorsal and ventral profiles almost similarly convex; tip of snout only slightly below axis of body; snout slightly rounded; tail elongated with rounded tips; posterior part of jaws reaching to about level of nostril; pored scales on lateral line: 48; scales between middle portion of spinous dorsal fin and lateral line: six. Lower edge of eye slightly (in the smaller individuals examined) to well above a line from tip of snout to middle of caudal fin fork; horizontal or sub-horizontal wavy blue lines or dashes on lower part of snout and on cheeks; pale blue speckles more or less visible on operculum. The lines or dashes become dark red or brown against paler background in preserved specimens; they do not extend up to the upper part of snout and their number slightly increases with size. Forehead, snout and upper lip of fresh specimens can be bright yellow, matched by similar yellow colouration of margin of operculum; loosely defined vertical dark bar crossing the eye; on fresh animals, dorsal, pectoral, anal and caudal fins drab, brownish or yellowish, with reddish to vermilion edges. Each lower jaw has a raw of three small, slender canines on each side of one large canine at front, and a lateral row of eight to 10 conical teeth; numerous villiform teeth form a brush behind the front canines; each upper jaw has a front row of six to 10 small, slender canines followed by four to five conical teeth and a patch of villiform teeth. Max length: 35.8 cm SL. Depth range: 10 - 35 m.

Etymology
Gymnocranius: from Greek, gymnos = naked + from Greek, kranion = skull.
oblongus: from Latin prefix, ob- = towards, against + from Latin, longus = far, long, extended, prolonged (here somewhat long, oblong). In reference to the oblong body shape.
Original description: Gymnocranius oblongus Borsa, Bearez & Chen, 2010 - Type locality: Southern lagoon, New Caledonia, depth about 8-15 meters.

Distribution
Coral sea: New Caledonia.

Biology
Occurs on coral-sand bottom in lagoons and large pools. Stomach contents include broken bivalve shells, shrimp and bivalve meat (but no shell fragment).

Similar species
Gymnocranius grandoculis (Valenciennes, 1830) - Reported from New Caledonia.
Gymnocranius griseus (Temminck & Schlegel, 1843) - Reported from Eastern Indian Ocean, Western Pacific: India east to Philippines, north to southern Japan.
Gymnocranius obesus (Chen, Miki & Borsa, 2017) - Reported from Ryukyu Islands to Bali, including Taiwan and the Flores Sea.