Cheliplana vaginalis Karling, 1983

Gobert, Stefan, Diez, Yander L., Monnens, Marlies, Reygel, Patrick, Van Steenkiste, Niels W. L., Leander, Brian S. & Artois, Tom, 2021, A revision of the genus Cheliplana de Beauchamp, 1927 (Rhabdocoela: Schizorhynchia), with the description of six new species, Zootaxa 4970 (3), pp. 453-494 : 485

Cheliplana vaginalis Karling, 1983

Synonyms. Rhinepera vaginalis nomen nudum Meixner, 1929.

Material examined. None.

Known distribution. Bay of Kiel, Germany ( Meixner 1938 in Karling 1983).

Remarks (summarised from literature). The most important morphological characteristics of the species are described by Karling (1983). Live specimens measure 0.8 mm. The proboscis hooks are ~18 μm long. The prepharyngeal lumen is long and armed with spines, which, according to Meixner (unpublished notes quoted in Karling 1983), are strongly developed in the dorsal part and less in the ventral part. Karling (1983) describes the pharyngeal spines as ‘soft, plasmatic tufts’. A single, continuous haptic girdle is present near the caudal body end. A single testis is situated ventrally, posterior to the pharynx.

The common genital opening and vaginal opening are located in front of the haptic girdle. The male copulatory bulb is tubiform, with a widened, proximal part containing the prostatic vesicle. A pair of seminal vesicles enters at the proximal end of the bulb. The cirrus is long and tubular and ornamented with longitudinal, sclerotised ridges. Distally, it ends in a small penis papilla, which protrudes into the tubiform male atrium. The male atrium connects to the common genital atrium. The vaginal opening is situated between the common genital opening and the haptic girdle. The vagina externa is a long, winding tube, lined with a thick and sclerotised basal lamina (pseudocuticula).A syncytial sheath and a single layer of circular muscles surround the vagina. A small bulb containing a number of cell nuclei is present where the tubular vagina connects to the non-muscular, syncytial bursa. A cytoplasmic bulb, which is somewhat separate from the bursa itself, connects directly to the ovary. No spermatic duct appears present.