Owstonia cf. aurora, Liao, Rodolfo & Shao, 2022

Owstonia cf. aurora

Figs 5 View Figure 5 , 6 View Figure 6 ; Tables 5 View Table 5 , 6 View Table 6

Owstonia totomiensis View in CoL (non Tanaka): Jhan and Ho in Koeda and Ho 2019: 984 (in part, misidentification; NMMB-P 29294 ).

Specimen examined.

All collected from off Dong-gang fishing port (ca 22°22'22"N, 120°27'34"E), Pingtung, southwestern Taiwan GoogleMaps • NMMB-P 29294 , 76.6 mm SL, 3 April 2018, collected by K. Koeda GoogleMaps • NMMB-P 42302 , 73.7 mm SL, collected by Y. Su, Y.-C. Hsu, H.-C. Ho GoogleMaps .

Description of Taiwanese specimens.

Meristic and morphometric data are provided in Tables 5 View Table 5 , 6 View Table 6 .

Dorsal-fin rays III, 20–21; pectoral-fin rays 22 / 22–23; pelvic-fin rays I, 5 / I, 5; anal-fin rays I, 13; principal caudal-fin rays 8 + 7, uppermost and lowermost rays unbranched; procurrent caudal-fin rays 3 on both upper and lower lobes. Gill rakers on outer face of first gill arch 12–13 + 24 = 36–37 (total); pseudobranchial filaments 25–26. Oblique body scale rows 46 – ca 57 / 47 – ca 50; cheek scale rows 7–9 / 9. Vertebrae 11 + 17 = 28; anal-fin pterygiophores anterior to 1 st haemal spine 2. Spines on preopercle 0 / 0. Premaxillary teeth 19–25 / 21; inner premaxillary teeth 0 / 0; lateral dentary teeth 9–13 / 10 – 14; symphyseal teeth 4–6 / 4 – 5; inner symphyseal teeth 1 / 1.

Body slender, depth at anal-fin origin 3.8–4.0 in SL; both dorsal and ventral profiles of body straight, slightly tapering to caudal fin. Head large, length 2.7–2.8 in SL; anterior profile of head rounded, gently curved to dorsal-fin origin. Eyes large, eye diameter 2.1–2.2 in HL. Two nostrils, with anterior one forming tube and short flap; posterior one oval, without flap, situated immediately in front of eye. Preoprecle and opercle covered by skin; posterior margin of preopercle smooth

Mouth lower in position, slightly oblique. Jaws terminated, with lower jaw slightly protruding before upper jaw. Upper-jaw length 1.6–1.7 in HL, its end reaching to vertical through middle of eye; posterodorsal tip of ascending premaxillary processes with two or three pairs of small papillae. Supramaxilla absent. Premaxilla with single row of canine teeth; teeth gradually smaller posteriorly; teeth slightly recurved and pointed or blunt. Dentary with single row of canine teeth; those on symphyseal slightly larger than others; some lateral teeth slightly enlarged anteriorly; teeth slightly recurved and pointed or blunt. Vomer and palatine without teeth.

Body scales cycloid and deciduous. Scales absent on isthmus, gular, both jaws, and interorbital space. Lateral line type 1; its origin from posttemporal and along dorsal-fin base; not extending beyond dorsal-fin origin. Lateral line terminates below 11 th total dorsal-fin ray ( n = 1).

Dorsal fin with long base, originated at vertical through upper end of gill slit; its distal nearly straight, with slight elevation on soft rays; no distinct notch between spines and soft rays. Pectoral-fin tip rounded; its length 1.4–1.5 in HL; its origin at same horizontal through lower margin of eye; its tip reaching to anal-fin origin. Pelvic fin elongated, its length 1.4–1.5 in HL; its origin below 3 rd dorsal-fin spine; its tip reaching to anus when adpressed. Anal-fin base moderately long, its posterior end slightly anterior to that of dorsal fin; its origin below 12 th total dorsal-fin ray; fin rays gradually longer posteriorly; its distal margin nearly straight. Caudal fin rounded, slightly pointed; its length 0.8 in HL ( n = 1). Caudal peduncle broad, length and depth 2.1–2.2 and 3.6–3.9 in HL, respectively.

Coloration.

When fresh (Fig. 4 View Figure 4 ), body, pectoral fin, with dorsum, top of head, dorsal- and anal-fin soft rays, distal margin of pelvic-fin soft rays, and caudal fin red. Distal and proximal margins of dorsal and anal fins with white band. Caudal fin with ca three large white blotches. When preserved (Fig. 5 View Figure 5 ), body uniformly pale. Black stripe or blotch on dorsal fin between second spine and sixth soft ray. Membrane between premaxilla and maxilla pale or slightly dusky (with small dusky blotch on right side of NMMB-P 42302 ). Inner face of preopercle slightly dusky. Anal fin with black spots (spots fewer and more faint in NMMB-P 42302 ).

Remarks.

Jhan and Ho (2019) reported three specimens of O. totomiensis ( NMMB-P 23318 , NMMB-P 23838 , and NMMB-P 29294 ), of which the latter is here identified as O. cf. aurora , and the other two specimens are identified as O. totomiensis .

Liao et al. (2022) stated that their O. aurora has lateral line ends below 17 th – 22 nd dorsal-fin soft ray; however, it is apparently an error as they provided 21 dorsal-fin soft rays throughout the article. See Discussion for further comparison.