Tajikacelis nematoplanoides, 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 : 520-521

Tajikacelis nematoplanoides n. sp.

( Fig. 1C , 2C , 4E , 10C )

Diagnosis. Species of Tajikacelis with a very slightly curved stylet, about 35 μm in its maximum length. Concave and convex side of the stylet are markedly different in length, resulting in a strongly oblique proximal opening about 16 μm wide, narrowing to 5 μm wide at the distal end. The convex side is more strongly sclerotized than the rest of the stylet. The distal opening is straight, about 8 μm wide, and provided with a sharply pointed tip. With 10–12 testes arranged in a single row behind the ovaries. Ovaries in the anterior ¼ of body. Neither a bursa or vagina, nor a postpenial widening of the female duct could be seen in the specimen studied.

Occurrence. Port Lincoln , SA, Australia, Kirton Point, in poorly sorted silty coarse sand in tide pools between the rocks, in front of the Lincoln Marine Science Centre (34°43’33.8”S 135°53’09.3”E) (type locality) (January 2001 by M.C-G) ,

Material studied. One animal studied alive and mounted (holotype, QM G238523 )

Etymology. The specific epithet reflects the similarity between the stylet with those of species of Nematoplana Meixner, 1938 (Platyhelminthes, Proseriata, Unguiphora).

Additional remarks. With two parallel rows of cnidosacs clearly visible behind the pharynx and one row in front of it. Due to the thickness of body it was difficult to discern the cnidosacs above the gonads and it was impossible to see where the single row of cnidosacs in front of the ovaries splits.

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 4. Tajikacelis macrostomoides n. sp. (A) The copulatory stylet in the holotype (B, C) copulatory stylet in two paratypes. (scale bar = 20 µm) (D) micrograph of the copulatory stylet of the specimen from Kirra Beach. Tajikacelis nematoplanoides n. sp. (E1–E2) Micrograph and drawing of the copulatory stylet in the holotype (scale bar = approximately 20 µm).

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