Owstonia doryptera ( Fowler, 1934 )

Owstonia doryptera ( Fowler, 1934) View in CoL

Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4 ; Tables 3 View Table 3 , 4 English name: Spear-finned Bandfish New Chinese name: 矛鰭歐氏鰧 View Table 4

Loxopseudochromis doryptera Fowler, 1934: 354, fig. 106 (type locality: off northern Mindanao Island, Philippines, depth 175 fathoms [= 320 m]. Lectotype: USNM 93166).

Owstonia doryptera ( Fowler 1934). Smith-Vaniz and Johnson 2016: 45 (redescription and lectotype designation). Liao et al. 2022: 127 (listed in comparative material). View in CoL

Owstonia dorypterus ( Fowler 1934). Imai 2000: 625 (listed, South China Sea). Smith-Vaniz 2001: 3332 (listed). Liao et al. 2009: 522 (compared to the new species described). View in CoL

Owstonia psilos View in CoL (non Smith-Vaniz and Johnson). Jhan and Ho 2019: 982, unnumbered figure (in part, misidentification; NMMB-P 30640 ).

Specimens examined.

All collected from off Dong-gang fishing port (ca 22°22'22"N, 120°27'34"E), Pingtung, southwestern Taiwan GoogleMaps • NMMB-P 001317 , 86.6 mm SL, 31 May 1985, coll. H.-C. Chang GoogleMaps • NMMB-P 30640 , 158.3 mm SL, 10 September 2018, coll. K. Koeda and Y. Hibino GoogleMaps • NMMB-P 31226 , 108.9 mm SL, 29 July 2018, coll. H.-C. Ho GoogleMaps • NMMB-P 32875 , 108.4 mm SL • NMMB-P 32884 , 200.2 mm SL, 5 April 2019, coll. H.-C. Ho GoogleMaps • NMMB-P 33730 , 2 specimens, 90.1–119.3 mm SL, 22 February 2020, coll. H.-C. Ho GoogleMaps • NMMB-P 34605 , 233.7 mm SL, 30 July 2020, coll. H.-C. Ho GoogleMaps • NMMB-P 34901 , 86.1 mm SL, 11 August 2020, coll. H.-C. Ho and C.-N. Tang GoogleMaps • NMMB-P 36076 , 80.6 mm SL, 16 September 2020, coll. Y. Su, T.-K. Chou and N.-S. Leung GoogleMaps • NMMB-P 36133 , 89.7 mm SL, 14 July 2021, coll. Y. Su, Y.-H. Kuo, and L. C. Halasan GoogleMaps • NMMB-P 38848 , 2 specimens, 131.3–140.4 mm SL, 28 May 2022, coll. Y. Su GoogleMaps • NMMB-P 38895 , 159.9 mm SL, 6 January 2023, coll. Y. Su, R.-Y. Hung, and Y.-C. Fan GoogleMaps • NMMB-P 42298 , 78.3 mm SL, 9 May 2024, coll. Y. Su and Y.-C. Hsu GoogleMaps • NMMB-P 42267 , 296.1 mm SL, 11 February 2025, coll. K.-H. Wu GoogleMaps • NMMB-P 42299 , 109.1 mm SL, 8 March 2025, coll. K.-H. Wu GoogleMaps • NMMB-P 42300 , 143.0 mm SL, 26 September 2024, coll. Y. Su and Y.-C. Hsu GoogleMaps • NMMB-P 42301 , 105.2 mm SL, 2 April 2025, coll. H.-C. Ho and J.-Y. Chiang GoogleMaps .

Description of Taiwanese specimens.

Meristic and morphometric data are provided in Tables 3 View Table 3 , 4 View Table 4 .

Dorsal-fin rays III, 21 ( one specimen with 20); pectoral-fin rays 20–22 / 20 – 22; pelvic-fin rays I, 5 / I, 5; anal-fin rays I, 14; principal caudal-fin rays 8 + 7, uppermost and lowermost rays unbranched; procurrent caudal-fin rays 3–4 and 3–5 on upper and lower lobes, respectively. Gill rakers on outer face of first gill arch 15–17 + 28–31 = 43–48 (total); pseudobranchial filaments 24–43. Oblique body scale rows 39–56 / 39 – 59; cheek scale rows 4–6 / 4 – 6. Vertebrae 11 + 17 = 28 ( n = 15); anal-fin pterygiophores anterior to 1 st haemal spine 2 ( n = 15). Spines on preopercle 11–19 / 7 – 16. Premaxillary teeth 14–24 / 13 – 25; inner premaxillary teeth 0–1 / 0 – 1; lateral dentary teeth 12–19 / 12 – 18; symphyseal teeth 3–5 / 3 – 5; inner symphyseal teeth 0–6 / 0 – 6.

Body stout, depth at anal-fin origin 3.5–3.9 in SL; both dorsal and ventral profiles of body straight, slightly tapering to caudal fin. Head large, length 2.9–3.7 in SL; anterior profile of head rounded, gently curved to dorsal-fin origin. Eyes large, eye diameter 1.9–2.8 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 with enlarged spines, those on vertical portions forming serrations.

Mouth lower in position, slightly oblique. Jaws terminal, with lower jaw slightly protruding before upper jaw. Upper-jaw length 1.6–1.9 in HL, its end reaching vertical through middle of eye to slightly anterior to vertical through posterior margin of eye; posterodorsal tip of ascending premaxillary processes with four larger papillae associated with smaller ones. 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 anterior lateral teeth slightly enlarged or not; 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 3; its anterior end forming complete loop. Lateral line terminates below 18 th – 24 th / 19 th – 24 th total dorsal-fin ray.

Dorsal fin with long base, originating 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 1.2–1.5 in HL; its origin slightly above horizontal through lower margin of eye; its posterior end variable, reaching from anterior to vertical through anal-fin origin to reaching beyond vertical through anal-fin origin. Pelvic fin elongated, length 0.9–1.4 in HL; its origin below third dorsal-fin spine; its tip also variable reaching from anus to 4 th total anal-fin ray when adpressed (correlated with specimen size). Anal-fin base moderately long, its posterior end slightly anterior to that of dorsal fin; its origin below 11 th or 12 th total dorsal-fin ray; fin rays gradually longer posteriorly; its distal margin nearly straight. Caudal fin pointed; its length 0.5–0.8 in HL. Caudal peduncle broad, depth 2.4–3.4 in HL and length 1.5–2.3 in HL.

Coloration.

When fresh (Fig. 2 View Figure 2 ), body, pectoral fin, and dorsal-, pelvic-, anal-, and caudal-fin membranes pink, with dorsum, top of head, and distal margin of dorsal, pelvic, anal, and caudal fins red. Dorsal-, pelvic-, anal-, and caudal-fin rays paler than their fin membranes. When preserved (Fig. 3 View Figure 3 ), body and fins uniformly pale, except for NMMB-P 42299 , which has dusky middle caudal-fin rays. Black stripe or blotch on dorsal fin variable (Fig. 4 View Figure 4 ), from uniformly pale to black between second spine and first soft ray or between second and third spines. Membrane between premaxilla and maxilla uniformly black. Inner face of preopercle slightly dusky.

Distribution.

Previously known only from the type series collected from northern Mindanao Island, Philippines at depth 320 m. Our specimens represent the northernmost record of this species. This species appears to be rather commonly collected by bottom trawl in southern Taiwan. The estimated depth of catch is about 200– 400 m.

Remarks.

Our specimens are identified as O. doryptera in having: anal-fin rays I, 14; cheek scales present; lateral line of type 3, forming complete loop in front of dorsal fin ( Smith-Vaniz and Johnson 2016). Compared to the type specimens, several major differences were found between our specimens and the type series. Our specimens possess a more posterior end of lateral line (ending at 18 th – 24 th total dorsal-fin ray, vs 15 th or 17 th in O. doryptera ; Smith-Vaniz and Johnson 2016; Table 3 View Table 3 ); and more lateral dentary teeth (12–19 vs 9). As other characters, such as the number of oblique scale rows and premaxillary teeth display considerable variation, and some traits (e. g. pseudobranchial filaments, lateral dentary teeth, end of pelvic fin, head length, and caudal-fin length) are growth dependent, these differences are interpreted as intraspecific variation.