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
Planes marinus
Rathbun, 1914
(
Fig. 51A, B
)
Planes marinus
Rathbun, 1914: 120
[
Type
locality:
Lower
California
,
23°49’N
, 12°750’W].
Trindade specimens.
1 juvenile
female (
MZUSP 40330
)
,
1 juvenile
(
MZUSP 40240
),
Trindade Island
,
Praia
da Calheta
,
20°30’28.89’’S
,
29°18’37.76”W
,
J.B. Mendonça
coll.,
11.xii.2017
, on washed log, low tide
.
Size of largest female (juvenile): cl
7 mm
, cw
8 mm
.
Comparative material examined.
Planes marinus
:
United States
:
2 males
,
1 female
(
USNM 88069
)
,
Oregon
,
Lincoln Beach
,
29.xii.1947
, from
Japanese
mine [
F.A. Chace
det.]
.
Brazil
:
São Paulo
: 3 ovigerous females (
MZUSP 2112
),
Alcatraz Island
,
Instituto
de Pesca coll.,
v.1965
.
Rio Grande do Sul
: 1 ovigerous female (
MZUSP 13285
),
Praia do Cassino
,
Rio Grande
,
A. Santos
coll.,
18.ii.2000
.
Distribution.
Brasil
(
São Paulo
, Santa Catarina,
Rio Grande do Sul
) (Prado & Melo 2002),
Argentina
(Mar Chiquita) (
Spivak & Bas 1999
). This is the first record of
P. marinus
from Trindade. Central Atlantic:
Saint Helena
(Chace 1966), Trintan da
Cunha
(
Holthuis & Sivertsen 1967
). Eastern Pacific: from
Canada
to
Mexico
(Lower California) and
Chile
(Valdivia,
Atacama
Trench) (
Chace 1951
). Central Pacific and South
China
Sea:
Japan
,
China
(Xisha Island), Hawaii,
New Zealand
(including Kermadec Islands) (
Kepel
et al.
2002
and references therein).
Ecological notes.
Little is known about the biology of
Planes marinus
. This is an epipelagic species associated with drifting flotsam, sometimes syntopically with other invertebrates (e.g.
Caprella andreae
Mayer
,
Lepas anatifera
Linnaeus
,
Mytilus galloprovincialis
Lamarck
,
Plagusia depressa
, and
Planes minutus
), and as epibiont of the sea turtle
Lepidochelys olivacea
(Eschscholtz)
(
Spivak & Bas 1999
;
Kepel
et al.
2002
;
Frick
et al.
2011
;
Pinheiro
et al.
2013
). Prevalence of limb autotomy can be high (
Spivak & Bas 1999
), likely as a result of agonistic interactions (
Frick
et al.
2011
). Adults occur in heterosexual pairs, ovigerous females carry between 5,000 and 20,000 eggs, and megalopae can recruit to host turtles (
Spivak & Bas 1999
;
Frick
et al.
2011
). The diet of
P. marinus
collected from the sea turtle
L. olivacea
from the eastern tropic Pacific and the Hawaiian islands included
Planes
and
Plagusia
megalopae,
Pleuroncodes planipes
Stimpson
, ciprid larvae and cirri of cirripeds, cnidarian, salps, and unidentified animal and plant material. Apparently,
P. marinus
consumes less animal materials and more plant materials than
P. minutus
(
Frick
et al.
2011
,
P. minutus
as
P. major
).
Remarks.
Among the specimens examined by
Spivak & Bas (1999)
from
Argentina
,
3 males
and
3 females
had a large white spot that covered most of the anterior half of the carapace similar to that of the juvenile female MZUSP 40330 from Trindade (
Fig. 51A
).
Planes marinus
and
P. minutus
(
Fig. 51A–D
) have both been recorded from Trindade (this report) and
St. Helena
, while neither of the two species were recorded from the
Ascension Island
to date (Chace 1966;
Manning & Chace 1990
;
De Grave
et al.
2017
).
The specimens from
Brazil
previously identified by Prado & Melo (2002) with
P. marinus
were reassessed and their identity is here confirmed as
P. marinus
(see above under comparative material). The main morphological differences between
Planes marinus
and
P. minutus
are briefly discussed below under
P. minutus
.