Tajikacelis acuta, 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 acuta n. sp.

( Figs 1E , 2E , 6 , 10E )

Diagnosis. Species of Tajikacelis with a slightly recurved stylet, 37–41 μm long (N=2), with a straight proximal opening 16–17 μm wide, with a slit-like oblique terminal opening and ending into a sharp point. With elongate seminal vesicles. Six testes in a row in front the ovaries. Neither widened female duct nor a vagina were seen in the living the animal.

Occurrence. Gulf of Panama, off Isla Pacheca (Las Perlas Is., Panama) (8°40’22.87”N; 79° 3’12.58”W), about 20 m deep, coarse sand with shell fragments (type locality) (December 2011 by M.C-G) .

Material studied. Two whole mounts, one of them designated as holotype ( FNMH http://id.luomus.fi/KV.667), the other as paratype ( CZM830 ). Micrographs of the living animal .

Etymology. the species name refers to its sharply pointed stylet.

Additional remarks. Dark, roundish pigmented areas are present over the whole body, particularly apparent in the head region ( Fig. 6 B ). The species is cited as Archimonocelididae gen. n. 2 sp. n. 1 and Archimonocelididae gen. n. 2 sp. 3 in Scarpa et al. (2017) .

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 6. Tajikacelis acuta n. sp. (A) Genital organs in the living animal. (B) The head in the living animal showing the dark pigmented spots. (C1–C2) Drawing and micrograph of the copulatory stylet in the holotype. (D1–D2) Drawing and micrograph of the copulatory stylet in the paratype (scale bar = 20 µm).

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