Choerodon vitta Ogilby, 1910

Martin F., Martin F., 2017, A review of the tuskfishes, genus Choerodon (Labridae, Perciformes), with descriptions of three new species, Memoirs of Museum Victoria 76, pp. 1-111 : 59-61

Choerodon vitta Ogilby, 1910

Blackstripe Tuskfish

Choerodon vitta Ogilby, 1910a: 13 , Aru Islands ( Indonesia).

Diagnosis. Dorsal fin rays XIII, 7; anal fin rays III, 10; pectoral fin rays ii, 14, rarely 15, dorsalmost ray of moderate length 25.5–41.7% pectoral fin length, ventralmost rays shorter than those above, posterior edge of fin obliquely straight, dorsoposterior corner bluntly pointed, posteroventral corner angular; body moderately deep, 29.8–39.6%SL, head depth 22.2–31.8% SL, caudal peduncle depth 12.0–14.9% SL; head broadly pointed, dorsal profile of snout oblique, snout length 10.9–15.3% SL; predorsal scales approximately 12–15, reaching forward on dorsal midline to or almost to above middle of eye; cheek with small partially embedded scales in about 8 diagonal rows, posteriormost with about 12 or 13 scales to upper extent of free preopercular edge, reaching forward almost to corner of upper lip crease above mouth, with broad naked margin posteriorly and ventrally on preopercle; about 2 rows of 10–12 small scales (2–4 scales in second row dorsally) on subopercle adjacent preopercular edge extending forward nearly to anterior end of ventral preopercular margin; each lateral line scale with mutlple branching laterosensory canal tube; scales above lateral line about 4 or 5; few cephalic sensory canal pores confined to lines or short branches associated with major canals; second pair of canines in lower jaw directed dorsolaterally and curved posteriorly; dorsal and anal fins with very low basal sheath comprising 1 or 2 slightly smaller accessory scales at deepest; posterior lobe of dorsal and anal fins not reaching hypural crease; caudal fin double emarginate, upper and lower corners rounded, posterior margin of fin concave, smoothly curved; pelvic fin reaching to or just short of anus, length 20.4–25.0% SL. (See Table 2 for additional meristic and morphometric ranges.) Brown to grey above, white below with dark midlateral stripe from eye to base of tail, usually followed by prominent darker spot.

Reaches moderately small maximum size, largest specimen examined 174 mm SL.

Pigmentation in alcohol. Juveniles pale with broad dark dusky lateral stripe from snout across lower half of eye to caudal fin base, intensified as elongate dark spot on rear half of caudal peduncle and caudal fin base (fig. 29A). Adults pale, slightly duskier dorsally with distinct dusky stripe on lateral midline continuing on head beneath eye and crossing snout in front of eye, ending posteriorly in distinct horizontally elongate spot on posterior half of caudal peduncle; fins mostly pale, dorsal fin slightly dusky anteriorly and basally.

Fresh colours. Juveniles white with grey dorsum and black midlateral stripe.

Adults grey dorsally, white ventrally with broad dark edged reddish brown stripe midlaterally from ventral half of eye to caudal peduncle followed by black elongate oval spot on caudal fin base (fig. 28B & C); head greenish grey above with yellow on cheeks and above midlateral stripe behind eye, with 2–4 anastomosing, silvery blue lines on cheek and preorbital. Dorsal and caudal fins grey; anal fin white. ( Sainsbury & Kailola, 1984: 259, centre; Allen, 1985: 2407, fig. 333)

Etymology. The name vitta is Latin for “ribbon” or “stripe”, in reference to the characteristic dark midlateral stripe on the side of this species.

Distribution. Confined to northern Australia and the Aru Islands in south-eastern Indonesia, reaching south to the Exmouth Gulf in Western Australia and to the southern part of the Great Barrier Reef on the east coast of Australia (fig. 30). Found on open sand or rubble bottom adjacent coastal reefs at depths of 4–75 m ( Kuiter, 2010: 62; Allen & Erdmann, 2012: 648).

Comments. Ogilby (1910a: 13) described Choerodon vitta from a 190 mm TL specimen (QMB I. 1555, 148 mm SL) collected at Dobo in the Aru Islands ( Indonesia). The symmetrical, snapper-like form and dark brown to black midlateral stripe with black spot on the base of the caudal fin are diagnostic for the species.

Material examined. 40 specimens, 29.5–174 mm SL; see appendix.