Cheliplana terminalis Brunet, 1968

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 : 483-484

Cheliplana terminalis Brunet, 1968

Fig. 8C–D

Synonyms. Cheliplana asica terminalis Brunet, 1968

Material examined. New material. AUSTRALIA • 2 whole mounts; Port Lincoln , Coffin Bay, Kellidie Bay; 34°36’41”S, 13°31’03”E; 8 Dec. 2010; along turn-off to airstrip, coarse-grained sand and shell gravel; HU X.2.02– X.2.03 .

FRANCE • 1 whole mount; Cerbère, Terrimbo; 19 Jul. 2007; mixture of fine and coarse sand, fairly clean with little silt, from within the bay at a depth of 8 m; HU VIII.4.28 • 1 whole mount; Cerbère, Terrimbo, Les Aloès; 27 Jul. 2012; directly in front of the scaffold, 50 m into the sea, fine sand from a depth of 6 m; HU VIII.4.29 • 2 whole mounts; Canet-en-Rousillon, Canet-Plage; 31 Aug. 2016; pure, fine sand from beach in front of parking harbour, from a depth of 0.5 m; HU VIII.4.36 & HU VIII.4.38 • 3 whole mounts; Canet-en-Rousillon, Canet-Plage; 31 Aug. 2016; pure, fine sand from bend in beach, from a depth of 0.4 m; HU VIII.4.37 & HU VIII.4.39–HU VIII.4.40.

SPAIN • 1 whole mount; Catalonia, Blanes ; 20 Jul. 2012; sand patches from the north side of a rock with footpath; coarse, clean sand with vegetal debris from a depth of 3 to 4 m; HU VIII.4.34 .

Reference material. Two serially sectioned specimens from France, one of which the holotype ( SMNH Type 2816, SMNH 82468 ) .

Known distribution. Provence-Alpes-Côte d’Azur, France ( Brunet 1968). Djezira, Mogadishu, Somalia ( Schockaert 1982). Mombasa, Kenya ( Jouk & De Vocht 1989). Santiago de Cuba and Chivirico, Cuba ( Diez et al. 2019).

Remarks. According to Brunet’s (1968) description, live specimens are pink and measure ~ 1.6 mm. The proboscis hooks reach a length of 15–16 μm. The copulatory organ is highly similar to that of C. asica as described by Marcus (1952), but differs in the sclerotised distal end of the cirrus ( Fig. 8C–D ) and the sclerotised penis papilla that surrounds it (pp, Fig. 8C–D ). The female system also exhibits a number of differences. According to Brunet (1968), the bursa in C. terminalis connects to the ovary via a well-differentiated spermatic duct provided with a small sclerotised piece, while in C. asica , the bursa connects to the female genital duct (ductus communis).

While we were unable to confirm the bursa-female duct connection on material of C. asica , we would argue that the above-mentioned features of the male and female system, if correctly observed, are differential diagnostic characters. As such, we consider C. terminalis and C. asica two separate species.

The specimens collected from Somalia and described by Schockaert (1982) likely belong to C. terminalis , because of the presence of a sclerotised penis papilla and the greater degree of sclerotisation of the distal end of the cirrus (compared to Marcus’ (1952) description of C. asica ). However, it should be noted that without additional information on the female system, the identification of these specimens as C. terminalis is somewhat tenuous. Furthermore, the specimens from Somalia are substantially smaller than the size ranges described by Brunet (1968). The new specimens from Australia fall more or less within the size range reported by Brunet (1968) and share the long, sclerotised and largely unarmed cirrus with a distal, sclerotised penis papilla. The characters of the female system, however, were not observed.

Figures

FIGURE 8. A–B. Cheliplana remanei (Meixner, 1928) Karling, 1983 from Sylt, Germany. A. Camera lucida drawing of the cirrus. B. Drawing of the copulatory bulb, including cirrus and seminal vesicle. C–D. Cheliplana terminalis Brunet, 1968. C. Camera lucida drawing of the cirrus. D. Photograph of the distal end of the cirrus showing the sclerotised penis papilla. Scale bars: A, C = 50 μm; B = 100 μm; D = 20 μm.