Acrochordonoposthia reversa Reisinger, 1924

Houben, Albrecht M., Proesmans, Willem, Bert, Wim & Artois, Tom J., 2014, Revision of Acrochordonoposthia Reisinger, 1924 (Rhabditophora, Typhloplanidae, Protoplanellinae) with the description of one new species, Zootaxa 3790 (1) : -

Acrochordonoposthia reversa Reisinger, 1924

( Figs 6 A–J)

Known literature. Acrochordonoposthia reversa Reisinger (1924a) : 77–78; Schwank (1981): 110

New localities. Kreuzberg, Weyer, Austria (47°51’36”N; 14°39’09”E), in moss growing on a dead tree trunk (29 August 2011)

Known distribution. Graz, Austria, in mosses ( Reisinger 1924a); Hessen, Germany, in damp mosses (doubtful record; see Schwank 1981).

Material. Two animals studied alive, both whole-mounted from Kreuzberg (HU, nos. VI.3.01–VI.3.02).

Remarks. Our observations are generally in accordance with the original description by Reisinger (1924a). The animals are up to 0.8 mm long, with a small tail. Protonephridiopores are situated anteriorly to the pharynx (pers. obs.; never mentioned elsewhere in literature). The copulatory organ measures about 70 µm in length and is provided with a conical pouch. A group of prostate glands enters the cirrus, which, in the living animal, shows three to four bends in the proximal part. The cirrus straightens when the specimens are whole-mounted. Except for its distal fifth, the cirrus is entirely covered with small sclerotized warts. In the proximal part of the cirrus these warts are slightly smaller than in the distal part. At the distal two-thirds of the cirrus a few larger hooks are present. The cirrus is widest at one third of its length. At two-thirds it suddenly narrows. The specimens we studied showed a simple sac-like organ next to the copulatory organ. Most probably this is the bursa. We never observed a stalked, pear-shaped bursa with 5–6 strong sphincters around its stalk, as was described by Reisinger (1924a). This could be because of a difference in developmental state of the female system between our specimens and those of Reisinger, but this cannot be taken for granted. Therefore, we refrain from designating one of our specimens as a neotype.

The whole-mounted specimen depicted in Figs 6 G–J (HU no. VI.3.02) was accidently squashed after it was studied.

Figures

FIGURE 6. Acrochordonoposthia reversa: (A) Habitus of live animal, (B) Organization of the male copulatory organ of a live animal, (C – F) Male copulatory organ of a whole mount (HU no. VI. 3.01). Scale bar = 10 µm, (G – J) Male copulatory organ of another whole mount (HU no. VI. 3.02); A. robusta: (K) Male copulatory organ (after Luther 1963). Scale bar = 10 µm.