Tajikacelis artoisi, Curini-Galletti & Schockaert, 2021

Curini-Galletti, Marco & Schockaert, Ernest R., 2021, Six new species ofArchimonocelididae Meixner, 1938 (Platyhelminthes, Proseriata) from the Pacific, with proposal of a new genus, Zootaxa 4965 (3), pp. 515-528 : 521

Tajikacelis artoisi n. sp.

( Figs 1D , 2D , 5 , 10D ).

Diagnosis. Species of Tajikacelis with a curved stylet, 39–50 μm long (N=5). Concave and convex side of the stylet markedly different in length, resulting in a strongly oblique proximal opening 15–20 μm wide, narrowing to 6–9 μm at around 1/3 of its length and 3–4.5 μm wide at the distal end. The distal opening is 8.5–11 μm wide, and is provided with a sharply pointed tip. The wall at the convex side is particularly thick, and protrudes proximally as an obtuse lobe. With small globular seminal vesicles and a very small prostate vesicle that is partly incorporated in the stylet. Testes all behind the ovaries, 10–12 in a row. Female duct postpenially widened; no vagina was seen in the living animal.

Occurrence. Sampan Channel , Kanehoe Bay, O’ahu, Hawai’I, USA, north side, sandy channel among coral outcrops, coarse sand, at about – 3 m (type locality) (21°27’22.8”N 157°46’39.6”W) (24 May 2017 by M.C-G.). Sampan Channel, south side, large sand patch among coral rubble, coarse sand at about – 3 m (21°27’06.5”N, 157°46’52.0”W) (May 2017 by M.C-G) .

Material studied: several animals studied alive and mounted, one of them, designated as holotype ( FNMH http://id.luomus.fi/KV.666); the other three as paratypes ( CZM827-829 ). Micrographs of living animals .

Etymology. The species name honours our friend and colleague Prof. Dr. Tom Artois (Hasselt University, Belgium), for his distinguished contribution to the knowledge of free-living Platyhelminthes.

Figures

FIGURE 1. General appearance of the species of Tajikacelis. (A) T. tajikai n. sp. (B) T. macrostomoides n. sp. (C) T. nematoplanoides n. sp. (D) T. artoisi n. sp. (E) T. acuta n. sp. (F) T. truncata n. sp. (G) T. itoi (after Tajika 1981).

FIGURE 2. Genital organs of (A) T. tajikai n. sp. (B) T. macrostomoides n. sp. (C) T. nematoplanoides n. sp. (D) T. artoisi n. sp. (E) T. acuta n. sp. (F) T. truncata n. sp. (G) T. itoi (after Tajika 1981).

FIGURE 5. Tajikacelis artoisi n. sp. (A) Genital organs in the living animal (B1–B2) Micrograph and drawing of the copulatory stylet in the holotype. (C1–C2) Micrograph and drawing of the copulatory stylet in a paratype (scale bar = 20 µm).

FIGURE 10. The copulatory stylets in the holotypes of the species of Tajikacelis n. gen. (scale bar = 20 µm).