Owstonia macrophthalma (Fourmanoir)

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 : 64-65

Owstonia macrophthalma (Fourmanoir)

( Figure 53 )

Sphenanthias macrophthalmus Fourmanoir, 1985:38 , fig. 3 (original description; Philippines, 14°0.1'N, 120°17.1'E, MUSORSTOM II, station 2; depth 184–186 m).

Material examined. 2 specimens, 49‒67 mm SL: MNHN 1982‒0557 (67), holotype of Sphenanthias macrophthalmus , Philippines, 14°0.1'N, 120°17.1'E – 13°59.9'N, 120°17.5'E, trawled in 184–186 m, MUSORSTOM II, sta. 2, 20 Nov. 1980; MNHN 1983–0558 (1, 49), paratype, Philippines, 14°1'N, 120°18.5'E –14°1.2'N, 120°17.9'E, trawled in 188–195 m, MUSORSTOM II, sta. 10, 21 Nov. 1980.

Diagnosis. A species of Owstonia with LL pattern type 1; dorsal fin IV, 22‒23; anal fin I, 17‒18; lower limb of preopercle with 9‒10 small spines; gill rakers 16+33‒34.

Description. (Where counts vary those of 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 23rd or (22nd) ray. Dorsal fin IV, 23 (22); anal fin I, 18 (17); pectoral fin 21 (20); gill rakers 16 + 33/ 34 in both specimens. 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 54; nape scaly and cheek scale rows 4 or 5. Lower limb margin of preopercle with 9‒10 small spines. Papillae in slight depression behind tip premaxillary ascending processes 4, arranged in 2 almost equally spaced pairs. Teeth in outer row of each premaxilla 37/33 (28/32); 0 or (1) inner teeth anteriorly. Teeth in lateral row of each dentary ca. 19–23; symphyseal teeth 2‒3, spike-like, and with 1/2 (0) smaller inner teeth anteriorly. Depressed pelvic fin of holotype extending to anal-fin soft ray 2. Caudal fin lanceolate. Holotype with caudal fin 2.3‒2.6 times in SL; head 3.1 times in SL; body depth at anal-fin origin 3.6 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 ascending process, and inner membrane covering posterior part of dentary also black. Fourmanoir (1985) recorded the dominant life coloration as yellow, including the dorsal fin, with the top of head, outline of upper jaw, dorsum, base of caudal, anal and pelvic fins dark pink.

Proportions of 67 mm SL holotype are given first, followed by those of the 49 mm SL paratype (in parentheses) as percentages of SL: predorsal length 30.9 (33.6); preanal length 57.7 (53.6); dorsal-fin base 63.8 (63.1); anal-fin base 38.2 (36.2); pelvic-fin length 31.6 (27.5); caudal-fin length 43.4 (38.3); body depth at anal-fin origin 28.0 (26.1); head length 32.0 (33.8); upper jaw length 15.9 (16.2); upper jaw depth 7.7 (7.2); orbit diameter 16.4 (16.2). As percentages of head length: upper jaw length 49.8 (47.9); orbit diameter 51.2 (47.9).

Comparisons. Six other superficially similar species differ (with characters for O. macrophthalma given in parentheses) as follows: O. geminata and O. hastata have anal fin I, 16 or II, 14 (vs. I, 17–18), fewer lower gill rakers 26‒30 (vs. 33‒34) and more precaudal vertebrae and anal-fin pterygiophores anterior to 1st haemal spine 13 and 5 respectively (vs. 11 and 3); O. sibogae has a shorter 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. 54), larger cheek scales, in 3 rows (vs. 4‒5) and anal fin II, 15‒17 (vs. I, 17–18); O. contodon differs in having anal fin II, 16 (vs. I, 17–18) and lower limb of preopercle with 7–16 moderate spines (vs. 9–11 weak spines); O. elongata has fewer oblique body scale rows in mid-lateral series 30–33 (vs. about 54), shallower body depth 10.8–14.0% SL (vs. 26–28%) and more precaudal vertebrae and pterygiophores anterior to 1st haemal spine, 16 and 8 respectively (vs. 11 and 3); the Indian Ocean O. whiteheadi has fewer anal-fin soft rays 15‒16 (vs. 17–18), more total gill rakers 50‒60 (vs. 49‒50) and teeth in outer row of each premaxilla 39–45 (vs. 28–37).

Etymology. A combination of the Greek makros (long, but used in original description to mean large) and the Greek ophthalmos (eye).

Distribution. ( Fig. 26 ) Known only from the Philippine type localities where trawled in 184– 195 m.

Remarks. In the original description, the number of dorsal-fin spines was erroneously reported to be III, 23–24 (actually IV, 22–23). Fourmanoir (1985) gave measurements of the holotype and smaller paratype as 68 and 52 mm SL respectively, in contrast to our measurements made with needle-point calipers of 67.2 and 49.4 mm; these discrepancies could partially be the result of specimen shrinkage. Another paratype (reportedly 70 mm SL), also from MUSORSTOM II, sta. 10, is apparently missing. Bauchot and Desoutter (1989:25) reported that the holotype was lost (subsequently found) and designated one of the original paratypes as the " neotype " (= lectotype); with discovery of the "lost" type, the original catalog numbers are used here. The above description of the holotype is based on our examination of it, including a radiograph, and supplemented by recent observations of Nalani Schnell.

Figures

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

FIGURE 53. Owstonia macrophthalma, holotype, MNHN 1982 ‒ 557, 67 mm SL, Philippines. After Fourmanoir, 1985, fig. 3.