Cheliplana hawaiiensis Gobert & Diez & Monnens & Reygel & Van Steenkiste & Leander & Artois 2021, n. sp.

Cheliplana hawaiiensis n. sp. Gobert, Reygel, Van Steenkiste & Artois Fig. 2A–C, Fig. 3A–C, Fig. 4 Etymology. The species epithet refers to the Hawaiian archipelago, where the species was first found. Material examined. Holotype. UNITED STATES • 1 whole mount; Hawaii, Oahu, Waimanalo Beach; 21°19’36”N, 157°40’59”W; 31 May 2010; intertidal zone, fine sand with organic detritus among blocks of coral; KV.635. Other material. UNITED STATES • 6 whole mounts and two serial sections; Hawaii, Oahu, Waimanalo Beach; 21°19’36”N, 157°40’59”W; 31 May 2010; intertidal zone, fine sand with organic detritus among blocks of coral; HU X.2.26–X.2.33. CANADA • 3 whole mounts; British Columbia, Calvert Island, West Beach; 51°39’24”N, 128°08’41”W; 3 Jun. 2015; intertidal zone, medium-grained sand from the beach surface; MI4186–MI4188 • 3 whole mounts; British Columbia, Calvert Island, North Beach; 51°39’52”N, 128°08’46”W; 7 Jun. 2017; coarse sand in lower intertidal; MI4189–MI4191 • 1 whole mount; British Columbia, Calvert Island, Foggy Cove; 51°39’07”N, 128°08’32”W; 9 Apr. 2016; medium-grained sand in between boulders in the lower intertidal; MI4192. Description. Specimens are largely transparent, with a weak brown to orange colouration (Figs. 3A, 4A). A caudal haptic girdle is present (ag, Fig. 2A). The proboscis of the Hawaiian specimens is ~37 μm long with 18-μmlong muscular hook supports and a pair of smooth proboscis hooks ~20 μm long (h, hs, Fig. 3B). The proboscis of the Canadian specimens is about 28 μm long with 10-μm-long hook supports and 18 μm long hooks (h, hs, Fig. 4B; 4D). The proboscis sidepieces are straight, non-sclerotised rods, with enlarged distal ends, bearing a single bristle (sp, Figs. 3B; 4B). The mouth is situated directly posterior to the proboscis. The pharynx is positioned in the anterior part of the body (ph, Figs. 2A; 3A; 4A) and connects to the mouth via a long, slender oral cavity lined with spines (ppc, Fig. 2A; 4A). The anterior edge of the pharynx is lined with papillae. In some specimens, the body contains large numbers of diatom frustules. A single testis is present in the anterior body half, just behind and/or alongside the pharynx (t, Fig. 2A; 3A; 4A). The posterior part of the testis shows a globular accumulation of sperm, probably corresponding to the area where the testis connects to the vas deferens. The male copulatory bulb measures ~117 μm in the Hawaiian specimens (cb, Fig. 3A) and 75–100 µm in the Canadian specimens (cb, Fig. 4A,C,E). Two seminal vesicles enter the copulatory bulb proximally (vs, Figs. 2A; 4A,C). The copulatory bulb is of the conjuncta duplex type (Karling 1956) and is surrounded by a sheath of longitudinal muscles. The presence of circular muscles surrounding the copulatory bulb could not be determined. The large prostatic glands also enter the copulatory bulb proximally and form a prostatic vesicle in the proximal part of the bulb (pg, vg, Figs. 2A; 3A; 4A,C). The distal part of the bulb holds the ejaculatory duct, the distal end of which forms an armed cirrus (Figs. 2C; 3C; ci, Figs. 2A; 3A; 4A,C,E) measuring 30–40 μm (Canada) or 41–68 μm (Hawaii). The cirrus is differentiated in three distinct regions (Figs. 2C; 4E): the most proximal part is tubular, with a length of 15–31 μm (x = 21 μm, n = 6; Hawaii) or 12–18 μm (x = 15 μm, n = 7; Canada) and a diameter of 8–16 μm (x = 12 μm, n = 6; Hawaii) or 7–9 μm (x = 8 μm, n = 7; Canada). This part is armed with very fine spines with a rectangular base. This proximal tube is followed distally by a ring of six long, curved spines of ~12 μm long (measured on Canadian specimens), each set in sclerotised pockets. The most distal region is 23–34 μm (x = 27 μm, n = 6; Hawaii) or 12–17 μm (x = 15 μm, n = 7; Canada) long, with a diameter of ~17–26 μm (x = 22 μm, n = 6; Hawaii) or 12–17 μm (x = 14 μm, n = 7; Canada). This distal part is lined with densely stacked, bristle-like spines with a length of ~8 μm (Hawaii) or ~5 μm (Canada). A single, large ovary is present near the copulatory apparatus (ov, Fig. 4A). A bursa is situated posterior to the common genital opening (b, Fig. 4A,C). No spermatic duct or vagina externa were observed.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.