Owstonia kamoharai Endo, Liao and Matsuura

Smith-Vaniz, William F. & Johnson, David, 2016, Hidden diversity in deep-water bandfishes: review of Owstonia with descriptions of twenty-one new species (Teleostei: Cepolidae: Owstoniinae), Zootaxa 4187 (1), pp. 1-103 : 58-60

Owstonia kamoharai Endo, Liao and Matsuura

( Figures 46−48 )

Owstonia kamoharai Endo, Liao and Matsuura, 2015 :[2], figs. 2 & 3 and 2016:32, figs. 2 & 3 (original description; Mimase fish market, off Kan-no-ura, Toyo Town, Kochi Pref., Shikoku Island, southern Japan; holotype NSMT-P 109686). Owstonia sp. Ikeda and Nakabo, 2015:168, 441, pl. 167, color photographs 4–6 (brief description).

Material examined. 10 specimens, 122‒408 mm SL: Japan BSKU 74538 (1, 147), Suruga Bay , off Heta, Numazu City, Shizuoka, 300–350 m, 20 Feb. 1992 ; BSKU 98751 (1, 263, x-ray only), off Nachi-katsuura , Wakayama, Kii Peninsula, 260 m. Arafura Sea NTM S.12450‒005 (1, 338), N. of Bathurst Island, 9°42'S, 130°22'E, 210 m, M. Sachse, Jul. 1988 ; NTM S.12567‒004 (1, 212), S. of Tanimbar Island, 9°20'S, 131°8'E, 298 m, Jul. 1988 . Western Australia CSIRO 3596 (1, 282), SW of Imperieue Reef , 17°56'S, 118°21'E, 420 m, 5 Feb. 1983 ; CSIRO H2075‒001 (1, 407), NNW of Port Hedland , 18°00'S, 118°13'E, 375 m, 11 Feb. 1989 ; CSIRO H2099‒007 (1, 408), E. of Rowley Shoals , 16°58'S, 120°13'E, 413 m, 2 Apr. 1989 ; CSIRO H7136‒02 (1, 408), S. of Scott Reefs , 14°16'S, 122°16'E, 358 m, R/ V Heron sta. 6‒6‒2004 shot 2, 6 Jun. 2004 ; NTM S.12631‒017 (2, 122‒206), Western Australia, off Rowley Shoals, NW Shelf, 17°37'S, 118°40'E, 400 m, Nov. 1985 .

Diagnosis. A species of Owstonia with LL pattern type 1; cheek scale rows 7–10, with scales relatively small and usually slightly separated from adjacent scales ( Figs. 12 E, 12F); caudal fin of adults rounded posteriorly; lower limb margin of preopercle without spines; dorsal fin III, 21‒22 without black blotch anteriorly in adults (except smallest, 147 mm SL, paratype from Japan has four dark blotches along base of fin on interradial membranes between spine 3 and ray 4).

Description. (Includes data for 5 type specimens, including the holotype, 263–402 mm SL, from Japan based solely on original description.) A species of Owstonia with LL pattern type 1, consisting of a simple lateral line that originates from posttemporal sensory canal near anterodorsal margin of gill opening, curves upward and backward then continues posteriorly just below dorsal-fin base to soft rays 14–18. Dorsal fin III, 21–22 (rarely 22); anal fin I, 13–14 (rarely 13); pectoral fin 21‒23; gill rakers 13‒15 + 24‒26 = 37‒40. Vertebrae: precaudal 11, caudal 17 (rarely 18), total 28 (29); anal-fin pterygiophores anterior to 1st haemal spine 2. Oblique body scale rows in midlateral series about 53–56; nape scaly and cheek scale rows usually 7‒10 ( Figs. 12 E, 12F); some cheek scales usually slightly separated from adjacent scales ( Fig. 12 F). Lower limb margin of preopercle without spines. Papillae in slight depression behind tip of premaxillary ascending processes all very small and difficult to discern, essentially a few larger papilla around which are smaller papillae in no regular pattern. Upper jaw when tightly closed usually extending to or slightly beyond vertical from posterior margin of orbit. Teeth in outer row of each premaxilla 15‒24; 0–3 inner teeth anteriorly. Teeth in lateral row of each dentary 8‒14 including 1−4 teeth at anterior end that continue behind symphyseal teeth in larger specimens; symphyseal teeth 4‒7, short and spike-like ( Fig. 9 B), and with 1‒2 inner teeth anteriorly. Pelvic fin short, depressed fin not extending to anus. Caudal fin of adults rounded posteriorly. In 7 specimens, 122‒408 mm SL, caudal fin 2.6‒3.0 times in SL; head 3.0‒3.6 times in SL; body depth at anal-fin origin 3.9‒4.2 times in SL.

Color pattern in alcohol: Adults with dorsal fin usually uniformly pale, but smallest (147 mm SL) paratype with dark blotches on interradial membranes along base between spine 3 and soft ray 4; membrane connecting maxilla and premaxilla usually with prominent black stripe extending to near anterior end of premaxilla, but mottled in three western Australia specimens (CSIRO 3596, NTM S.12450–005 and NTM S.12567–004), and inner membrane covering posterior part of dentary also black. Color of fresh specimens according to Endo et al (2016): “head, body, and fins reddish, ventral side whitish …margin of vertical fins and branched rays of caudal fin slightly whitish …; black blotches on posterior part of dorsal fin in holotype; two black spots on middle part of dorsal fin in FAKU 98751.” Unpreserved fresh specimens from off Rowley Shoals ( Fig. 48 ) also have dorsal, anal, and caudal fins with narrow white margins.

Proportions, as percentages of SL, for 8 non-Japan specimens 122‒408 mm SL listed above, and for 6 types from Japan 147–402 SL (given in parentheses), based on data given in the original description: predorsal length 27.7‒32.2 (25.1–29.0); preanal length 55.1‒61.5 (55.0–58.5); dorsal-fin base 59.8‒66.0 (58.5–63.5); anal-fin base 27.3‒31.2 (27.6‒30.9); pelvic-fin length 16.6‒20.1 (17.2–18.6); caudal-fin length 33.7‒39.2 (36.7–40.1); body depth at anal-fin origin 23.1‒25.3; head length 27.6‒34.7 (27.2–30.6); upper jaw length 15.8‒20.0 (16.3–18.1); upper jaw depth 6.9‒9.3 (7.1–8.2); orbit diameter 8.2‒15.7 (8.5–11.5). As percentages of head length: upper jaw length 56.6‒69.8 (56.4–61.9); orbit diameter 30.4‒45.0 (29.0–37.6).

Comparisons. Two other species, the allopatric Owstonia ainonaka and O. simotera , have most of the diagnostic characters listed above but differ (characters of O. kamoharai in parentheses) as follows: O. ainonaka has caudal fin lanceolate and relatively long, 54.5% SL (vs. rounded posteriorly and shorter, 33.7‒40.0% SL), larger cheek scales that contact adjacent scales (vs. smaller cheek scales some of which are usually slightly separated from adjacent scales), and when mouth completely closed upper jaw extends only to vertical from posterior margin of pupil (vs. closed mouth with upper jaw usually extending to or slightly beyond vertical from posterior margin of orbit); adults of O. simotera have caudal fin lanceolate and shorter, 27.9 % SL (vs. rounded posteriorly and longer, 33.7‒40.1% SL) and large curved dentary canines (vs. no large curved dentary canines). All three are large robust species with relatively high numbers of pectoral fin rays 21‒23, and short pelvic fins that do not extend to anus.

Etymology. Named for Toshiji Kamohara (1901–1972) (see Okamura, 1972), who described three new species of cepolids from Japan that are still recognized as valid.

Distribution. ( Fig. 27 ) Known from southern Japan (Shikoku and Honshu islands) in depths of about 200–350 m and from off Western Australia and the Arafura Sea, where trawled in about 200‒ 410 m.

Remarks. The original description of O. kamoharai and one of the paratypes from Japan that we subsequently examined agree very well with our material from off Western Australia. Owstonia kamoharai is the largest species of the genus, attaining at least 408 mm SL (560 mm TL), with four of 14 specimens exceeding 400 mm SL.

Figures

FIGURE 9. Frontal view of teeth in selected species of Owstonia (note widely spaced, spike-like, symphyseal, dentary teeth in C and D): A, O. ainonaka, AMS I. 33437 – 002, 213 mm SL; B, O. kamoharai, CSIRO 3596, 282 mm SL; C, O. psilos, NTM S. 12608 – 002, 75 mm SL; D, O. simotera, USNM 276514, 65 mm SL; E, O. simotera, SAIAB 605, 298 mm SL (photo by Ofer Gon, © SAIAB); F, O. weberi, ANSP 146627, 317 mm SL.

FIGURE 12. Cheek scales on left side in selected species of Owstonia: A, O. ainonaka, AMS I. 33437, 213 mm SL; B, O. doryptera, USNM 93166, 65 mm SL; C, O. elongata, MNHN 2008 – 1350, 110 mm SL; D, O. grammodon, USNM 93167, 67 mm SL; E, O. kamoharai, NTM S. 12631 – 017, 206 mm SL; F, O. kamoharai, CSIRO H. 2099 – 007, 408 mm SL; G, O. maccullochi, AMS I. 25806 ‒ 012, 141 mm SL; H, O. raredonae, SAIAB 82406, 97.4 mm SL; I, O. sibogae, CAS 33843, 126 mm SL.

FIGURE 27. Distributions of selected species of Owstonia based on specimens examined.

FIGURE 46. Owstonia kamoharai, FAKU 98751, 263 mm SL, Japan, Kii Peninsula, Wakayama. Photograph by Hiromi Ikeda.

FIGURE 47. Owstonia kamoharai, CSIRO H. 2075 – 01, 407 mm SL, Western Australia, off Port Hedland. Photograph courtesy of CSIRO.

FIGURE 48. Owstonia kamoharai, size not recorded, Western Australia, off Rowley Shoals, continental shelf in 380 – 400 m. Photographer unknown.