Owstonia contodon, 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 : 40-42

Owstonia contodon new species

( Figures 29 , 30 )

Holotype. PNM 15193 (ex USNM 438011 ), 165 mm SL, female, Philippines, Iloilo Prov., Panay Island, found in Iloilo City "super" fish market, exact locality and depth of capture unknown (vendor stated that he received the shipment containing these fresh fish from Palawan); Exped . Philippines 2015 FDA Survey, PHIL-2015‒15; tissue voucher number PHI-401; 23 Jul. 2015; J. T. Williams, K. Carpenter, M. Mendiola, M . Flores and D. Carpenter.

Paratypes. 7 specimens, 146‒303 mm SL, all from the Philippines: MNHN 2002–2971 (1, 146) , Philippines, Leyte Island, 11°42'3.6"N, 121°45'10.8"E, beam trawl in 205–214 m, Exped. MUSORSTOM 3, sta. 143, Jun. 1985; USNM 438013 (1, 162), same collection data as holotype ; USNM 437757 (1, 303), USNM 437759 (1, 260), USNM 437761 (1, 240), USNM 437766 (1, 262), USNM 437775 (1, 193), same collection data as holotype except PHIL- 2015‒07, 17 Jul. 2015.

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal-fin spines IV, 21‒23; anal-fin spines II, 16; oblique body scale rows in mid-lateral series 47‒53; preopercle lower limb margin with about 8−11 spines; dark premaxillary stripe.

Description. (When 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 rays 21 (20−23). Dorsal fin IV, 23; anal fin II, 16; pectoral fin 20 (20−21); gill rakers 17 (16-18) +33 (32−35) = 50 (48−53). Vertebrae: precaudal 11, caudal 18, total 29; anal-fin pterygiophores anterior to 1st haemal spine 3. Oblique body scale rows in mid-lateral series about 47/51 (48−53); nape scaly and cheek scale rows 4−5. Preopercle lower limb margin with about 8−11 spines ( Fig. 8 A). Pattern of papillae in slight depression behind tip of premaxillary ascending processes not clearly discernible, although small papillae can be seen in some specimens. Teeth in outer row of each premaxilla 27/30 (29−33), no inner teeth. Teeth in lateral row of each dentary teeth 20/23 (18−25) including a few at anterior end that continue behind symphyseal teeth; symphyseal teeth 4−6, relatively short and peg-like, and with 2−4 inner teeth anteriorly. Pelvic fin long, depressed fin extending to anal-fin soft rays 4‒7, except to behind last ray in largest 303 mm SL (male). Caudal fin lanceolate. Caudal fin 1.4‒2.1 times in SL; head 3.7‒5.4 times in SL; body depth at anal-fin origin 4.2‒5.1 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, upper part of head and body reddish orange becoming grayish purple to white below; dorsal, anal and caudal fins orange-red; pectoral fin pink to orange- red and pelvic fins pink or gray with elongate outermost ray paler; iris reddish orange.

Proportions of 165 mm SL holotype are given first, followed by those of 7 paratypes, 145–303 mm SL (in parentheses), as percentages of SL: predorsal length 30.0 (18.5−25.8); preanal length 46.0 (23.6−52.0); dorsal-fin base 60.9 (66.7−71.0); anal-fin base 39.1 (36.3−41.6); pelvic-fin length 39.0, in 6 presumed females 145−262 mm SL (34.9‒46.0) and in 1 male 303 mm SL (84.8); caudal-fin length 66.1 (46.6−71.0); body depth at anal-fin origin 23.9 (19.4−23.6); head length 25.8 (18.7−26.8); upper jaw length 12.2 (9.8−12.4); upper jaw depth 5.7 (4.4−6.2); orbit diameter 9.3 (6.6−10.3). As percentages of head length: upper jaw length 47.2 (46.2−52.7); orbit diameter 36.2 (34.9−38.5).

Comparisons. The following three species with LL pattern type 1 have and the same number of dorsal- and anal-fin spines as those of O. contodon but differ (with characters for O. contodon given in parentheses) as follows: all three have fewer oblique body scale rows in mid-lateral series, 27‒38 (vs. 47−53); Owstonia hastata further differs in having anal fin II, 14 (vs. II, 16) and more precaudal vertebrae and pterygiophores anterior to 1st haemal spine 13 and 5 respectively (vs. 11 and 3); O. sibogae has cheek scale rows 3 (vs. 4−5) and a shorter premaxillay stripe, extending only about 2/3 length of premaxilla (vs. long premaxillary stripe, extending entire length of premaxilla); O. elongata usually has anal-fin spines I (exceptionally II, see Table 4) (vs. II), cheek scale rows 3 (vs. 4) and more precaudal vertebrae and pterygiophores anterior to 1st haemal spine 16 and 8 respectively (vs. 11 and 3).

Etymology. The specific epithet is a combination of the Greek kontos (short) and odon (tooth), in reference to the peg-like symphyseal dentary teeth ( Fig. 10 A).

Distribution. ( Fig. 23 ) Known only from the Philippines. Collected from Leyte Island, where trawled in 205– 214 m; holotype and other paratypes reportedly caught off Negros Oriental. Photographs seen by us of other specimens (not retained) taken by Abner Bucol at Dumaguete fish market were reportedly collected from the local area.

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

FIGURE 29. Owstonia contodon, USNM 437757, male, 303 mm SL, Philippines, Palawan. Photograph by Jeffrey T. Williams.

FIGURE 30. Owstonia contodon, holotype, NPM 15193, female, 165 mm SL, Philippines, Palawan. Photograph by Jeffrey T. Williams.