Lagoon Cardinalfish

Description: Characterized by semi-transparent with silvery blue reflections; yellow belly; last dorsal fin ray with small white spot below; base of anal fin with blackish patch above; adult males sometimes with yellow lips and yellowish bar behind eye; sometimes with dusky area on caudal fin base; variety from western Sumatra and East Andaman Sea, generally paler, lacks dusky area on caudal fin and dark patch above base of anal fin (Ref. 90102).

Mouthbrooders (Ref. 240). Distinct pairing during courtship and spawning (Ref. 205).

Dorsal spines (total): 7; Dorsal soft rays (total): 9; Analspines: 2; Analsoft rays: 9

Coastal, often silty reefs or shallow lagoons, forming schools just above branching corals (Ref. 48635).

Apogon perlitus

DIAGNOSIS.—A tiny basicaudal spot; dark mark on gular area; many diffuse melanophores on side of caudal peduncle; 4 to 8 short, dark, vertical lines on body just above base of anal fin; second dorsal spine not produced as a filament, less than 21% of standard length.

DESCRIPTION.—Important morphometric and meristic data are treated in Tables 4–6. For general shape and pigment pattern see Figure 15. Proportions (as percent standard length, holotype in parentheses): body depth (39.7) 29–40; head length (40.4) 39–44; eye length (13.5) 13–15; snout length (8.7) 7–10; bony interorbital width (8.7) 8–10; upper jaw length (18.7) 17–19; caudal peduncle depth (16.1) 13–17; caudal peduncle length (22.5) 22–26; dorsal spine lengths—First (9.0) 7–11, second (18.4) 15–21, third 16–20, fourth 13–17, spine in second dorsal (15.6) 15–18; anal spine lengths—First 2–4, second (13.0) 13–16; pectoral fin length (26.7) 25–28; pelvic fin length (20.8) 19–21.

Second dorsal fin I, 9; 2 anal spines; pectoral fin 14 (rarely 15); pelvic fin I, 5; well-developed gillrakers 25–27 (5–6 + 19–21), including rudiments 26–29 (0–2 + 5–6; 19–21 + 0–1), holotype 2 + 5 - 21 +0; pored lateral–line scales 24; transverse scale rows above lateral line 2; median predorsal scales 6; circumpeduncular scales 12 (5 + 2 + 5).

COLOR OF PRESERVED SPECIMENS.—The only conspicuous color mark is a small, dark, round to slightly oval, discrete basicaudal spot, its diameter almost one-half that of pupil; a diffuse, broad patch of melanophores scattered over caudal peduncle anterior to basicaudal spot; four to eight dark, short, moderately intense vertical lines on body just above anal fin base; a dark to dusky gular spot; a dark mark between tip of snout and eye; a dark spot between angle of jaw and eye; outer membranes black between second and third, and third and fourth dorsal spines; some scattered melanophores dorsally on head and nape, on dorsal midline of trunk and laterally on trunk above the midline; remainder of body mostly pale and the fins transparent.

ETYMOLOGY.—The specific name perlitus is a Latin word meaning smeared or bedaubed, in reference to the large, dark, diffuse cluster of chromatophores on the caudal peduncle.

GEOGRAPHIC DISTRIBUTION.—Known from the Philippines and Palau, southeastward to the Bismark Archipelago (Figure 16).

DISTRIBUTION.—This species has a fairly restricted distribution, limited to the Philippines and some eastern Indonesian islands and to Belau and Yap islands (Figure 18).

MATERIAL EXAMINED.—1719 specimens, ranging in size from 23–42 mm SL.

Holotype: USNM 51941, 32.6 mm SL, Philippines, Negros I., 1901, Bashford Dean coll. (specimen bears label designated “Type”).

Paratypes: USNM 211818, 36.4 mm SL, taken with holotype. SU 9135, 34.3 mm SL, Southern Negros, Philippine Is., Bashford Dean coll.

Other Material: INDONESIA: USNM 225695, 7 (34–42), Halmahera I. BORNEO: USNM 225697, 89 (33–42), Darvel Bay. PHILIPPINES: USNM 183749 (A. 8429) (35), W Luzon, Port Matalvi. USNM 211819, 2 (34, 35), Luzon I., Port Matalvi. USNM 112919 (38), Palawan I., Endeavour Strait. USNM 211820 (A. 16540) (36), W Luzon, Port Matalvi. USNM 225696, 10 (34–40), Palawan I., Makesi I. USNM 183737, 98 (28–34), Luzon I., Palag Bay. USNM 183766 (A. D5143) (32), vicinity Jolo I. USNM 183777 (31), E coast Luzon, Port Palapag. USNM 183773, 8 (32–36), Albatross-Philippine. CELEBES (Sulawesi): USNM 211316, 11 (32–36), Bouri I., Tifu Bay. PALAU ISLANDS (Belau): GVF 1397, 33 (27–38), Babelthuap Atoll. GVF 483, 4 (30–37), Urukthapel I. GVF 1853, 77 (29–42), Arakabesan I. CAROLINE ISLANDS: CAS 28781 2 (28, 34); CAS 28780 (39); GVF 1910, ∼900 (25–40); GVF 1903, ∼200 (23–35); GVF 1942, ∼100 (26–38); GVF 1949, 51 (24–37); GVF 1912, 2 (32, 35); GVF 1917 (33); GVF 1929, 14 (27–37); GVF 1909, 44 (27–33); GVF 1908, 26 (24–36); all from Yap I.