Acrochordonoposthia diademula Schwank, 1980

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 diademula Schwank, 1980

( Figs 4 A–I)

Known literature. Acrochordonoposthia diademula Schwank (1980) : 473–474, figs 3E–3H

Known distribution. Graswiesenbach, Vogelsberg, Oberwald, Hessen, Germany (590m) ( Schwank 1980)

Material. The holotype (a whole mount) ( SMNH Type-8568).

Remarks. Animals 0.90–0.95 mm long. The extended copulatory organ is 70 µm long and is provided with a cylindrical pouch. Two elongated prostate glands open into the cirrus, which is about 50 µm long (measured on one specimen). This cirrus is slightly bent and lined with fine spines (<0.5 µm broad). The distal, strongly-sclerotized part is a 21 µm-high cylinder, with a diameter of 20 µm. It is provided with eight crown spines (8–9 µm long), which are arranged into two groups in the live animals ( Fig. 4 B: cs), but are organized in a circle after fixation ( Fig. 4 C, E). A 65 µm-long, sclerotized bursa with a simple musculature is situated next to the copulatory organ. The bursa consists of a distal, cylindrical, sclerotized part and a balloon-shaped proximal end. The proximal end of the bursa is about 30 µm long. A pear-shaped diverticulum appears to be associated with the bursa at the proximal end, although we could not clearly observe its connection (see dotted line in Fig. 4 E: bu?). The proximal part of the oviduct forms a seminal receptacle.

The sclerotized cylinder of the bursa is not visible in the fixed specimen, while the cirral pouch is. Probably these structures are of a different histological nature.

Figures

FIGURE 4. Acrochordonoposthia diademula: (A) Habitus of live animal, (B) tip of the cirrus, (C) crown spines of the copulatory organ after fixation, (D) Male copulatory organ and bursa in live animal, (E – I) Male copulatory organ and bursa copulatrix of the holotype (SMNH Type- 8568). Scale bar = 20 µm. (A – D after Schwank 1980).