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
3b24340c-ddcb-45bc-a12b-a3f21832e794
11755334
7626155
52C3E5E3-80B6-49DB-BC9C-194560D491F7
Planes minutus
(
Linnaeus, 1758
)
(
Fig. 51C, D
)
Cancer minutus
Linnaeus, 1758: 625
[
Type
locality: “in Pelagi
Fuco
natante”].
Nautilograpsus major
MacLeay, 1838: 66
[
Type
locality:
Cape
of
Good Hope
].
Planes cyaneus
Dana, 1851b: 250
[
Type
locality: “in mare Pacifico”, i.e. Pacific Ocean,
28°N
,
174°E
”].
Trindade specimens.
1 ovigerous female (
MZUSP 40350
),
Trindade Island
,
Praia
da Calheta, J.B
. Mendonça coll.,
2.xii.2014
, on drifting roape. 1 ovigerous female (
MZUSP 40257
),
ibidem
,
20°30’28.89’’S
,
29°18’37.76”W
,
J.B. Mendonça
coll.,
11.xii.2017
, on washed log, low tide.
1 male
,
5 females
(adult and juveniles) (
MZUSP 40347
),
ibidem
,
Praia
das Tartarugas
,
20°31’03.8’’S
,
29°18’20.7”W
,
J.B. Mendonça
coll.,
12.vii.2012
, on washed buoy.
1 male
,
2 females
,
2 juveniles
(
MZUSP 40341
),
2 males
,
5 juveniles
(
MZUSP 33828
),
ibidem
,
Praia
dos Andradas
,
20°30’45.7’’S
,
29°18’21.9”W
,
J.B. Mendonça
coll.,
28.iii.2014
, washed ashore.
2 males
,
1 juvenile
(
MZUSP 40331
),
ibidem
,
C.H. Guimarães
coll.,
29.i.2012
, stranded shoe
.
Size of largest male: cl
19 mm
, cw
20 mm
; largest female: cl
20 mm
, cw
21 mm
.
Comparative material examined.
Planes minutus
:
United States
:
2 males
,
1 female
(
USNM 4558
), off
Martha’s Vineyard
,
39°49’25”N
,
69°49’W
,
United States
Fish Commission
stn 937 coll.,
4.viii.1881
, surface [
F.A. Chace
det.].
Europe
:
2 males
(
MZUSP 42001
),
Saint Tropez
,
Pampelonne
,
iv. 2009
.
Central Atlantic
:
2 males
,
2 females
(
USNM 112487
),
St. Helena
, off
Rupert’s Bay
,
A. Loveridge
coll.,
11.ii.1963
, from buoy [
F.A. Chace
det. as
P. major
]
.
Brazil
:
São Paulo
:
1 male
(
MZUSP 913
),
São Sebastião, E. Garbe
coll., 1915.
1 male
(
MZUSP 8334
),
São Sebastião
,
Praia do Araçá
,
A. Fransozo
coll.,
25.ix.1981
.
1 male
(
MZUSP 9084
),
ibidem
,
Baraqueçaba, S. A. Rodrigues
coll.,
3.x.1987
.
1 male
(
MZUSP 4174
),
Bertioga
,
Praia de Guaratuba
,
F. Val
, coll., 1971.
1 male
, 1 ovigerous female (
MZUSP 1413
),
Itanhaém. R. Sptiz
coll.,
viii.1927
.
1 female
(
MZUSP 914
),
Iguape, R. Krone
coll., 1900 [
M.J. Rathbun
id., 1918, as
P. cyaneus
].
1 male
, 1 ovigerous female (
MZUSP 24677
),
Juréia-Itatins
,
R. B. Pettan
coll.,
17.ix.2011
, stranded
.
Distribution.
Several authors recorded
Planes minutus
as
P. cyaneus
or
P. major
. Western Atlantic: Gulf of Mexico,
Brazil
(
Piauí
,
Rio Grande do Norte
to
Rio Grande do Sul
),
Uruguay
and northern
Argentina
. Brazilian oceanic islands (Rocas Atoll and Trindade) (
Chace 1951
; 1966;
Shirley 1974
;
Juanic 1976
;
Manning & Holthuis 1981
;
Melo 1996
;
Spivak & Bas 1999
; Prado & Melo 2002;
Lima
et al.
2010
;
Pons
et al.
2011
; Spivak
et al.
2019). This is the first record of
P. minutus
from Trindade. Central Atlantic:
Saint Helena
(Chace 1966). Mediterranean Sea (
Manning & Holthuis 1981
). Eastern Atlantic: recorded from
Gabon
by
Crosnier (1967)
(see also
Pfaller
et al.
2019b
and comments from
Manning & Holthuis 1981
, as
P. cyaneus
). Eastern Pacific and Indian Ocean (
Chace 1951
;
Manning
& Holthuis 1981; Vanini & Valmori 1981;
Pfaller
et al.
2019b
).
chelys
imbricata
(Linnaeus)
,
Chelonia mydas
(Linnaeus)
and
Lepidocheles olivacea
(
Chace 1951
;
Carranza
et al.
2003
;
Bugoni
et al.
2007
;
Pons
et al.
2011
). One single loggerhead turtle was found to carry up to five crabs (
Pons
et al.
2011
), usually above the tail and beneath the carapace, more rarely among the epibionts on the host’s carapace. Heterosexual pairs and megalopae, juveniles singletons associated or not with adult crabs occur on turtles (
Frick
et al.
2004
;
Frick
et al.
2011
). Crabs are infrequently found associated with nesting sea turtles (
Pfaller
et al.
2019b
).
Planes minutus
also colonizes plant material (
Sargassum
) and a large variety of flotsam including buoys (
Pons
et al.
2011
), drifting roape, washed materials such as log, buoy and shoe (this study). Fishing buoys colonized by crabs after being left in the water for only approximately 12 hours were taken as an indication that crabs rapidly move between substrates and colonize whatever substrates are available (
Pons
et al.
2011
).
Planes minutus
feeds upon the turtles’ epibiotic community composed primarily of neustonic invertebrates and algae (
Davenport 1994
;
Frick
et al.
2004
). Ovigerous females obtained from turtles were carrying 8,934 eggs in average (
Frick
et al.
2004
); only the first zoeal stage is known to date (
Cuesta
et al.
1997
).
FIGURE 51.
A, B,
Planes marinus
(
Rathbun, 1914
)
, juvenile female, cl 7 mm, cw 8 mm (MZUSP 40330). C, D,
Planes minutus
(
Linnaeus, 1758
)
, ovigerous female, cl 12.9 mm, cw 13.5 mm (MZUSP 40257). Note in (C) setae on the upper anterior margin of the propodi of the pereopods 2–5 forming a natatory fringe (arrow); natatory fringe worn in (A). Habitus, dorsal (A, C) and ventral (B, D) aspects. Photographs by A. Pol.
Remarks.
The species of
Planes
are easily confused with one another.
Chace (1951)
carried out an in-depth revision of the genus and provided a synopsis of the characters that best differentiate the species in this genus.
Planes minutus
(
Fig. 51C, D
) and
P. marinus
are both provided with setae on the upper anterior margin of the propodi of P2–P5 forming a natatory fringe (Chace 1966) (natatory fringe worn away in the specimen
P. marinus
MZUSP
40330 from Trindade,
Fig. 51A, B
).
Planes minutus
and
P. marinus
can be differentiated from each other by a combination of characters which includes (characters for in
P. marinus
between brackets): 1) carapace about as wide as long (longer than wide in the Trindade specimens) (vs carapace distinctly wider than long) and 2) carapace laterally
The juveniles of
P. minutus
recovered at Trindade have nearly square carapaces and natatory fringes on P2–P5 already at cl
3.9 mm
and cw
4.1 mm
(e.g. MZUSP 40341).
The specimens from
Brazil
previously identified by Prado & Melo (2002) with
P. cyaneus
were reassessed and reidentified as
P. minutus
(see above under comparative material).