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 trachycephalus
(
Bleeker 1855
)
English name: Striped Stingfish
Figures 9D–F
,
10
,
13D, E
,
14–18
,
19G–K
,
20E
,
24B
; Tables 1–5, 7
Aploactis trachycephalus
Bleeker 1855
: 451
(original description; type locality: Manado, Sulawesi, Indonesia; holotype: RMNH.PISC. 5901).
Corythobatus trachycephalus
:
Bleeker 1865
: 282
(listed).
Minous trachycephalus
:
Eschmeyer
et al
. 1979
: 465
, figs. 1, 6 (northeastern Indian Ocean and northwestern Pacific oceans; description, synonymy, nomenclatural remarks on holotype);
Allen & Erdmann 2012
: 243
, unnumbered fig. (East Indies; short description); Motomura 2013: 85, unnumbered fig. (Thailand, Gulf of Thailand; short description; specimen: KAUM–I. 23829); Matsunuma
et al
. 2017: 1289, figs. 1b, 2a (Red Sea; description).
Minous pictus
not of
Günther: Günther 1880
: 41, pl. 18, fig. D (Arafura Sea, south of New
Guinea
; in part);
Allen
et al
. 2003
: 380, unnumbered fig. (Pacific Ocean; ecological and identification notes);
Naranji
et al
. 2017
: 1, fig. 1 (Visakhapatnam,
India
, Bay of Bengal; in part; description).
Holotype.
RMNH.
PISC
. 5901,
55.9 mm
SL,
Manado
,
Sulawesi
,
Indonesia
.
Paralectotype
of
M
.
pictus
.
BMNH 1879.5
.14.372,
36.6 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
.
Non-type Bleeker specimens:
5 specimens,
33.1–43.8 mm
SL: BMNH 1880.4.
21.110,
43.8 mm
SL, Manado,
Sulawesi
,
Indonesia
;
RMNH
.PISC. 38554,
53.9 mm
SL, RMNH.PISC. 38555, 52.0 mm SL, RMNH.PISC. 38556,
45.9 mm
SL, RMNH.
PISC
. 38557,
33.1 mm
SL,
Manado
,
Sulawesi
,
Indonesia
.
Other non-type specimens:
51 specimens
,
16.5–70.4 mm
SL:
Thailand
(
Gulf of Thailand
):
KAUM
–I. 23829,
43.5 mm
SL,
KAUM
–I. 23830,
49.7 mm
SL,
KAUM
–I. 24086,
51.2 mm
SL,
KAUM
–I. 24087,
56.8 mm
SL,
Gulf of Thailand
, trawl
;
KAUM
–I. 47803,
47.6 mm
SL,
Fish
landing bridge at
Klong Wan
,
Prachuab Khirikhan Province
,
11°44′33″N
,
99°47′26″E
, trawl; URM-P 9 0 22,
54.6 mm
SL,
Songkhla
fish market, trawl,
9 Apr. 1984
;
URM-P12 155,
35.8 mm
SL,
Songkhla
fish market, trawl,
21 Oct. 1983
.
Thailand
(Andaman Sea):
KAUM
–I. 33284,
70.4 mm
SL,
KAUM
–I. 33285,
61.2 mm
SL,
KAUM
–I. 33286,
59.6 mm
SL,
KAUM
–I. 33287,
56.5 mm
SL,
KAUM
–I. 33288,
55.7 mm
SL,
KAUM
–I. 33289,
44.3 mm
SL,
Pak Nam
Ranong
fishing port
,
Ranong
,
09°56′N
,
98°35′E
, trawl.
Malaysia
(
Borneo
):
KAUM
–I. 49280,
55.2 mm
SL,
KAUM
–I. 49281,
44.5 mm
SL,
KAUM
–I. 49282,
50.8 mm
SL, off
Kota Kinabalu
,
Sabah
,
06°00′N
,
116°07′E
,
12 Aug. 2012
.
Philippines
:
CAS
29371,
39.4
mm
SL,
Buenavista
,
Mindanao, F. B
.
Steiner
,
14 Apr. 1973
;
USNM 272154
,
39.7
mm
SL, east of
Sicogon Island
,
Visayan Sea
between
Northern Negross
and
Masbate
,
11°27′45″N
,
123°23′45″E
,
47.6 m
depth,
L. Alcala
et al
.,
RV
Sting Ray
,
4 June 1978
.
Vanuatu
:
USNM 350129
, 26.0 mm SL,
Ranon Bay
,
Ambrym Island
,
Vanuatu
Islands
,
17°51′34″S
,
168°07′01″E
,
9–16 m
depth,
J. T. Williams
and
D. G. Smith
,
26 May 1997
.
New Caledonia
:
MNHN
2005-2618
,
49.6
mm
SL,
Belep Island
,
19°45′00′′S
,
163°45′00′′E
, RV
Vauban
,
16 June 1985
.
Australia
(
Arafura Sea
):
AMS I.21842-007,
53.2 mm
SL
,
Northern
Territory
,
Arafura Sea
,
10°37′11′′S
,
133°46′48′′E
, RV
Soela
,
16 Nov. 1980
;
NTM
S.12970-001,
53.7 mm
SL
,
Arafura Sea
,
Northern
Territory
,
09°53′S
,
136°18′E
,
54–55 m
depth,
H. Larson
,
29 Oct. 1990
;
NTM
S.13270-003,
2 specimens
,
45.6–58.1 mm
SL,
Gulf of Carpentaria
,
Queensland
,
11°04′S
,
139°56′E
,
57 m
depth,
R. Williams
,
29 Nov. 1991
.
Australia
(
Western
Australia
):
CSIRO
H1477-2,
43.2 mm
SL, north of
Dampier Archipelago
,
Western
Australia
, 20°06′–09′S, 116°39′–40′E,
49–50 m
depth, FRV
Soela
, demersal trawl,
24 Sept. 1988
;
NMV
A29708
-007,
22.7 mm
SL,
northwestern
Australia
, 16°44′25″–07″S,
121°01′54″E
,
109–112 m
depth,
Broome L
25 transect,
RV
Southern
Surveyor
,
30 June 2007
;
NTM
S.11673-005,
52.2 mm
SL, south of
Rowley Shoals
,
Northeast Shelf
,
Western
Australia
,
19°12′S
,
118°41′E
,
76–80 m
depth,
NT Fisheries
,
1 June 1985
.
Coral Sea
:
CSIRO
H3442-02,
47.1 mm
SL, east of
Cape York Peninsula
,
Queensland
,
11°34′S
,
143°30′E
,
40 m
depth,
30
May 1993
;
CSIRO
H4151-03,
54.6 mm
SL, east of
Cape York Peninsula
,
Queensland
,
11°42′S
,
143°27′E
, FRV
Gwendoline May
, trawl,
14 Mar. 1995
.
Maldives:
BMNH 1901.12.31.21-23, 3 specimens,
16.5–24.4 mm
SL, Maldives.
Yemen
:
CAS 227832
,
44.8
mm
SL,
Aden
.
Egypt
(
Red Sea
):
MNHN 1966-0437
,
47.4
mm
SL,
El-bahr El-ahmar
,
28°52′12′′N
,
32°45′00′′E
, RV
Al Sayad
,
8 Dec. 1928
.
Israel
(
Red Sea
):
HUJ 1633
, 55.0 mm SL,
Eilat
,
May 1951
; HUJ 14005,
32.6 mm
SL, Eilat,
8 Sept. 1986
; HUJ 14681,
55.2 mm
SL, Eilat,
23 June 1965
; HUJ 14682,
52.8 mm
SL, Eilat,
14 July 1965
;
SAIAB 4152
, 56.0 mm SL,
Eilat
,
29°32′59′′N
,
34°57′00′′E
, M.
Dor
,
1 June 1965
.
Eritrea
:
HUJ
20655,
25.3
mm
SL,
Horgigo Bay
,
3 Apr. 1961
.
Saudi Arabia
:
KAUMM 422
, 35.0 mm SL, off
Jizan
,
16°34′N
,
42°33′E
,
30–32 m
depth,
4 Nov. 2014
;
SMF
35844, 38.0 mm SL, off
Jizan
,
16°45′N
,
42°29′E
,
28–30 m
depth,
5 Nov. 2014
.
Madagascar
:
SAIAB 53292
,
3 specimens
,
48.9–60.9 mm
SL, east of
Nosy Komba
,
13°23′59′′S
,
48°16′59′′E
, H.
Phillip
, bottom trawl,
2 Sept. 1995
.
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 or XI, 9–11 (modally XI, 10), total rays 20–23 (21); anal-fin rays I–III, 7–9 (II, 8), total rays 9–11 (10); anterior and posterior lacrimal spines sharp, anterior spine tip canted anteroventrally, posterior spine tip usually canted ventrally to posteroventrally (angle to horizontal axil of head and body variable) but never curved anteroventrally as in
M
.
roseus
; body grayish dorsally (
Figs. 14
,
15
), without oblique alternating dark and light stripes; pectoral fin inner surface with many dark bordered bright yellow (whitish in preserved specimens) blotches basally, forming somewhat hexagonal pattern when fresh, distal portion largely yellow (whitish) when fresh (
Figs. 13E
,
16
); pore above pectoral-fin base with or without short blunt rounded skin flap.
Distribution.
Minous trachycephalus
is widely distributed throughout the Indo-West Pacific region, from the
Red Sea
and
Madagascar
east to
Vanuatu
and
New Caledonia
, and northern
Australia
north to the Gulf of
Thailand
(based on examined specimens) (
Fig. 10
). Although the species has actually been recorded from a more widespread area, including
Taiwan
,
Vietnam
,
Sumatra
(
Indonesia
),
India
and
Sri Lanka
(
Eschmeyer
et al
. 1979
;
Mishra
et al
. 1999
;
Poss 1999
), confirmation of this extended range based on voucher specimens is necessary, owing to previous taxonomic confusion of the species with congeners (see synonym lists). Underwater photographs of the species from the East Indies, also reported by
Allen & Erdmann (2012)
, are shown here as
Fig. 13D, E
(from Lembeh Strait,
North
Sulawesi
,
Indonesia
). Sampling data for eight specimen lots recorded their collection mostly by bottom trawl at depths of
9–112 m
(mostly>
50 m
depth).
Remarks.
Meristic and morphometric values taken from examined specimens are given in Tables 1–5, 7. The other meristic values without individual variations are as follows: pectoral-fin rays 12; pelvic fin rays I, 5; vertebrae 11 + 14 = 25.
An underwater photograph reported by
Allen
et al
. (2003)
as
M
.
pictus
was identified here as
M
.
trachycephalus
, lacking oblique alternating dark and light stripes on the body and a longitudinal yellow band on the dorsal fin (see Species comparisons). Although
Naranji
et al
. (2017)
recorded
M
.
pictus
from
India
, their photograph is also identical with
M
.
trachycephalus
, based on the diagnostic coloration of the dorsal fin and pectoral fin inner surface. However,
Naranji
et al
.’s (2017)
description of highly variable coloration on the pectoral fin inner surface and broad range of dorsal-fin ray meristics (IX–XII, 9–13) suggests that their materials included several species of
Minous
.
Variations in diagnostic characters.
Individual or geographical variations in several morphological features were apparent in the examined specimens of
M
.
trachycephalus
. Specimens from
Sabah
,
Malaysia
(Borneo) differed from those from the Andaman Sea by having a paler caudal fin (
Fig. 15D, F
) [vs dusky and scattered with numerous minute melanophores in the latter (
Fig. 15A, B
)] and relatively pale dorsum, with a distinct dark blotch below the middle of the dorsal-fin base in small specimens (
ca.
40–50 mm
SL) (
Fig. 13F
) (vs darker dorsum without a distinct blotch). The coloration of specimens from the Gulf of
Thailand
(geographically between the Andaman Sea and Borneo) and
Australia
(
Fig. 15C, E, G, H
) appeared to be intermediate between those of the Andaman Sea and Bornean specimens. Moreover, the Bornean specimens also had the posterior lacrimal spine tip tending to be more ventrally canted (
Fig.
19I
) than in the Andaman Sea specimens (
Fig. 19J
) in a range of comparable growth stages. Further morphological and genetic analyses based on a greater number of specimens of
M
.
trachycephalus
from throughout its distributional range are necessary to determine the trends in such variations.
FIGURE 14.
Preserved specimens of
Minous trachycephalus
. (A, B) KAUM–I. 33284, 70.4 mm SL, Gulf of Thailand; (C) NTM S.13270-003, 1 of 2 specimens, 58.1 mm SL, Australia; (D) SAIAB 53292, 1 of 3, 48.9 mm SL, Madagascar; (E) MNHN 2005-2618, 49.6 mm SL, New Caledonia; (F) USNM 272154, 39.7 mm SL, Philippines.
Note on the holotype.
Minous trachycephalus
was originally described by
Bleeker (1855)
(as
Aploactis trachycephalus
) based only the holotype from Manado, Sulawesi, Indonesia, stating “Longitudo speciminis unici 75′′′. [Length (= total length) of the single specimen
75 mm
]”. Subsequently,
Hubrecht (1879)
reported a total of eight Bleeker specimens of
M
.
trachycephalus
(group A, 5 specimens; group B, 2 specimens; group C, 1 specimen). Five group A specimens were originally registered as RMNH.PISC. 5901 [
55.9 mm
SL (caudal fin broken),
53.9 mm
SL (caudal fin broken), 52.0 mm SL (
65.7 mm
TL),
45.9 mm
SL (caudal fin broken) and
33.1 mm
SL (
44.4 mm
TL)] (
Fig. 17A–E
). Another Bleeker specimen of
A
.
trachycephalus
is registered as BMNH 1880.4.21.110 [
43.8 mm
SL (
59.5 mm
TL)] (
Fig. 17F
). According to
Hubrecht (1879)
, the primary type specimen was included within group A,
Eschmeyer
et al
. (1979)
also pointing out that the holotype of
A
.
trachycephalus
was included in RMNH.PISC. 5901 (mixed up with four non-type specimens). Among the original five specimens of RMNH.PISC. 5901, the total lengths (
65.7 mm
TL and
44.4 mm
TL) of 52.0 mm-SL and 33.1 mm-SL specimens are inconsistent with that of the holotype of
A
.
trachycephalus
. Although the caudal fins of the remaining three specimens (
55.9 mm
SL,
53.9 mm
SL and
45.9 mm
SL) are damaged, the total lengths of the specimens could be estimated as
75.4 mm
TL,
72.8 mm
TL and
62.3 m
TL, respectively, based on measurements of 26 undamaged specimens of
M
.
trachycephalus
(TL = 1.3043*SL + 2.4503). The total length (estimated) of the largest Bleeker Group A specimen (
55.9 mm
SL,
75.4 mm
TL), being closest and similar to that of the holotype of
A
.
trachycephalus
given by
Bleeker (1855)
, is therefore regarded here as the holotype of the species (
Fig. 17A
), the remaining four specimens (reregistered as RMNH.PISC. 38554–38557) having no type status (
Fig. 17B–E
).
FIGURE 15.
Fresh specimens of
Minous trachycephalus
. (A) KAUM–I. 33284, 70.4 mm SL, Thailand (Andaman Sea); (B) KAUM–I. 33285, 61.2 mm SL, Thailand (Andaman Sea); (C) KAUM–I. 24087, 56.8 mm SL, Thailand (Gulf of Thailand); (D) KAUM–I. 49280, 55.2 mm SL, Malaysia (Borneo); (E) KAUM–I. 23830, 49.7 mm SL, Thailand (Gulf of Thailand); (F) KAUM–I. 49281, 44.5 mm SL, Malaysia (Borneo); (G) CSIRO H4151-03, 54.6 mm SL, Australia (Queensland); (H) CSIRO H1477-2, 43.2 mm SL, Australia (Western Australia). Photos: Thor Carter (G and H).
FIGURE 16.
Pectoral fin inner surface in fresh specimens of
Minous trachycephalus
. (A) KAUM–I. 33285, 61.2 mm SL, Thailand (Andaman Sea); (B) KAUM–I. 49280, 55.2 mm SL, Malaysia (Borneo); (C) KAUM–I. 49281, 44.5 mm SL, Malaysia (Borneo); (D) KAUM–I. 23829, 43.5 mm SL, Thailand (Gulf of Thailand).
Species comparisons.
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
vs other congeners.
Minous roseus
sp. nov.
,
M
.
groeneveldi
sp. nov.
and
M
.
trachycephalus
all have the pectoral fin inner surface broadly yellow distally, with dark radial stripes along the rays (
M
.
roseus
and
M
.
groeneveldi
) or a dark hexagonal or nearly hexagonal pattern (
M
.
trachycephalus
). Although
M
.
pusillus
possesses similar pectoral fin markings (
Fig. 4F–H
), such markings form radial stripes in small specimens (<
ca.
40 mm
SL) (
Fig. 4H
), becoming a minute hexagonal or nearly hexagonal pattern in larger specimens (
Fig. 4G, H
), whereas the dark markings in
M
.
roseus
and
M
.
trachycephalus
(no information for
M
.
groeneveldi
) do not change with growth.
Minous pusillus
is also readily distinguished from
M
.
trachycephalus
and
M
.
groeneveldi
by the absence of a yellow or light-colored band on the dorsal fin (vs present in
M
.
trachycephalus
and
M
.
groeneveldi
) and a largely grayish dorsum [vs almost entirely pinkish or reddish when fresh (entirely creamy-white in preserved specimens) in
M
.
roseus
].
Moreover,
M
.
pusillus
possesses relatively long, hair-like dorsal-fin spines (thinner than soft rays) (
Fig. 3G, H
) [first dorsal-fin spine length 8.1–15.7% (mean 11.3%) of SL], compared with relatively short strong (inflexible) dorsal-fin spines in
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
[first dorsal-fin length 3.9–7.7% (6.0%) of SL in
M
.
roseus
, 5.8% of SL in
M
.
groeneveldi
and 3.2–9.3% (6.3%) of SL in
M
.
trachycephalus
] (
Fig. 18D
).
Minous pusillus
also has a relatively smaller head [length 38.3–45.6% (mean 42.0%) of SL in
M
.
pusillus
vs 41.9– 47.6% (45.8%) of SL in
M
.
roseus
, 45.1% of SL in
M
.
groeneveldi
and 42.4–48.3% (45.1%) of SL in
M
.
trachycephalus
], shorter snout [length 11.1–15.6% (13.6%) of SL vs 16.2–18.6% (17.4%) of SL, 17.0% of SL and 14.9–17.1% (16.1%) of SL] and narrower interorbital space [width at mid-orbit 5.9–9.9% (7.3%) of SL vs. 10.1– 12.5% (11.4%) of SL, 11.0% of SL and 8.4–12.1% (10.2%) of SL] (
Fig. 18A–C
).
Minous pusillus
further differs from
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
in having modally 21 total dorsal-fin rays (vs
22 in
M
.
roseus
and
M
.
groeneveldi
), modally 10 total anal-fin rays (vs
11 in
M
.
roseus
and
M
.
groeneveldi
), modally 11 lower gill-rakers (vs
8 in
M
.
roseus
and
M
.
groeneveldi
;
9 in
M
.
trachycephalus
), modally 13 total gill rakers (
10 in
M
.
roseus
and
M
.
groeneveldi
;
11 in
M
.
trachycephalus
) and 11 + 14 = 25 vertebrae (11 + 15 =
26 in
M
.
roseus
and
M
.
groeneveldi
) (see Tables 1, 2, 4, 5).
In addition to the differences in pectoral fin inner surface coloration,
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
can be readily distinguished from
M
.
andriashevi
,
M
.
monodactylus
,
M
.
quincarinatus
,
M
.
usachevi
and
M
.
versicolor
(
Fig. 3A–F
) by the first dorsal-fin spine being much shorter than the second spine (first dorsal-fin spine length 29–37%, 36% and 19–61% of second spine length in
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
, respectively), with bases close together, whereas both spines are of similar length (first dorsal-fin spine length 91–152% of second spine length) with well separated bases in the other five species. Moreover,
M
.
inermis
and
M
.
longimanus
(
Fig.
3I
, J
) differ from
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
in having a longer pectoral fin, its length 45.2–59.3% (mean 51.2%) of SL and 51.7–63.6% (57.9%) of SL in
M
.
inermis
and
M
.
longimanus
, respectively, with the tip almost reaching to or extending beyond the end of the anal-fin base [pectoral-fin length 34.8–44.4% (39.8%) of SL, 38.0% of SL and 38.0–49.6% (43.3%) of SL in
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
, respectively: tip never reaching to the end of anal-fin base]. The remaining congeners, including
M
.
coccineus
,
M
.
dempsterae
,
M
.
pictus
and
M
.
radiatus
sp. nov.
(
Figs. 3K, L
,
23
,
24
), can be also readily distinguished from
M
.
roseus
,
M
.
groeneveldi
and
M
.
trachycephalus
by their oblique alternating dark and light stripes on the body (absent in the latter three species).
FIGURE 17.
Preserved holotype (A) and Bleeker non-type specimens (B–F) of
Minous trachycephalus
from Manado, Indonesia. (A) RMNH.PISC. 5901,
holotype
, 55.9 mm SL; (B) RMNH.PISC. 38554, 53.9 mm SL; (C) RMNH.PISC. 38555, 52.0 mm SL; (D) RMNH.PISC. 38556, 45.9 mm SL; (E) RMNH.PISC. 38557, 33.1 m SL; (F) BMNH 1880.4.21.110, 43.8 mm SL. Photos: Gota Ogihara.
FIGURE 18.
Relationships of (A) head length; (B) snout length; (C) interorbital width at mid-orbit; and (D) 1st dorsal-fin spine length (all as % of standard length) to standard length (mm) in
Minous roseus
sp. nov.
(blue circles),
M
.
groeneveldi
sp. nov.
(yellow star, holotype),
M
.
trachycephalus
(purple squares) and
M
.
pusillus
(black crosses). Open arrowhead indicates paralectotype of
M
.
pictus
(=
M
.
trachycephalus
). Closed arrowheads indicate holotypes of
M
.
roseus
and
M
.
trachycephalus
, and lectotype of
M
.
pusillus
.
Minous trachycephalus
vs
M
.
roseus
and
M
.
groeneveldi
.
Minous trachycephalus
differs from
M
.
roseus
and
M
.
groeneveldi
in having fewer dorsal-fin soft rays [9–11 (modally 10) in
M
.
trachycephalus
vs 10–12 (11) in
M
.
roseus
and
11 in
M
.
groeneveldi
], total dorsal-fin rays [20–22 (21) vs 21 or 22 (22) and 22], anal-fin soft rays [7–9 (8) vs 8–10 (9) and 9], total anal-fin rays [9–11 (10) vs 10–12 (11) and 11], lateral-line tubes [13–18 (15) vs 15–19 (17) and 16] and vertebrae (11 + 14 = 25 vs 11 + 15 =
26 in
M
.
roseus
and
M
.
groeneveldi
) (Tables 1–3), in addition to morphometric differences: narrower interorbital width at preocular spine base [6.4–9.4% (mean 7.7%) of SL in
M
.
trachycephalus
vs 7.8–10.8% (9.1%) in
M
.
roseus
and 9.2% in
M
.
groeneveldi
] and shorter second dorsal-fin spine [11.1–18.1% (14.1%) of SL vs 15.3–21.0% (18.3%) and 15.9%] (
Fig. 19B, C
). Moreover, the pectoral fin inner surface in
M
.
trachycephalus
has darkly margined bright yellow (lighter in preserved specimens) blotches, forming a hexagonal or nearly hexagonal pattern (
Figs. 9D–F
,
13E
16
), whereas dark stripes along the rays on a bright yellow background characterize the other two species (
Figs. 7B
,
9A–C
,
11D
,
13B
). The body of
M
.
trachycephalus
is primarily grayish dorsally in large specimens>
50 mm
SL (
Figs. 14A, B
,
15
), but broadly pinkish or yellowish (lighter in preserved specimens), except for dark blotches below the middle and posterior portions of the dorsal-fin base, in
M
.
roseus
and
M
.
groeneveldi
(
Fig. 6B, C
,
7
,
11B, C
,
12
).
FIGURE 19.
Relationships of (A) head depth; (B) interorbital width at preocular spine base; and (C) 2nd dorsal-fin spine length (all as % of standard length) to standard length (mm) in
Minous roseus
sp. nov.
(blue circles),
M
.
groeneveldi
sp. nov.
(yellow star, holotype) and
M
.
trachycephalus
(purple squares). Open and closed arrowheads indicate paralectotype of
M
.
pictus
(=
M
.
trachycephalus
) and holotype of
M
.
roseus
, respectively.
Minous roseus
vs
M
.
groeneveldi
and
M
.
trachycephalus
.
Minous roseus
sp. nov.
is clearly distinguished from
M
.
groeneveldi
and
M
.
trachycephalus
in having sharp anterior and posterior lacrimal spines, the tip of the former canted anteroventrally and that of the latter canted anteroventrally or ventrally in large specimens>
60 mm
SL (
Fig. 20D–F
), whereas both lacrimal spines are relatively bunt with ventrally canted tips in
M
.
groeneveldi
(
Fig. 20B
); sharp, with the anterior spine tip canted anteroventrally and that of the posterior spine usually canted ventrally or posteroventrally (angle to horizontal axis of head and body variable) but never curved anteroventrally in
M
.
trachycephalus
(
Fig. 20H–K
). Moreover,
M
.
roseus
differs from
M
.
groeneveldi
and
M
.
trachycephalus
in having an elongate tentacle-like skin flap [blunt and short or absent in 3 of 13 examined specimens] on a pore above the pectoral-fin base in specimens>
40 mm
SL, the tentacle length much greater than the pore diameter (
Fig. 21B–D
), whereas a blunt, thick skin flap (absent in 3 of 18 examined specimens of
M
.
trachycephalus
) occurred in the latter two species (
Fig. 21E, F
).
FIGURE 20.
Lateral view of head (A, C, G) and lacrimal spines (semi-schematic) in
Minous groeneveldi
sp. nov.
(A, B),
M
.
roseus
sp. nov.
(C–F) and
M
.
trachycephalus
(G–K). (A, B) NTM S.11031-002,
holotype
, 77.7 mm SL, Indonesia; (C, D) CSIRO CA1844,
holotype
, 72.1 mm SL, Western Australia; (E) CSIRO CA1589,
paratype
, 53.9 mm SL, Western Australia; (F) NMV
A29660
-012,
paratype
, 33.5 mm SL, Western Australia; (G) RMNH.PISC. 5901,
holotype
, 55.9 mm SL, Indonesia; (H) KAUM–I. 33284, 70.4 mm SL, Thailand (Gulf of Thailand); (I) KAUM–I. 49280, 55.2 mm SL, Malaysia (Borneo); (J) KAUM–I. 33288, 55.7 mm SL, Thailand (Andaman Sea); (K) BMNH 1879.5.14.372,
paralectotype of
M
.
pictus
, 36.6 mm SL, Arafura Sea. Red dotted lines (in A and C) indicate horizontal line through top of snout bulge. Red and blue arrowheads indicate anterior and posterior lacrimal spines, respectively. Bars indicate 1 mm.
FIGURE 21.
Pores above pectoral-fin base and associated skin flap in
Minous roseus
sp. nov.
(A–D),
M
.
trachycephalus
(E) and
M
.
groeneveldi
sp. nov.
(F). (A) NTM S.13974-005,
paratype
, 63.9 mm SL, Western Australia; (B) CSIRO CA1844,
holotype
, 72.1 mm SL, Western Australia; (C) NMV
A29712
-004,
paratype
, 40.6 mm SL, Western Australia; (D) NMV
A29660
-012,
paratype
, 33.5 mm SL, Western Australia; (E) KAUM–I. 33284, 70.4 mm SL, Gulf of Thailand; (F) NTM S.11031-002,
holotype
, 77.7 mm SL, Indonesia. Red arrowhead (in A) indicates pore location. Blue arrowheads indicate skin flaps (absent in
M
.
trachycephalus
). Right side, reversed in A–C. Bars indicate 0.5 mm.
Minous groeneveldi
vs
M
.
roseus
.
Minous groeneveldi
sp. nov.
is closely related to
M
.
roseus
, sharing a similar color pattern on the pectoral fin inner surface. However,
M
.
groeneveldi
differs in having lesser head depth [17.6% of SL in the former vs 18.8–21.6% (20.0%) of SL in
M
.
roseus
] (
Fig. 19A
), a horizontal line parallel to the head and body axis through the top of the snout bulge meeting the ventral margin of pupil in the
77.7 mm
SLholotype (
Fig. 20A
) (compared with well below the ventral margin of pupil in>
60 mm
SL-specimens of
M
.
roseus
;
Fig. 20C
).
Minous groeneveldi
also has the body yellowish dorsally, with a relatively broad dark stripe centrally, in the fresh
holotype
(
77.7 mm
SL) (
Fig. 12
), compared with largely pale pink or yellow, with a narrow dusky stripe centrally, in large specimens of
M
.
roseus
.
TABLE 7. Selected meristic and morphometric values (expressed as percentages of standard length) recorded from specimens of
Minous trachycephalus
(including holotype of
Aploactis trachycephalus
and paralectotype of
M
.
pictus
).
Holotype of
A
.
trachycephalus
|
B
leeker non-type specimens
|
Paralectotype of
M
.
pictus
|
Other non-type specimens |
RMNH.PISC. 5901 |
n
= 5
|
B
MNH 1879.5.14.372
|
n
= 38
|
Modes |
Dorsal-fin rays |
XI, 10 |
XI, 10 |
XI, 10 |
X or XI, 9–11 |
XI, 10 |
Anal-fin rays |
II, 8 |
II, 8 |
II, 8 |
I–III, 7–9 |
II, 8 |
Lateral-line tubes |
15 |
14–17 |
16 |
13–18 |
15 |
Gill rakers |
2 + 9 =11 |
2 or 3 + 8–11 =10–13 |
2 + 10 =12 |
2 or 3 + 8–11 = 10–14 |
2 + 9 = 11 |
Standard length (mm) |
55.9 |
33.1–53.9 |
36.6 |
16.5–70.4 |
Means |
B
ody depth (% of SL)
|
34.0 |
30.1–33.5 |
35.5 |
31.8–41.0 |
35.1 |
B
ody width
|
23.4 |
19.3–23.4 |
— |
21.4–34.1 |
28.4 |
Head length |
43.5 |
42.5–45.9 |
46.2 |
42.4–48.3 |
45.0 |
Head width |
— |
— |
18.8 |
17.2–20.5 |
18.8 |
Head depth |
— |
— |
19.6 |
17.9–20.8 |
19.4 |
Snout length |
14.5 |
15.0–15.8 |
15.1 |
14.9–17.1 |
16.1 |
Orbit diameter |
13.2 |
13.9–17.8 |
16.0 |
13.1–16.7 |
14.9 |
Interorbital width at mid-orbit |
— |
— |
10.9 |
8.4–12.1 |
10.2 |
Interorbital width at preocular spine base |
— |
— |
9.4 |
6.4–9.4 |
7.7 |
Width between interorbital ridges |
— |
— |
2.7 |
1.6–3.3 |
2.3 |
Upper-jaw length |
18.8 |
18.1–21.1 |
21.8 |
17.9–22.7 |
20.1 |
Maxillary depth |
7.9 |
7.2–8.2 |
8.1 |
6.5–8.4 |
7.6 |
Postorbital length |
16.5 |
15.4–17.7 |
16.2 |
14.3–18.7 |
16.9 |
Pre-dorsal-fin length |
32.9 |
32.5–36.6 |
36.1 |
32.8–38.1 |
34.9 |
Pre-anal-fin length |
63.9 |
62.1–68.7 |
67.2 |
65.3–80.7 |
70.7 |
Pre-pelvic-fin length |
37.4 |
35.3–39.7 |
43.5 |
38.0–45.6 |
41.4 |
1st dorsal-fin spine length |
— |
5.9–6.3 |
8.6 |
3.2–9.3 |
6.3 |
2nd dorsal-fin spine length |
— |
11.0–12.2 |
14.2 |
11.1–18.1 |
14.1 |
3rd dorsal-fin spine length |
13.1 |
12.2–14.0 |
— |
11.6–17.6 |
14.4 |
4th dorsal-fin spine length |
— |
14.4–14.5 |
— |
10.8–17.1 |
14.7 |
……continued on the next page
TABLE 7. (Continued)
Holotype of
A
.
trachycephalus
|
B
leeker non-type specimens
|
Paralectotype of
M
.
pictus
|
Other non-type specimens |
RMNH.PISC. 5901 |
n
= 5
|
B
MNH 1879.5.14.372
|
n
= 38
|
Modes |
5th dorsal-fin spine length |
— |
14.8–15.8 |
— |
13.2–19.0 |
15.7 |
6th dorsal-fin spine length |
16.1 |
17.1 |
— |
14.8–18.8 |
16.5 |
7th dorsal-fin spine length |
17.2 |
16.9 |
— |
12.9–18.3 |
16.4 |
8th dorsal-fin spine length |
— |
17.6 |
— |
13.9–18.6 |
16.7 |
9th dorsal-fin spine length |
— |
— |
— |
13.8–19.2 |
16.8 |
10th dorsal-fin spine length |
15.9 |
— |
— |
13.3–18.7 |
16.2 |
11th dorsal-fin spine length |
— |
— |
— |
13.3–17.6 |
15.6 |
1st anal-fin spine length |
— |
8.1 |
6.8 |
3.1–9.6 |
6.6 |
2nd anal-fin spine length |
— |
— |
8.4 |
6.6–10.4 |
8.6 |
Pectoral-fin length |
43.5 |
34.9–38.6 |
— |
38.0–49.6 |
43.3 |
Lowermost pectoral-fin ray length |
35.2 |
— |
— |
31.6–43.2 |
37.0 |
Pelvic-fin spine length |
— |
17.8–20.3 |
18.3 |
15.7–20.8 |
18.6 |
Longest pelvic-fin soft ray length |
— |
— |
30.5 |
28.1–35.8 |
31.4 |
Pelvic-fin base length |
— |
— |
16.6 |
14.4–22.7 |
18.8 |
Caudal-fin length |
— |
34.5 |
— |
31.3–39.3 |
35.2 |
Caudal peduncle depth |
10.0 |
9.8–11.1 |
9.3 |
9.2–11.7 |
10.7 |
Anterior lacrimal spine length |
2.5 |
2.5–3.7 |
4.1 |
3.3–4.9 |
4.2 |
Posterior lacrimal spine length |
6.3 |
5.0–6.3 |
4.9 |
5.6–8.0 |
6.5 |
Gill raker counts include upper + lower = total gill rakers. Modes and means include all specimens.