| Habrotrocha ligula, whirling specimen; dorsal view. The conspicuous ligula in the sulcus is visible (arrow). See also Habrotrocha ligula var. (1) |
| |
 |
| Habrotrocha ligula, detail of the head, dorsal view; focus plane on the ligula. The arrows mark the width of the sulcus, which -in contrast to the original description by Bryce (1913)- is about 2/3 of the witdth of the trochal columns. (1) |
| |
 |
| Habrotrocha ligula, optical longitudinal section of the anterior part while creeping. (1) |
| |
  |
Habrotrocha ligula; two images of the foot. Left image: bulbous spurs with distinct tips and wide interspace. The white arrows mark the base of the spurs (SB); the yellow double arrow marks the interspace (IS); the green arrow marks the length of the spurs (SL). The ratio: SB : IS : SL is approx. 1 : 1 :1. Insofar the specimens in this sample differ from the description given by Bryce (1913) and are more congruent with the drawing in Bielanska-Grajner,
Ejsmont-Karabin et Iakovenko, (2013). Right: focus plane on the toes. (1) |
| |
|
|
| Habrotrocha ligula; ramate trophi in cephalic view; dental formula 3/4. (1) |
|
| |
 |
| Habrotrocha ligula; whirling specimen from (2) |
| |
|
| Habrotrocha ligula; 4 aspects of the anterior part/ head from the same whirling specimen, different focus planes. Upper left: dorsal view, focus plane on the tip of the ligula and the cilia of the rostrum. Upper right: focus on the triangular/ cuneiform base of the ligula. Lower left: optical median section showing the membranes on the inner sides of the trochal columns (arrowheads): Lower right: ventral view; focus plane on the buccal field and buccal tube. (2) |
| |
  |
| Habrotrocha ligula; Left: ventral view the foot with 3 toes and two short spurs with interspace. Right: ramate trophi (cephalic view) with dental formula (DF): 4/4. (2) |
| |
| |
| The specimens from these samples deviate in certain traits (sulcus, spurs) from some descriptions of this species. Also Donner (1965) presumed that there might be several species. |
| |
| |
| |
| Location: NSG Koffituten near Hopsten (1); Capo di Stella, Elba, Italy; (2) |
| Habitat: dry moss (1); leaf litter of Eucalyptus-trees (2) |
| Date: coll.: 16.06.2018, img: 28.06.2018; (1); coll.: 10.09.2020, img.: 19.01.2021 (2) |
|
|
| |
|
