Owstonia melanoptera, 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 : 65-66

Owstonia melanoptera new species

( Figure 54 )

Holotype. AMS I.36454‒005, 116 mm SL, Philippines, Albay Gulf, 13°8.98'N, 124°4.73'E –13°9.84'N, 124°0.01'E, trawled in 363‒385m, J. Paxton, 3 Sep. 1995.

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal fin III, 21; anal fin I, 14; LL ends below dorsal-fin soft rays 7‒8; oblique body scale rows in mid-lateral series about 48–53; total gill rakers 38‒39; dark premaxillary stripe; dorsal fin anteriorly with a black blotch.

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 8 or 7th soft ray. Dorsal fin III, 21; anal fin I, 14; pectoral fin 22; gill rakers 13/14 + 25. 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 48–53 (many scales missing on left side); nape scaly and cheek scale rows 7. Lower limb margin of preopercle without spines. Papillae in slight depression behind tip of premaxillary ascending processes 5, arranged in 2 rows with outer papillae in each row approximately same size and equally spaced, and the additional middle papilla in posterior row smaller than adjacent papillae. Teeth in outer row of each premaxilla 18/19; 0/1 inner teeth anteriorly. Dentary lateral row teeth 14/15; symphyseal teeth 3‒4, spike-like, and with 1 inner tooth anteriorly. Pelvic fin short, depressed fin extending only to anus. Caudal fin lanceolate. Caudal fin 2.5 times in SL; head 3.1 times in SL; body depth at anal-fin origin 4.2 times in SL.

Color pattern in alcohol: Dorsal fin interradial membranes between 2nd spine to 5th soft ray black, melanophores faint between spines 2–3 but intense between spine 3 and 2nd soft ray (but with narrow clear area immediately anterior to 1st soft ray), with dark pigment extending from near base of fin to at least 2/3 length of spines and soft rays; heavy concentration of melanophores on interradial membranes of posterior 5 anal-fin soft rays, membrane connecting maxilla and premaxilla with prominent dark stripe extending to near anterior end of premaxilla, and inner membrane covering posterior part of dentary unpigmented. Life coloration unknown.

Proportions of 116 mm SL holotype as percentages of SL: predorsal length 30.9; preanal length 58.9; dorsalfin base 59.0; anal-fin base 28.2; pelvic-fin length 20.0; caudal-fin length 40.7; body depth at anal-fin origin 23.7; head length 32.4; upper jaw length 18.9; upper jaw depth 8.4; orbit diameter 13.7. As percentages of head length: upper jaw length 58.2; orbit diameter 42.3.

Comparisons. Only two other species, Owstonia similis and O. psilos , have most of the diagonostic characters of O. melanoptera , at least as small individuals, but differ (with characters of O. melanoptera given in parentheses) as follows: O. similis has lateral-line ending below dorsal-fin soft ray 17 (vs. 7–8), fewer gill rakers 10 + 22‒23 (vs. 13‒14 + 25, see also Remarks in O. similis account), posterior anal-fin soft rays with heavy concentration of melanophores on interradial membranes (vs. posterior anal-fin soft rays with pale interradial membranes) and dorsal fin with interradial membranes between 2nd spine to 3rd soft ray with heavy concentration of melanophores (vs. melanophores faint between spines 2–3 but intense between spine 3 and 2nd soft ray and with narrow clear area immediately anterior to 1st soft ray); O. psilos has fewer oblique body scale rows in mid-lateral series about 32 (vs. about 48–53), and premaxillary stripe absent, with a few scattered melanophores or pale and incomplete (vs. premaxillary stripe well-developed).

Etymology. From the Greek melanos (black) and pteron (wing or fin), in reference to the large black blotch on the dorsal fin of the adult holotype. The name is treated as a noun in apposition.

Distribution. ( Fig. 24 ) Known only from Albay Gulf, Philippines where trawled in 363– 385 m.

Figures

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 54. Owstonia melanoptera, holotype, AMS I. 36454 ‒ 005, 116 mm SL, Philippines, Albay Gulf; insert of dorsal fin below. Photographs by Sandra J. Raredon.