Lepadella biloba (Hauer, 1958)
Most likely ID: n.a.
Synonym: Lepadella patella f. biloba
Sampling location: Simmelried
Phylogenetic tree: Lepadella biloba
Diagnosis:
- lorica ovate, dorso-ventrally flattened
- lorica posteriorly extended in two pointed projections
- length of lorica 80–107 µm, width 59–64 µm
- dorsal side convex, ventral side almost flat
- dorsal sinus semi-circular
- ventral sinus V-shaped with a granulated fringe
- ventral side of lorica with fine, shorts folds
- foot groove is parallel-sided
- foot of three segments, toes pointed
- terminal segment of foot longer than basal section of foot
The very common rotifer Lepadella patella (Müller, 1773) has very many form variants. In 1958 the form Lepadella patella f. biloba was described by Hauer, which is characterized by two posterior projections of the lorica (s. figs. 1b, 1c, 2a and 3). This form has been elevated to species rank as Lepadella biloba in the meantime. I find Lepadella biloba regularly in the Simmelried, among floating plant masses. In my population the specimens have a length of 105–112 µm, which is at the upper end of the range given by Hauer.
Fig. 1 a-c: Lepadella biloba. L = 110 µm (of lorica). Three focal planes of a slightly squashed specimen in brightfield illumination. Note the two posterior projections of the lorica (arrows). Obj. 40 X.
Fig. 2 a-c: Lepadella biloba. L = 110 µm (of lorica). Three focal planes of a slightly squashed specimen from ventral in DIC. Note the delicate folds of the ventral side of the lorica (c). Obj. 60 X.
Fig. 3: Lepadella biloba. L = 110 µm (of lorica). A squashed specimen from ventral with the focal plane on the two posterior projections (PP) of the lorica. Obj. 100 X.
Fig. 4: Lepadella biloba. L = 110 µm (of lorica). A squashed specimen from ventral with the focal plane on the ventral, V-shaped sinus and the foot groove. Note the granulated fringe of the ventral sinus. Obj. 100 X.