Ocosia dorsomaculata, Chungthanawong & Motomura, 2022

Chungthanawong, Sirikanya & Motomura, Hiroyuki, 2022, A new species of the waspfish genus Ocosia (Teleostei: Tetrarogidae) from the Coral Sea, with a key to species in the genus, Zootaxa 5091 (3), pp. 429-442 : 430-433

Ocosia dorsomaculata n. sp.

[New English name: Blotch-finned Waspfish]

Figures 1–4 ; Tables 2 , 3

Ocosia apia (not of Poss & Eschmeyer 1975): Rivaton 1989: 148, pl. 1, fig. B (Chesterfield Island, New Caledonia); Struthers 2015: 1102, fig. 157.1 (Chesterfield Island, New Caledonia).

Holotype. MNHN 2003-1836, 127.2 mm SL, Chesterfield Island , New Caledonia, 22°16′58.8′′S, 159°25′01.2′′E, 315–320 m depth, RV Coriolis, 12 Oct. 1986.

Paratypes. 55 specimens, 26.8–128.2 mm SL. AUSTRALIA: QM I. 21499 , 2 specimens, 86.7–87.5 mm SL, Swain Reefs , Queensland, 22°00′S, 153°31′E, 270 m depth, trawl, 1 Nov. 1983; QM I. 23903, 76.5 mm SL, Swain Reefs , Queensland, 22°57′S, 153°25′E, 330 m, trawl, 2 Nov. 1983; QM I. 34221, 48.9 mm SL, Cape Moreton , Queensland, 26°51′S, 153°36′E, 140 m, trawl, 5 Aug. 2001; QM I. 34263, 45.6 mm SL, Caloundra , Queensland, 26°48′S, 153°37′E, 165 m, trawl, Queensland Fisheries Services , 17 Jul. 2002. NEW CALEDONIA: KAUM –I. 153734, 108.2 mm SL, collected with holotype; KAUM –I. 153735, 62.4 mm SL, KAUM –I. 153736, 119.0 mm SL, KAUM –I. 153737, 104.7 mm SL, KAUM –I. 153738, 101.1 mm SL, KAUM –I. 153739, 99.2 mm SL, KAUM –I. 153740, 95.0 mm SL, Chesterfield Island , 22°20′04.2′′S, 159°24′18′′E, 320– 315 m, RV Alis , 10 Oct. 2005; MNHN 2002-1301 , 2 , 91.7 –98.0 mm SL, Chesterfield Island , 23°09′00′′S, 159°31′01.2′′E, 280 m, RV Coriolis , 11 Oct. 1986; MNHN 2002-3244 , 2 , 104.4 – 110.4 mm SL, Chesterfield Island , 25°09′00′′S, 159°55′01.2′′E, 295 m, RV Coriolis , 7 Oct. 1986; MNHN 2003-1825 , 2 , 44.5–45.9 mm SL, 19°07′01.2′′S, 163°28′58.8′′E, 215 m, RV Vauban , 19 Sep. 1985; MNHN 2003-1837 , 37 mm SL, Chesterfield Island , 22°25′01.2′′S, 159°13′01.2′′E, 315 m, RV Coriolis , 13 Oct. 1986; MNHN 2003-1849 , 31.1 mm SL, 22°39′00′′S, 167°07′58.8′′E, 215 m, RV Vauban , 28 Sep. 1985; MNHN 2003-1851, 110.7 mm SL, Chesterfield Island , 22°25′01.2′′S, 159°24′00′′E, 330 m, RV Coriolis , 13 Oct. 1986; MNHN 2003-1853 , 3 , 102.2 – 128.2 mm SL, MNHN 2010-0521 , 2 , 29.7 –40.0 mm SL, 19°07′01.2′′S, 163°28′58.8′′E, 215 m, RV Vauban , 19 Sep. 1985; MNHN 2011-0164 , 3 , 33.1–47.6 mm SL, 23°22′44.4′′S, 168°01′58.8′′E, 240 m, RV Coriolis , 1 Nov. 2003; MNHN 2014-1022 , 8 , 26.8–43.4 mm SL, 18°30′43.2′′S, 163°06′09.6′′E, 240 m, RV Alis , 7 May 2008; MNHN 2014-1039 , 3 of 4, 42.1–47.5 mm SL, Coral Sea , 18°30′17.4′′S, 163°04′07.2′′E, 275–305 m, RV Alis , 7 May 2008; MNHN 2014-2243 , 4 , 57.0– 65.1 mm SL, Chesterfield Island , Coral Sea , 19°42′40.7′′S, 158°26′28.5′′E, 225–239 m, RV Alis , 17 Oct. 2005; MNHN 2014-2353 , 3 , 87.8–103.8 mm SL, Chesterfield Island , 22°45′49.2′′S, 159°20′19.2′′E, 315–325 m, RV Alis , 9 Oct. 2005; MNHN 2014-2488, 106.8 mm SL, Chesterfield Island , Coral Sea , 22°17′17.6′′S, 159°25′16.6′′E, 323–331 m, RV Alis , 10 Oct. 2005; MNHN 2014-2577, 100.9 mm SL, Chesterfield Island , 24°43′42′′S, 159°41′30.6′′E, 285–545 m, RV Alis , 6 Oct. 2005; MNHN 2014-2606 , 6 , 64.3–118.3 mm SL, Chesterfield Island, 22°20′04.2′′S, 159°24′18′′E, 320– 315 m, RV Alis, 10 Oct. 2005 .

Diagnosis. A new species of Ocosia characterized by the following combination of characters: 5–7 (mode 6) anal-fin soft rays; 12–14 (13) pectoral-fin rays; 15–20 (18) lateral-line pores; 9–14 (10) total gill rakers; no papillae on upper and lower lips; supraocular spine present; small lateral lacrimal spine present (sometimes absent in specimens larger than 87.8 mm SL); suborbital spine present (sometimes absent in specimens larger than 93.8 mm SL); second dorsal-fin spine length 26.5–42.8% (mean 33.9%) of SL; third dorsal-fin spine shorter or subequal to second spine, its length 74.8–97.9% (83.8%) of D 2 L; membrane of spinous portion of dorsal fin incised; body with 11–15 longitudinal pale brown to dark brown bars along lateral line from behind opercular margin to caudal-fin base; 1 or 2 irregular pale brown to dark brown blotches on dorsal-fin membrane between fifth to ninth spines.

Description. Selected meristics and morphometrics are given in Tables 2 and 3 . The description and data for the holotype are presented first, followed by those of paratypes in parentheses (if different). Dorsal fin with 16 spines [15–17, usually 16; two abnormal specimens with 13 spines (MNHN 2014-2353, 1 of 3, 102.1 mm SL; MNHN 2014-2606, 1 of 6, 64.3 mm SL)] and 8 soft rays [7–9, usually 8; two abnormal specimens with 11 soft rays (same specimens as those with 13 spines)]; origin of dorsal fin level with vertical through middle of eye (level with vertical through middle of eye or behind posterior margin of orbit, usually behind posterior margin of orbit); first spine shortest, its length 4.8 (2.6–6.2) in second spine length; second spine longest, slightly longer than third spine; third to penultimate spines becoming progressively shorter; last spine slightly longer than penultimate spine but shorter than first dorsal-fin soft ray; distance between bases of third and fourth spines greatest. Membranes of spinous portion of dorsal fin deeply incised; membrane between second to fourth spines incised more than two-thirds of length; membrane from fourth to last spine incised less than half of length and progressive shallower. All dorsal-fin soft rays branched; third (first to fifth, usually second) soft ray longest, its length 0.9 (0.7–0.9) in last dorsal-fin spine; dorsal-fin membrane posteriorly connected to dorsal edge of caudal peduncle, but not extending onto basal margin of caudal fin, posterior margin of fin rounded. Anal fin with 3 spines [three abnormal specimens with 2 spines (MNHN 2014-2353, 1 of 3, 102.1 mm SL; MNHN 2014-2606, 2 of 6, 64.3 mm SL, 107.2 mm SL)] and 6 soft rays [5–7, usually 6; three abnormal specimens with 8 soft rays (same specimens as those with 2 spines)]; anal-fin base short, 3.6 (3.0–4.7) in dorsal-fin base length; origin of anal fin level with (rarely anterior or posterior to) vertical through penultimate dorsal-fin spine base; first anal-fin spine shortest; third spine longest, but shorter than first analfin soft ray, its length 0.9 (0.7–0.9) in second spine length; second (rarely first or third) soft ray longest, membranes of spinous portion of anal fin deeply incised; membrane of last anal-fin soft ray posteriorly separated from caudal peduncle; posterior margin of fin rounded. Pectoral fins each with 13 rays (12–14, usually 13); without free rays; fin origin anterior to fifth dorsal-fin spine base; fin length slightly greater than caudal-fin length, its length 1.4 (1.2–1.6) in head length; posterior tip of fin short of (rarely extending beyond) vertical through anal-fin origin; posterior margin of fin rounded. Pelvic fin with 1 spine and 5 soft rays; origin of fin level with vertical through lower end of pectoral-fin base; second soft ray longest, fin length shorter than pectoral-fin length; posterior tip of depressed fin short of (rarely reaching to) anus. Caudal fin with 14 segmented rays, its length slightly greater than anal-fin base length; posterior margin of fin rounded. Swim bladder absent. Formula for configuration of supraneural bones, anterior neural spines, and anterior dorsal pterygiophores 2+1/1/1/1/1/1/1/1/1/1/1/1/1/1/ (2+1/1/1/1/1/1/1/1/1/1/1/1/1/ in MNHN 2003-1853, 1 of 3, 102.2 mm SL). Vertebrae 11 + 15 (10 + 16 in MNHN 2003-1853, 1 of 3, 102.2 mm SL, 2014-1022, 1 of 8, 43.4 mm SL).

Body somewhat elongated; moderately compressed anteriorly, progressively more compressed posteriorly; relatively shallow, depth much less than head length. Body and fins without scales, tentacles, cirri, or skin flaps, except minute skin flaps at nasal openings. Lateral line complete, continuous, extending from above upper end of gill opening to caudal-fin base, one lateral-line pore on caudal fin near base; end of tube associated with each lateralline pore normally directed upward; lateral line well separated from dorsal-fin base. Head profile angular, concave in front of eye. Two pairs of nasal openings, subequal in diameter; anterior nostril tubular, with minute dermal flap; posterior nostril simple rounded pore with low raised rim on anteroventral margin of orbit. Eyes relatively small, diameter 4.3 (3.3–4.4) in head length; bony rim of orbit forming shallow ridge. Ascending process of premaxilla well developed. Interorbital space narrow, its width 1.4 (1.3–2.8) in orbit diameter; interorbital ridges moderately developed, converging at horizontal level of orbit and diverging posteriorly, each ending with small lump in front of dorsal-fin spine origin; median interorbital ridge absent. Nasal spines absent. Supraocular spine present. Parietal, nuchal, pterotic, and posttemporal forming ridges with small spines protruding from skin. Supracleithral spine present. Suborbital ridge moderately developed, connected posteriorly to base of uppermost preopercular spine; small, downward projecting spine originating anterior to vertical through middle of orbit (absent in MNHN 2014-2488 and KAUM–I. 153737). Preopercle with 5 (rarely 4) simple spines; uppermost longest, protruding from skin, its posterior tip not reaching to opercular margin; second and third spines progressive shorter, protruding from skin; fourth and fifth spines hidden under skin (fifth spine sometimes indiscernible). Opercle with smooth V-shaped crests ending with spines. Upper end of gill opening reaching to or above horizontal line through lowermost margin of eye. Lacrimal with 2 broad, simple spines; anterior spine short, directed posteroventrally; posterior spine long, directed backward, its posterior tip reaching to (slightly beyond) posterior margin of upper jaw and short of vertical through middle of orbit; small spine on lateral surface of lacrimal directed upward (absent in 4 of 56 specimens examined: MNHN 2003-1853, 1 of 3, 102.2 mm SL, 2014-2488; KAUM–I. 153736, 153737). Mouth moderate, terminal, slightly oblique; posterior margin of maxilla beyond anterior margin of orbit but not reaching to vertical through middle of pupil, surface of maxilla smooth, lacking ridge. Upper and lower jaws with bands of villiform teeth on jaws, vomer, and palatines. Lips thick, without papillae. Symphyseal knob absent. No slit behind last gill arch; gill rakers short, blunt.

Color of preserved specimens ( Fig. 1A–C ): Head and body yellowish (creamy white to yellowish); two series of dark brown (pale brown to dark brown) bars on body, one series on dorsal-fin base and one series of 12 (11–15) longitudinal bars along lateral line from behind opercular margin to caudal-fin base; head with 5 dark brown stripes radiating from pupil. Fins yellowish (creamy white to yellowish); dorsal fin with dark brown (pale brown to dark brown) mottling; 1 (1 or 2, usually 2) prominent irregular dark brown (pale brown to dark brown) blotches on membrane between fifth to eight (fifth to eight or sixth to ninth) dorsal-fin spines; anal, pectoral, and pelvic fins with scattered diffuse brownish spots (faded in all specimens collected from Australia); caudal fin with 2 (2 or 3) vertical rows of diffuse brownish spots on posterior half of fin.

Distribution. Currently known only from the Coral Sea (Great Barrier Reef, Queensland, Australia and Chesterfield Island, New Caledonia), in depths between 140–545 m ( Fig. 2 ).

Etymology. The name dorsomaculata is derived from Latin and refers to the blotch(es) on the spinous portion of the dorsal fin in the new species. Treated as an adjective.

Comparisons. Ocosia dorsomaculata n. sp. closely resembles O. apia and is distinguished from all other congeners in sharing modally XVI, 8 dorsal-fin rays, a long second dorsal-fin spine (length 26.5–42.8% of SL), and the presence of supraocular, lateral lacrimal, and suborbital spines ( Tables 2–3 ; Fig. 1 ). However, it is clearly distinguished from the latter in having 5–7 (mode 6) anal-fin soft rays (vs. 4 or 5), 12–14 (13) pectoral-fin rays (vs. 12, rarely 13), and 9–14 (10) total gill rakers (vs. 12–21, usually 16–18). Morphometric differences between the two species include: greater upper-jaw length [13.1–15.9% (mean 14.6%) of SL in O. dorsomaculata vs. 12.5–14.8% (13.9%) in O. apia ], third dorsal-fin spine length [74.8–97.9% (83.8%) of D 2 L vs. 60.8–64.9% (62.6%)], fourth dorsal-fin spine length [57.8–87.1% (73.5%) of D 2 L vs. 51.3–53.1% (52.2%)], fifth dorsal-fin spine length [50.4–83.2% (68.5%) of D 2 L vs. 47.5–50.4 % (48.9%)], and sixth dorsal-fin spine length [49.7–76.6% (64.5%) of D 2 L vs. 45.6%] ( Fig. 3 ). The color pattern of O. dorsomaculata differs from that of O. apia in having 1 or 2 prominent pale brown to dark brown blotches on the membrane between the fifth to eighth or sixth to ninth dorsal-fin spines (vs. single blotches on membranes around the third dorsal-fin spine and between sixth and eighth spines, respectively), and the body with 11–15 longitudinal pale brown to dark brown bars along the lateral line (vs. irregular brown specks).

Analyses of 35 measurements taken from 56 specimens (26.8–128.2 mm SL) of O. dorsomaculata indicated that several morphometric proportions (% of SL) changed with growth. Whereas the relative lengths of the head, caudal fin, pectoral fin, longest anal-fin soft ray, pelvic-fin spine, longest pelvic-fin soft ray, orbit diameter, and caudal-peduncle depth decreased with growth ( Fig. 4A–C ), the relative lengths of the snout and second to sixth dorsal-fin spines, body depth, and body width increased ( Fig. 4D–F ). These proportional changes indicated that small specimens of O. dorsomaculata have a relatively shorter snout and dorsal-fin spines, and shallower narrower body, in addition to a longer head, caudal and pectoral fins, anal- and pelvic-fin soft rays, and pelvic-fin spine, greater caudal-peduncle depth, and larger eyes.

Remarks. A photograph of a fresh specimen published by Rivaton (1989: 148, pl. 1, fig. B) as O. apia from the Chesterfield Islands, New Caledonia was re-identified here as O. dorsomaculata on the basis of the presence of a blackish blotch on the dorsal-fin membrane between the fifth to eighth spines, 11 longitudinal dark-brown bars along the lateral line, the third and fourth dorsal-fin spines not markedly shorter than the second dorsal-fin spine, and the absence of a blotch on the dorsal-fin membrane around the third spine. Although Struthers (2015: 1102, fig. 157.1) published an illustration of a specimen as O. apia from the Chesterfield Islands with diagnostic and field characters, the illustration showed that the lengths of the third and fourth dorsal-fin spines are not markedly shorter than the second dorsal-fin spine and it is herein re-identified as O. dorsomaculata .

Figures

FIGURE 1. Preserved specimens of Ocosia dorsomaculata n. sp. (A–C) and Ocosia apia (D). A MNHN 2003-1836, holotype, 127.2 mm SL; B KAUM–I. 153740, paratype, 95.0 mm SL; C QM I. 34221, paratype, 48.9 mm SL; D USNM 214814, paratype, 49.7 mm SL.

FIGURE 2. Distributional map of Ocosia apia (blue square), O. fasciata (cyan triangles), O. possi (pink star), O. ramaraoi (green open triangle), O. sphex (yellow inverted open triangle), O. spinosa (yellow inverted triangles), O. vespa (purple open circles), O. zaspilota (brown open squares), and O. dorsomaculata n. sp. (red circles). Arrowheads indicate type localities.

FIGURE 3. Relationships of A third dorsal-fin spine length; B fourth dorsal-fin spine length; C fifth dorsal-fin spine length; and D sixth dorsal-fin spine length (all as percentages of second dorsal-fin spine length) to standard length (mm) in Ocosia dorsomaculata n. sp. (red circles) and Ocosia apia (blue squares). Arrowhead indicates holotype.

FIGURE 4. Relationships of A orbit diameter; B caudal-fin length; C pelvic-fin spine length; D fourth dorsal-fin spine length; E fifth dorsal-fin spine length; and F sixth dorsal-fin spine length (all as percentages of standard length) to standard length (mm) in Ocosia dorsomaculata n. sp. Arrowhead indicates holotype.