Dussumieria hasseltii Bleeker, 1851

Dussumieria hasseltii Bleeker, 1851 View in CoL

( Fig. 1 View Figure 1 ; Tables 1 View Table 1 , 2 View Table 2 )

Material examined.

NMMB-P 07123 , 138.6 mm SL, Dong-gang fishing port , Pingtung, southwestern Taiwan, 26 Dec. 2003, coll. Yu-Ming Chu. NMMB-P 27653 , 2 specimens, 143.4–144.5 mm SL, Ke-tzu-liao fishing port , Kaohsiung, Southwestern Taiwan, 29 Mar. 2017, coll. Hsuan-Ching Ho .

Description.

Counts and measurements, expressed as percentages of SL, given in Tables 1 View Table 1 , 2 View Table 2 , respectively. Body cylindrical, laterally compressed, deepest at dorsal-fin origin. Dorsal profile of body gradually rising from snout tip to dorsal-fin origin, then declining posteriorly to uppermost point of caudal-fin base. Ventral profile of body lowering from snout tip to pelvic-fin insertion and subsequently rising to lowermost point of caudal-fin base. Abdomen soft, not covered with keeled scutes. Pelvic scute joined to pelvic girdle, W-shaped. Mouth projecting, terminal. Premaxilla rectangular. Posterior tip of maxilla not reaching vertical through anterior margin of orbit. Single row of conical teeth on ventral margins of premaxilla and maxilla. First and second supramaxillae elongate. Teeth absent on vomer and parasphenoid. Teeth patches on palatines and pterygoids joined to each other, forming broad teeth patch with numerous rows of conical teeth. Lower jaw with single row of conical teeth. Two or three rows of sharp conical teeth on dorsal surface of basihyal. Orbit, eye and iris round. Eye completely covered with well-developed adipose eyelid. Vertical slit opening on eyelid exposing central part of iris. Interorbital space flat. Nostrils close to each other, located on middle of snout. Posterior margins of opercle and preopercle smooth. Preopercular margin angular. Gill rakers long, slender. Small asperities on both surfaces and inner edge of gill rakers. Pseudobranchial filaments present, exposed. Isthmus pointed anteriorly. Anteriormost point of pectoral-fin insertion slightly posterior to posteriormost point of opercle. Upper, posterior and ventral margins of pectoral fin nearly linear; posterior tip of pectoral fin pointed, not reaching to vertical through dorsal-fin origin. Dorsal-fin origin anterior to pelvic-fin insertion. Dorsal-fin base end posterior to posteriormost point of pelvic-fin insertion. Pelvic-fin insertion just below origin of 9 th or 10 th dorsal-fin ray. Anal-fin origin posterior to vertical through posteriormost point of dorsal-fin base. Caudal fin forked, both lobes with nearly straight outer profiles, posterior tips pointed. Anus on ventral midline, slightly anterior to anal-fin origin, posterior to midpoint of body. No lateral line. All lateral body scales lost. Predorsal scales arranged in median row. Scales absent on head and fins.

Coloration of preserved specimens.

Lateral surface of body uniformly pale brown. Dorsum to upper part of lateral surface of body dark brown. Numerous melanophores scattered on dorsum to lateral surface of body, reaching to level of middle of eye. All fins pale yellow. Posterior margin of caudal fin dusky. Melanophores scattered along fin rays of dorsal and caudal fins. No melanophores scattered on pelvic and anal fins, gill rakers, gill filaments, and pseudobranchial filaments. Melanophores scattered on 8 th to 14 th pectoral-fin rays from uppermost ray, inner surfaces of hyoid arch and opercle. Melanophores scattered on area between left and right tooth bands of pterygoids. Tongue and mouth floor uniformly black.

Distribution.

Dussumieria hasseltii is widely distributed in the Indo – west Pacific from the Persian Gulf to Taiwan and Papua New Guinea ( Hata et al. 2022 a, 2022 b, 2024 b, 2025; Hata 2023; this study).