Upeneus vanuatu, Uiblein, Franz & Causse, Romain, 2013

Uiblein, Franz & Causse, Romain, 2013, A new deep-water goatfish of the genus Upeneus (Mullidae) from Vanuatu, South Pacific, Zootaxa 3666 (3), pp. 337-344 : 338-342

Upeneus vanuatu n. sp.

Vanuatu goatfish

( Figs. 1–3 ; Tables 1, 2)

Holotype. MNHN 2001-3361, 100 mm SL, Espiritu Santo Island, Vanuatu , South Pacific, 15°7'1"S, 166°52'59"E, Musorstom 8 cruise, R/V Alis, station cp1120, 282– 321 m, beam trawl, 9/Oct/1994.

Paratypes. 4 specimens (80–84 mm SL). MNHN 2002-0028, 84 mm SL, same area as holotype, 15°7'59"S, 166°52'59"E, Musorstom 8 cruise, R/V Alis, cp1119, 254- 300 m, beam trawl, 9/Oct/1994; MNHN 2002-0103, 2 specimens, 80–83 mm SL, same area as holotype, 15°7'59"S, 166°52'59"E, Musorstom 8 cruise, R/V Alis, station cp1119, 191– 284 m, beam trawl, 9/Oct/1994; MNHN 2008-1331, 83 mm SL, Malo Island, Vanuatu Archipelago, Coral Sea, South Pacific, 15°39'54"S, 167°1'59"E, Santo 0 6 cruise, R/V Alis, station at17, 267– 270 m, beam trawl, 21/Sept/2006.

Diagnosis. Dorsal fins VIII + 9; pectoral fins 14–16; gill rakers 7–8 + 19–20 = 27–28; measurements in % SL: body depth at first dorsal-fin origin 21–25; body depth at anus 17–19; caudal-peduncle depth 7.9–8.4; maximum head depth 18–23; head depth through eye 14–18; interorbital length 7.0–7.6; head length 29–32; orbit length 7.4– 10; upper jaw length 11–13; barbel length 16–22; interdorsal distance 13–15; caudal-fin length 27–28; anal-fin height 14–17; pelvic-fin length 17–19; pectoral-fin length 21–24; first dorsal-fin height 19–20; second dorsal-fin height 15–17; total number of oblique caudal-fin bars 7, with 4 dark bars on upper caudal-fin lobe (including one bar close to rear end of lateral line) and 3 dark bars on lower caudal-fin lobe; bars differ in colour intensity and width; barbels white; no lateral body stripes; head and body pale rose, dorsally reddish and belly whitish; preserved fish pale brown, caudal-fin bars and black dorsal-fin tips retained.

Description. Measurements as % SL and counts are given in Table 1; morphometric data as ratios of SL for holotype, data for paratypes in brackets: body moderately deep, its depth at first dorsal-fin origin 4.1[4.4–4.7]; body depth at anal-fin origin 5.3[5.3–5.8]; head depth through eye 5.6[5.8–7.1]; head length 3.1[3.2–3.5], clearly longer than maximum depth of body and caudal-fin length (3.8[3.6–3.7]); first dorsal-fin height 5.1[4.9–5.3]; second dorsal-fin height 5.9[6.3–6.7]; barbel length 4.5[5.3–6.4]; pectoral-fin length 4.3[4.2–4.8], longer than pelvic-fin length (5.4[5.2–6.1]); orbit length 10[11–14], subequal to caudal-peduncle depth (12[12–13]).

Fresh colour (based on holotype; Figure 1 ): Head and body pale-rose; fore- and uppermost part of head and dorsal margin of body slightly darker; reddish markings along snout and around dorsal-fin bases; belly white; no lateral body stripes; barbels white; caudal fin with 7 dark oblique bars (the two distal-most bars covering the fin tips); 4 bars (including one bar close to rear end of lateral line and one at tip) on upper lobe, 3 bars on lower lobe (one at tip); colour of the three most anterior caudal-fin bars changing from pale brown proximally to dark grey or black towards rear caudal-fin margin, the other four bars uniformly dark grey or black; bars anterior to fin tips wider than all other bars; white interspaces between bars of subequal width; dorsal fins with two dark bands each, one band close to base and the other at and surrounding fin tip; paired fins hyaline or whitish, without dark pigmentation.

Preserved colour: Head, body and barbels uniformly pale brown, head with a dark patch on opercle; holotype with dark belly pigmentation; first and second dorsal-fin tip and caudal-fin bar pigmentation retained; colour of caudal-fin bars weaker than in fresh fish, but variation in colour and width similar as in fresh fish.

Size: Upeneus vanuatu n. sp. attains at least 10 cm SL.

Distribution. Only known from off Espiritu Santo and Malo Islands, Vanuatu , South Pacific; depth range 191– 321 m.

Etymology. The name “ vanuatu ” is used as a noun in apposition and is based on the type locality, which is currently the only known locality for this species.

Comparisons. Upeneus vanuatu n. sp. differs from all other congeneric species by the combination of the following characteristics (Tables 1, 2): 19–20 (17–18 developed) gill rakers on lower limb, caudal-peduncle depth 7.8–8.4 % SL, interorbital length 7.0–7.6 % SL, and interdorsal distance 13–15 % SL.

Upeneus vanuatu n. sp. differs from the most closely related Pacific species as follows (Tables 1, 2): from U. stenopsis in a deeper and longer caudal peduncle, shallower, shorter and narrower head with narrower interorbital and shorter jaws, first dorsal fin lower, second dorsal fin shorter at base, more developed gill rakers on lower limb, and the caudal-fin bars more irregular in width; from Upeneus subvittatus it differs in shallower body, a shallower, narrower, and longer caudal peduncle, shallower, narrower and shorter head with shorter jaws, shorter interdorsal distance, shorter and narrower pectoral fins, lower first dorsal fin, and more developed gill rakers on lower limb; and from U. vittatus it differs in a shallower body, shallower and narrower caudal peduncle and head, shorter interdorsal distance, shorter pelvic fin, narrower pectoral fin, lower and shorter first dorsal fin, more developed gill rakers on lower limb, less lateral-line scales, and lateral body stripes absent.

From the two deep-water Upeneus species of the Western Indian Ocean region, U. vanuatu n. sp. differs as follows (see also Uiblein & McGrouther 2012; Table 2 ; morphometric characters as % SL): from U. davidaromi in a shallower body (body depth at first dorsal-fin origin 21–25 vs 24–28; body depth at anal-fin origin 17–19 vs 20– 23), shallower, narrower and longer caudal peduncle (caudal-peduncle depth 7.9–8.4 vs 8.5–9.7; caudal-peduncle width 2.6–2.9 vs 3.0–4.3; caudal-peduncle length 22–25 vs 18–22) shallower, narrower and shorter head (maximum head depth 18–23 vs 24–27; head depth through eye 14–18 vs 20–24; interorbital length 7.0–7.6 vs 7.9– 8.9; head length 29–32 vs 32–35), shorter jaws (upper-jaw length 11–13 vs 14–15; lower-jaw length 10–12 vs 12– 14), shorter barbels (barbel length 16–22 vs 20–25), shorter caudal fin (caudal-fin length 27–28 vs 28–30), shorter pelvic fins (pelvic-fin length 17–19 vs 18–20), narrower pectoral fins (pectoral-fin width 3.1–3.8 vs 4.1–5.3), shallower first dorsal fin (first dorsal-fin height 19–20 vs 20–24), and more developed gill rakers on lower limb (17–18 vs 13–16); and from U. mascareinsis it differs in narrower and longer caudal peduncle (caudal-peduncle width 2.6–2.9 vs 2.9–4.1; caudal-peduncle length 22–25 vs 19–23), shorter snout (snout length 9.6–11 vs 11–12), shorter jaws (upper-jaw length 11–13 vs 12–14; lower-jaw length 10–12 vs 11–14), shorter interdorsal distance (13–15 vs 15–18), slightly more gill rakers on lower limb (18–20 vs 20–22), and less lateral-line scales (33–34 vs 34–37).

Remarks. The larger holotype differs from the four smaller-sized paratypes clearly in several characters having a deeper body, larger head and larger eyes, longer jaws, and longer barbels (Table 1). When plotted against standard length, all these characters reveal allometric relationships (see example for body depth in Figure 2 ), while other characters such as caudal-peduncle depth and width, interorbital length, interdorsal distance, and pectoral-fin width do not (Table 1, Figure 2 ).

Figures

FIGURE 1. Top: Upeneus vanuatu n. sp., left: Paratype (PT 4 in Table 1), MNHN 2008 - 1331, 8.3 cm SL, off Malo island, Vanuatu Archipelago (C. Ferrara); right: Drawing of caudal fin of preserved paratype MNHN 2002 - 0028, 8.4 cm SL, off Espiritu Santo Island, Vanuatu. Bottom: Upeneus stenopsis, left: Holotype, AMS I. 20918 - 017, 13.1 cm SL, NE Australia (D. F. Hoese); right: drawing of caudal fin of preserved holotype. The photograph of U. stenopsis is shown mirror-inverted to facilitate comparison.

FIGURE 2. Relationships between SL and six morphometric characters (as % SL) in five closely related species of the vittatu s group, Upeneus vanuatu n. sp., Upeneus davidaromi, U. mascareinsis, U. stenopsis, and U. subvittatus.

FIGURE 3. Relationship between total number of gill rakers on lower limb, interdorsal distance and interorbital length (morphometric characters as % SL) in five closely related species of the vittatu s group, Upeneus vanuatu n. sp., Upeneus davidaromi, U. mascareinsis, U. stenopsis and U. subvittatus.