Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean
Author
In, First Published
text
Zootaxa
2022
2022-06-02
5146
1
129
journal article
10.11646/zootaxa.5146.1.1
11755334
7626155
52C3E5E3-80B6-49DB-BC9C-194560D491F7
Moreiradromia antillensis
(
Stimpson, 1858
)
(
Figs. 7A–C
,
8A–F
)
Dromidia antillensis
Stimpson, 1858: 225
.
Evius ruber
Moreira, 1912: 322
, figs. 1, 2 [
Type
locality:
Brazil
] [see
Guinot & Tavares, 2003: 84
].
Trindade specimens.
1 female
(
MZUSP 41181
), off
Espírito Santo
,
Trindade Island
,
Ponta do Monumento
,
20º30’10.3’’S
,
29º20’36.1’’W
,
J.B. Mendonça
coll.,
3.vii. 2015
,
23 m
. 1 male (
MZUSP 33350
),
ibidem
,
Enseada dos Portugueses
,
Farol
,
20º29’52.3’’S
,
29º19’15.6’’W
,
J.B. Mendonça
coll.,
8.iv.2014
,
13.2 m
.
1 juvenile
female (
MZUSP 40359
),
ibidem
,
Ponta
da Calheta
,
20º30’18.7’’S
,
29º18’31.6’’W
,
J.B. Mendonça
coll.,
30.iv.2014
,
15.6 m
.
Size of largest male: cl
6.9 mm
, cw
6.5 mm
; largest female: cl
5.9 mm
, cw 6.0 mm.
FIGURE 7.
A–C,
Moreiradromia antillensis
(
Stimpson, 1858
)
, scanning electron micrographs. A–C, Female, cw 8.8 mm (MZUSP 5905). Note in (A) very pilose carapace and appendages, which help the crab to hold sponges and other materials firmly against the dorsal body surface. B, Detail of the antennule and antenna. C, Detail of the first article of antenna much wider than long, beaked medially. Scales: A, 1 mm. B, 0.5 mm. C, 0.1 mm.
Comparative material examined.
Moreiradromia antillensis
:
United States:
1 male
,
2 females
(
USNM
101383), Gulf coast of Florida, west of Anclote Keys, R/V “Silver Bay”, stn 54,
28°09’00.0”S
,
83°49’48.0”W
,
37 m
.
Brazil
:
Bahia
:
1 male
(
MZUSP 41232
),
Minerva Bank
,
17º03.108’S
,
37º37.216’W
,
J. Coltro
coll.,
12.viii.2012
,
69 m
.
Espírito Santo
:
1 male
(
MZUSP 41183
),
Vitória
–
Trindade Seamount Chain, R
/V “Marion Dufresne”,
TAAF
MD55/
Brésil Expedition
,
Vitória Bank
, stn 10 CP23,
20º43.1’S
,
37º50.1’W
,
13.v.1987
,
52 m
. 1 female
(
MZUSP 41221
),
ibidem
,
Columbia Bank
, stn 30 DC50,
20º44.2’S
,
31º49.9’W
,
19.v.1987
, calcareous sand and stones,
95–
120 m
. 1 juvenile (MZUSP 41228),
REVIZEE Expedition, off the coast of Linhares, PS/V “Astro Garoupa”, stn 28C, 19º48.47’S, 37º56.33’W, 31.x.1997, 54 m. 1 male (MZUSP 41230)
,
ibidem
, off the coast of São Mateus, H/V “Antares”, stn
D32,
18º52’S
,
39º35’W
,
28.ii.1996
,
52 m
. 1 male
,
2 females
(
MZUSP 41227
),
ibidem
, off the coast of
Guarapari
, stn 35C,
20º52.00’S
,
40º10.00’W
,
3.xi.1997
,
55 m
.
Rio de Janeiro
:
1 male
(
MZUSP 41222
),
ibidem
, off the coast of
São João da Barra
, stn 6 DC15,
21º37.1’S
,
40º18.1’W
,
11.v.1987
,
37 m
. 1 female
(
MZUSP 11919
),
Bacia
de Campos
, no further details.
3 males
,
1 female
(
MZUSP 41224
),
REVIZEE Expedition, off the coast of
Cabo Frio, H
/V “Antares”, stn D3,
22º52.97’S
,
41º9.24’W
,
M. Tavares
coll.,
23.ii.1996
,
80 m
.
1 ovigerous female (
MZUSP 41231
),
REVIZEE Expedition, off the coast of Cabo Frio, H/V “Antares”, stn D1,
22º48.92’S
,
41º9.33’W
,
M. Tavares
coll.,
23.ii.1996
,
69 m
. 1 male
(
MZUSP 41229
),
ibidem
, off the coast of
Maca
, stn D7,
22º19’S
,
40º50’W
,
M. Tavares
coll.,
24.ii.1996
,
60 m
. 1 female
(
MZUSP 41223
),
Niterói
,
Itaipú Lagoon
, channel,
J.B. Mendonça
coll.,
2.v.2001
, around
1.5 m
.
1 male
,
2 females
(
MZUSP 17914
),
6 males
,
12 females
(4 ovigerous,
2 juveniles
), (
MZUSP 41225
),
Baía da Ilha Grande
,
i.2007
.
Distribution.
Bermuda
, North Carolina,
Bahamas
, Gulf of Mexico,
Honduras
, Antilles,
Cuba
,
Colombia
,
Venezuela
,
Suriname
, Guianas, and
Brazil
(
Amapá
to
Rio Grande do Sul
, including Fernando de Noronha) (
Alves
et al.
2012b
, and references therein). Central Atlantic:
Ascension and Saint Helena
(
Manning & Chace, 1990
). This is the first record of
M. antillensis
from the Minerva Bank (off the coast of Bahia), Vitória–Trindade Seamount Chain (Vitória and Columbia banks), and Trindade Island.
Ecological notes.
Although not rare, little is known about the biology of
Moreiradromia antillensis
. This species inhabits hard bottoms, broken shells beds, loose rubbles, calcareous sand and stones, between 1 and
330 m
.
The larval development goes through six zoeal stages and a megalopa in laboratory conditions (
Rice & Provenzano 1966
). Bright red megalopae were seen forming a swarm during the pelagic phase (Arraial do
Cabo
,
Rio de Janeiro
. M. Tavares pers. obs.). Juveniles and adults hold sponges and, more rarely, ascidians and anthozoans on the dorsal surface of the carapace (Rathbun 1937; Lavaleye &
Hartog 1995
;
Padua
et al.
2019
). The very pilose body and carapace convexity help the crab to hold sponges and other materials firmly against the dorsal body surface (
Fig. 7A–C
).
Remarks.
Juvenile males and females of
Dromia erythropus
and
M. antillensis
are commonly collected together during field studies and are frequently confused with each other due to superficial morphological similarities. Juveniles of both sexes of
M. antillensis
can be recognized on the basis of the distal end of the merus of P5, which extends to (or close to) the branchial spine of the carapace (vs P5 merus falling much shorter that spine in juveniles of
D. erythropus
), and in having the carapace usually longer than wide with the posterior margins subparallel (vs carapace wider than long with margins converging posteriorly in
D. erythropus
).
Juvenile females of
M. antillensis
(cw
5.4 mm
) are readily recognized in that the thoracic sternal suture 7/8 extends well beyond the gonopore on the coxa of P3 (
Fig. 8A, B
). The suture 7/8 continues to extend forward with growth (
Fig. 8C, D
), so that in mature females the spermathecal openings at the distal end of the suture 7/8 are positioned at the level of P1 (
Fig. 8E, F
) (
Tavares & Franco 2004
;
Guinot
et al
. 2013
). Contrary, in juvenile females of
D. erythropus
the thoracic sternal suture 7/8 extends forwards to the level of the gonopore on the coxa of P3 (even in a female at cw
20 mm
, e.g. MZUSP 33351); in large ovigerous females (e.g. cw
73 mm
, MZUSP 16990) the sternal suture 7/8 extends a little beyond the gonopore on the coxa of P3, but well before the coxa of P2.
Males of
M. antillensis
, both juveniles (e.g. cl
7 mm
, cw
6.2 mm
, MZUSP 41224) and adults (e.g. cl
32 mm
, cw
30 mm
, MZUSP 17914) have paired, uniramous vestigial pleopods on somites 3–5, showing as tiny, membranous buds. The uropods, showing dorsally as small plates in males do not play a role in the pleonal holding system (see also
Guinot & Tavares 2003: 83
, fig. 14B). The pleon is held folded ventrally by a tubercle on the base of the P2 coxa that overhangs the pleonal somite 6.