Owstonia scottensis, Smith-Vaniz, William F. & Johnson, David, 2016

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 : 81

Owstonia scottensis new species

( Figure 71 , 72 )

Holotype. CSIRO H.7136‒03, 100 mm SL, Western Australia, south of Scott Reefs , 14°16'S, 122°16'E, trawled in 358 m, R/ V Heron sta. 6‒6‒2004, shot 2 , 6 Jun. 2004.

Paratypes. 4 specimens, 70‒110 mm SL: CSIRO H.7136−04 (2, 103‒103) and USNM 427156 (1, 110), same data as holotype ; CSIRO B.4011 (1, 70), SW of Scott Reefs, 14°37'S, 121°47'E, 304 m, sta. S00184 /82, 16 Feb. 1984.

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal fin III, 21; anal fin I, 14–15; oblique body scale rows in mid-lateral series about 40–45; lower limb margin of preopercle with 5–8 weak spines; cheek scale rows 4‒5; dorsal fin pale anteriorly and in fresh specimens median fins mostly red; each dentary with 3‒4 spikelike symphyseal teeth.

Description. (Where counts vary, those of the paratypes are given in parentheses.). 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 ray 19 (left side holotype). Dorsal fin III, 21; anal fin I, 14 or 15; pectoral fin 2 0–21; gill rakers 16 + 27 (15–16 + 25–27 = 40–43). Vertebrae: precaudal 11, caudal 17, total 28; anal-fin pterygiophores anterior to 1st haemal spine 2 or 3 (3 in 1 of 5 specimens.). Oblique body scale rows in mid-lateral series about 40–45 (some scales missing on sides of body in all specimens due to trawl abrasion); nape scaly and cheek scale rows about 4–5. Preopercle lower limb margin with 5–8 weak spines ( Fig. 8 H). Papillae in slight depression behind tip of premaxillary ascending processes 4, arranged in 2 almost equally spaced pairs. Teeth in outer row of each premaxilla 15/18 (12‒20), with some anterior teeth spike-like; no inner teeth anteriorly. Teeth in lateral row of each dentary 11/12 (9‒15); symphyseal teeth 3 or 4, spike-like, and with 0–3 very small inner teeth anteriorly. Depressed pelvic fin extending to or slightly behind anal-fin origin. Caudal fin lanceolate. Caudal fin 1.9‒2.6 times in SL; head 3.3‒3.6 times in SL; body depth at anal-fin origin 4.1‒4.4 times in SL.

Color pattern in alcohol: Adults with dorsal fin uniformly pale; membrane connecting maxilla and premaxilla with prominent black stripe extending to near anterior end of premaxilla, and inner membrane covering posterior part of dentary also black. In fresh specimens, median and pelvic fins mostly red, except anterior 1/3 of dorsal fin and 3/4 of anal fin whitish proximally; pectoral fin pale yellow and iris red; body red with paler chest and belly, but appearing mostly straw-colored in Fig. 71 due to missing scales.

Proportions of 100 mm SL holotype are given first, followed by those of 4, 70‒ 110 mm SL, paratypes (in parentheses), as percentages of SL: predorsal length 28.8 (28.1–31.3); preanal length 52.6 (52.1–57.2); dorsal-fin base 66.4 (58.4–63.9); anal-fin base 30.6 (29.9–32.5); pelvic-fin length 25.8 (25.3–27.5); caudal-fin length 39.1 (45.4–55.4); body depth at anal-fin origin 24.3 (22.6–24.1); head length 29.2 (29.4–29.7); upper jaw length 16.0 (15.4–15.9); upper jaw depth 8.0 (7.8–8.1); orbit diameter 15.1 (15.3–17.4). As percentages of head length: upper jaw length 54.6 (51.8–53.6); orbit diameter 51.7 (51.5–59.3).

Comparisons. Owstonia japonica and O. dispar have most of the diagnostic characters of O. scottensis but differ (characters of O. scottensis in parentheses) as follows: both species have smaller orbit diameters 10.4–13.9% SL (vs. 15.3–17.5%); O. dispar also has fewer cheek scale rows 3 (vs. 4‒5); O. japonica has a shorter upper jaw 13.0–16% SL (vs. 15.4–16%), each dentary with 4‒6 blunt, conical, symphyseal teeth (vs. 3‒4 spike-like symphyseal teeth), and in fresh specimens of O. japonica the median fins have white margins and a narrow, red submarginal stripe (vs. fins mostly red and without white margins); life coloration of O. dispar unknown.

Etymology. The specific epithet in a combination of Scott Reefs, the nearest area from where all the known specimens have been collected and the Latin suffix ensis (meaning belonging to). The name is treated as a noun in apposition.

Distribution. ( Fig. 23 ) Known only from Scott Reefs vicinity, off Western Australia where trawled in 304– 358 m.

Figures

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 23. Distributions of selected species of Owstonia based on specimens examined.

FIGURE 71. Owstonia scottensis, holotype, CSIRO H. 7136 ‒ 03, 100 mm SL, Western Australia, south of Scott Reefs. Photograph by Louise Conboy, courtesy of CSIRO.

FIGURE 72. Owstonia scottensis, head of holotype showing position of upper jaw tightly pressed against lower margin of infraorbitals.