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
52C3E5E3-80B6-49DB-BC9C-194560D491F7
Ranilia constricta
(A.
Milne-Edwards, 1880
)
Raninops constricta
A.
Milne-Edwards, 1880: 35
[
Type
locality: near Sombrero Island,
86 m
].
Ranilia guinotae
Melo & Campos Junior, 1994: 69
[
Type
locality: Santos,
São Paulo
, from the stomach of the sand perch
Diplectrum formosum
(Linnaeus)
].
Trindade and Martin Vaz specimens.
1 female
(
MZUSP 41564
), R/V “Marion Dufresne”,
TAAF
MD55/Brésil
Expedition
,
Trindade Island
, stn 35 DC59,
20°30’S
,
29°18’W
,
22.v.1987
, sand,
60 m
. 8 juvenile females (
MZUSP 41477
), R/V “Marion Dufresne”,
TAAF
MD55/Brésil
Expedition
,
Martin Vaz Archipelago
, stn 32 DC52,
20° 29’S
,
28°51’W
,
20.v.1987
, sand,
64–
80 m
.
Size of largest female: cl
10.8 mm
, cw
16 mm
.
Comparative material examined.
Ranilia constricta
:
United States
:
1 female
(
USNM 169699
), R/V “Triton”,
Gulf of Mexico
,
Florida
,
Monroe County
, off
Sombrero Light
,
6.vi.1950
,
91–110 m
. Martinique:
1 female
(
MZUSP 17319
), IGMAR 3 Expedition, stn 419,
14°41.73’N
,
60°50.05’W
, IFREMER coll.
14.ix.1994
, dredge [
J. Poupin
don.]. Brazil: Espírito Santo:
1male
,
1 female
juvenile (
MZUSP 41566
),
R/V “Marion Dufresne”,
TAAF
MD55/ Brésil Expedition, off the coast of Linhares, stn 52 CB90,
19°33’S
,
39°34’W
,
29.v.1987
, mud and dead shells,
34 m
. 3 juvenile
females (
MZUSP 41478
),
ibidem
, Vitória–Trindade Seamount Chain, Columbia Bank, stn 27 DC47,
20°41’S
,
32°12.85’W
,
19.v.1987
,
94–105 m
. 10 females (
8 juveniles
) (
MZUSP 41563
),
ibidem
, off the coast of Guarapari, stn 30 DC50,
20°44’S
,
39°49’W
,
19.v.1987
, calcareous sand and stones,
95 m
.
Rio de Janeiro
:
1 male
,
2 females
(
1 juvenile
) (
MZUSP 41565
),
ibidem
, off the coast of
Arraial do Cabo
, stn 60 CB101,
22°58’S
,
42°06’W
,
1.vi.1987
, mud,
50 m
. 1 male
,
1 female
juveniles (
MZUSP 41567
),
stn 60 CB100,
22°59’S
,
42°06’W
,
1.vi.1987
, mud,
33–45 m
.
Ranilia guinotae
: Brazil:
holotype
male badly damaged (
MZUSP 10932
),
1 male
paratype
badly damaged (
MZUSP 11106
) [junior synonym of
R. constricta
], Santos, São Paulo, from the stomach of the sand perch
Diplectrum formosum
(Linnaeus)
[no further details informed]
.
Distribution.
Amphi-Atlantic. Western Atlantic: North Carolina, Gulf of Mexico, Antilles,
Venezuela
, and
Brazil
(
Amapá
to
Rio Grande do Sul
) (
Manning & Holthuis 1981
;
Melo 1996
;
Felder
et al.
2009
).
Ranilia constricta
is also known from the Pliocene of
Curaçao
(
Luque
et al.
2017
) and the late Pleistocene of
Calabria
,
Italy
(
Vazzana 2008
;
Garassino
et al.
2014
). This is the first record of
R. constricta
from Trindade and Martin Vaz and the Vitória–Trindade Seamount Chain (Columbia Bank). Central Atlantic:
Ascension Island
and perhaps
Saint Helena
(
Manning & Chace 1990
;
De Grave
et al.
2017
). Eastern Atlantic: west African coast from
Cape Verde
Islands to
Gabon
(
Manning & Holthuis 1981
;
González 2018
).
Ecological notes.
This species has been recorded from the inner shelf from
20 m
to the upper slope down to
481 m
in soft bottoms including sand, calcareous sand and rubble, and mud with dead shells. It is preyed by the sand perch
Diplectrum formosum
. Swarming of a raninid megalopa, possibly referable to
Ranilia
, were seen at
St. Lucia
and
Barbados
(Chace & Barnish 1976;
Kidd & Rice 1986
). Megalopae attributable to
Ranilia
have been found in the stomachs of albacores in the Gulf of
Guinea
(
Monod 1965
).
Remarks.
The male
holotype
and
paratype
of
Ranilia guinotae
, both obtained from the stomach of the sand perch
Diplectrum formosum
, were partially digested. According to
Melo & Campos Junior (1994)
, the supraorbital margin is devoid of teeth in
R. guinotae
(vs toothed supraorbital margin in
R. constricta
). However, the toothless supraorbital margin in
R. guinotae
is clearly an artifact due to the partial digestion of the exoskeleton. Still according to Melo & Campos Junior,
R. guinotae
further differs from
R. constricta
in that its rostral margin is sulcate. Actually, this characteristic is shared by both species and in the absence of other characters to support their distinction the two species are herein considered each other’s synonyms.