PI. 3D, Fig. 10

Material examined. (29 specimens: 14-114 mm). AUSTRALIA Great Barrier Reef region, AMS 1.32476 - 004 (2: 16 mm), AMS 1.34911 - 011 (1: 30 mm), AMS 1.34911 - 012 (1: 25 mm), AMS 1.34933 - 001 (2: 14 mm), AMS 1.34934 - 001 (2: 28-47 mm), AMS I.34935-001 (3: 34-35 mm), AMS 1.34936 - 001 (1: 32 mm), AMS 1.36201 - 001 (1: 15 mm), AMS 1.37803 - 001 (1: 16 mm), USNM 336691 (3: 26-35 mm), not retained (9: 24-69 mm); FIJI Suva, AMS 1.22232 - 016 (1: 114 mm); INDONESIA EasternArchipelago, NMV 46329 (1: 73 mm); PAPUA NEW GUINEA Trobriand Islands, AMS I.17102-015 (1: 38 mm).

Diagnosis. Body slender, body depth 3.1-3.5 in SL; 4.5 dorsal scale rows, 13-14 ventral scale rows; maxillary serrations absent at greater than 23 mm; cheek scales retained until 47-50 mm; dorsal spine 4 the longest.

Diagnostic colour notes. Dorsum finely-mottled grey-tan, seldom with dark banding, dorsal margin of lateral-line off-white; dark mid-lateral stripe semi-permanent, yellowish brown, width approximately 4.0 in body depth, shoulder blotch inconspicuous or absent; ventral half of body abruptly silvery off-white; dark suborbital blotch at greater than 30 mm; fins hyaline.

Pre-settlement colour notes. At 14-16.5 mm (Fig. 10): head and body translucent off-white, melanophores overlying yellow-orange xanthophore pigmentation; distinct dark stripe extending from lips to orbit margin, continuing as dark mid-lateral stripe between posterior margin of orbit and caudal peduncle, may appear as series of irregular blotches; lateral-line cryptic, 3-5 irregular blotches along dorsum, interspaces silver, occasionally 3- 6 less-distinct blotches extending below dark mid-lateral stripe from pectoral fin to mid-way along caudal peduncle, further 2-3 irregular blotches adjacent to anal fin; fins hyaline.

Colour notes. A distinctive species with minimal ontogenetic variation following settlement, few differences noted between field and captive or freshly-killed colouration. At 25-50 mm: dorsum and nape finely-mottled grey-tan, 4-6 narrow dark bands above lateral-line and 2- 3 similar bands along caudal peduncle, often switched off in field, lateral-line bordered dorsally by silvery off-white interspace in field; yellow-brown mid-lateral stripe extending from lips through orbit to base of upper caudal rays, semi-permanent (cf. intermittent stripe in other species), width 4.0 in body depth, may appear as series of dark blotches in captivity (PI. 3D), blotch below dorsal spines 3-4 forming diffuse cuboidal shoulder blotch; ventral half of body and head abruptly silvery white, without dark markings in field, often 2-3 diffuse brown stripes or bands between pectoral and anal fins in captivity (PI. 3D) or after death, 3-4 dark blotches on cheek and operculum from 25 mm; fins mostly hyaline, anterior half of spinous fins with diffuse dark patches over off-white to pale yellow, caudal fin pale yellow with 2-3 indistinct dark bands at greater than 40 mm.

Colour in alcohol. At 25-50 mm, dorsum and nape uniform pale tan; lips and snout with dense melanophores, dark dorsal bands retained though dulled, often connecting with broad blotches on flank, dark mid-lateral stripe identical hue to dorsum, shoulder blotch usually visible; body abruptly off-white ventrally, faintly mottled; fins hyaline, sparse melanophores retained along spines.

Ecology. Moderately common in shallow seagrass beds on lagoonal or fringing coral reefs (Cymodocea, Halodule, Thalassia; 0.2-4 m), absent from non-seagrass areas at Green Island at less than 100 mm; solitary when recentlysettled (20-40 mm), larger juveniles occasionally join small multi-species schools with congeners, particularly L. atkinsoni, L. genivittatus, L. harak, and L. obsoletus; observed resting on the substrate among seagrass shoots at night, not fleeing when approached.

Field identification. Distinguished from other Lethrinus species by its elongate body and snout profile, and prominentyellow-brownmid-lateralstripe. Whenobserved from behind, may be confused with species such as L. obsoletus or L. genivittatus on the basis of their similar dark mid-lateral stripes. When freshly collected, particularly at night, may appear a uniform pale olivaceus cream; the dark mid-lateral stripe and shoulder blotch becoming visible after 10-30 seconds.

Previous descriptions. Colour plates of juveniles were included in Kuiter & Debelius (1994) and Kuiter (1996) (size not given in each case), and Lee (1993) (specimen 147 mm, misidentified as L. semicinctus).