Cheliplana mauii, Gobert & Diez & Monnens & Reygel & Van Steenkiste & Leander & Artois, 2021

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 : 461-462

Cheliplana mauii n. sp. Gobert, Reygel & Artois

Fig. 2D–E

Etymology. The species epithet refers to the heroic trickster and demigod Mâui, who according to Polynesian mythology, hauled up the islands of the Hawaiian archipelago from the depths of the ocean.

Material examined. Holotype. UNITED STATES • 1 whole mount; Hawaii, Oahu, Waimanalo Beach ; 21°19’36”N, 157°40’59”W; 28 May 2010; medium coarse, very clean coral sand at a depth of ~ 2 m; KV.669.

Other material. UNITED STATES • 1 whole mount; Hawaii, Oahu, Waimanalo Beach ; 21°19’36”N, 157°40’59”W; 28 May 2010; medium coarse, very clean coral sand at a depth of ~ 2 m; HU X.2.05 .

Description. Live specimens are transparent to slightly pinkish in colour. The total body length measures ~ 0.75 mm (measured on a squeezed, whole-mounted specimen). Proboscis hook supports are 20–26 μm long (x = 23 μm, n = 2; hs, Fig. 2D ) and bear a pair of robust, more or less straight proboscis hooks (h, Fig. 2D ). These hooks are 28–36 μm long (x = 32 μm, n = 2). Proboscis sidepieces were not observed. The horizontal pharynx is situated in the anterior body half and connects to the mouth via a long, unarmed prepharyngeal cavity. The anterior edge of the pharynx bears a number of well-developed papillae.

An unpaired testis is situated alongside and partly posterior to the pharynx. An unpaired seminal vesicle and long prostatic glands enter the proximal end of the male copulatory bulb. The proximal 2/3 of the bulb is taken up by the prostatic vesicle. Distally, the prostatic vesicle connects directly to a short cirrus (~9 μm; Fig. 2E ) with a proximal diameter of ~15 μm and a distal diameter of ~7 μm. The distal edges of the cirrus fold backwards, forming a weakly sclerotised cap or papilla around the cirrus.

Details of the female reproductive system could not be observed. A single ovary appears to be present adjacent to the male copulatory apparatus.

Figures

FIGURE 2. A–C. Cheliplana hawaiiensis n. sp. A. Habitus of the live specimen. B. Camera lucida drawing of the proboscis. C. Camera lucida drawing of the sclerotised cirrus. D–E. Cheliplana mauii n. sp. D. Camera lucida drawing of the proboscis. E. Camera lucida drawing of the sclerotised cirrus. F–H. Cheliplana longissima n. sp. F. Camera lucida drawing of the sclerotised cirrus and penile papilla. G. Camera lucida drawing of the proboscis. H. Reconstruction from the left-hand side of the male and female genital organs in the posterior part of the body. Scale bars: B-D, G = 20 μm; E = 10 μm; F = 50 μm.