Brachyuran crabs (Crustacea, Decapoda) from the remote oceanic Archipelago Trindade and Martin Vaz, South Atlantic Ocean
Author
TAVARES, MARCOS
0000-0002-7186-5787
Museu de Zoologia, Universidade de São Paulo. CEP 04263 - 000, São Paulo, SP, Brazil
mdst@usp.br
Author
MENDONÇA, JOEL BRAGA DE JR.
0000-0002-4593-8495
Museu de Zoologia, Universidade de São Paulo. CEP 04263 - 000, São Paulo, SP, Brazil
text
Zootaxa
2022
2022-06-02
5146
1
1
129
http://dx.doi.org/10.11646/zootaxa.5146.1.1
journal article
10.11646/zootaxa.5146.1.1
3b24340c-ddcb-45bc-a12b-a3f21832e794
11755334
7626155
52C3E5E3-80B6-49DB-BC9C-194560D491F7
Mithraculus forceps
A. Milne-Edwards, 1875
(
Fig. 21A–D
)
Mithraculus forceps
A. Milne-Edwards, 1875: 109
, pl. 23, fig. 1 [
Type
locality:
Cayenne
,
French Guiana
].
Trindade and Martin Vaz specimens.
1 male
(
MZUSP 33739
),
Trindade Island
,
Enseada das Orelhas
,
20°29’40.2”S
,
29°20’32.9”W
,
J.B. Mendonça
coll.,
01.xi.2014
,
12 m
.
1 male,
1 female
(
MZUSP 39840
),
ibidem
,
2.vii.2015
,
14.7 m
.
1 ovigerous female (
MZUSP 39681
),
ibidem
,
1.vii.2016
,
9.2 m
.
1 male
(
MZUSP 39853
),
ibidem
,
Ponta da Calheta
,
20°30’18.72”S
,
29°18’31.67”W
,
J.B. Mendonça
coll.,
20.x.2014
,
17 m
.
1 male
,
1 female
, 2 ovigerous female, 1 ju venile female (
MZUSP 40741
),
ibidem
,
20°30’19.5”S
,
29°18’47.3”W
,
J.B. Mendonça
coll.,
26.vi.2012
,
14.3 m
.
1 ovigerous female (
MZUSP 40602
)
,
1 juvenile
female (
MZUSP 40245
),
ibidem
,
24.xi.2017
,
17 m
. 1 male, 3 ovigerous females (
MZUSP 39911
),
ibidem
,
20°30’18.72”S
,
29°18’31.6”W
,
J.B. Mendonça
coll.,
29.iv.2014
, 15,
9 m
. 1 ovigerous female (
MZUSP 40568
),
ibidem
,
24.vi.2017
,
19.3 m
.
1 male
(
MZUSP 39682
),
ibidem
,
20°30’29.5”S
,
29°18’37.0”W
,
J.B. Mendonça
coll.,
20.vi.2016
,
8.2 m
.
3 males
, 6 ovigerous females (
MZUSP 40586
),
ibidem
,
20°30’16.59”S
,
29°18’30.11”W
,
J.B. Mendonça
coll.,
30.i.2019
,
15.1 m
.
1 male
,
1 juvenile
female (
MZUSP 33738
)
,
1 juvenile
female (
MZUSP 40759
)
,
1 male
,
3 females
(
MZUSP 41131
),
ibidem
,
Enseada dos Portugueses
,
Farol
,
20°29’52.3”S
,
29°19’15.6”W
,
J.B. Mendonça
coll.,
8.iv.2014
,
12.9 m
.
3 males
,
3 juvenile
males,
1 juvenile
(
MZUSP 41132
),
22.iv.2014
,
13.7 m
.
2 males
, 4 ovigerous females (
MZUSP 39637
),
ibidem
,
25.vii.2018
,
10 m
. 1 male (
MZUSP 40187
),
ibidem
,
25.vii.2018
,
10 m
. 1 female (
MZUSP 39859
),
ibidem
,
Enseada
dos
Portugueses
,
20°30’17.7”S
,
29°18’56.7”W
,
J.B. Mendonça
coll.,
18.iv.2014
,
10.2 m
.
1 male
,
1 juvenile
male,
1 juvenile
(
MZUSP 40703
),
ibidem
,
20°30’20.9”S
,
29°18’43.7”W
,
J.B. Mendonça
coll.,
29.iv.2014
,
9.9 m
.
1 ovigerous female (
MZUSP 40561
),
ibidem
,
Ponta Norte
,
20°29’18.7”S
,
29°20’18.3”W
,
J.B. Mendonça
coll.,
31.vii.2018
,
12.4 m
.
1 male
,
2 females
(
MZUSP 39919
),
ibidem
,
2.vii.2015
.
2 males
,
1 male
and
1 female
juveniles (
MZUSP 39827
),
ibidem
,
Ponta do Monumento
,
20°30’10.3”S
,
29°20’36.1”W
,
J.B. Mendonça
coll.,
3.vii. 2015
,
15.5 m
.
1 male
,
3 juvenile
males, 1 ovigerous female,
2 juvenile
females (
MZUSP 39619
),
ibidem
,
Ilha da Racha
,
20°30’26.5”S
,
29°20’48.0”W
,
J.B. Mendonça
coll.,
30.vii. 2018
,
24.8 m
.
3 males
,
1 juvenile
male,
1 female
(
MZUSP 39883
),
ibidem
,
Praia das Cabritas
,
20°29’41.38”S
,
29°19’39.99”W
,
J.B. Mendonça
coll.,
25.vi. 2015
,
12 m
.
1 damaged male (
MZUSP 39847
)
,
1 juvenile
male (
MZUSP 40669
),
Martin Vaz
,
Ilhote Principal
,
20°28’26.98”S
,
28°51’20.98”W
, coralligenous sediment,
C.H. Guimarães
coll.,
22.i.2012
,
19.2 m
.
Size of largest male: cl
15 mm
, cw
17.5 mm
; largest female: cl
12.9 mm
, cw
14.9 mm
.
Comparative material examined.
Mithraculus forceps
:
United States
:
2 males
,
2 females
(
USNM 16046
),
Florida
,
Indian Key
, along shore, low tide, no further details.
Caribbean Sea
:
Grenada:
1 male
(
MZUSP 28066
),
Grand Anse
Bay
,
12°1’45.68”S
,
61°46’18.67”W
,
L.R.L. Simone
et al.
coll.,
8.x.2012
,
10 m
.
Brazil
: Central Atlantic:
3 males
(
MZUSP 41237
),
São Pedro
and
São Paulo
Archipelago
,
Cabea da Tartaruga
, W. Santana
et al.
coll.,
18.ii.2009
to
5.iii.2009
.
Rocas Atoll
:
1 juvenile
male,
1 female
(
MZUSP 12476
),
R.L. Moura
and
R.S. Rosa
coll.
Paraíba
:
3 males
,
2 females
(
MZUSP 11804
),
Projeto Algas
, stn 69-b,
6°46’S
,
34°47’W
,
19.v.1981
,
18 m
.
1 male (
MZUSP 15524
), João Pessoa,
Ponta do Cabo Branco
, M.F.
C. Lima coll.,
21.iii.2000
.
Fernando de Noronha Archipelago
:
1 juvenile
male (
MZUSP 20561
),
3°50’11”S
,
32°23’53.4”W
,
L.R. Simone
and C.M. Cunha coll.,
8.iii.2009
.
2 males
(
MZUSP 20540
),
ibidem
,
Praia do Porto
,
3°50’S
,
32°24’01.6”W
,
L.R. Simone
and C.M.
Cunha
coll.,
10.iii.2009
.
1 juvenile
male (
MZUSP 34303
),
ibidem
,
Buraco da Raquel
, next to the
Port, L.R.L. Simone
coll.,
4.v.2013
.
Pernambuco
:
1 male
(
MZUSP 32455
),
Tamandar
,
Praia de Tamandar
, R.
Silva coll.,
i.1990
.
Bahia
:
7 males
, 11 ovigerous females (
MZUSP 41233
),
Minerva Bank
,
17°03.108’S
,
37°37.216’W
,
J. Coltro
coll.,
12.viii.2012
,
69 m
.
Rio de Janeiro
:
1 male
,
1 female
(
MZUSP 20322
),
Búzios,
Praia dos Ossos.
1 juvenile
male, 6 ovigerous females,
1 juvenile
female (
MZUSP 21339
),
Maricá
,
Ilhas Maricás, M. Tavares
coll.,
21.iv.1985
, on
Schizoporella
.
2 males
,
2 juvenile
females,
5 juveniles
(
MZUSP 2826
),
Angra dos Reis
,
Praia de Vila Velha, G.A.S. Melo
coll.,
14.vii.1966
. 3 males, 2 juvenile males, 3 ovigerous females, 3 juvenile females (MZUSP 3662), Ilha Grande, Praia do Furado, G.A.S. Melo coll. 20.vii.1966.
Distribution.
From North Carolina, through Gulf of Mexico, Caribbean Sea, north coast of South America to
Brazil
(
Maranhão
to Santa Catarina) (
Melo 1996
;
Serejo
et al.
2006
;
Bouzon & Freire 2007
;
Felder
et al.
2009
). Brazilian oceanic islands: known from São Pedro and
São Paulo
, Rocas Atoll, Fernando de Noronha and Trindade and Martin Vaz.
Mithraculus
cf.
forceps
has been reported from the late Pleistocene of
Jamaica
(
Klompmaker
et al.
2015
, and references therein).
FIGURE 21.
A–D,
Mithraculus forceps
A. Milne-Edwards, 1875
. A, Male MZUSP 33739, cl 11.8 mm, cw 13.5 mm. B, Ovigerous female (MZUSP 40602), cl 11.9 mm, cw 13.4 mm. C, Ovigerous female (MZUSP 40568), cl 8.5 mm, cw 9.5 mm. D, Juvenile female (MZUSP 40245), cl 5.8 mm, cw 6.2 mm. Habitus, dorsal (A, C, D) and ventral (B) view. Photographs by A. Pol.
Ecological notes.
Mithraculus forceps
is commonly associated with different substrata, including the sponges
Amphimedon viridis
Duchassaing & Michelotti
and
Stematumenia strobilinia
(Lamarck)
, the calcareous bryozoans
Schizoporella unicornis
(Johnston in Wood) and
S. errata
(Waters)
,
Porites
spp.
corals, sand reefs of
Phragmatopoma caudata
Krøyer
, mangroves (Caribbean coast), seagrass (
Thalassia
) and macroalgae, and also has been found under stones and in coralligenous sediment, from the tide mark down to
100 m
(
Rodríguez 1980
;
Gore
et al.
1981
;
Williams 1984
;
Melo 1996
;
Rieger & Giraldi 1996
;
Mantelatto & Souza-Carey 1998
;
Morgado & Tanaka 2001
;
Cobo 2002
;
Alves
et al.
2012b
,
2012
c, 2013
;
Lane-Medeiros
et al.
2021
).
Mithraculus forceps
is very common in Trindade (seemingly less so in Martin Vaz), where it has been found between 8 and
24 m
. It also has been reported to be the commonest crab species in insular coastal habitats (
Alves
et al.
2012b
).
Mithraculus forceps
is a prey for
Octopus insularis
juveniles in the Rocas Atoll (
Bouth
et al.
2011
). The average size of adult females has been estimated in 11.2 mm ± 1.5 mm. The females attain morphological sexual maturity at a larger sizes than males at around
12.9 mm
(
Cobo 2002
, 2006;
Cobo & Alves 2009
). Females can use stored sperm to fertilize eggs for more than one consecutive spawn without mating (
Penha-Lopes
et al.
2006
). Ovigerous females have been reported all year-round, which translates into constant larval supply. The mean larval duration from hatching to crab I is of about 8.3 ± 0.5 days; the duration for the zoea I and II stages is of about 2 days each, and 3–8 days for the megalopa in laboratory conditions (
Rhyne
et al.
2005
). Larval duration may be longer (over 14 days) depending on the rearing conditions (
Wilson
et al.
1979
).
Mithraculus forceps
is said to have facultative lecithotroph larvae, which can also ingest prey when available. It also has been found that late megalopa starvation has no significant influence on the survival to juvenile or larval duration and that temperature is the most important factor regulating survival and growth of larvae and juveniles in laboratory conditions (
Figueiredo
et al.
2008
). However, observations by W. Santana (pers. com.) stand in contradiction to the results derived by
Figueiredo’s
et al.
(2008)
observations, as all non feeded larval stages of
M. forceps
reared in laboratory conditions by Santana tended to die faster and in more quantity than the fed larvae. If the facultative lecithotrophic development is confirmed for
M. forceps
, it might help to explain (along with constant larval supply) the ability of the widely distributed
M. forceps
to colonize new areas offshore.
Mithrax forceps
is a popular species in the aquarium trade and may come under pressure from the pet trade in the future (
Penha-Lopes
et al
. 2006
;
Figueiredo
et al
. 2008
).
Remarks.
Mithraculus forceps
can co-occur with
Teleophrys pococki
and very small juveniles of the two species can be mistaken for each other at a first glance. However, those of
M. forceps
can be easily recognized by having the carapace more flattened and grooved and the cheliped carpus with acute spines — cheliped carpus with only a tubercle of variable size near the inner anterolateral angle in aged specimens (
Fig. 21A–D
) (vs carapace markedly swollen, particularly at the branchial, cardiac and intestinal regions, and cheliped carpus devoid of acute spines in
T. pococki
) (
Fig. 24A–G
).
The carapace becomes distinctly wider than long with growth in males and females of
M. forceps
. The pereopods P2–P5 have many stiff setae and are spiny in developing specimens (denticulate in aged ones), which favor the adherence of fouling organisms (
Fig. 21A–D
). The ejaculatory canal aperture of the first gonopod is not fully formed until the males attain
8.8 m
(cw) (
Mollemberg
et al.
2021
). The carapace and chelipeds are glabrous and practically never have fouling organisms adhered to it (
Fig. 21A, C
).
In the specimens from the São Pedro and
São Paulo
Archipelago the dorsal surface of the carapace looks more polished and the carapace grooves more faint.
A. Milne-Edwards
(1875: pl. 23, fig. 1) depicted the
holotype
male (cw
35 mm
) of
M. forceps
and stated that it was from Cayenne. Therefore, its type locality can be narrowed down to
Cayenne
,
French Guiana
.