Adenoplea meridionalis Kolasa, 1981

Houben, Albrecht M., Schwank, Peter, Proesmans, Willem, Bert, Wim & Artois, Tom J., 2015, Notes on some enigmatic taxa of limnoterrestrial rhabdocoels, with the description of two new species, Zootaxa 4040 (1), pp. 83-92 : 85-86

Adenoplea meridionalis Kolasa, 1981

( Fig. 1 B)

New localities. The “Lommelse Sahara”, Lommel, Belgium (51°14’48”N; 5°17’46”E), moss in a pine forest (23 July 2008)

Known distribution. Fosso Contesora, Italy, found on mosses on the banks of a helocrene spring ( Kolasa, 1981).

Material. A horizontally-sectioned and three sagittally-sectioned specimens from Lommel (UH nrs. VI.4.09– VI.4.12).

Descriptive notes and remarks. The studied specimens have the same habitus and internal organization as Adenoplea meridionalis Kolasa, 1981 , at least as far as could be judged from the description and drawings of Kolasa (1981). Animals about 1 mm long. Rostrally, two groups of adenal rhabdites are present. Protonephridiopores open in the mouth pouch. The rosulate pharynx lies just caudally from the body’s midpoint.

The gonopore ( Fig. 1 B: gp) is situated at ±80 % of the body and opens into a genital atrium ( Fig. 1 B: ga), which is lined with a high epithelium and is surrounded with muscles. Testes were not observed. The paired vasa deferentia ( Fig. 1 B: vde) unite before entering the 35-µm-long copulatory organ. This organ contains an intracapsular seminal vesicle ( Fig. 1 B: vs), a muscular, sclerotized ejaculatory duct ( Fig. 1 B: de) and extracapsular ( Fig. 1 B: gg1) as well as intracapsular ( Fig. 1 B: gg2) basophilic prostate glands. It is entirely surrounded by two layers of strong spiral muscles ( Fig. 1 B: mu). The thin-walled male duct is very short and is surrounded by a thin muscle layer. The copulatory bursa ( Fig. 1 B: bu) opens directly in the genital atrium.

The vitellaria ( Fig. 1 B: vi) extend from the middle of the body to the posterior end, where they fuse. Coarsegrained, eosinophilic female glands ( Fig. 1 B: fg) open into the long female duct ( Fig. 1 B: fd), which proximally receives the oviduct ( Fig. 1 B: od), the seminal receptacle ( Fig. 1 B: rs) and the unpaired vitelloduct.

Discussion. See the discussion following the descriptive notes and remarks on Adenoplea perigraptopera .

B

vde vi od ov vde

od

fd gp

bu

ga gg2

ph m vg md gp

de ga fd

C E ph

pp

vde

ov

gu vi

vg

gg2 D

ph gu