The identities of three species of Parahelice Sakai, Türkay & Yang, 2006 (Crustacea: Brachyura: Varunidae) from the western Pacific, based on morphological and molecular evidence
Author
Shih, Hsi-Te
Author
Hsu, Jhih-Wei
Author
Li, Jheng-Jhang
Author
Ng, Ngan Kee
Author
Lee, Jung-Hsiang
text
Zootaxa
2020
2020-01-22
4728
2
249
265
journal article
24282
10.11646/zootaxa.4728.2.6
9be44e7f-6ff4-4cf9-ab42-18418ebc28e5
1175-5326
3621165
E2493FB9-5082-40A5-9408-54F3645D53C3
Parahelice pilimana
(A.
Milne-Edwards, 1873
)
(
Figs. 3
,
4
)
Helice pilimana
A.
Milne-Edwards, 1873: 313
(part), pl. 18(1a) [not pl. 18(1, 1b) =
Pse. subquadrata
] (
type
locality:
New Caledonia
);
Serène 1968: 109
(list).
Pseudohelice
(
Parahelice
)
pilimana—
Sakai
et al.
2006: 50
, figs. 65, 71, 73, 82, 83 (part?) (
New Caledonia
;
Indonesia
: Lombok;
Maluku
;
Flores
).
Parahelice pilimana
—
Ng
et al.
2008: 227
(list);
Nishigaki
et al.
2011: 88
, figs. 2, 3 (part) [not fig. 2F =
Par. daviei
] (Ishigaki,
Japan
).
Material examined
.
Taiwan
:
1 ♂
(
8.6 mm
) (
NMMBCD 4055
),
Baoli
R
. estuary,
Pingtung
, coll.
J.-J. Li
,
28 Mar. 2014
;
1 ♂
(
10.4 mm
) (NCHUZOOL 15666),
Baoli
R
. estuary,
Pingtung
, coll.
J.-J. Li
,
23 June 2016
;
2 ♂♂
(7.9–8.0 mm) (NCHUZOOL 15667),
1 ♀
(
10.7 mm
) (NCHUZOOL 15668), 1 ovig.
♀
(
10.7 mm
) (NCHUZOOL 15669),
Baoli
R
. estuary,
Pingtung
, coll.
P.-Y. Hsu
&
J.-W. Hsu
,
3 Sep. 2017
;
1 ♂
(
11.6 mm
) (NCHUZOOL 15678),
1 ♀
(
7.4 mm
) (NCHUZOOL 15681),
Baoli
R
. estuary,
Pingtung
, coll.
P.-Y. Hsu
,
18 Mar. 2018
.
Diagnosis
. Carapace quadrate, slightly broader than long, 1.21 times as broad as long (
n
= 8); surface convex, weakly punctate, granulate, with distinct groove between epigastric regions. Frontal margin slightly concave. Anterolateral margin with 3 teeth. Infraorbital ridge in male heteromorphic, proximal part with 6–8 rounded tubercles, followed by elongate, laterally, particularly vertically inflated crest, distal part with 2 rounded tubercles; female with 18–22 concentrated isomorphically interspaced, rounded tubercles. Chelipedal palm stout, surface conspicuously finely punctate; usually unequal in male, distinct patch of setae at base of fingers, mostly expanding onto fixed finger; chelipeds in females usually equal, distinct patch of setae at base of fingers but less than in males. Ambulatory legs broad, anterior margins of merus, carpus, and propodus covered with short setae. Male G1 slender, tapering, slightly curved towards distal end; female vulvae sunken in lateral part, with elongate semicircular operculum.
Ecological notes
. The habitat is muddy substrate, with or without vegetation in southern
Taiwan
, at a distance of
600–800 m
from a river mouth (
Fig. 7A, B
). This species is sympatric with
Par. daviei
,
Par. pilosa
,
and
Pse. subquadrata
in southern
Taiwan
, with burrow depths of ca.
50 cm
or less.
FIGURE 3.
Parahelice pilimana
(A.
Milne-Edwards, 1873
)
. A, dorsal view of male; B, ventral view of male; C, chela of male; D, chela of female. A–C, ♂ (CW 10.4 mm), D, ♀ (CW 10.7 mm) (NCHUZOOL 15666; Baoli R. estuary, Pingtung, Taiwan). Scale bars: 2.0 mm.
Distribution
. From
Japan
(southern Ryukyus),
Taiwan
(
Pingtung
) (new record),
Indonesia
(Lombok;
Maluku
;
Flores
), to
New Caledonia
.
Remarks
. Although we did not examine specimens of
Parahelice pilimana
from its
type
locality (
New Caledonia
) or the adjacent area, the Taiwanese specimens agree well with the descriptions in A.
Milne-Edwards (1873)
and
Sakai
et al
. (2006)
, including carapace (
Fig. 4A
;
Sakai
et al
. 2006
: figs. 82, 83), male chelae (
Fig. 4B; A
. Milne- Edwards 1873: pl. 18(1a);
Sakai
et al
. 2006
: fig. 82), male infraorbital ridges (
Fig. 4C
;
Sakai
et al
. 2006
: fig. 65), and G1s (
Fig. 4
E–H;
Sakai
et al
. 2006
: fig. 71).
Morphological differences of males and females among
Par. daviei
,
Par. pilimana
,
and
Par. pilosa
are shown in
Table 2
(also see Remarks under
Par. daviei
).
Of the type series of
Par. pilimana
, examined by A.
Milne-Edwards (1873: 313
, pl. 18(1, 1b)) only the male
holotype
can be considered as that species, and the rest of the specimens (MNHN-B 10996S) were later shown to be
Pse. subquadrata
instead by
Sakai
et al.
(2006: 51)
, and so the morphology of the female is unknown.
Sakai
et al.
(2006: 50)
reported female specimens of
Par. pilimana
from
Flores
,
Indonesia
. While the female vulva was described (
Sakai
et al.
2006
: fig. 73), only a short description of the important character of the infraorbital ridge (“16 small mesial ones, followed by 2 larger, and 4 even larger lateral ones”; but not figured as in other species), and the condition of the patch of setae at base of fingers is not known. The female vulva structure, and the number of infraorbital tubercles of
Par. pilimana
and
Par. daviei
are similar (
Figs. 2D, I
,
4D, I
;
Table 2
), and as such further examination of the morphologies of the infraorbital tubercles and chelae is necessary to confirm the species in
Sakai
et al.
(2006)
. Judging from the figure of a female
Par. pilimana
provided in
Nishigaki
et al.
(2011
: fig. 2F), their specimens should be
Par. daviei
instead, because of the setal patch of the finger and the morphology of infraorbital ridge (cf.
Figs. 1
,
2
).
FIGURE 4.
Parahelice pilimana
(A.
Milne-Edwards, 1873
)
. A–C, E–H, ♂ (10.4 × 8.6 mm, NCHUZOOL 15666); D, I, ♀ (10.7 × 8.9 mm, NCHUZOOL 15668). A, carapace; B, outer view of male left cheliped; C, male left infraorbital ridge; D, female left infraorbital ridge; E, F, dorsal view of right G1; G, H, ventral view of right G1; I, right vulva. Scale bars: A–D, 1.0 mm; E–I, 0.5 mm.
In
Taiwan
, this species is rare compared to other species of
Parahelice
(see Material examined), and only eight specimens were collected from southern
Taiwan
.