Pseudobiceros wirtzi sp. nov. (Polycladida: Cotylea) from Senegal with revision of valid species of the genus
Author
Bahia, Juliana
Author
Schrödl, Michael
text
Zootaxa
2016
4097
1
101
117
journal article
10.11646/zootaxa.4097.1.5
4f180553-8a41-4157-902b-8f27fdabcdc2
1175-5326
267125
6149A40D-2514-41D6-ADC9-79677262AC55
Pseudobiceros wirtzi
sp. nov.
Figures 1
and
2
Type
material.
Holotype
: One specimen
21 x
16
mm collected
October 2009
at
Senegal
, near Ngor Island (Voucher
ZSM
20160015HT).
Paratypes
: Two specimens in 96% ethanol collected
14.10.2009
at Santo Antão,
Cape Verde
(Voucher
ZSM
20160016PT)
Geographic distribution.
Senegal
and
Cape Verde
. Additional photographic records from Madeira (
17.03.2009
, photo cortesy prof. Dr. Peter
Wirtz
) and Canarias Islands (
Vera
et al.
2008
).
Etymology.
The species is named after Prof. Dr. Peter
Wirtz
, who provided the material and has contributed with numerous marine invertebrate field guides over the years.
Diagnosis.
Black to very dark brown background color with narrow yellow lines, some of them partly white, mostly on their tips. Thin lines scattered on dorsal surface, without distinctive orientation; most transverse but not straight, curving and some even splitting.
FIGURE 1.
A—
Pseudobiceros wirtzi
sp. nov.
in situ
from Madeira; B—detail of the ventral surface; C—
P. wirtzi
sp. nov.
in situ
from Senegal. fg: female gonopore; mg: male gonopore; mo: mouth; ph: pharynx; pt: pseudotentacles; su: sucker.
Description.
Color: Black to very dark brown background color. Narrow yellow lines, some of them partly white, mostly on their tips. Thin lines scattered on dorsal surface, without distinctive orientation; most transverse but not straight, curving and some even splitting. In
Senegal
specimen lines white when nearer to margin; in Madeira worms, yellow lines and all white lines in middle of body (
Fig. 1
A, C).
Form: body rounded, delicate constitution, ruffled margin.
Pseudotentacles: pointed ear-like, about
2 mm
long (
Fig. 1
C,
Fig. 2
A).
Eyes: cerebral eyespots arranged in horseshoe shape cluster of approximately 18 eyespots. Deep dark coloration and contracted pseudotentacular area making eyespots counting difficult. Ventral pseudotentacular eyespots in four groups, two in sinus between folds, and other two on each broad flap of marginal tentacles (
Fig. 1
A). Dorsally, two groups with evenly spaced eyespots in broader part of pointed ear-like tentacle, and two groups, one in each pseudotentacular tips (
Fig. 1
A). These more densely arranged as in main pseudotentacle structure.
Digestive system: mouth opens at
4 mm
from anterior margin, pharynx short with 4 to 5 shallow folds, 1.7 mm long (
Fig. 1
B).
FIGURE 2.
A—
Pseudobiceros wirtz
sp. nov.
dorsal and ventral diagrams of the pseudotentacular area; B and D—sagittal sections of male reproductive structures; C—diagram of reconstruction of slides. ce: cerebral eyespots; de: dorsal eyespots; ed: ejaculatory duct; me: middle ventral eyespots; pp: penis papilla; pv: prostatic vesicle; te: pseudotentacular tip eyespots; sd: seminal duct; st: stylet; sv: seminal vesicle; ve: ventral eyespots.
Body wall: sucker
1 mm
in diameter, located at 1.2 mm from female gonopore. Ventrally, epidermis almost twice as thick as basement membrane, densely ciliated. Muscular layers thin, outer longitudinal, followed inward by circular and inner diagonal.
Gonopores: two male and one female gonopores. Male pores 0.5 mm in diameter at 5.5 mm from anterior margin; female pore
1 mm
behind male gonopore,
6 mm
in diameter (
Fig. 1
B).
Male reproductive system: seminal vesicle large and elongated, 0.5 mm long and 0.3 mm broad. Prostatic vesicle rounded and 0.19 mm in diameter (
Fig. 2
B, C, D). Ejaculatory duct straight, 0.2 mm long. Male atrium shallow, penis papillae 0.25 long and stylet short.
Female reproductive system: specimen seems to be immature, since we have not found in our slides female structures, like cement glands, vagina and uteri.
Taxonomic remarks.
The presence of two male gonopores, smooth dorsal surface, simple and shallow folded pharynx and complex folded pseudotentacles place the new species in the genus
Pseudobiceros
.
Pseudocerotidae
species with black background and yellow and white lines color pattern are not common.
Pseudoceros zebra
generally resembles the studied species in its color pattern (
Rüppell & Leuckart 1828
), but, they belong to different genera.
Pseudoceros zebra
present the complex ruffled pharynx typical for
Pseudoceros
, while
Pseudobiceros wirtzi
sp. nov.
has few simple folds in its pharynx. In addition, the newly described species lacks a marginal band and exhibits a dorsal surface with thin yellow and white transverse and multiple lines in multiple directions, mostly transverse, instead of the lack of pigmentation between black areas showed by
Pseudoceros zebra
.
In Marcus’ (1950), Faubel’s (1984), and Newman & Cannon’s (1994) revisions of accepted
Pseudoceros
and
Pseudobiceros
species, no other
Pseudobiceros
species match the color pattern presented by
P. wirtzi
. Newman & Cannon pointed out species with transverse lines pattern such as
Pseudobiceros bedfordi
,
P. dendricticus
,
P. flavolineatus
,
P. fulgor
,
but all present a distinctive margin, which is lacking in our specimens.
Pseudobiceros bedfordi
, (
Laidlaw 1903a
) has a much more complex color pattern with wider stripes instead of lines, and with blotches, mottling, and different colored dots that are absent from
P. wirtzi
.
Pseudobiceros dendricticus
, has yellow background color and brown longitudinal lines and a yellow median line (
Prudhoe 1989
), instead of black background color and yellow and white lines as the studied specimens.
Pseudobiceros flavolineatus
(
Prudhoe 1989
)
is the one that most resembles
P. wirtzi
, but it presents a double row of dark spots on its margin, has a reddish brown background color and the narrow yellow lines are disposed from the median line to the margin without touching each other, in a concentric design, which is not the case in
P. wirtzi
. The Australian species
P. fulgor
(
Newman & Cannon 1994
)
has white stripes instead of yellow and a lighter background color of brownish orange or deep pink, and presents yellow or cream blotches and black margin that are absent in
P. wirtzi
, in addition to a rounded seminal vesicle instead of elongated. The studied specimens belong to the same species as the ones illustrated in Pérez Sanchéz & Moreno Batet (1990, p: 101),
Wirtz
& Debelius (2003, p: 84)
and
Newman & Cannon (2003, p: 84)
. It was also recently reported, but not described, as
Pseudocerotidae
sp4 from Canary Islands by
Vera
et al.
(2008)
.