Upeneus heterospinus, Uiblein & Gledhill & Pavlov & Hoang & Shaheen, 2019

Uiblein, Franz, Gledhill, Daniel C., Pavlov, Dimitri A., Hoang, Tuan Anh & Shaheen, Shaker, 2019, Three new goatfishes of the genus Upeneus (Mullidae) from the Indo-Pacific, with a redescription of colour patterns in U. margarethae, Zootaxa 4683 (2), pp. 151-196 : 180-185

publication ID

https://doi.org/10.11646/zootaxa.4683.2.1

publication LSID

lsid:zoobank.org:pub:4365B195-E427-421E-9C4D-6DB746F66B8A

DOI

https://doi.org/10.5281/zenodo.3797677

persistent identifier

https://treatment.plazi.org/id/B829390B-FFD2-FFD1-FF27-FDEB3DF34572

treatment provided by

Plazi

scientific name

Upeneus heterospinus
status

n. sp.

Upeneus heterospinus n. sp. Uiblein & Pavlov

Varied-spine goatfish

( Figures 1 View FIGURE 1 , 9–12 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 ; Tables 2, 4–11)

Upeneus australiae Kim & Nakaya, 2002 : Uiblein & Heemstra 2010 (Nha Trang, South-central Vietnam, South China Sea).

U. bensasi (Temminck & Schlegel, 1843) : Provincial Keelung Girls’ High School, Keelung, Taiwan 1985 (fresh-colour photo, no locality, but size information (92 mm SL) and collecting date (03/12/1979).

U. guttatus (Day, 1868) : Motomura et al. 2017 (vouchered fresh-colour photo, central Philippines, W Pacific).

U. margarethae: Pavlov & Emel’yanova 2016 (fresh-colour photos, South-central Vietnam, South China Sea).

U. cf. margarethae : Emel’yanova & Pavlov 2014; White et al. 2013 (vouchered fresh-colour photo, S Indonesia).

U. spottocaudalis Uiblein & Gledhill, 2017 : Bandai et al. 2018 (vouchered fresh-colour photo and comparative data, S Japan, W Pacific).

U. tragula: Froese & Pauly 2019 (fresh colour photo by A. Cornell from off Hong Kong, South China; https://www.fishbase. de/photos/PicturesSummary.php?StartRow=5&ID=5443&what=species&TotRec=14).

Upeneus sp.: Kimura et al. 2018 (vouchered fresh colour photo, N Vietnam, Ha Long Bay).

Upeneus sp.1: Uiblein & Lisher 2013 (Nha Trang, South-central Vietnam, South China Sea).

Holotype. VNMN-I 2015 , adult, 91 mm SL, W Pacific, South China Sea, South-central Vietnam, Khanh Hoa province, Nha Trang , N of Hon Tre, 12º 13′21′′ N, 109º 18′30′′ E, obtained from hookah divers, 23 Feb. 2010, collector: Dimitri Pavlov (fresh-colour photo) GoogleMaps

Paratypes. (28 adults, 1 subadult: 56–152 mm SL, 15 fresh-colour photos). W Pacific, South China Sea, Southcentral Vietnam: Phu Yen province, Vung Ro Bay , 12º 52.11′ N, 109º 24.66′ E GoogleMaps , obtained from hookah divers: VNMN-I 2016 , 70 mm SL, (fresh-colour photo) ; VNMN-I 2017, 101 mm SL (fresh-colour photo); VNMN-I 2018 , 96 mm SL (fresh-colour photo) ; VNMN-I 2019 , 56 mm SL (fresh-colour photo); Khanh Hoa province, Nha Trang Bay : N of Hon Tre, 12º 13′21′′ N, 109º 18′30′′ E GoogleMaps , obtained from hookah divers: VNMN-I 2020 , 97 mm SL (fresh-co- lour photo) ; VNMN-I 2021, 112 mm SL; VNMN-I 2022, 106 mm SL (fresh-colour photo); VNMN-I 2023, 113 mm SL (fresh-colour photo); VNMN-I 2024, 105 mm SL (fresh-colour photo); VNMN-I 2025, 109 mm SL; VNMN-I 2026, 100 mm SL (fresh-colour photo); VNMN-I 2027, 112 mm SL; VNMN-I 2028, 104 mm SL; VNMN-I 2029, 104 mm SL; VNMN-I 2030, 103 mm SL; VNMN-I 2031 , 96 mm SL ; VNMN-I 2032, 103 mm SL; S of Hon Tre , obtained from hookah divers : HIFIRE F 58110 View Materials , 120 mm SL ; HIFIRE F 58115 View Materials , 109 mm SL ; VNMN-I 2033, 123 mm SL; Cua Be : CSIRO H 8427-01 View Materials , 90 mm SL (fresh-colour photo), landing site, 12º 12.09′ N, 109º 12.12′ E GoogleMaps ; HIFIRE F 58203 View Materials , 105 mm SL (fresh-colour photo), fish market, 12º 12.10′ N, 109º 12.05′ E GoogleMaps ; Nha Trang city, fish market: CSIRO H 8428-01 View Materials , 82 mm SL (fresh-colour photo) ; CSIRO H 8428-02 View Materials , 82 mm SL (fresh-colour photo) ; HIFIRE F 58178 View Materials , 152 mm SL ; NHMO J 7217, 114 mm SL (fresh-colour photo); NHMO J 7218, 103 mm SL (fresh-colour photo); Nha Trang , no further locality details : MNHN 1965-272 View Materials , 90 View Materials mm SL ; ZMUC P49483 View Materials , 84 View Materials mm SL .

Non-types. (72 adults, 6 subadults: 43–127 mm SL, 30 fresh colour photos). W Pacific, South China Sea, N Vietnam, Quảng Ninh province, Ha Long Bay, Van Don landing site, 21° 03.61’ N, 107°25.81’ E: HIFIRE F 58382 View Materials , 97 mm SL (fresh-colour photo) GoogleMaps ; NHMO J 7219, 104 mm SL (fresh-colour photo); VNMN-I 2034, 109 mm SL (fresh-colour photo); VNMN-I 2035, 113 mm SL (fresh-colour photo); VNMN-I 2036, 104 mm SL (fresh-colour photo); VNMN-I 2037, 108 mm SL; VNMN-I 2038, 108 mm SL (fresh-colour photo); Ha Long: VNMN-I 2039 , 83 mm SL (fresh-colour photo) ; VNMN-I 2040 , 83 mm SL (fresh-colour photo) ; VNMN-I 2041, 122 mm SL (fresh-

colour photo); VNMN-I 2042 , 93 mm SL (fresh-colour photo) ; VNMN-I 2043, 108 mm SL (fresh-colour photo); VNMN-I 2044 , 94 mm SL (fresh-colour photo) ; VNMN-I 2045, 117 mm SL (fresh-colour photo); VNMN-I 2046 , 87 mm SL (fresh-colour photo) ; VNMN-I 2047 , 72 mm SL (fresh-colour photo) ; VNMN-I 2048 , 82 mm SL (freshcolour photo) ; VNMN-I 2049 , 80 mm SL (fresh-colour photo) ; VNMN-I 2050 , 77 mm SL (fresh-colour photo) ; VNMN-I 2051 , 81 mm SL (fresh-colour photo) ; VNMN-I 2052 , 64 mm SL (fresh-colour photo) ; VNMN-I 2053 , 60 mm SL (fresh-colour photo); South-central Vietnam, Khanh Hoa province, Nha Trang Bay : HIFIRE F 58231 View Materials , 123 mm SL, N of Hon Tre Island, 12°14’18”N 109°15’54”E, obtained from hookah divers (fresh-colour photo); Gulf of Thailand, S Vietnam, Phu Quoc, An Thoi market, 10° 0.90’ N, 104° 0.86’ E GoogleMaps : HIFIRE F 58287 View Materials , 93 mm SL (freshcolour photo) ; NHMO J 7220 View Materials , 88 View Materials mm SL (fresh-colour photo) ; VNMN-I 2054 , 83 mm SL (fresh-colour photo) ; VNMN-I 2055, 114 mm SL (fresh-colour photo); Gulf of Thailand, Thailand, Ko-Sichang Island : CAS 17679 View Materials , 41 View Materials (of 141): 56–94 mm SL, 13°8’ N, 100°51’ E, trawl, 18–24 m depth; Singapore GoogleMaps : NHMO J 2134 View Materials , 2 View Materials , 78–81 mm SL; Philippine Sea, Central Philippines, Panay Island : UPVMI 155 , 96 mm SL (fresh-colour photo); Indonesia, Bali Sea, E Java : CSIRO H 7360-04 View Materials , 3 View Materials : 43–66 mm SL, Banguwangi , 08°09’ S 114°23’ E; Lombok (border of W Pacfic to Indian Ocean) GoogleMaps : MZB, unregistered (field code LM308 (large)), 54 mm SL; CSIRO H 8409-02 View Materials , 65 mm SL, and CSIRO H 7364-02 View Materials , 127 mm SL, Tanjung Luar , 8°45’ S, 116°35’ E (both with fresh-colour photo) GoogleMaps ; BPBM 29896 View Materials , 96 View Materials mm SL, no locality information (fresh-colour photo) .

Fresh-colour photos of specimens not retained (n =79): W Pacific, Vietnam (D.A. Pavlov & F. Uiblein), South China Sea: 20 adults, Ha Long Bay, N Vietnam; 10 adults, Nha Trang Bay, South-central Vietnam; Gulf of Thailand, S Vietnam, Phu Quoc: 37 adults and 1 subadult or adult (in-situ photo); South China Sea, other areas: 1 adult, Hong Kong, China (A. Cornell); 1 adult, Taiwan (Provincial Keelung Girls’ High School, Keelung, Taiwan, 1985); Philippine Sea, Philippines: 7 adults, 1 subadult, Central Philippines (various localities, in-situ photos; Philippe & Guido Poppe—www.poppe-images.com); Japan: adult, 96 mm SL, Satsuma Peninsula, Kagoshima, S Japan ( Bandai et al. 2018).

Diagnosis. Dorsal fins VII or VIII + 9, the first spine minute in 8-spined fish; pectoral fins 13–15; gill rakers 4–6 + 15–18 = 21–24; lateral-line scales 28–30; measurements in % SL, adults: body depth at first dorsal-fin origin 22–26; body depth at anus 18–22; caudal-peduncle depth 9.2–11; caudal-peduncle width 3.5–5.0; maximum head depth 19–23; head depth through eye 15–18; suborbital depth 8.3–11; interorbital length 7.2–9.2; head length 27–31; snout length 9.7–13; postorbital length 10–13; orbit length 5.9–8.3; upper-jaw length 9.4–13; barbel length 16–20; interdorsal distance 13–17; caudal-peduncle length 22–26; caudal-fin length 27–32; anal-fin height 15–19; pelvic-fin length 19–23; pectoral-fin length 19–22; pectoral-fin width 3.4–4.7; first dorsal-fin height 18–23; second dorsal-fin height 16–20; measurements in % SL, subadults: body depth at first dorsal-fin origin 22–24; body depth at anus 18–21; caudal-peduncle depth 9.1–10; caudal-peduncle width 3.6–3.8; maximum head depth 19–21; head depth through eye 15–18; suborbital depth 9.0–10; interorbital length 7.6–8.1; head length 29–30; snout length 11–12; postorbital length 11–13; orbit length 7.8–7.9; upper-jaw length 9.9–12; barbel length 18–19; interdorsal distance 12–14; caudal-peduncle length 22–25; caudal-fin length 29–31; anal-fin height 16–19; pelvic-fin length 21–22; pectoral-fin length 21; pectoral-fin width 3.8–4.2; first dorsal-fin height 21–22; second dorsal-fin height 17– 20; fresh colour: head and body dorsally red, brown or dark-grey mottled, ventrally white, often with pale beige or grey dots or red blotches (inactive, live fish with large red patches and broad vertical or oblique red bands on body); upper lobe of caudal fin with 4–6 red or brown bars (3 or 4 bars in subadults), lower caudal-fin lobe with 5–7 (3–5) red, brown or dark-brown bars, often crossed, entirely or ony dorsally, by a yellow, beige, pale red or pale brown stripe; bars on both lobes of pupil width or less in adults, interrupted by pale, partly hyaline interspaces of similar width or slightly narrower; lower caudal-lobe tip sometimes black; barbels entirely yellow; a single yellow, beige, or pale brown mid-lateral body stripe of pupil width from snout tip through eye to caudal-fin base; stripe sometimes covered by 1–4 sections with 1–4 dark dots, the posteriormost group of dots behind second dorsal-fin base, often connecting to a dark saddle behind second dorsal fin; first dorsal fin with 3 or 4 often fused, pale-red, pale-brown or beige stripes, the fin-tip area not darker pigmented; second dorsal fin with 3 or 4 red or brown well-separated stripes with hyaline interspaces; pectoral fins hyaline, pelvic and anal fins weakly pigmented and partly hyaline; preserved fish pale brown, often with remains of dark pigmentation deriving from caudal-fin bars, mid-lateral dots, saddle and/or second dorsal-fin distal stripe.

Description. Measurements in % SL and counts for types are given in Table 8; morphometric data as ratios of SL for holotype, data for paratypes in brackets: body elongate, body depth at first dorsal-fin origin 4.2 [3.8–4.6], body depth at anal-fin origin 5.0 [4.5–5.4], head length 3.5 [3.3–3.7], larger than maximum body depth and subequal to caudal-fin length (3.3 [3.2–3.7]), second dorsal-fin height 6.1 [5.3–6.4], slightly shallower than first dorsal-fin height (4.7 [4.5–5.6]), barbel length (5.5 [5.0–5.9]), pelvic-fin length 5.0 [4.5–5.3], similar to length of pectoral fins (5.2 [4.7–5.3]) and body depth at first dorsal-fin origin; caudal-peduncle depth 10 [8.9–10], clearly larger than orbit length (14 [12–17]); and caudal-peduncle width 21 [20–28], subequal to pectoral-fin width (23 [22–27]).

Colour. Freshly collected fish. ( Figure 9 View FIGURE 9 ). Head and body ventrally white and ventro-laterally white or palegrey whitish with numerous red, brown or dark-grey dots of half pupil size or less, placed mostly on individual scales ( Figure 9 A, B, E, F View FIGURE 9 ); in all six specimens shown in Figure 9 View FIGURE 9 (least in holotype, Figure 9 A View FIGURE 9 ), red blotches of different form and size or larger red pigmentation patches below or behind eye on gill cover and/or on body ventrally or ventro-laterally either covering larger areas ( Figure 9 B, C View FIGURE 9 ) or more restricted to smaller areas on or behind belly ( Figure 9 E, F View FIGURE 9 ); some of these blotches and patches may have catch/treatment-related context; head from above snout and eye and body above lateral line red-brown or dark-grey mottled, bordered below by a mid-lateral stripe of pupil width which runs rather straight or only slightly bent from caudal-fin base to eye in yellow, beige, pale red or pale brown colour and continues from eyes (with red or pale-red iris) to snout either in similar colour and intensity ( Figure 9 View FIGURE 9 B–D), or slightly darker, but weaker ( Figure 9 E, F View FIGURE 9 ), or rather faint and indistinct ( Figure 9 A View FIGURE 9 ); on the mid-lateral body stripe from behind head to behind second-dorsal fin up to 4 sections with 1–3 red, brown or black dots of less than pupil width; behind head until below base of second dorsal fin in adults, a thin white or pale creamy stripe separates the dorsal body pigmentation from the mid-lateral body stripe ( Figure 9 A, B, E View FIGURE 9 ); lateral line visible especially in subadult ( Figure 9 C View FIGURE 9 ) and small adult ( Figure 9 F View FIGURE 9 ) as a series of mostly red, dark-grey or black dots placed well above mid-lateral stripe in anterior half of body, then starting to cross the stripe just anterior of second dorsal-fin base, continuing behind dorsal fin just below stripe towards caudal-fin base; barbels entirely yellow; caudal fin with 9–13 red, dark brown or black oblique bars crossing mostly both lobes entirely, if not placed on fin base or fin tips; upper lobe covered by 4–6 (3–4 in subadults) red, red brown, or dark brown bars of pupil or slightly narrower width, the distal-most bar sometimes covering fin tip ( Figure 9 A, F View FIGURE 9 ); bars separated by hyaline interspaces of similar width or slightly wider; in large adult ( Figure 9 E View FIGURE 9 ) dark-brown blotches on three intermediate bars; lower caudal-fin lobe covered by 5–7 (3–5 in subadults) red, red brown or dark brown bars and hyaline interspaces of similar width or slightly narrower than on upper fin lobe in adults, whereas more variable in subadults; in four specimens ( Figure 9 View FIGURE 9 A–D), the lower caudal-fin lobe ends in a black tip; a red or brown stripe stretches entirely or only dorsally along the lower caudal-fin lobe covering partly the bars in both aduts and subadults; first dorsal fin almost entirely covered with pale-red, beige or pale-brown pigmentation; second dorsal fin with 3 red stripes of orbit width or less, one stripe at or close to fin base, one at or close to fin tip, the latter and in some fish also the middle stripe slightly darker; pelvic fins hyaline with up to 5 narrow red or brown stripes; anal fin with 1–3 red or brown stripes and hyaline or whitish interspaces; pectoral fins hyaline.

Live fish in situ. Active fish. ( Figure 10 View FIGURE 10 A–D). Head and body ventrally white, with numerous tiny red or beige dots associated with 4 scale rows and, in three of four fish, with additional, larger rounded and partly connected red blotches, ca. 25 of the latter visible in fish from the type locality which was kept in a tank ( Figure10 A View FIGURE 10 ); fewer and more ventrally positioned blotches in two fish photographed in situ in Central Philippines ( Figure 10 C, D View FIGURE 10 ); head from above snout and eye and body above lateral line pale-grey or rose mottled, bordered below by a mid-lateral stripe in red colour (that appears brown when photographed without flash, see Figure 10 B View FIGURE 10 ) of pupil width which runs rather straight from caudal-fin base to eye, continuing through eyes (with iris red-coloured in stripe shape) and then bending ventrally towards snout tip, becoming slightly narrower and weaker; 5 well separated, rectangular dark-red sections on mid-lateral body stripe (not well visible in Figure 10 B View FIGURE 10 ), one shorter behind gill cover, two longer ones below dorsal fins, one shorter behind second dorsal fin, and one less conspicuous, rather short section close to caudal-fin base; each section except for the posterior-most with a horizontal series of 2–4 black dots of a little less than pupil diameter; the dotted section behind the second dorsal fin connecting closely to red saddle in tank fish ( Figure 10A View FIGURE 10 ), the latter reaching from dorsal body margin behind second dorsal fin to stripe in V-form; lateral line, as also observed in freshly collected fish, proceeds parallel above mid-lateral body stripe during first half of body, then crossing and continuing just below stripe to caudal-fin base; lateral line marked by several small red, beige or grey dots that become more conspicuous in positions of dots on mid-lateral body stripe below; barbels entirely yellow; caudal fin with 8–12 red-brown oblique bars which appear dark-brown in the small possibly adult specimen photographed at distance without flash ( Figure 10 B View FIGURE 10 ); dorsal fin lobe crossed by 3–5 bars of pupil width, the distal-most bar covering fin tip in two specimens ( Figure 10 A, D View FIGURE 10 ); in three specimens the bars are reduced to dark red or dark brown blotches ( Figure 10 B, C, D View FIGURE 10 ) leaving the remaining parts of bars as pale, mostly hyaline traces ( Figure 10 C, D View FIGURE 10 ); bars on upper lobe separated by hyaline interspaces of similar width; lower caudal-fin lobe crossed in adults by 5–7 dark red (dark brown in Figure 10 B View FIGURE 10 ) bars which are similarly shaped and sized as bars on upper lobe; while in the tank specimen the bars are of varying intensity but typically shaped, the bars in the other three active fish show a blotch-like concentration of intense colour in the middle of the lower lobe, leaving the ventral and dorsal areas of each bar rather inconspicuous (however still visible, e.g. Figure 10 C, D View FIGURE 10 ); in addition, a red stripe is formed on the lower lobe of the tank specimen that covers the lobe almost entirely (apart from ventral margin) and a pale red stripe is also weakly visible along the dorsal half of lobe in two of the three other specimens ( Figure 10 C, D View FIGURE 10 ); the first dorsal fin (only well visible in Figure 10 A View FIGURE 10 ) is mostly weakly pale red, leaving the tip almost completely unpigmented hyaline; the second dorsal fin with 3-4 red to brown stripes of about pupil width or less, at least one of the distal two stripes more intensely coloured than the stripes (or single stripe) closer to fin base which appear rather pale red and partly hyaline; interspaces between stripes in part with white pigmented fin rays; pelvic and anal fins partly hyaline with weak pale grey pigmentation indicating stripes; pectoral fins hyaline, only very faintly visible.

Resting fish. ( Figure 10 E View FIGURE 10 , only differences from the above colour description indicated). Large areas on head and body covered with red, in particular below eye, on gill cover, above pectoral-fin base, two large red bands running from dorsal fins down to ventral margin, the anterior band rather straight from first dorsal fin, the posterior band obliqueand wider, covering also the area of and below saddle; the two bands connecting on ventral body margin with each other and covering most of ventral underside except for an inverted V-shaped pale area behind pelvicfin base and caudal peduncle; caudal peduncle mostly white with three round orbit-sized red blotches on ventral margin and one more elongated red blotch just above the last ventral-margin blotch; mid-lateral body stripe only visible in areas without red band markings and almost indistinct whitish on caudal peduncle, then orange anterior to second dorsal fin between the large red bands and behind head, turning into red on gill cover, then crossing eye (with iris red-colour in stripe shape) and bending towards snout tip, still in red colour; caudal fin with 9 oblique dark grey bars, on dorsal lobe 4 bars (including one on tip) which are dark pigmented only on dorsal margin of fin, while becoming ventrally pale grey and rather indistinct; the 5 bars on lower fin lobe entirely dark grey, slightly wider than whitish interspaces, with faint appearance of a grey stripe only close to caudal-fin base; area of red pigmentation on first dorsal fin concentrated centrally and in part of fin, leaving the tip entirely pale hyaline.

Preserved fish. Head and body mostly uniformly pale brown, pale greyish, greyish brown or brown, sometimes slightly darker dorsally, gill cover silvery or pale and partly transparent, lateral line, when intact, well visible in entire range from behind head to caudal-fin base; barbels pale brown or pale creamy; mid-lateral body stripe completely lost, but often remains of dark mid-lateral dots in the area of stripe below and posterior to dorsal fins (in 35 % of 100 adults vs. 33 % of 6 subadults); dark pigmentation remains also in other areas: saddle behind second dorsal fin (65 % vs. 67 %), caudal fin (98 % vs. 100 %) and second dorsal-fin distal stripe (92 % vs. 100 %); on caudal fin with retained pigmentation remains of up to 6 oblique bars visible on each lobe; in adults 96 % (of 101 fish) and all subadults show remains of bars on both lobes; of all adults only 2 % show no pigmentation remains (pigmentation degree 0) and 36 % have pigmentation in all body and fin regions (pigmentation degree 4); all studied subadults show pigmentation remains with pigmentation degree 4 occurring in 33 %. Unpigmented areas of caudal, second dorsal fins and other fins entirely pale and partly hyaline.

Etymology. The name refers to the variable number of 7 or 8 dorsal-fin spines in this species, which is in contrast to most other goatfish species and all other Indo-Pacific congeners which have either 7 or 8 dorsal-fin spines.

Distribution, habitat and size. W Pacific, from border to EIO in S Indonesia to Singapore, Gulf of Thailand, Vietnam, Central Philippines, South China, Taiwan, and S Japan; 6–24 m depth, sandy or muddy bottoms; maximum size 16 cm SL.

Intraspecific comparisons. To ensure that the dimorphic expression of seven and eight dorsal-fin spines in U. heterospinus n. sp. is indeed a single-species characteristic, as is unusual in goatfishes, the two morphs were compared using the entire set of studied characters. As was expected, no differences could be discovered in any single character ( Table 8), nor in any combinations of characters or in statistical comparisons of morphometric, meristic and colour characters.

Subadults of U. heterospinus n. sp. differ from adults in slightly shallower body at anal-fin origin (especially when analyzing populations separately; Figure 11 View FIGURE 11 ), fewer rudimentary gill rakers on lower limb ( Figure 11 View FIGURE 11 ; while total gill rakers do not differ among size classes), fewer oblique bars on caudal fin ( Tables 2, 9), and the bars slightly wider, almost interconnected in fresh subadults ( Figure 9 C View FIGURE 9 ) vs. narrower and more clearly separated in adults ( Figure 9 A, B View FIGURE 9 , D–F; Figure 10 View FIGURE 10 ).

Among the three populations of Upeneus heterospinus n. sp. from N Vietnam, South-central Vietnam and the Gulf of Thailand no clear distinction was found in any single or combination of morphological or colour characters occurs that would support separation into different taxa. However, each population can be distinguished statistically ( Table 11). For instance, the Gulf of Thailand population has a significantly higher maximum body depth than the other two populations. The N Vietnam population differs significantly from the two other populations in having a shallower body at anal-fin origin, shallower caudal peduncle, shallower maximum head and suborbital depth, shorter interorbital length, longer pectoral fins and higher second dorsal fin. The South-central Vietnam population has a significantly wider snout and longer barbels than the other two populations and differs in addition in pairwise comparisons with the northern population. As stated for U. margarethae , the considerable amount of significant differences among populations contrasts however with much greater differentiation among species, as revealed by the statistical comparisons among three of the five species ( Table 4, see also section on Interspecific comparisons further below).

Regarding meristic characters, the Gulf of Thailand population has a significantly lower gill-raker count than the other two populations ( Table 5). With respect to preserved colour patterns, the three populations differ significantly from each other with the South-central population showing the highest degree of dark pigmentation, followed by the N Vietnam and the Gulf of Thailand populations ( Table 6). In none of the three populations, individuals that completely lack dark pigmentation remains (pigmentation degree 0) occur. When comparing the four examined pigmentation patterns individually, the only significant differences exist in the presence/absence of a saddle and mid-lateral dots ( Table 7). The latter are completely lacking in the Gulf of Thailand population. Regarding fresh colour patterns, no clear population differences can be observed when comparing the available images (see also Figures 9 View FIGURE 9 , 10 View FIGURE 10 ).

Remarks. Upeneus heterospinus n. sp. has been reported from many areas using various names and most recently as U. spottocaudalis from Japan ( Bandai et al. 2018). From Vietnam, where it is a common species that is frequently encountered in fish markets, biological data have been recently collected and published using preliminary identification information ( Emel’yanova & Pavlov 2014; Pavlov & Emel’yanova 2016).

CSIRO

Australian National Fish Collection

NHMO

Natural History Museum, University of Oslo

ZMUC

Zoological Museum, University of Copenhagen

CAS

California Academy of Sciences

MZB

Museum Zoologicum Bogoriense

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Perciformes

Family

Mullidae

Genus

Upeneus

Loc

Upeneus heterospinus

Uiblein, Franz, Gledhill, Daniel C., Pavlov, Dimitri A., Hoang, Tuan Anh & Shaheen, Shaker 2019
2019
Loc

U. tragula:

Froese & Pauly 2019
2019
Loc

U. spottocaudalis

Uiblein & Gledhill 2017
2017
Loc

U. margarethae: Pavlov & Emel’yanova 2016

: Pavlov & Emel'yanova 2016
2016
Loc

U. cf. margarethae

: Pavlov & Emel'yanova 2016
2016
Loc

Upeneus australiae

Kim & Nakaya 2002
2002
Loc

Upeneus

Cuvier 1829
1829