A Small Collection of Subtidal Crabs (Crustacea: Decapoda: Brachyura) from the Palau Islands Collected by Dredging
Author
Shaga, I Bevin
Author
Priya, K
Author
Ramar, Selvakumar
Author
Srinidhi, S
Author
Mohan, G Chandra
Author
Ranganathan, Sukanya
Author
Moulvi, S M M
Author
Mani, Bhuvaneswari
text
Bulletin of the National Museum of Nature and Science. Series A, Zoology
2023
2023-02-22
49
1
7
42
http://dx.doi.org/10.4103/jpbs.jpbs_1095_23
journal article
303589
10.50826/bnmnszool.49.1_7
cc963576-f629-4950-92ca-062bbbcfd983
2434-091X
13826440
Trierarchus squamosus
(
Stephenson and Hudson, 1957
)
(
Figs. 8
,
10A
,
15F–G
)
Thalamita squamosa
Stephenson and Hudson, 1957
, pp. 320 (in key), 355, figs. 2K, 3K, pl. 5 fig. 4, pl. 8 fig. Q, pl. 10 fig. J. ─
Stephenson, 1976
, p. 24.
Trierarchus squamosus
(Stephenson and Hudson)
:
Evans, 2018
, p. 14 (in table), fig. 3J.
Material examined
.
Entrance
to
Toagel Mid in Arangel Channel
,
Babelthuap I.
,
Palau
Is., dredged,
30–40 m
in depth, with coralline algae; 1 ♂ (cb 12.6×cl
8.7 mm
), NSMT-Cr 30977;
June 19 1980
;
K. Baba
leg.
Remarks.
This species is most characteristic in having only four strong and sharp anterolateral teeth of the carapace including the external orbital tooth (
Figs. 8A
,
10A
); posterior three teeth are only slightly smaller than the first or the external orbital tooth. All the ridges of the carapace areolae are distinct (
Figs. 8A
,
10A
). The frontal margin is cut into four lobes (
Figs. 8A
,
10A
); each median lobe about two-thirds as wide as the lateral lobe, its outer end being shortly overlapped by the lateral lobe; the lateral lobe is slightly behind the frontal level of the median lobe, weakly concave in the middle, making the appearance of the six-lobed front. The frontal and supraorbital margins are narrowly crested along the whole lengths (
Fig. 10A
). The antennal basal segment is armed with a distinct ridge tipped with small granules along the distal half. The third maxilliped is as figured, with the anterodistal angle of the merus is narrowly extended forward (
Fig. 15F
). The male pleon is comparatively wide, with the bulged sixth pleonite (
Fig. 8B
). Both chelipeds are somewhat different in size and shape (
Fig. 8C–D
); the surfaces of the carpus and palm are of somewhat squamous appearance with depressed granules of variable sizes; the fingers are strongly and irregularly toothed throughout the lengths of both cutting edges. The G1 was roughly figured by Stephenson and Hudson (1957: fig. 2K) and in the present paper (
Fig. 15G
); the shaft is stout, parallel-sided throughout the length, strongly curved at the middle.
Distribution
. The Great Barrier Reef;
Rongelap
and Bikini Atolls in the
Marshall Islands
,
45–55 m
in depth. New to the
Palau
Islands.