Owstonia hastata, 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 : 51-52

Owstonia hastata new species

( Figure 39 )

Holotype. NTM S.11779‒002, 124 mm SL, Queensland, Australia, E. of Dunk Island , 18°0'S, 147°4'E, 260 m, Jan. 1986.

Paratype. AMS I.25812‒010 (1, 133), Queensland, N. of Townsville , 18°0'S, 147°01'E, trawled in 222‒228 m, R/ V Soela, sta. SO 1/86/24, 12 Jan. 1986

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal fin IV, 22; and anal fin II, 14; oblique body scales 38; lower margin of preopercle with about 11 or 12 well-developed spines; pelvic fin 34.4‒42.1% SL.

Description. (Where counts vary, those of the paratype 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 18. Dorsal fin IV, 22; anal fin II, 14; pectoral fin 19‒(20); gill rakers 16 + 29 (30) = 45 (46). Vertebrae: precaudal 13, caudal 17, total 30; anal-fin pterygiophores anterior to 1st haemal spine 5. Oblique body scale rows in mid-lateral series about 38; nape scaly and cheek scale rows 3–4. Lower limb margin of preopercle with about 8−12 well-developed spines. Papillae in slight depression behind tip of premaxillary ascending processes 4, arranged in 2 rows with posterior pair of papillae larger than the others. Teeth in outer row of each premaxilla 20 (21); no inner teeth anteriorly. Teeth in lateral row of each dentary 10/14 (10), with anterior ones moderately hooked and spaced apart; symphyseal teeth 4/5 (4), short and conical, and with 2/3 (2−3) inner teeth anteriorly. Pelvic fin possibly sexually dimorphic, depressed fin extending to anal-fin soft rays 4 (holotype) or 7 (paratype). Caudal fin lanceolate. Caudal fin 1.3‒2.3 times in SL; head 4.5‒4.6 times in SL; body depth at anal-fin origin 5.1‒5.2 times in SL. In 4 specimens 67‒127mm SL, caudal fin 1.8‒3.2 times in SL; head 3.1‒3.8 times in SL; body depth at anal-fin origin 3.4‒4.7 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 ( Fig. 15 A), and inner membrane covering posterior part of dentary also black. Life coloration unknown.

Proportions of 124 mm SL holotype are given first, followed by those of the 133 mm SL paratype (in parentheses) as percentages of SL: predorsal length 19.9 (20.7); preanal length 48.0 (46.0); dorsal-fin base 69.2 (69.2); anal-fin base 40.1 (37.3); pelvic-fin length 34.4 (42.1); caudal-fin length 54.4 (38.7); body depth at anal-fin origin 20.2 (17.5); head length 22.4 (21.7); upper jaw length 10.8 (10.3); upper jaw depth 4.3 (4.8); orbit diameter 8.2 (9.0). As percentages of head length: upper jaw length 48.3 (47.6); orbit diameter 36.8 (41.3).

Comparisons. Owstonia fallax is superficially most similar to O. hastata but differs (with characters for O. hastata given in parentheses) as follows: anal fin I, 16‒17 (vs. II, 14), pelvic fin 17.6‒19.3% SL (vs. 34.4‒42%), and lower margin of preopercle with small weak spines (vs. about 11 or 12 well-developed spines). Other species with LL pattern type 1 and IV dorsal-fin spines differ in having anal fin I, 15–19 or II, 15‒17 (vs. II, 14). Owstonia contodon further differs in having more oblique body scale rows in mid-lateral series, 47‒53 (vs. 38) and precaudal vertebrae and anal-fin pterygiophores anterior to 1st haemal spine 11 and 3 respectively (vs. 13 and 5). Owstonia sibogae has a short premaxillary stripe extending about 1/2 length of premaxilla (vs. long stripe extending entire length of premaxilla), fewer oblique body scale rows in mid-lateral series 27‒30 (vs. 38), and fewer precaudal vertebrae and anal-fin pterygiophores anterior to 1st haemal spine 12 and 4 respectively (vs. 13 and 5).

Etymology. From the Latin hastatus (spear-shaped), in allusion to the lanceolate caudal fin.

Distribution. ( Fig. 26 ) Known only from Queensland, Australia where trawled in 228‒ 260 m.

Figures

FIGURE 15. Premaxillary stripes in selected species of Owstonia: A, O. hastata, NTM S. 11779 – 002, 124 mm SL; B, O. nudibucca, ANSP 151993, 224 mm SL, Mentawai Islands; C, O. sibogae, CAS 32914, 96 mm SL, Philippines; D, O. ainonaka, AMS I. 33437 – 002, 213 mm SL. Photographs by Sandra J. Raredon.

FIGURE 26. Distributions of selected species of Owstonia based on specimens examined.

FIGURE 39. Owstonia hastata, paratype, AMS I. 1258112 ‒ 010, 133 mm SL, Queensland, Australia. Photograph by Sandra J. Raredon.