Owstonia dispar, 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 : 44

Owstonia dispar new species

( Figure 33 )

Holotype. MNHN 2002−3720, 82 mm SL, Solomon Islands, 10°12'7.2"S, 161°28'1.2"E, beam trawl in 381–383 m, Exped. Solomon 1, sta. 1837, 5 Oct. 2001.

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal fin III, 21; anal fin I, 14; lower limb margin of preopercle with about about 8‒9 spines; depressed pelvic fin extending to slightly behind anus; cheek scale rows 3.

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 ray 17 (both sides). Dorsal fin III, 21; anal fin I, 14; pectoral fin 23/22; gill rakers 15 + 30/28 = 43–45. Vertebrae: precaudal 11, caudal 17, total 28; anal-fin pterygiophores anterior to 1st haemal spine 2. Oblique body scale rows in mid-lateral series about 44–46; nape scaly and cheek scale rows 3. Lower limb margin of preopercle with about 8–9 spines. Papillae in slight depression behind tip of premaxillary ascending processes 4, the anterior 2 papillae partially embedded on each end of a slightly raised ridge of skin that closely abuts the posterior 2 papillae, which are widely spaced and more obvious because they are not associated with a ridge of skin ( Fig. 14 B). Teeth in outer row of each premaxilla 14, 0/1 inner tooth anteriorly. Teeth in lateral row of each dentary 10/12; symphyseal teeth 3, spike-like, and with 1 inner tooth anteriorly. Pelvic fin short, depressed fin extending to slightly behind anus (distinctly short of anal-fin origin). Caudal fin lanceolate. Caudal fin 2.1 times in SL; head 3.3 times in SL; body depth at anal-fin origin 3.8 times in SL.

Color pattern in alcohol: 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. Life coloration unknown.

Proportions of 82 mm SL holotype as percentages of SL: predorsal length 29.2; preanal length 63.0; dorsal-fin base 63.4; anal-fin base 31.4; pelvic-fin length 24.9; caudal-fin length 46.6; body depth at anal-fin origin 26.3; head length 30.6; upper jaw length 16.1; upper jaw depth 7.9; orbit diameter 13.7. As percentages of head length: upper jaw length 52.7; orbit diameter 44.7.

Comparisons. The allopatric Owstonia scottensis and O. japonica share most of the diagnostic characters of O. dispar but differ (characters of O. dispar in parentheses) as follows: O. scottensis has more cheek scales 4‒5 (vs. 3), larger orbit diameter 15.3‒17.5% SL (vs. 13.7%), depressed pelvic fin extending to or slightly beyond anal-fin origin (vs. pelvic fin extending to slightly behind anus), and in fresh specimens the median fins are uniformly red (life color of O. dispar unknown); O. japonica differs by having more cheek scale rows, 5–7 (vs. 3), shorter upper jaw at similar sizes, 14.4% SL (vs. 16%), depressed pelvic fin extending to anal-fin origin (vs. pelvic fin extending to slightly behind anus), and each dentary with 4‒6 blunt, conical symphyseal teeth (vs. 3 spike-like symphyseal teeth).

Etymology. From the Latin dispar (different) in reference to the discovery of yet another new species of Owstonia .

Distribution. ( Fig. 24 ) Known only from the Solomon Islands type locality where trawled in 381– 383 m.

Figures

FIGURE 14. Arrangement and relative sizes of papillae in slight depression at tip of ascending premaxillary processes (dorsal view, anterior to right) in selected species of Owstonia: A, O. crassa, MNHN 2002 – 3720; B., O. dispar, MNHN 2002 – 3720; C, O. maccullochi, CSIRO H 5946 – 20; D, O. mundyi, USNM 427880; E, O. sarmiento, NTM S. 11782 – 001; and F, O. totomiensis, NSMT – P 77978.

FIGURE 24. Distributions of selected species of Owstonia based on specimens examined, except records of O. mundyi from Kingman Reef based solely on submersible videos, and possibly could have been misidentifications of O. hawaiiensis.

FIGURE 33. Owstonia dispar, holotype, MNHN 2002 − 3720, 74 mm SL, Solomon Islands. Photograph by Sandra J. Raredon.