Polyclads (Platyhelminthes) in the southern Gulf of Mexico: unveiling biodiversity and descriptions of two new speciesAuthorCuadrado, Daniel0000-0001-5565-3023Department of Biodiversity and Evolutionary Biology, National Museum of Natural Science, MNCN (CSIC), Madrid 28006, SpainAuthorHernández-Gonzalez, Alejandro0000-0002-1557-5582Universidad Nacional Autónoma de México, Merida, MexicoAuthorNoreña, Carolina0000-0002-4580-7460Department of Biodiversity and Evolutionary Biology, National Museum of Natural Science, MNCN (CSIC), Madrid 28006, SpainAuthorSimões, Nuno0000-0001-7490-3147Universidad Nacional Autónoma de México, Merida, Mexico & Laboratorio Nacional de Resiliencia Costera, México, Mexico & International Chair for Coastal and Marine Studies, Harte Research Institute for Gulf of Mexico Studies, Corpus Christi, USAtextZooKeys20242024-12-131221103144journal article10.3897/zookeys.1221.128260EE34B942-57D8-456C-A6D5-F8046BB3A71EThysanozoon brocchii
(
Risso, 1818
)
Fig. 16Material examined.Campeche
coast,
Mexico
• 1;
Cayo Arcas
;
20.2°N
,
92.0°W
;
6.3 m
;
22 Apr. 2018
;
A. Hernández
leg.;
CRPPY
-0068
•
1;
Cayo Arcas
;
20.2°N
,
92.0°W
;
13.2 m
;
24 Apr. 2018
;
A. Hernández
leg.;
CRPPY
-0076
.
Distribution.
The species was described from Naples,
Italy
(
Risso 1818
). It is considered a cosmopolitan species, reported in the Mediterranean Sea, the
United Kingdom
, and southern and western Africa. In the western Atlantic,
Thysanozoon brocchii
has been recorded in the Gulf of
Mexico
(
Hyman 1952
;
Marcus and Marcus 1968
); Caribbean coast of
Colombia
(
Quiroga et al. 2004 a
,
2004 b
);
Brazil
(
Bahia et al. 2014
,
2015
,
2017
;
Bahia and Schrödl 2018
); Canary Islands (
De Vera et al. 2009
);
Argentina
(
Brusa et al. 2009
). In the Pacific it has been recorded in
Japan
and
New Zealand
(
Prudhoe 1985
). The record for Cayo Arcas,
Campeche
, represents the first record for
Mexico
.
Description.
Body oval-shaped and firm consistency,
1.5 cm
in length and
0.5 cm
in width. Background colour ranges from brown to yellowish-ochre. Two stripes of paler cream spots, one longitudinally and the other perpendicular, form an inverted cross (Fig.
16 A, B
). The dorsal surface is covered with characteristic papillae, decreasing in size towards the margin. Pseudotentacles complex with multiple folds (Fig.
16 D
). Ruffled pharynx located in the first 1 / 3 of the body, with the oral opening in the middle.
Two male
copulatory apparatus and positioned close to the female organ in the ventral central region of the body. Sucker at the beginning of the second 1 / 2 of the body (Fig.
16 C
).
Remarks.Thysanozoon brocchii
is noted for the abundance of papillae covering its dorsal surface and its cosmopolitan distribution. Various morphological descriptions with distinct colour patterns occur for different localities (
Bahia et al. 2014
). Molecular analysis of the different populations of this species is needed to identify potential divergences among the cited locations.
Thysanozoon brocchiiA
dorsal view
B
In situ
C
ventral view
D
detail of the dorsal surface; papillae, cerebral eyes, and pseudotentacles.