Suezichthys notatus (Kamohara, 1958)

TANG, Chi-Ngai, CHEN, Hong-Ming & HO, Husan-Ching, 2021, A new record of a rare labrid, Suezichthys notatus (Actinopterygii: Labridae), from Taiwan, with comparison to related species from Taiwan, Acta Ichthyologica et Piscatoria 51 (4), pp. 393-401 : 393

Suezichthys notatus (Kamohara, 1958)

Figs 1 , 2 , 3 , 4

Pseudolabrus notatus Kamohara, 1958: pl. 3, fig. 2 (type-locality: Okinoshima, Japan).

Suezichthys tripunctatus Randall et Kotthaus, 1977: 34, figs. l-3 (type-locality: Oahu, Hawaiian Islands)

Description of Taiwanese specimens.

Proportional measurements are given in Table 1 . Dorsal-fin elements IX, 11, all soft rays segmented and branched; anal-fin elements III, 10, all soft rays segmented and branched; pectoral-fin rays 13, uppermost rudimentary and second uppermost unbranched; pelvic-fin elements I, 5, all soft rays segmented and branched; caudal-fin rays 6 (dorsal unsegmented) + 2 (dorsal segmented and unbranched) + 12 (branched) + 2 (ventral segmented and unbranched) + 5-6 (ventral unsegmented); lateral line complete, bent abruptly downward beneath 10th dorsal-fin ray, with pored and tubed scales 25-26 (including enlarged and pointed pored scale on base of caudal fin; pored scale attached to opercular membrane excluded), simple and unbranched; scales above lateral line to origin of dorsal fin 2½; scales below lateral line to origin of anal fin 7½; low scaly sheath present at base of dorsal and anal fins; predorsal scales rows 5; cheek scale rows behind eye 2, scale rows below eye 2-3; circumpeduncular scales 15-16; total gill rakers 17-20; pseudobranchial filaments 19; branchiostegal rays 6; vertebrae 9 (precaudal) + 16 (caudal) = 25; ribs present from 3rd to 9th vertebra; epineural bones ending on 12th vertebra; hemal arches associated with anterior caudal vertebrae of 10th to 12-13th vertebrae forming large hemal canal (Fig. 4A ).

Body moderately elongate, its depth at dorsal-fin origin 3.7-3.9 in SL; moderately compressed, width behind gill opening 2.8-3.6 in HL. Head small, its length 2.8-3.0 in SL; snout short, length 3.5-4.0 in HL; orbital diameter 4.2-4.5 in HL; bony interorbital width 6.4-6.7 in HL; suborbital depth 7.4-8.5 in HL. Least depth of caudal peduncle 2.7-2.8 in HL; length of caudal peduncle 2.4-2.7 in HL. Caudal fin slightly rounded, its length 1.6 in HL. Pectoral-fin length 1.8-1.9 in HL, reaching level of 7th dorsal-fin spine. Pelvic fin short, 2.2-2.5 in HL, first pelvic-fin ray not elongated. Length of dorsal-fin base 1.7-1.8 in SL; dorsal-fin spines progressively longer; first spine 6.4-7.3 in HL; last spine (9th) longest, 3.2-3.9 in HL; longest dorsal-fin ray (6th) 2.6-2.8 in HL. Length of anal-fin base 2.9-3.0 in SL; first anal-fin spine 9.3-9.9 in HL; third spine longest, 4.2-4.5 in HL; longest anal-fin ray (4th) 2.8-3.0 in HL.

(Based on NMMB-P34163) Mouth terminal, horizontal, and small, posterior end of maxilla reaching vertical through posterior nostril; lips moderately fleshy; upper lip with 6 longitudinal plicae and lower lip with 1; upper jaw with two pairs of enlarged canines at front, anteriormost pair of canine largest and recurved, second one about half length of first; 15/16 progressively smaller canine teeth laterally in upper jaw, with inner row of 6 (on left)/4 (on right) small canines behind anteriormost teeth; enlarged and antrorse canine at posterior end of upper jaw; lower jaw with 2 pairs of enlarged anterior canines, second canine slightly shorter than first; 11/13 progressively smaller lateral teeth in lower jaw, with inner row of 6/6 pairs of smaller canines behind anteriormost teeth; no teeth on palatine.

Nostrils small, in two pairs just in front of orbit; anterior nostril terminating in small membranous tube; posterior nostril without flap or prominent ridge at margin. Gill membranes not attached to isthmus, forming free fold posteriorly. Gill rakers short, longest less than half length of longest gill filament. Preopercle entire, free posterior margin reaching just above level of lower rim of orbit, free lower membrane extending forward to below level of middle of lower rim of orbit. Opercular membrane broadly rounded, extending posterior to pectoral-fin base. About 26 pores in lateralis system around orbit; ca. 22 pores along free edge of preopercle (based on NMMB-P34163).

Opercle with 6 large scales posteriorly, almost extending to posterior margin of preopercle. Preopercle with 2 rows of cheek scales behind eye, and 2-3 rows below eye, extending forward to beneath middle of lower rim of orbit. Thorax fully scaled, scales about one half to three quarters of size of body scales. Basal portion of caudal fin scaled; forehead, snout, ventral side of head naked; subopercle naked. Body scales large, cycloid.

Dorsal-fin origin above upper pectoral-fin base; anal-fin origin below first dorsal-fin soft ray; pelvic-fin base slightly anterior to pectoral-fin base.

Coloration.

(TP individuals) When fresh (Fig. 1A-C ), body color pink to purple, paler on abdomen. Faint yellow reticulated pattern on lateral body. Group of prominent dark blotches extending from interorbital region dorsoposteriorly. Snout yellow, extending on operculum as two yellow stripes. Three faint yellow stripes gradually narrower extending from behind operculum to caudal peduncle. Dorsal fin pinkish to purple, yellow wavy lines above base and on upper edge of fin. Black spot between membrane of first and second dorsal-fin spine. Anal fin pinkish to purple, its edge yellow. Caudal fin yellow, with 2-3 vertical purple stripes. Pectoral fin translucent pink. Pelvic fin white.

When preserved (Fig. 2 ), body pale. Prominent black blotches or spots on forehead and dorsal fin consistent with fresh condition. Forehead and dorsal-fin base dusky. Few faint dusky lines along, above and below lateral line. Edge of anal fin black.

Distribution.

Suezichthys notatus is known from scattered localities across the Pacific Ocean and the easternmost Indian Ocean. Its type locality is Okinoshima, Kochi Prefecture of Japan. Suezichthys notatus also occurs in deep waters off northwestern Australia and Oahu, of the Hawaiian Archipelago. In the Hawaiian Archipelago, S. notatus has been observed along the edges of sand patches near irregular, hard surfaces, and foraging by picking at objects on rocks and sand at depths of 119-272 m ( Russell 1985; Chave and Mundy 1994). The Taiwanese specimens described here were caught off the coast of Keelung, near the "Northern Three Islands", at depths of ca. 100-150 m, and off Kaoshiung, southwestern Taiwan (depth unknown); its habitat was assumed to be deep sandy-rocky bottom.

Figures

Figure 1. Fresh coloration of Suezichthys notatus from Taiwan. (A) NMMB-P 34163, 119.5 mm SL, TP individual. (B) NMMB-P 35255, 121.5 mm SL. (C) NMMB-P 35256, 110.4 mm SL.

Figure 2. Preserved specimen of Suezichthys notatus, NMMB-P 34163. (A) lateral view; (B) lateral side of head; (C) dorsal view of head and pre-dorsal region.

Figure 3. Radiograph of Suezichthys notatus, NMMB-P 34163.

Figure 4. Radiographs showing the hemal arch formation associated with the anterior caudal vertebrae, arrows and asterisks are indicating the hemal arch on the 10 th vertebra (anterior-most caudal vertebra) of two Suezichthys. (A) S. notatus, NMMB-P 34163, on 10 th to 13 th vertebrae; (B) S. gracilis, NMMB-P 26425, on the 10 th vertebra.