Multisepta fengari, Noreña, 2017

Noreña, Carolina, 2017, The Polycladida (Platyhelminthes) of the Canary Islands. New genus, species and records, Zootaxa 4312 (1) : -

Multisepta fengari n. gen. and n. sp.

( Figs. 9 and 11 R)

Holotype. One specimen from the cove El Salto (17/06/2015), close to La Restinga, El Hierro, Canary Archipelago ( Fig. 1 , H2; Table 1 and 2) by Leopoldo Moro and Daniel Cuadrado. 20 slides of sagittal serial sectioned specimen and stained with AZAN; Catalogue number: MNCN 4.01/ 1197-1217.

Type locality. El Hierro, Canary Islands.

Etymology. The specific name fengari is the Greek word for moon, and refers to the dorsal colour pattern resembling the delicate translucent moonlight.

Description. Body shape oval. Length 6 mm. Smooth dorsal surface. With two small nuchal tentacles (0.5 mm long); tentacular eyes at the tentacle bases and cerebral eyes within the tentacles ( Fig. 9 B and C). Translucent, with delicate orange tones on the margin. Middle body region whitish. Dorsally, the ovaries provide a mottled appearance to the animal ( Fig. 9 A). Without genital sucker or corrugated surface on the ventral side. Ruffled pharynx, centrally located along the body axis. Oral pore is in the second third of the body and in the middle in the pharynx.

Reproductive system: Both copulatory organs, male and female, are located in the posterior end, near de caudal region. Male and female gonopores close to each other ( Fig. 9 F).

Male organ contains seminal vesicle, interpolated prostatic vesicle and ejaculatory duct surrounded by muscular penis papilla. Whole male organ frontal orientated. Seminal vesicle involved in its own muscular bulb ( Fig. 9 D and F). Prostatic vesicle also muscular, very complex, with a glandular lining and differentiated into two parts. Proximal section with 30 septa or perforated discs that form chambers with a conspicuous glandular coating. Distal section tubular, glandular but less than the proximal region, with numerous cilia and connected to penis papilla ( Fig. 9 D and F). Penis papilla muscular and elongated, with a sclerotized ejaculatory duct broad and conical shaped. Male atrium covered with long cilia near the gonopore.

Female organ is caudo-frontal orientated and present a much thickened muscular vagina, the so called bulbous vagina. Compact masses of cement and shell glands empty before the distal muscular widening ( Fig. 9 E and F). Female canal ends with a rounded Lang's vesicle.

Biology. The specimen was collected near La Restinga in a cave with low light and at shallow waters. Multisepta fengari presents a characteristic locomotion with pulsatile movements in which the left and right halves of the body flap alternatingly. These types of movements have been observed in species of the suborder Acotylea, such as those within the genus Comoplana Faubel, 1983 where the anterior region of the body is webbed and divided into two lobes.

Discussion. The new genus Multisepta belong to Cryptocelidae due to the presence of a ruffled pharynx slightly anterior orientated. Male genital complex behind pharynx and directed backwards, an interpolated prostatic vesicle divided into two distinct sections, with transversal septa and gonopores in the posterior half of the body. The family Cryptocelidae include six genera: Cryptocelis Lang, 1884 ; Notoplanella Bock, 1931 ; Phaenocelis Stummer-Traunfels, 1933 ; Macginitiella Hyman, 1953 ; Hylocelis Faubel, 1983 and Adenodactyplana Bulnes, Faubel & Ponce de Leon, 2003.

Multisepta fengari differs from species of Cryptocelis , Notoplanella and species of Phaenocelis by the presence of a sclerotic ejaculatory duct different from the naked ejaculatory duct of the above mentioned genera.

Macginitiella sp. lacks tentacles and a Lang’s vesicle at the end of the internal vagina, while Multisepta fengari presents nuchal tentacles and a conspicuous spherical vesicle. Moreover, the prostatic vesicle of Macginitiella (only one species M. delmaris Hyman, 1953 ) is “lined with a scalloped epithelium but is not chambered” ( Hyman 1953) different to the chambered prostatic vesicle present in Multisepta fengari .

The most notable difference between the new species and Hylocelis spp. is in the prostatic vesicle: Multisepta fengari shows whole septa-like perforated discs in the proximal region and tubular channels in the distal region of the prostatic vesicle, and Hylocelis spp. present short septa or wide rings, without distal channels.

Finally, the genus Adenodactyplana presents a ridged glandular lining within the prostatic vesicle similar to Multisepta fengari , but an adenodactylus at the proximal end of the male atrium, absent in Multisepta fengari .

Figures

FIGURE 1. Sampling station of the Canary Islands (for explanation of legends see Table 1).

FIGURE 9. Multisepta fengari n. sp. (MNCN 4.01 / 1197 - 1217). A. In vivo, dorsal view; B. Anterior region with tentacles; C. Sagittal section of the anterior region; D. Sagittal section of the prostatic vesicle; E. Sagittal section of the female organs; F. Sagittal reconstruction of the reproductive system. af, female atrium; am, male atrium; b, brain; cg, cement glands; e, eyes; ed, ejaculatory duct; lv, Lang’s vesicle; ov, oviduct; pb, penis bulb; ph, pharynx; pv, prostatic vesicle; s, stylet; sv, seminal vesicle; te, tentacle; vb, bulbous vagina.

FIGURE 11. Species located in the Canary archipelago, in vivo. A. Eurylepta guayota n. sp. B. Prostheceraeus giesbrechtii Lang, 1884. C. Prostheceraeus roseus Lang, 1884. D. Enchiridium magec n. sp. E. Anonymus virilis Lang, 1884. F. Anonymus ruber n. sp. G. Pericelis cata Marcus and Marcus, 1986. H. Phrikoceros mopsus (Marcus, 1952) Quiroga, 2008. I. Pseudobiceros wirtzi Bahia and Schrödl, 2016. J. Pseudoceros maximus Lang, 1884. K. Pseudoceros velutinus (Blanchard, 1847) Lang, 1884. L. Pseudoceros mororum n. sp. M. Pseudoceros sp. N. Thysanozoon brocchii (Risso, 1818) Grube 1840. O. Acanthozoon aranfaibo n. sp. P. Yungia aurantiaca (Delle Chiaje, 1822) Lang, 1884. Q. Cestoplana rubrocincta (Grube, 1840) Lang, 1884. R. Multisepta fengari n. sp. S. Planocera pellucida (Mertens, 1833) Örsted, 1844.