Cheliplana cubana, 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 : 458-459

Cheliplana cubana n. sp. Diez, Gobert, Reygel & Artois

Fig. 1C–E

Etymology. Species epithet refers to the island of Cuba, where the species was found.

Material examined. Holotype. CUBA • 1 whole mount; Holguín province, Gibara municipality, Bahía de Gibara ; 17 Feb. 2016; sublittoral, to a depth of up to 0.4 m, sandy bottom with many seashell fragments and organic material, salinity 32‰; KV.634.

Other material. CUBA • 5 whole mounts; Holguín province, Gibara municipality, Bahía de Gibara ; 17 Feb. 2016; sublittoral, to a depth of up to 0.4 m, sandy bottom with many seashell fragments and organic material, salinity 32‰; X.3.21–X.3.25 • 15 whole mounts; Holguín province, Banes municipality, Guardalavaca; 28 Feb. 2017; intertidal, superficial fine sand around roots of Avicennia germinans , salinity 35‰; HU X.2.08–X.2.22 • 3 whole mounts; Holguín province, Banes municipality, Macabi; sublittoral fine sand, 0.3 m deep, salinity 34‰; HU X.2.23–X.2.25 .

Description. Whole-mounted specimens are 0.6–1.6 mm (x = 0.9 mm; n = 16) long. The body is unpigmented, transparent. The proboscis (p, Fig. 1C ) has a pair of small, curved hooks measuring 10–19 µm (x = 15 µm, n = 8), each with a dilated base and pointy tip. Hook supports are ~ 11 µm long. The pharynx bulb is relatively small and measures approximately 1/9 of the total body length (ph, Fig. 1C ). The anterior edge of the pharynx bulb bears a number of anteriorly projecting papillae. The mouth is situated behind the proboscis and connects to the pharynx bulb via a long, unarmed, oral tube (ppc, Fig. 1C ).

The common genital opening, situated anterior to the haptic girdle at approximately 7/8 of the body length, is surrounded by clusters of glands that are conspicuous in live specimens.

One large testis is located in the anterior half of the body, posterior to the pharynx (t, Fig. 1C ). The male copulatory organ is situated in the posterior part of the body. A pair of elongated seminal vesicles enter the proximal end of the copulatory bulb separately (vs, Fig. 1C ). A small prostatic vesicle occupies the proximal part of the copulatory bulb (vg, Fig. 1C ). The tubular cirrus is 117–173 µm long (x = 152 μm, n = 21), with the distal part forming a U-shaped bend (ci, Fig. 1C ; Fig. 1D–E ). The cirrus is armed with small spines over its entire length, though only the distal end was observed to be eversible. Few details of the female system could be observed: aAsingle ovary is present near the caudal end of the body (ov, Fig. 1C ). A large, vacuolated bursa is situated beside the male copulatory bulb (b, Fig. 1C ).

Figures

FIGURE 1. A–B. Cheliplana asinaraensis n. sp. A. Habitus of the live specimen. B. Camera lucida drawing of the scerotised cirrus. C–E. Cheliplana cubana n. sp. C. Habitus of the live specimen. D. Camera lucida drawing of the cirrus with the distal part everted. E. Camera lucida drawing of the cirrus and prostatic vesicle of the holotype specimen. Scale bars: B = 20 μm; D, E = 50 μm.