Typhlopolycystis errata Artois and Schockaert, 2019

Schockaert, Ernest R., Moons, Patricia, Janssen, Toon, Tessens, Bart S., Reygel, Patrick C., Revis, Nathalie, Jouk, Philippe E. H., Willems, Wim R. & Artois, Tom J., 2019, On the genus Typhlopolycystis Karling, 1956 (Platyhelminthes, Kalyptorhynchia, Polycystididae), with data on the five known species and the description of eleven new species, Zootaxa 4603 (1), pp. 81-104 : 99

Typhlopolycystis errata Artois and Schockaert , n. sp.

( Fig. 14 )

Typhlopolycystis n.sp. in Tessens et al. 2014

Diagnosis. Colourless species of Typhlopolycystis , about 1 mm long with two small eyes and a proboscis of 1/4 of the body length. The prostate stylet is a broad curved gutter, 46 µm with rounded “lips”, slightly thickened at the concave side and at the proximal rims. The proximal diameter is 25 µm. The curved accessory stylet is 107 µm with a proximal “head” of 21 µm and a sharp terminal end. Both stylets are not attached to each other. There is no clear accessory glandular reservoir.

Genbank accession code: KJ887476 and KJ887545

Occurrence. Italy: Costa Paradiso , (Sardinia), Grotta Niedda, N41°03'08.84" W8°56'15.71", very coarsegrained sediment, shell gravel and pieces of coral, 32 m deep (type locality) (by Artois & Moons, 0 1 September 2010).

Material examined. Observations on living animals and micrographs of the living animals. One whole mount (holotype SMNH nr 8914).

Etymology. The species name refers to high similarity of hard parts with those of T. sarda n. sp. for which it was mistaken in the field; they occurred in the same sample. Errare (Lat.): to make a mistake.

Additional data. T. sarda n. sp. and T. errata n. sp. are very similar in many aspects: size (1 mm or less), colourless, the proboscis of 1/4 of body length, a large seminal vesicle and no apparent accessory secretion reservoir. Whether this secretion reservoir is indeed completely lacking, should be confirmed on sections. The bundle of glands that opens in the genital atrium should be confirmed for both species as well. The copulatory organ is very similar in both species and the most striking similarity is the fact that the prostate stylet and the accessory stylet are not attached to each other. But there are clear differences in the hard parts: the prostate stylet of T. errata n. sp. is more slender than in T. sarda n. sp. and obviously larger. The accessory stylet is much longer than in the other species, with a very sharp end but with a relatively much smaller “head”.

Figures

FIGURE 14. Typhlopolycystis errata n. sp. (A) Micrograph of the living animal. (B) The copulatory organ in the holotype (B3 in the living animal). (scale = 20 µm)