New taxonomic and distributional information on hermit crabs (Crustacea: Anomura: Paguroidea) from the Gulf of Mexico, Caribbean Sea, and Atlantic coast of South America
Author
Lemaitre, Rafael
Author
Tavares, Marcos
text
Zootaxa
2015
3994
4
451
506
journal article
10.11646/zootaxa.3994.4.1
76173501-dcf8-4df8-947d-0e53637508c8
1175-5326
242551
A26ADF37-7936-486B-850D-C5932E13F2EC
Nematopaguroides pusillus
Forest
& de Saint Laurent, 1968
(
Figs. 19
,
20
)
Nematopaguroides
?
pusillus
Forest & de Saint Laurent, 1968: 159, figs 142–146 (
type
locality: off Pernambuco,
Brazil
,
Calypso
, sta 23,
8°19.5’S
,
34°39’W
).
Nematopaguroides pusillus
.
—
Coelho & Ramos, 1973
: 166
.—
Coelho & Santos, 1980
: 143
.—Reed
et al.
, 1982: 768.—Reed
et al.
, 1982: 768.—
Abele & Kim, 1986
: 386
, figs i–k.—Coelho & Ramos-Porto, 1987: 43.—
Rieger, 1998
: 417
.—
Melo, 1999
: 118
, figs 63, 64.—
Wang & McLaughlin, 2000
: 956
.—
Coelho
et al.,
2007
: 10
, tab. 4.—
McLaughlin
et al.
, 2010
: 31
.
New material.
Southeastern Florida
. R/V
Johnson
, Jeff’s Reef,
27°32.8’N
,
79°58.8’W
, in
Oculina
reef samples, Cr. 27, JSL-II, dive 129a,
77.7 m
,
23 Sep 1976
:
2 males
1.3–1.5 mm
,
1 female
1.2 mm
, 1 ov female
1.1 mm
(
HBOI
089:06387); Cr. 42, JSL-II, dive 184a,
80.2 m
,
15 Apr 1977
:
2 males
1.1,
1.3 mm
,
1 female
0.8 mm
, 1 ov female
1.3 mm
(
HBOI
089:06385); Cr. 47, JSL-II, dive 438b,
81.4 m
,
23 Aug 1977
: 4 sex indet. (dismembered)
0.7–0.8 mm
(
HBOI
089:06386).
Brazil
.
Espírito Santo,
TAAF
MD55, sta 23 DC 40,
20°39.8’S
,
34°41.1’W
,
60 m
,
17 May 1987
:
1 male
1.4 mm
(
MZUSP
16832).
FIGURE 19.
Nematopaguroides pusillus
Forest
& de Saint Laurent, 1968: male 1.4 mm, Brazil, TAAF MD55, sta DC 40 (MZUSP 16832). A, shield and cephalic appendages, dorsal; B, right cheliped, dorsal; C, left cheliped, dorsal; D, same, lateral; E, sternum, coxae of pereopods, and sexual tubes, ventral. Scale: 0.5 mm.
Diagnosis.
(See also Forest & de Saint Laurent 1968). Shield (
Fig. 19
A) about as long as broad, naked or with scattered short setae; lateral projections terminating in minute spine; rostrum broadly triangular, rounded. Ocular peduncles slightly constricted medially, with scattered setae dorsally; cornea weakly dilated; acicles subtriangular, each terminating in simple terminal spine or rarely 2 small spines. Antennular peduncles exceeding distal margin of cornea by half length of ultimate segment, naked. Antennal peduncle exceeding distal margin of cornea by onefourth length of fifth segment; second segment with distolateral angle produced and terminating strong spine; antennal acicle reaching to proximal margn of cornea, terminating in sharp spine, unarmed except for tuft of setae on mesial margin and long setae distally; flagellum with scattered short setae ≤ 1 article in length. Chelipeds (
Fig. 19
B, C) markedly dissimilar, stout. Right cheliped sparsely setose; fingers distinctly shorter than palm, cutting edges each with 3 (dactyl) or 1 (fixed finger) large calcareous teeth; chela with row of small spines on dorsomesial and dorsolateral margins; carpus with dorsomesial row of small spines and scattered small spines on dorsal surface. Left cheliped with scattered, moderately long setae on merus, carpus, and chela; fingers twice as long as palm; chela with dorsolateral margin elevated and armed with row of sharp, mostly forwardly curving spines; carpus with a few dorsomedial spines; carpus with strong dorsodistal spine. Ambulatory legs (
Fig. 20
A, B) each with dactyl slightly longer than propodus, with ventromesial row of 6–8 long, slender spinules; meri, carpi and propodi with long setae or tufts of setae on dorsal margins; segments unarmed except for small, blunt dorsodistal spine on carpi. Fourth pereopod (
Fig. 20
C) semichelate, propodal rasp consisting of single row of ovate scales; lacking preungual process. Anterior lobe of sternite XII (
Fig. 19
E) subsemicircular. Uropods markedly asymmetrical. Telson (
Fig. 20
D) with prominent median cleft separating slightly asymmetrical posterior lobes; rounded terminal margins of posterior lobes each with row of 4 or 5 spines of similar size. Male with coxae of fifth pereopods symmetrical, each coxa with long, slender, and distally filamentous sexual tube (
Fig. 19
E) directed obliquely outward. Female with paired gonopores.
Distribution.
Western Atlantic: known only from off southeastern Florida, and
Brazil
(Espírito Santo). Depth:
60 to 81.4 m
.
FIGURE 20.
Nematopaguroides pusillus
Forest
& de Saint Laurent, 1968, male 1.4 mm, Brazil, TAAF MD55, sta DC 40 (MZUSP 16832): A, right second pereopod, lateral; B, right third pereopod, lateral; C, propodus and dactyl of right fourth pereopod, lateral; D, telson, dorsal. Scale: 0.5 mm.
Remarks.
This rarely collected species was previously known only from the
type
material used by Forest & de Saint Laurent (1968) from off Pernambuco,
Brazil
, and specimens collected off southeastern Florida as part of an
Oculina
deep reef ecology study by Reed
et al.
(1982). In the latter study, however, only the number of specimens collected was reported, without including any taxonomic or morphological details. Various listings from Florida (
Abele & Kim 1986
) and
Brazil
(
Coelho & Santos 1980
; Coelho & Ramos-Porto 1987;
Rieger 1998
;
Melo 1999
;
Coelho
et al
. 2007
) have also included this species without reporting any new material. The discovery of an additional specimen of
N. pusillus
from the coast of Espírito Santo,
Brazil
, confirms the presence of this rare species along that portion of the southwestern Atlantic, while still leaving a large gap in its distribution between Bahia and Florida.
At the time Forest & de Saint Laurent (1968) described
N. pusillus
, they questionably placed it in
Nematopaguroides
because the only male known had paired sexual tubes, whereas males of the only other known species and
type
of the genus,
N. fagei
Forest
& de Saint Laurent, 1968, had unpaired right sexual tube. When
Wang & McLaughlin (2000)
made the remarkable discovery of a third species of
Nematopaguroides
,
N. reconditus
Wang & McLaughlin, 2000
, in the South
China
Sea, with males having a long sexual tube on the right side and a short sexual tube on the left side, they concluded that a left sexual tube could be present as well in species of
Nematopaguroides
, and thus concluded that both
N. reconditus
and
N. pusillus
could correctly belong in this genus.
Individuals of
Nematopaguroides pusillus
are minute in size, ranging in shield length
0.7–1.5 mm
. The rareness of collections of this species may be attributed, in part, to the small size as well as the cryptic habitat, such as the dense
Oculina coral
reefs off the coast of eastern Florida, where it has been found.