New findings of rare or little-known alpheid shrimp genera (Crustacea, Decapoda) in Moorea, French Polynesia
Author
Anker, Arthur
text
Zootaxa
2010
2403
23
41
journal article
10.5281/zenodo.194125
6ae8ac53-d51b-4bdc-b3c9-856e0a3ef8a0
1175-5326
194125
Richalpheus palmeri
Anker & Jeng, 2006
Figures 7
,
8
Richalpheus palmeri
Anker & Jeng 2006: 381
, figs. 1–6.
Material examined
.
French
Polynesia
, Society Islands.
1 female
(CL
3.35 mm
),
FLMNH
UF Arthropoda 16524, Moorea, lagoon, between Papetoai and Hotel Intercontinental, sand flat with mounds and some rubble, nearby coral heads, numerous
Holothuria atra
Jaeger, 1833
, from burrow, suction pump, depth:
0.5–1 m
, coll. A. Anker,
23.XI.2008
[fcn BMOO-5632].
Description
. See Anker & Jeng (2006).
Colour pattern
. Uniformly hyaline-white, semitransparent, tiny red chromatophores hardly visible on abdomen, along branchiostegial margin of carapace, on uropods and telson, and on antennular peduncle; ovaries visible through semi-translucent carapace, extending from carapace into first abdominal somites, pale yellow (
Figs. 7
,
8
).
Type
locality
. Panglao, the
Philippines
.
Ecology
. The Moorea specimen was collected in the lagoon, on a shallow sand flat about
0.5–1 m
depth at low tide, with isolated coral heads and numerous sea cucumbers (
Holothuria atra
), from burrows of unknown hosts. Similarly, the
holotype
was collected from a burrow on a sand flat, in slightly deeper water (
3–4 m
). Some
Callianassidae
, in particular larger species of
Glypturus
Stimpson, 1866
and
Neocallichirus
Sakai, 1988
are the most likely candidates for being the actual burrowing host(s) of
R. palmeri
(see also Anker & Jeng 2006).
Distribution
. Previously known only from the
holotype
from Panglao, the
Philippines
(Anker & Jeng 2006); herewith recorded for the first time from Moorea,
French
Polynesia
, representing a considerable range extension from the “Coral Triangle” area into the central-western Pacific Ocean.
Remarks
.
Richalpheus palmeri
is the
type
species of the recently established genus
Richalpheus
. The Moorea specimen agrees in most aspects with the
holotype
; the only noticeable differences are the distinctly more concave posterior margin of the uropodal exopod (
Fig. 8
B, C, cf. Anker & Jeng 2006, fig. 2j) and the slightly shorter second segment of the antennular peduncle (
Fig. 5
A, cf. Anker & Jeng 2006, fig. 2a). Considering these relatively minor differences and the large distance between the
Philippines
and
French
Polynesia
, more specimens from both localities (and from other areas) and DNA comparisons are desirable to confirm the identity of specimens collected far outside the
type
locality. A second species of
Richalpheus
,
R. dahabensis
Anker & Dworschak, 2007
, was recently described from the Red Sea, also based on a single specimen, but this species can be separated from
R. palmeri
by the absence of a fossa/tooth system on the major cheliped fingers (
Anker & Dworschak 2007
).