Kalyptorhynchia (Platyhelminthes: Rhabdocoela) from KwaZulu-Natal (South Africa), with the description of six new species
Author
Willems, Wim R.
Author
Reygel, Patrick
Author
Steenkiste, Niels Van
Author
Tessens, Bart
Author
Artois, Tom J.
text
Zootaxa
2017
4242
3
441
466
journal article
36297
10.11646/zootaxa.4242.3.2
0abf37ce-8190-42a4-87bc-96f3c8e10a38
1175-5326
376905
C67937C9-844F-461E-AABB-121B9C3CE5FA
Lagenopolycystis mandelai
Willems & Artois
n. sp.
(
Fig. 5
C–E)
Lagenopolycystis
n. sp.
2 in
Tessens
et al.
(2014)
Locality.
iSimangaliso
Wetland Park
, Sodwana
Bay
,
Jesser Point
(lighthouse) (
27°32'28.4"S
,
32°40'47.9"E
), coarse-grained sand from swirl holes on rocky plateau in mid-eulittoral, covered with the acoel
Symsagittifera macnaei
(
Du Bois-Reymond Marcus, 1957
)
Kostenko & Mamkaev, 1990
from a highly-exposed, steep beach,
December 10, 2009
(
type
locality)
;
same locality, fine-grained sand from swirl holes on rocky plateau in mideulittoral, covered with the acoel
S. macnaei
,
December 10, 2009
.
Material.
Two animals studied alive. One whole mount, designated holotype (SMNH, type-8858).
Etymology.
Species name in honour of Nelson Mandela (
1918–2013
), famous anti-apartheid activist, Nobel Peace Prize laureate (1993, together with Frederik Willem de Klerk) and former president of
South
Africa
(
1994– 1999
).
Diagnosis.
Species of
Lagenopolycystis
with ± 115-µm-long prostate stylet
type
III, with proximal funnel-like part and distal tubular part, which is bent perpendicularly at 2/3 and has a blunt, club-shaped end. Slightly bent, needle-shaped accessory stylet
type
II ± 65 µm long and attached to prostate stylet
type
III.
Description.
Habitus and internal organisation similar to that of
Lagenopolycystis peresi
(
Brunet, 1965
)
Artois & Schockaert, 2000
. In live animals, the proboscis is approximately 1/4 of the total body length, although appearing slightly shorter in
Fig. 5
C because of stretching of the observed individual. Animal colourless, ±
0.9 mm
long (measured on whole mount), with two eyes.
The prostate stylet
type
III (
Fig. 5
C–D: pst3) is 115 µm long and rather complex. Proximally it is funnelshaped, 30 µm wide, with a thickened rim on one side. This rim shows a subtle striation and ends in a rounded knob. Following the funnel-shaped part, the stylet is straight, but bends perpendicularly at 2/3 of its length. It ends in a blunt, club-shaped part. The accessory stylet
type
II (
Fig. 5
C–D: ast2) is attached to the thickened rim of the prostate stylet through a narrow bridge that ends in a comma-shaped part, which constitutes the proximal rim of the accessory stylet proper. The accessory stylet curves away from the club-shaped end of the prostate stylet. It is hook shaped and 65 µm long. A rather large, globular accessory vesicle
type
II opens close to the accessory stylet. The prostate vesicle
type
III can barely be seen on the whole mount as it is very small and probably (partly) obscured by the prostate stylet.
The female duct receives the oviduct and a large female bursa. A seminal receptacle could not be observed.
Discussion.
Although some diagnostic features could not be observed (e.g. parallel cone retractors, 4+1 retractor system, seminal receptacle),
L. mandelai
n. sp.
fits the diagnosis of the taxon
Typhlopolycystidinae
Evdonin, 1977
(see
Artois & Schockaert 2000
). In addition, the molecular phylogenetic analysis of
Tessens
et al.
(2014)
shows that this species belongs to the monophyletic taxon
Lagenopolycystis
Artois & Schockaert, 2000
. Within
Typhlopolycystidinae
, only representatives of
Lagenopolycystis
and
Typhlopolycystis
Karling, 1956
have both a prostate stylet
type
III and an accessory stylet
type
II, whereas species of
Myobulla
Artois & Schockaert, 2000
and
Sabulirhynchus
Artois & Schockaert, 2000
possess a prostate stylet
type
III, and species of
Limipolycystis
Schilke, 1970
and
Brunetorhynchus
Schockaert
et al.
, 2014
have an accessory stylet
type
II (see
Artois & Schockaert 2003
;
Artois
et al.
2012
; Schockaert
et al.
2014). Furthermore, species of
Typhlopolycystis
and
Limipolycystis
are characterised by the presence of a pear-shaped seminal receptacle (
Karling 1956
,
1978
;
Brunet 1965
;
Schockaert & Karling 1975
;
Noldt & Reise 1987
;
Artois & Schockaert 2005
). According to
Brunet (1965)
, a seminal receptacle is absent in
L. peresi
, but both the description and figures show a strong sphincter on the bursal stalk. Detailed study of sectioned material of
L. peresi
shows a short, blind-ending, sclerotized tube that is distally surrounded by strong circular muscles (
Artois & Schockaert 2000: p. 157
). This structure is found exactly at the location of the seminal receptacle in species of
Typhlopolycystis
and therefore both structures were considered to be homologous by
Artois & Schockaert (2005: p. 115)
. A similar structure is also found in other undescribed representatives of
Lagenopolycystis
(own unpublished data). However, since no sectioned material is available for
L. mandelai
n. sp.
, the presence of a seminal receptacle cannot be confirmed.
The overall construction of the hard parts (pst3 + ast2) of the new species is similar to that of
L. peresi
, albeit with some obvious differences. In both species the prostate stylet
type
III has a clear, funnel-like part proximally, with the accessory stylet attached to it at the transition to a more or less tubular part. However, the prostate stylet of
L. peresi
only bends slightly distally, while
in
L. mandelai
n. sp.
it bends perpendicularly. Furthermore, the prostate stylet of
L. mandelai
n. sp.
is approximately twice the size of that of
L. peresi
(
Brunet 1965: 53–69 µm
). The accessory stylets of both species are highly similar, but clearly shorter in
L. peresi
(40–43 µm, measured on drawings of
Brunet 1965
).