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
Carcharodorhynchus
spec.
(
Fig. 8
D–E)
Locality.
iSimangaliso
Wetland Park
, Sodwana
Bay
,
Jesser Point
(lighthouse) (
27°32'28.4"S
,
32°40'47.9"E
), green algae from swirl holes on rocky plateau in mid-eulittoral from a highly-exposed, steep beach,
December 10, 2009
.
Material.
One whole mounted individual (HU, no. VII.4.8).
Description and remarks.
This single specimen was initially thought to be juvenile, but upon fixation it clearly showed some hard structures, most probably cirrus spines. Therefore, the description of this specimen is very incomplete and should be regarded as provisional.
The slender animal is
0.6 mm
long (measured on the whole mount) and lacks eyes. The position of the rosulate pharynx could not be determined on the fixed material. The symmetrical proboscis is 63 µm long (measured on the whole mount) and carries two identical fields of denticles, one on each proboscis half. These fields are U-shaped, approximately 30 µm long, with one half of the field double the width of the other one, and with larger denticles. These denticles are not in rows, but rather randomly positioned. Unfortunately, very little information on the genital system is available. In the caudal third of the body, a 21-µm-long cirrus-like structure is present. Its detailed structure is hard to discern, but it consists of at least three needle-like spines, some of which have a cup-shaped proximal part.
This species can easily be recognised as belonging to the taxon
Carcharodorhynchus
Meixner, 1938
, based on the presence of denticles on the schizorhynch proboscis. Of the 17 described species, only five (
C. ambronensis
Schilke, 1970
,
C. arista
Noldt & Hoxhold, 1984
C. flavidus
Brunet, 1967
,
C. involutus
Jouk & De Vocht, 1989
and
C. polyorchis
L’Hardy, 1963
) have a symmetrical proboscis, as in the
South
African specimen. However, they clearly differ in the distribution of the denticles on the proboscis and the detailed structure of the male copulatory organ, none of them having such long, needle-like spines as in
Carcharodorhynchus
spec. (see L’Hardy 1963;
Brunet 1967
;
Schilke 1970
;
Noldt & Hoxhold 1984
;
Jouk & De Vocht 1989
;
Reygel
et al.
2014
). In addition to
C. involutus
from the Kenyan coast (
Jouk & De Vocht 1989
), this is the second record of a specimen of
Carcharodorhynchus
from the African coasts. Although this specimen clearly represents a new species, we refrain from formally describing it as there is only one specimen available. This is, in our opinion, not sufficient in a taxonomically-challenging genus such as
Carcharodorhynchus
.