The names of decapod and stomatopod Crustacea from Tahiti, French Polynesia, established by Anthony Curtiss in 1938 and 1944
Author
Ng, Peter K. L.
Author
Eldredge, Lucius G.
Author
Evenhuis, Neal L.
text
Zootaxa
2011
2011-11-16
3099
43
56
journal article
45981
10.5281/zenodo.206896
b4c7e4b1-cc25-42ef-91ae-a205918bf357
1175-5326
206896
Cancer scarpellonis
Curtiss, 1938
[
toetoe
]
Grapsus crinipes
Dana, 1851: 249
.
Cancer scarpellonis
Curtiss, 1938: 173
,
n. syn.
Curtiss (1938: 172)
identified a group of crabs Tahitians call “
toetoe
” that live “in cliffs overhanging the sea, where the waves beat”. The descriptions of the morphology and habits of
Cancer scarpellonis
and
C. ballantei
(see below) leave no doubt that both are grapsids of the genera
Grapsus
or
Geograpsus
.
As
both
C. scarpellonis
and
C. ballantei
were described as having “behind each eye, on the side of the upper shell … a single spine, and a tooth behind it” (
Curtiss 1938: 173
), they also cannot be species of
Pachygrapsus
or even
Metopograpsus
(Grapsidae)
, members of which have entire lateral carapace margins. They are unlikely to be species of
Plagusia
(Plagusiidae)
or
Percnon
(Percnidae)
as members of both these genera do not live in the supralittoral zone, having fully aquatic habits even if they may live in the surf zone of the intertidal.
Plagusia
species have in addition two teeth behind the external orbital tooth.
Cancer scarpellonis
was described as being “an inch wide, and almost square in form … The joints of the pincer-legs nearest the body have a toothed crest on the upper side. The four hinder pairs have white bristles on them, a quarter of an inch long … body is olive brown above, whitish underneath” (
Curtiss 1938: 173
). This description perfectly matches species of
Geograpsus
, which have the inner margin of the merus of the cheliped prominently dilated and armed with numerous sharp teeth; and the propodi and dactyli of the ambulatory legs are lined with long stiff almost vertical setae. While generally acknowledged as semiterrestrial and can be found some distance inland, two species,
Geograpsus crinipes
(
Dana, 1851
)
and
Geograpsus stormi
De
Man
, 1895
, are often found in or near sea cliffs. The colours of the carapace and leg setae best match
Geograpsus crinipes
. The colour of its carapace and legs varies from whitish cream to dark grey, but is most often olive-brown; and the vertical bristles on the ambulatory legs are yellowish white. The other
Geograpsus
species on Tahiti,
G. grayi
(H.
Milne Edwards, 1853
) (
Poupin & Juncker 2010
)
has more terrestrial habits, living on the forest floor beyond the supralittoral zone, and has a purple carapace with dark bristles.
Geograpsus stormi
has a red carapace with orange to yellow ambulatory leg bristles.