Description
Dorsal spines (total): 7; Dorsal soft rays (total): 8-10 (usually: 9); Anal spines: 1; Anal soft rays: 7-9 (usually: 8); Pectoral fin ray: 18-19. Pelvic fin: 1 + 5; Caudal fin rays: 17; Lateral ligne scales: 22-24 (usually: 23-24); Transverse scales: 6-8 (usually: 7). Dorsal spine, second spine longest, in some specimens elongated into short filament (reaching first segmented rays of second dorsal fin in some males); First ray of second dorsal fin usually unbranched (unbranched in specimens < 14 mm SL, but also unbranched in about two-thirds of adults), anterior element of last element branched; Anal fin, first ray usually branched (often unbranched in specimens < 14 mm SL), anterior element of last ray branched; Pectoral fins, upper: 5-8 rays unbranched, central: 4-9 rays branched and lowe:r 6-11 rays unbranched; Pectoral fin reaching just posteriorly to vertical in line from urogenital papilla to about second segmented ray of anal fin; Pelvic fins, fins widely separate with short basal membrane, covered by median scale, distance between bases of fins slightly less than base of each pelvic fin; First four rays with one sequential branch, fifth ray with one dichotomous branch (two terminal tips) or unbranched, 50-70 % length of fourth ray, which reaches posteriorly to below point between anal spine and second segmented anal ray. A fish with a deep interorbital trench, a moderately deep groove behind the upper half of the eye in adults; The predorsal midline almost completely covered with ctenoid scales in 5-7 rows extending anteriorly to just behind the interorbital trench, the anterior-most scale just behind a small naked patch and not distinctly larger than the second scale on the midline; Opercle and preopercle naked. Max. length: 3.5 cm SL. Depth range: 8 - 35 m.

Color
Head with large yellow to yellowish-orange, irregularly shaped spots and bars, bordered by white rim; Vertical band of same color, less than pupil diameter, extending from below anterior pupil margin to upper jaw and similar shaped band below posterior margin of pupil extending to beyond posterior end of jaws, interspace between two bands grey to bluish-grey; Spots near posterior preopercular margin normally joined into thin vertical bar extending upward to behind eye or sometimes separated into separate spots; Snout usually grey, with small yellow to yellowish orange spot at anteroventral margin of eye; Pale yellowish orange vertically elongate spot ventrally on opercle and similar spot near dorsal margin of opercle; Two small round yellowish-orange spots ventrally on branchiostegal membranes below opercle and preopercle (absent in some populations), pale orange vertically elongate spot ventrally on opercle; Pectoral-fin base with upper and lower yellow-orange large spot, with two spots almost touching; Nape with large yellowish-orange spots, some connected across nape forming bars; Yellow to reddish-orange spots on body vertically elongate, but becoming smaller posteriorly and ventrally, spots usually not forming distinct horizontal rows on caudal peduncle; Dorsal and anal fins with large spots of similar coloration to body spots, with largest spots near base of fin, followed by 3-4 rows of smaller spots distally; Pectoral fin whitish; Pelvic fin clear to white, with yellowish-orange pigment near base of fins; Caudal fin with 3-5 rows of smaller spots of similar coloration to body spots.

Etymology
Trimma: from Greek, trimma, -atos = something crushed.
okinawae: named from the type locality; Okinawa island - Japan.
Original description: Eviota caesiura okinawae Aoyagi, 1949 - Type locality: Itoman, Okinawa Island, Ryukyu Islands, Japan.

Distribution
Indo-West Pacific: Indonesia east to Marshall Islands and Fiji, north to Ryukyu and Ogasawara islands and southern Japan, south to northern Australia and New Caledonia.

Biology
Inhabits clear coastal reefs, near sponges. Usually hovers upside-down in small caves in coral reefs. Forms small loose groups, usually lives in social groups comprising a large male and one or more smaller females.

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