Owstonia taeniosoma (Kamohara)

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 : 88-89

Owstonia taeniosoma (Kamohara)

( Figure 78 )

Pseudocepola taeniosoma Kamohara, 1935:136 , fig. 4 (original description; off Mimase, near Kôchi Prov., Tosa, Japan; depth 80 fathoms [146 m]); Kamohara, 1961:8 (designation of BSKU 4219 as neotype); Okada and Suzuki, 1956:190, fig. 2 (osteological description); Shiino, 1972:116 (common name Slender jawfish); Machida in Masuda et al., 1984:201, pl. 351-D (brief description, figure after Kamohara 1935); Shin, et al., 1993:436 (brief description); Nakabo, 2002:914 (diagnosis, in pictorial key).

Material examined. 9 specimens, 26‒169 mm SL: Japan CAS 133928 (1, 126) , CAS 133932 (1, 89) and CAS 133933 (1, 149) all from, Kochi Pref. ; Kochi, T. Kamohara, 1937 ; BSKU 57075 (1, 132), Kochi Pref., Kuroshio Town, Saga fish market, Shikoku Island , 10 Aug. 2001 ; BSKU 71222 (1, 142), Saga fish market, 17 Jun. 2004 ; BSKU 75249 (1, 169), Saga fish market, 4 Jul. 2005 . Andaman Sea USNM 344576 (1, 48 C&S), NE of Similan Islands , 8°77'N, 97°77'E, beam trawl in 0‒82 m, Te Vega cruise 2, sta. 80, 4 Nov. 1963 . New Caledonia MNHN 2004–2527 (1, 26), 20°34'58.8"S, 164°58' 58.8"E, 227–250 m, Exped. BATHUS 1, sta. dw691, 17 Mar. 1993 . Australia AMS I.33445‒002 (1, 83), New South Wales off Newcastle , 32°53'S, 151°56'E, trawled in 62‒77 m, FRV Kapala, 14 Apr. 1992 .

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal fin III, 25–26; oblique body scale rows in mid-lateral series about 28; total gill rakers 36‒40; body depth at anal-fin origin 14.5–21.9% SL; precaudal vertebrae and pterygiophores anterior to 1st haemal spine 15 and 6 or 7 respectively.

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 21–25. Dorsal fin III, 25–26 (rarely 25); anal fin I, 18– 19 (rarely 19); pectoral fin 16–18; gill rakers 12–14 + 24–26 = 36–40. Vertebrae: precaudal 15, caudal 16–18 (rarely 18), total 31–33 (usually 31); anal-fin pterygiophores anterior to 1st haemal spine 6 or 7 ( Fig. 7 D). Oblique body scale rows in mid-lateral series about 28; nape scaly and cheek scale rows 3. Lower limb margin of preopercle with about 5−6 small to moderate, partially skin-covered spines ( Fig. 8 J). Papillae in slight depression behind tip of premaxillary ascending processes in a posterior row consisting of 3 papillae, middle papilla smallest, and with 1 or 2 smaller papillae anteriorly that do not appear to be arranged in any obvious pattern. Teeth in outer row of each premaxilla 22–38 (22 in 83 mm specimen); no inner teeth anteriorly. Teeth in lateral row of each dentary 14‒30 (14 in 83 mm specimen) and with mid-lateral teeth higher ( Fig. 10 K), like O. fallax ; symphyseal teeth 4−6, very short and peg-like, and with 1‒4 inner teeth anteriorly. Pelvic fin short, not extending posteriorly behind anus. Caudal fin lanceolate. In 6 specimens 83‒169 mm SL, caudal fin 2.5‒2.9 times in SL; head 4.7‒6.5 times in SL; body depth at anal-fin origin 4.6‒6.9 times in SL.

Color pattern in alcohol: Adults with dorsal fin uniformly pale; dark premaxillary stripe variable in length, short and extending only about half of premaxilla to long and extending to near anterior end of premaxilla (in largest, well-preserved specimen [BSKU 75249] the stripe is definitely only half length of premaxilla), and inner membrane covering posterior part of dentary consistently with prominent black stripe. Kamohara (1934) described the life color of Owstonia taeniosoma as: "Dorsal and anal light reddish, with a broad longitudinal yellow band running along the middle of each fin, whitish in margin, anterior part of anal whitish. Pectoral light reddish, ventral pale. Caudal yellowish and bordered with whitish." Unlike most species, iris is bright yellow.

Proportions of 6 specimens 88–169 mm SL, as percentages of SL: predorsal length 15.4–20.1; preanal length 36.9–45.0; dorsal-fin base 70.7–75.4; anal-fin base 40.4–51.1; pelvic-fin length 14.6–16.1; caudal-fin length 34.6– 40.4; body depth at anal-fin origin 14.5–21.9; head length 15.5–21.1; upper jaw length 7.1–9.1; upper jaw depth 4.3–4.5; orbit diameter 5.7–7.8). As percentages of head length: upper jaw length 43.2–51.1); orbit diameter 36.9– 42.4).

Comparisons. Owstonia taenisoma is most likely to be confused with O. elongata but differs (characters of O. taeniosoma in parentheses) in having fewer dorsal-fin spines IV (vs. III), deeper body depth at anal-fin origin 10.8‒14.0% SL (vs. 14.5–21.9%), fewer total gill rakers 41–46 (vs. 36–40), and fewer precaudal vertebrae and anal-fin pterygiophores anterior to 1st haemal spine 16 and 8 respectively (vs. 15 and 6‒7). Owstonia taeniosoma also superficially resembles O. sibogae , O. geminata and O. hastata in having large cheek scales and relatively few oblique body scale rows in mid-lateral series but differs in having fewer dorsal-fin spines, III (vs. IV); the latter two species further differ in having fewer anal-fin soft rays 14 or 16‒17 (vs. 18‒19), and O. hastata has more anal-fin spines II (vs. I).

Etymology. A combination of the Greek taenia (band or ribbon) and soma (body), in reference to the elongate body.

Distribution. ( Fig. 25 ) Known from of Japan, Andaman Sea, and eastern Australia; a relatively shallow-water species trawled between 62‒ 250 m.

Remarks. Kamohara's (1961) neotype designation was considered to be invalid by Eschmeyer et al. (2016) because it was not made in a revisionary work.

Figures

FIGURE 7. Radiographs of selected species of Owstonia to show number of anal-fin pterygiophores anterior to first haemal spine (indicated by white arrowhead): A, O. japonica, NSMT P. 32720, 137 mm SL, Japan; B, O. sarmiento, AMS I. 25826 – 0 0 7, 76 mm SL, eastern Australia; C, O. tosaensis, CSIRO H. 6431 – 03, 155 mm SL, western Australia; D, O. taeniosoma, BSKU 75249, 169 mm SL, Japan; E, O. elongata, MNHN 2014 ‒ 29345, 111 mm SL, New Caledonia. Number of anterior analfin pterygiophores in these specimens are: A = 2, B = 3, C = 4, D = 6 and E = 8.

FIGURE 8. Margins of preopercle lower limb (not drawn to scale), showing relative spine development in selected species of Owstonia: A, O. contodon, USNM 438013, 162 mm SL; B, O. elongata, USNM 432454, 110 mm SL; C, O. geminata, ASIZP 68128, 79 mm SL; D, O. maccullochi, holotype (right side reversed), AMS IA. 5815, 156 mm SL; E, O. maccullochi, NTM S. 11765 − 001, 146 mm SL; F, O. rhamma, holotype, MNHN 1995 – 0005, 102 mm SL; G, O. sarmiento, ANSP 165126, 82 mm SL; H., O. scottensis, CSIRO H. 7136 − 04, 103 mm SL; I, O. sibogae, ANSP 152035, 113 mm SL; J, O. taeniosoma, CAS 133928, 126 mm SL; K, O. tosaensis, ANSP 153169, 100 mm SL; L, O. weberi, ZMUC P. 531552, 127 mm SL.

FIGURE 10. Premaxilla and dentary (mostly right side reversed) to show dentition in selected species of Owstonia. A, O. contodon, USNM 438013, 162 mm SL; B, O. fallax, CSIRO H. 763 ‒ 06, holotype, 110 mm SL; C, O. grammodon, USNM 149321, 127 mm SL; D, O. hawaiiensis, BPBM 29600, holotype, 124 mm SL; E, O. ignota, USNM 344400, holotype, 118 mm SL; F, O. japonica, ANSP 151948, 136 mm SL.

FIGURE 25. Distributions of selected species of Owstonia based on specimens examined.

FIGURE 78. Owstonia taeniosoma, AMS I. 33445 – 002, 83 mm SL, Australia, NSW. Photograph by Ken Graham.