Review of the systematics of the genus Roboastra Bergh, 1877 (Nudibranchia, Polyceridae, Nembrothinae) with the description of a new species from the Galápagos Islands
Author
Pola, M.
Author
Cervera, J. L
Author
Gosliner, T. M.
text
Zoological Journal of the Linnean Society
2005
2005-06-30
144
2
167
189
https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2005.00167.x
journal article
5404
10.1111/j.1096-3642.2005.00167.x
7b2437dc-af23-4f18-a2de-8604d0626989
0024-4082
4634644
ROBOASTRA EUROPAEA
GARCÍA GÓMEZ, 1985
(
FIGS 3D
,
4D
,
6C
,
7E
)
Material examined:
Torre
,
Marbella
,
Spain
,
July 1995
,
1 specimen
,
10 m
depth
,
30 mm
, collected by
J.L. González
(
MNCN 15.05
/46612).
Torre
,
Marbella
,
Spain
,
September 1995
,
1 specimen
,
10 m
depth
,
18 mm
, collected by M.
T
.
Barrea
(
CASIZ 166049
)
.
Torre
,
Marbella
,
Spain
,
August 1996
,
2 specimens
, 10.7 m depth, 15 &
19 mm
, collected by
K.L. Schick
(
CASIZ 166053
)
.
La Herradura
,
Granada
,
Spain
,
February 1993
,
1 specimen
,
12 m
depth
,
14 mm
, collected by
A. Barrajón
and
M. Zarauz
(
MNCN 15.05
/29203).
Arrecife La Cañonera
,
Strait
of
Gibraltar
,
Spain
,
June 2002
,
1 specimen
,
17 m
depth
,
50 mm
, collected by
Alma Sánchez
(
MNCN 15.05
/46650).
Funchal
,
Madeira
,
June 1999
,
1 specimen
,
100 m
depth
,
35 mm
(
MMF
31021)
.
Ponta do Baleeira
,
Sagres
,
Portugal
,
July 2002
,
1 specimen
,
20 m
depth
,
14 mm
, collected by
M. Pola
(
MNCN 15.05
/46613).
Ponta do Baleeira
,
Sagres
,
Portugal
,
July 2002
,
1 specimen
,
20 m
depth
,
10 mm
, collected by
M.A. Malaquias
(
MNCN 15.05
/ 46613).
Specimens
were collected on rocks and were measured following preservation
.
Distribution:
This species is known mainly from the Strait of
Gibraltar
and southern Iberian Peninsula (
García Gómez, 1985
,
2002
;
Cervera
et al
., 1988
;
García Gómez
et al
., 1989
,
1991
;
Moreno & Templado, 1998
;
Schick, 1998
;
Megina, 2000
;
Ocaña
et al
., 2000
;
Sánchez-Tocino, Ocaña & García 2000
;
Grande
et al
., 2002
;
Megina & Cervera, 2003
). One misidentified specimen of
Plocamopherus
from Madeira deposited at the Natural History Museum (London) (1863.9.19.3), supposedly collected by Rev. R. Lowe, was correctly identified as belonging to
Roboastra
, very probably
R. europaea
. This hypothesis has been strongly supported by the recent collection of one specimen (also photographed) of this species at Funchal harbour.
This species has been also recorded in southwestern
Portugal
(Calado
et al
., in press) and Catalonian coasts (north-eastern Iberian Peninsula, Mediterranean Sea) (Schick, pers. comm.).
Poddubetskaia & Petit de Voice (2003)
provide an illustration of
R. europaea
from
Dakar
(
Senegal
). This is the southernmost record of this species in the Atlantic.
External and internal morphology:
Described in detail and figured by
Pola
et al
. (2003)
. Regarding the colour pattern, this species can exhibit two colour varieties (
Fig. 6C
1
, C
2
). The radular formula of two 15- mm-long specimens (preserved) is 23 ¥ 4.1.1.1.4; that of the 30-mm-long specimen (preserved) is 25 ¥ 4.1.1.1.4 (
Fig. 7E
). The reproductive system is triaulic (
Figs 3D
,
4D
). The hermaphroditic duct widens into a S-shaped ampulla that has thick walls. The bursa copulatrix is rounded and the seminal receptacle is elongate; both are similar in size. The seminal receptacle has a short duct that connects to the vagina, near the bursa. The deferent duct, which lacks a morphologically well-differentiated prostate, is long and coiled, ending in a dilated penial atrium. The vaginal gland is large with muscular walls, convex on one side and concave on the other. The penis is located within the distal end of this muscular portion and is armed with at least three different kinds of hooked and chitinous spines arranged in helicoidal rows. Anatomical descriptions are based on the illustrations by
Pola
et al
. (2003)
.
Remarks:
Roboastra europaea
was described by
García Gómez (1985)
as the first species of the genus in the Atlantic Ocean, from the Strait of
Gibraltar
.
Pola
et al.
(2003)
redescribed the species and updated its geographical range to south-western
Portugal
(Calado
et al
., in press) and the Catalonian coast (north-eastern
Spain
).
The anatomy of this species and the reproductive system of the specimen examined (MNCN 15.05/ 46650) are very similar to those descriptions and no substantive differences have been found, except with regard to identification of the uterine duct, which was not reported before. The uterine duct is long and convoluted, going from the middle of the vagina to the oviduct.
García Gómez (1985)
mentioned the presence of a fertilization duct, but did not draw it. More recently,
R. europaea
was included in studies relating to molecular phylogeny (
Grande
et al
., 2002
) and feeding ecology (
Megina & Cervera, 2003
).