A revision of the genus Cheliplana de Beauchamp, 1927 (Rhabdocoela: Schizorhynchia), with the description of six new species
Author
Gobert, Stefan
0000-0003-1949-9174
Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & stefan. gobert @ uhasselt. be; https: // orcid. org / 0000 - 0003 - 1949 - 9174
stefan.gobert@uhasselt.be
Author
Diez, Yander L.
0000-0001-8741-4799
Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & University of Oriente, Departement of Biology and Geography, Avenida Patricio Lumumba s / n, CP 90500, Santiago de Cuba, Cuba. Beaty Biodiversity Research Centre, Departments of Botany and Zoology, University of British Columbia, 3529 - 6270 University Blvd, Vancouver, BC, V 6 T 1 Z 4 Canada. & yander @ uo. edu. cu; https: // orcid. org / 0000 - 0001 - 8741 - 4799
yander@uo.edu.cu
Author
Monnens, Marlies
0000-0002-9133-1512
Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & marlies. monnens @ uhasselt. be; https: // orcid. org / 0000 - 0002 - 9133 - 1512
marlies.monnens@uhasselt.be
Author
Reygel, Patrick
0000-0001-8721-6290
Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & patrick. reygel @ uhasselt. be; https: // orcid. org / 0000 - 0001 - 8721 - 6290
patrick.reygel@uhasselt.be
Author
Van Steenkiste, Niels W. L.
0000-0002-2676-7862
niels. vansteenkiste @ botany. ubc. ca; https: // orcid. org / 0000 - 0002 - 2676 - 7862
niels.vansteenkiste@botany.ubc.ca
Author
Leander, Brian S.
0000-0003-0798-0470
bleander @ mail. ubc. ca; https: // orcid. org / 0000 - 0003 - 0798 - 0470
bleander@mail.ubc.ca
Author
Artois, Tom
Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium.
text
Zootaxa
2021
2021-05-17
4970
3
453
494
journal article
6258
10.11646/zootaxa.4970.3.2
281c9017-f55b-47bf-bea0-e511a7173605
1175-5326
4766692
FEABE248-E1EA-48F5-A1AF-0077FE40C257
Cheliplana gemmifera
Noldt, 1989
Fig. 6G–H
Material examined. New material
.
GERMANY
• observations and photographs of 1 live specimen;
Sylt
;
55°01’55”N
,
8°29’12”E
;
28 Apr. 2015
; fine to medium-grained sand with many diatoms, some flocculent organic matter and lumps of clay, taken at a depth of
11.7 m
.
Known distribution
. Sylt,
Germany
(
Noldt 1989
).
Note.
No reference material was available to us at the time of this study.
Remarks
. The newly collected specimen from Sylt was light brown when alive.
Noldt (1989)
reports body lengths between 1.7 and
1.9 mm
. No new measurements of total body length could be taken, as the newly collected specimen was completely contracted. The proboscis has an overall length of 30–35 μm, with the sclerotised hooks reportedly measuring 11–13 μm. The proboscis hooks of the new specimen measure ~13 μm. According to
Noldt (1989)
, proboscis sidepieces are absent. The postrostral bulb is 65–70 μm long, with a diameter of 15 μm according to
Noldt (1989)
, but we were not able to measure these dimensions in our specimen. The prepharyngeal cavity is unarmed. The cylindrical pharynx measures 350–400 μm. A single testis is situated alongside the pharynx. The seminal vesicles are enveloped by longitudinal muscles and separately enter the copulatory bulb. Three
types
of prostatic glands surround the copulatory bulb and enter the proximal end of the bulb: large glands containing strongly refractive ‘pearl-like’, acidophilic granules (x in
Fig. 6H
) (Noldt mentions that these large ‘pearls’ stain both acidophilic and basophilic, but that the latter is probably the result of an artefact); glands with fine, acidophilic secretions; and coarse-grained, basophilic glands. The ‘pearls’ measure 7–11 μm in diameter.
The copulatory bulb is pear-shaped, with a length of 200 to 270 μm (160 μm in the newly collected specimen) and a proximal diameter of up to 85 μm. The proximal 2/3 of the bulb is filled with an internal seminal vesicle. Within the copulatory bulb, the prostatic vesicle contains the fine-grained, acidophilic gland secretions, as well as the ‘pearl-like’ secretions. The ejaculatory duct runs from the distal end of the inner seminal vesicle through the prostatic bulb. A sclerotised cirrus is situated in the distal part of the copulatory bulb (
Fig. 6G
). It is more or less cylindrical and is ~20 μm in long in the new specimen, a bit smaller than the 28–35 μm range reported by
Noldt (1989)
. The interior surface of the cirrus is armed with fine spines. According to
Noldt (1989)
, the spines measure 5–7 μm. The quality of the new specimen did not allow for accurate measurements of the cirrus spines.
A uterus is present, which connects to the common genital atrium. The single ovary is connected to the atrium through a short female duct. A copulatory bursa is positioned adjacent to the ovary. A sclerotised spermatic duct is lacking according to
Noldt (1989)
. Neither vagina interna, nor vagina externa were observed. The vitellarium is unpaired and extends throughout the specimen, from beyond the ovary to the pharynx.