Cheliplana orthocirra Ax, 1959

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 : 475

Cheliplana orthocirra Ax, 1959

Material examined. New material. ITALY • 1 whole mount; Sardinia, Asinara National Park, Cala del Bianco ; 41°04’27”N, 8°20’12”E; 25 Sep. 2014; medium-grained sand between Posidonia sp. , at 2.5 m deep; HU X.2.40 .

Note. No reference material was available to us at the time of this study.

Known distribution. Florya, Sea of Marmara, Turkey ( Ax 1959). Southern and Western Sweden ( Atherton & Jondelius 2020).

Remarks. The proboscis hooks are smooth, fairly straight and ~11 μm long in the specimen from Sardinia. Ax (1959) does not give any measurements except those pertaining to the cirrus. Cheliplana orthocirra has a pair of partially fused testes, positioned on one side of the pharynx. The copulatory bulb is positioned in the posterior half of the body and contains a proximal prostatic vesicle, which connects directly to the distal cirrus. A pair of large, globular seminal vesicles and prostatic glands enter the proximal end of the copulatory bulb. The cirrus is armed with very fine spines over its entire length. These spines decrease in size towards the distal end of the cirrus. A single gonopore and bursa are present near the caudal end of the specimen. In the specimen from Sardinia, the cirrus is 35 μm long, which is significantly shorter than the ~56 μm reported by Ax (1959). Nevertheless, given the cirrus shape and generally similar internal morphology, we feel confident in ascribing this specimen to C. orthocirra .