Three new species of the Indo-Pacific stingfish genus Minous (Synanceiidae: Minoinae) with redescriptions of M. trachycephalus (Bleeker 1855) and M. pictus Günther 1880
Author
Matsunuma, Mizuki
Author
Motomura, Hiroyuki
text
Zootaxa
2018
2018-08-02
4455
2
201
257
journal article
29108
10.11646/zootaxa.4455.2.1
d0dc8fdd-32b0-446a-9ff0-63562ba0d7ed
1175-5326
1457101
6C257211-8AE2-4F69-8692-9E8F8ADF08D3
Minous pictus
Günther 1880
English name: Painted Stingfish
Figures 21D–F
,
22G, H
,
23D–F
,
24A
,
25
; Tables 1–5, 8
Minous pictus
Günther 1880
: 41
, pl. 18, fig. D (Arafura Sea, south of New
Guinea
,
09°59′S
,
139°42′E
; in part;
lectotype
designated herein);
De Beaufort & Briggs 1962
: 111
(Arafura Sea; referred to “
holotype
” of the species);
Eschmeyer
et al
. 1979
: 467
, figs. 1, 8a (Arafura Sea,
Philippines
,
Vietnam
,
Hong Kong
and
Taiwan
; in part; description and synonymy; referred to “
holotype
” of the species).
Minous coccineus
not of
Alcock 1890
:
Gloerfelt-Tarp & Kailola 1984
: 110
, unnumbered fig. (Western Australia; short description; specimen: CSIRO CA1679);
Sainsbury
et al
. 1985
: 94
(Western Australia; short description; specimen: CSIRO CA1679);
Allen
et al
. 2006
: 905
(Western Australia; listed, ecological and distributional notes).
Lectotype
.
BMNH 1879.5
.14.371,
45.5 mm
SL,
Arafura Sea
, south of New
Guinea
,
09°59′S
,
139°42′E
, 28 fm. (
ca.
51 m
) depth,
Challenger station
188,
10 Sep. 1874
.
Other
specimens examined.
Nine
specimens,
57.3–101.8 mm
SL (all from
Australia
):
CSIRO
CA1679
, 82.0 mm SL,
CSIRO
CA1680
,
80.7
mm
SL, east of
Stewart Island
, west of
Cape Preston
,
Western Australia
,
20°53′S
,
115°53′E
,
16 m
depth, FRV
Soela
,
7 Dec. 1979
;
CSIRO
H
1489-4, 101.8 mm
SL, west of
Barrow Island
,
Western
Australia
,
20°55′S
,
115°08′E
,
58–68 m
depth, Frank and Bryce demersal trawl, FRV
Soela
,
27 Sep. 1988
;
NTM
S.12920-002,
57.3 mm
SL
Arafura Sea
, northwest of
Cape Wessel
,
Northern Territory
,
09°21′S
,
135°15′E
,
80 m
depth,
R. Williams
,
12 Nov. 1990
;
NTM
S.12973-004,
77.2 mm
SL,
Arafura Sea
,
Northern Territory
,
09°41′S
,
134°41′E
,
87 m
depth,
H. Larson
,
30 Oct. 1990
;
NTM
S.12977-004,
70.1 mm
SL,
Arafura Sea
,
Northern Territory
,
09°42′S
,
134°35′E
,
92–94 m
depth,
H. Larson
,
30 Oct. 1990
.
Diagnosis.
A species of
Minous
distinguished from other congeners by the following combination of characters: 1st dorsal-fin spine much shorter than 2nd dorsal-fin spine, their bases close together; dorsal-fin rays X–XI, 12–13 (modally XI, 12), total rays 22 or 23 (23); anal-fin rays II, 10–11 (II, 10), total rays 12 or 13 (12); lateral-line tubes 17–21 (19); width between interorbital ridges 3.0–4.2% (mean 3.7%) of SL; pelvic-fin base length 15.2–19.3% (17.4%) of SL; body entirely pinkish, with oblique alternating dark and light stripes; pectoral fin inner surface largely yellow, with irregular dark interconnected blotches along rays, together with small dark spots.
Description.
Pectoral-fin rays 12, lowermost ray free from membrane; pelvic fin rays I, 5. Vertebrae 11 + 15 = 26. Other meristics and morphometrics shown in Tables 1–5, 8. Body oblong, moderately compressed laterally, without scales (
Fig. 22D–F
). Lateral-line tubes continuous, except for posteriormost isolated tube on caudal peduncle; each tube with a pore opening to short dermal tube on posterior end, short cirri associated with pore. Single slit-like pore opening above pectoral-fin base behind gill opening, associated with relatively long tentacle (subequal to maximum pore diameter).
Head moderately large, exposed bony surface relatively smooth; interorbital space shallow, interorbital ridges developed, well separated from each other; occipital pit shallow. Anterior and posterior lacrimal spines sharp, posterior spine longer than anterior spine, anterior spine canted anteroventrally, posterior spine posteroventrally; suborbital ridge with numerous small spines; preopercle with 5 spines, uppermost spine behind end of suborbital ridge longest, lower 3 spines blunt, plate-like; 3 sensory pores on underside of each dentary; small pore on each side of symphysial knob; lateral and ventral surfaces of anterior portion of lower jaw with many cirri or tentacles; a pair of relatively long tentacles located between middle and posteriormost sensory pore, tips not reaching posterior margin of maxilla when laid flat.
Snout blunt; dorsal profile of snout relatively steep, forming angle of
ca.
40° (
ca.
40–50°) to horizontal axis of head and body. Mouth moderately large, slightly oblique, forming angle of
ca.
30° to horizontal axis of head and body; posterior margin of maxilla almost reaching a vertical through mid-orbit. Lower jaw tip slightly projected anteriorly when mouth closed. Symphyseal gap separating premaxillary teeth bands very narrow, less than width of each band; both jaws with a band of small, conical teeth,
ca.
6 (or 7) and
ca.
4 teeth rows at widest portions of upper and lower jaw, respectively; 2 small elongate patches of small conical teeth on vomer; palatine teeth absent.
FIGURE 24.
Fresh specimens of
Minous pictus
—lateral view (A, C);—pectoral fin inner surface (magnified) (B, D). (A, B) CSIRO H1489-4, 101.8 mm SL, Australia; (C, D) CSIRO CA1679, 82.0 mm SL, Australia. Right side, reversed in A. Photos: Thor Carter (A and B) and Richard Martin (C and D).
Eye moderately large, with numerous tentacles on dorsal portion, longest tentacle branched, tips extending beyond dorsal contour of orbit. Eye set relatively low on head, dorsal contour of orbit (about one-fifth of orbit) extending beyond a line between snout tip and dorsal-fin origin. Preocular, supraocular and postocular (surrounding orbit) relatively smooth.
Dorsal-fin origin behind occipital pit, surrounded by parietal spine clefts; 1
st spine
relatively short, thin, much shorter than 2nd spine, its length 33% (20–28%) of 2nd spine length, their bases close together; 3rd spine subequal to 2nd spine, its length 96–102% of 2nd spine length; 3rd to 6th spines gradually becoming longer posteriorly, remaining posterior spines subequal in length; membranes on anterior spinous portion well incised, remaining membranes moderately incised; 2nd and 3rd spines not associated with dermal flaps. Dorsal contour of soft-rayed portion of dorsal fin rounded, longest soft ray length subequal to 2nd spine length; last soft ray attached to caudal peduncle by broad membrane. Anal-fin origin below 9th dorsal-fin spine base; spines tiny, covered with skin; longest anal-fin soft ray length subequal to longest dorsal-fin soft ray length; last soft ray attached to caudal peduncle by broad membrane. Pectoral fin rounded, moderately large, 5th (or 4th) ray longest, its tip extending far beyond (almost reaching in largest specimen) a vertical through middle of anal-fin base but not reaching end of anal-fin base; lowermost ray long, slightly thickened, free from membrane, its base well separated from base of above membrane associated rays, its tip extending slightly beyond a vertical through anal-fin origin when depressed. Pelvic-fin origin below 4th dorsal-fin spine base, spine covered with skin, last soft ray attached to abdomen by broad membrane, end of pelvic-fin base not reaching level of anus; 4th (or 3rd) soft ray longest, its tip extending beyond (not reaching in CSIRO H
1489-4, 101.8 mm
SL) a vertical through anal-fin origin when depressed. Caudal fin moderately long, posterior margin slightly rounded (based on
paratypes
). All segmented rays in dorsal, anal, pectoral, pelvic and caudal fins unbranched.
FIGURE 25.
Pectoral fin inner surface in preserved specimens of
Minous radiatus
sp. nov.
(A–C) and
M
.
pictus
(D–F). (A) NSMT-P 54646,
paratype
, 106.5 mm SL, China; (B) KAUM–I. 39286,
holotype
, 89.6 mm SL, Taiwan; (C) KAUM–I. 22370,
paratype
, 57.2 mm SL, Malaysia; (D) CSIRO H1489-4, 101.8 mm SL, Australia; (E) NTM S.12973-004, 77.2 mm SL, Australia (right side, reversed); (F) BMNH 1879.5.14.371,
lectotype
, 45.5 mm SL, Arafura Sea. Photo: Gota Ogihara (D).
Fresh coloration
, based on color photographs of non-type specimens (CSIRO H1489-4 and CSIRO CA1679) (
Fig. 24
). Head and body entirely pink, darker dorsally, posterior portion of maxilla, ventral portions of head and chest whitish; body with poorly defined oblique alternating dark and light stripes dorsally, extending onto dorsal fin; eye pale yellow, pupil black. Dorsal fin coloration same as that of dorsum, with black tinged margin. Anal fin pink, with large blackish distal portion. Pectoral fin outer surface of pectoral fin black with irregular, poorly defined lighter bands; inner surface with extensive yellow area dorsally, darker ventrally, with many interconnected black blotches along upper rays; lowermost free ray dark pink (
Fig. 24B, D
); axil without markings. Pelvic fin pink, blackish distally. Caudal fin pale pink without markings.
Coloration of preserved specimens
, based on all specimens (
Figs. 22D–F
). Head and body entirely pale brown (or creamy-white), paler ventrally, with poorly defined oblique alternating dark and light stripes centrally and dorsally, extending onto dorsal fin. Dorsal fin pale creamy-white, tips of spines tinged with black; soft-rayed portion brownish dorsally. Anal fin creamy-white, brownish distally. Pectoral fin outer surface brown with irregular pale bands; inner surface whitish dorsally, brownish ventrally, with many irregularly shaped elongate brown (blackish) blotches along rays; lowermost free ray creamy-white (
Fig. 25D–F
). Pelvic fin dusky creamywhite, brownish distally. Caudal fin semi-translucent (or pale creamy-white), dusky distally, without distinct markings.
Distribution.
Minous pictus
is distributed off northern and northwestern
Australia
and south of New
Guinea
(based on examined specimens) (
Fig. 10
). Sampling data for seven specimen lots indicated collection depths of
16– 94 m
(mostly>
50 m
depth). Although the species has previously been reported as
M
.
coccineus
from Australian waters (
Gloerfelt-Tarp & Kailola 1984
;
Sainsbury
et al
. 1985
), no records of that species have so far been confirmed from
Australia
.
Remarks.
Minous pictus
was recorded by
Gloerfelt-Tarp & Kailola (1984)
and
Sainsbury
et al
. (1985)
(as
M
.
coccineus
) from northwestern
Australia
. Detailed comparisons of the two species are given below. On the other hand,
M
.
pictus
recorded by
Gloerfelt-Tarp & Kailola (1984)
was identified herein as
M
.
groeneveldi
sp. nov.
(see above).
FIGURE 26.
Lectotype (A) and paralectotype (B) of
Minous
pictus
, Arafura Sea
, south of New Guinea. (A) BMNH 1879.5.14.371, 45.5 mm SL; (B) BMNH 1879.5.14.372, 36.6 mm SL (=
M
.
trachycephalus
).
Lectotype designation.
In a report on fishes collected during the Challenger Expedition,
Günther (1880)
described
M
.
pictus
on the basis of syntypes from the Arafura Sea, south of New Guinea. Subsequently,
De Beaufort & Briggs (1962)
redescribed
M
.
pictus
based on a 63 mm-length (most likely total length) “holotype” [BMNH 1879.5.14.371 (caudal fin damaged but estimated total length
63.4 mm
)] (
Fig. 26A
).
Eschmeyer
et al
. (1979)
also regarded BMNH 1879.5.14.371 as the holotype of
M
.
pictus
. However,
Günther’s (1880)
description of
M
.
pictus
was not based solely on a single specimen, noting the lengths of
M
.
pictus
specimens as “
2 to 2.5 inches
”. Although
Günther (1880)
did not mention the number of specimens, two syntypes of
M
.
pictus
now exist at BMNH, their estimated total lengths [BMNH 1879.5.14.371,
45.5 mm
SL,
63.4 mm
TL (=
ca.
2.5 inches
) and BMNH 1879.5.14.372,
36.6 mm
SL,
50.2 mm
TL (=
ca.
2.0 inches)] being highly consistent with those given by
Günther (1880)
. Accordingly, the two BMNH specimens are regarded herein as the original syntypes of
M
.
pictus
, the larger syntype (BMNH 1879.5.14.371) (
Fig. 26A
) conforming to the species recognized herein as
M
.
pictus
, having the diagnostic color pattern on the pectoral fin inner surface (
Fig. 25F
). Moreover,
Günther (1880: pl. 18, fig. D)
provided an excellent drawing of
M
.
pictus
which was consistent with BMNH 1879.5.14.371. In contrast, BMNH 1879.5.14.372 (
Fig. 26B
) conformed strongly to
M
.
trachycephalus
Bleeker,
1855
in having dorsal-fin rays XI, 10; anal-fin rays II, 8; relatively short second dorsal-fin spine length 14.2% of SL (
Fig. 19C
); a pore above pectoral-fin base lacking an elongate tentacle; posterior lacrimal spine tip canted posteroventrally (
Fig. 20K
); and pectoral fin inner surface with hexagonal markings (
Fig. 9F
).
The ICZN (1999
: article 74.7, recommendation 74B) recommends that an illustrated specimen should be designated as a lectotype. Therefore, BMNH 1879.5.14.371 is designated here as the lectotype of
M
.
pictus
(
Fig. 26A
), the remaining syntype, BMNH 1879.5.14.372 (identical to
M
.
trachycephalus
), becoming a paralectotype (
Fig. 26B
).
Species comparisons.
M
.
radiatus
and
M
.
pictus
vs other congeners.
Although
M
.
coccineus
is most similar to
M
.
pictus
in having the pectoral fin inner surface yellow with many dark blotches, the former possesses relatively small rounded black blotches scattered over the entire fin (
Fig. 5D–F
), whereas the latter has large elongate, interconnected blotches radiating mostly along the rays (
Figs. 24B, D
,
25D–F
). Although
M
.
radiatus
also possesses dark markings on a yellow background on the pectoral fin inner surface, such markings comprise narrow stripes radiating mostly along the rays (
Figs. 23B, D, F
,
25A–C
). Although the
holotype
of
M
.
coccineus
was not available for this study,
Alcock (1890)
stated that it had a dark brown pectoral fin inner surface with canary yellow lines, forming a hexagonal pattern when fresh, such being consistent with the specimens identified herein as
M
.
coccineus
.
Minous pictus
is further distinguished from
M
.
coccineus
by having more lateral-line tubes [17–21 (modally 19) in the former vs 15–18 (17) in the latter] (Table 3).
FIGURE 27.
Relationships of (A) width between interorbital ridges and (B) pelvic-fin base length (all as % of standard length) to standard length (mm) in
Minous pictus
(yellow triangles) and
M
.
radiatus
sp. nov.
(green diamonds). Open and closed arrowheads indicate lectotype of
M
.
pictus
and holotype of
M
.
radiatus
, respectively.
Minous radiatus
and
M
.
pictus
are readily distinguished from
M
.
andriashevi
,
M
.
monodactylus
,
M
.
quincarinatus
,
M
.
usachevi
and
M
.
versicolor
(
Fig. 3A–F
), having the first dorsal-fin spine much shorter than the second spine (first spine length 26–44% and 20–33% of second spine length in
M
.
radiatus
and
M
.
pictus
, respectively) and their bases close together, whereas both spines are of similar length with well separated bases in the latter five species. Moreover,
M
.
radiatus
and
M
.
pictus
differ from
M
.
inermis
and
M
.
longimanus
(
Fig.
3I
, J
) in having a relatively short pectoral fin [36.0–47.3% (mean 40.8%) of SL in
M
.
radiatus
and 39.7–44.3% (42.1%) of SL in
M
.
pictus
], its tip just reaching a vertical through the mid-point of the anal-fin base, whereas the posterior tip of the pectoral fin [fin length 45.2–59.3% (51.2%) of SL in
M
.
inermis
and 51.7–63.6% (57.9%) of SL in
M
.
longimanus
] almost reaches or extends beyond the end of the anal-fin base in the latter two species.
TABLE 8. Selected meristic and morphometric values (expressed as percentages of standard length) recorded from specimens of
Minous radiatus
sp. nov.
and
M
.
pictus
.
M
.
radiatus
sp. nov.
|
M
.
pictus
|
Holotype |
Paratypes |
Lectotype of
M
.
pictus
|
Non-type specimens |
KAUM–I. 39286 |
n
= 53
|
Modes |
B
MNH 1879.5.14.371
|
n
= 9
|
Modes |
Dorsal-fin rays |
XI, 11 |
X or XI, 11–13 |
XI, 12 |
X, 12 |
X or XI, 12 or 13 |
XI, 12 |
Anal-fin rays |
II, 9 |
II or III, 8–11 |
II, 10 |
II, 10 |
II, 10 or 11 |
II, 10 |
Lateral-line tubes |
17 |
16–19 |
17 |
19 |
17–21 |
19 |
Gill rakers |
3 + 10 = 13 |
3–5 + 7–13 = 11–17 |
3 + 10 = 13 |
3 + 10 = 13 |
3 or 4 + 10–12 = 13–15 |
3 + 10 = 13 |
Standard length (mm) |
89.6 |
57.2–106.5 |
Means |
45.5 |
57.3–101.8 |
Means |
B
ody depth (% of SL)
|
31.5 |
30.0–36.2 |
32.6 |
37.2 |
32.5–36.5 |
34.5 |
B
ody width
|
24.8 |
20.1–29.8 |
24.3 |
25.7 |
23.1–27.0 |
25.5 |
Head length |
42.3 |
38.4–44.2 |
41.4 |
44.7 |
39.4–43.2 |
41.8 |
Head width |
17.0 |
15.4–18.3 |
17.0 |
18.4 |
16.6–18.5 |
17.9 |
Snout length |
14.8 |
13.0–16.0 |
14.5 |
14.9 |
13.0–15.3 |
14.6 |
Orbit diameter |
12.7 |
12.2–16.5 |
13.7 |
13.4 |
13.1–14.9 |
13.8 |
Interorbital width at mid-orbit |
10.0 |
8.5–11.3 |
10.0 |
10.5 |
9.7–11.2 |
10.4 |
Interorbital width at preocular spine base |
8.6 |
7.5–10.2 |
8.5 |
9.6 |
7.5–9.1 |
8.7 |
Width between interorbital ridges |
2.7 |
1.4–3.7 |
2.9 |
4.0 |
3.0–4.2 |
3.7 |
Upper-jaw length |
18.6 |
17.5–20.7 |
18.8 |
21.1 |
18.7–20.2 |
19.6 |
Maxillary depth |
6.8 |
5.6–7.3 |
6.5 |
7.9 |
6.2–7.6 |
7.1 |
Postorbital length |
17.4 |
14.9–18.9 |
17.1 |
18.2 |
15.5–18.7 |
17.1 |
Pre-dorsal-fin length |
32.7 |
29.4–35.0 |
32.1 |
35.3 |
30.6–35.0 |
32.9 |
Pre-anal-fin length |
66.2 |
58.5–69.4 |
63.0 |
68.5 |
59.7–68.1 |
64.7 |
Pre-pelvic-fin length |
35.7 |
33.7–40.2 |
36.4 |
42.1 |
33.6–38.4 |
37.2 |
1st dorsal-fin spine length |
4.7 |
3.9–7.6 |
5.3 |
5.5 |
3.2–5.6 |
4.5 |
2nd dorsal-fin spine length |
14.4 |
12.7–18.8 |
15.2 |
16.8 |
15.8–18.1 |
16.6 |
3rd dorsal-fin spine length |
— |
13.1–18.7 |
16.0 |
— |
15.2–18.7 |
17.1 |
4th dorsal-fin spine length |
— |
14.5–21.5 |
17.8 |
— |
16.2–19.9 |
18.2 |
5th dorsal-fin spine length |
17.3 |
15.6–21.1 |
18.6 |
— |
17.3–18.6 |
17.9 |
……continued on the next page
TABLE 8. (Continued)
M
.
radiatus
sp. nov.
|
M
.
pictus
|
Holotype |
Paratypes |
Lectotype of
M
.
pictus
|
Non-type specimens |
KAUM–I. 39286 |
n
= 53
|
Modes |
B
MNH 1879.5.14.371
|
n
= 9
|
Modes |
6th dorsal-fin spine length |
18.4 |
15.6–22.1 |
19.8 |
— |
18.3–19.4 |
18.8 |
7th dorsal-fin spine length |
— |
17.4–22.5 |
20.2 |
— |
19.9–19.9 |
19.9 |
8th dorsal-fin spine length |
19.4 |
17.0–22.0 |
20.5 |
— |
18.4–18.8 |
18.6 |
9th dorsal-fin spine length |
— |
17.3–22.3 |
20.5 |
— |
20.5–20.5 |
20.5 |
10th dorsal-fin spine length |
— |
15.7–23.6 |
20.4 |
— |
19.5–23.1 |
21.3 |
11th dorsal-fin spine length |
21.1 |
18.9–21.2 |
20.2 |
— |
20.7–20.7 |
20.7 |
1st anal-fin spine length |
5.9 |
3.6–8.1 |
6.1 |
— |
4.0–7.4 |
5.8 |
2nd anal-fin spine length |
9.5 |
5.8–12.1 |
9.5 |
— |
6.2–8.6 |
7.3 |
Pectoral-fin length |
43.7 |
36.0–47.3 |
40.8 |
42.8 |
39.7–44.3 |
42.1 |
Lowermost pectoral-fin ray length |
29.7 |
27.9–36.9 |
32.4 |
— |
30.0–33.9 |
32.5 |
Pelvic-fin spine length |
— |
15.6–20.3 |
16.9 |
17.3 |
15.6–18.3 |
16.9 |
Longest pelvic-fin soft ray length |
27.8 |
24.5–30.3 |
27.3 |
31.7 |
25.1–28.9 |
27.7 |
Pelvic-fin base length |
15.9 |
12.2–16.6 |
14.4 |
16.7 |
15.2–19.3 |
17.4 |
Caudal-fin length |
35.8 |
30.8–38.1 |
34.6 |
— |
33.1–37.4 |
35.3 |
Caudal peduncle depth |
11.2 |
9.3–11.6 |
10.7 |
11.1 |
8.4–10.7 |
10.0 |
Anterior lacrimal spine length |
4.5 |
3.3–5.2 |
4.2 |
4.4 |
3.7–5.2 |
4.4 |
Posterior lacrimal spine length |
8.7 |
6.7–10.1 |
8.2 |
9.0 |
7.3–9.2 |
8.5 |
Gill raker counts include upper + lower = total gill rakers. Modes and means include all specimens.
Minous dempsterae
is separable from
M
.
radiatus
and
M
.
pictus
due to numerous small light colored blotches scattered on a dark pectoral fin inner surface in preserved specimens (
Fig. 5C
), compared to dark markings on a lighter background in the latter two species (
Fig. 25
).
Minous radiatus
and
M
.
pictus
differ from
M
.
pusillus
,
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
in having oblique alternating dark and light stripes on the dorsum and dorsal fin (vs. absent in the latter), and differing counts of dorsal- and anal-fin rays and gill rakers (see Tables 1, 2, 5).
FIGURE 28.
Relationships of (A) body width, (B) pelvic-fin spine length and (C) orbit diameter (all as % of standard length) to standard length (mm) in
Minous monodactylus
(red asterisks) and
M
.
radiatus
sp. nov.
(green diamonds), showing ontogenetic proportional changes. Red and green lines indicate straight line approximations for
M
.
monodactylus
and
M
.
radiatus
, respectively.
M
.
radiatus
vs
M
.
pictus
.
Minous radiatus
and
M
.
pictus
share most diagnostic characters, including fin formula, overall body appearance and coloration. However,
M
.
radiatus
can be distinguished from
M
.
pictus
by having fewer lateral-line tubes [16–19 (modally 17) in the former vs 17–21 (19) in the latter], a narrower space between the interorbital ridges [1.4–3.7% (mean 2.9%) of SL vs 3.0–4.2% (3.7%) of SL] (
Fig. 27A
) and shorter pelvic-fin base length [12.2–16.6% (14.4%) of SL vs 15.2–19.3% (17.4%) of SL] (
Fig. 27B
). Additionally,
M
.
radiatus
has the dorsal half of the pectoral fin inner surface yellow (lighter in preserved specimens), with narrow dark stripes radiating along the rays and small dark spots, blotches or broken lines on the membranes (
Figs. 23B, D, F
,
25A–C
), compared with elongate dark interconnected blotches radiating mostly along the rays in
M
.
pictus
(
Figs. 24B, D
,
25D–F
). The reddish body in
M
.
radiatus
with brownish dorsum and many distinct alternating light and dark markings (creamy-white body with dark markings on the dorsum in preserved specimens) (
Figs. 22A–C
,
23A, C, E
) contrasts with the entirely pinkish body with pale alternating light and dark stripes (creamy-white body with pale markings on the dorsum) of
M
.
pictus
(
Figs. 22D–F
,
24A, C
).