Heterolepadella heterostyla Murray, 1913
Most likely ID: n.a.
Synonyms: Lepadella heterostyla, Metopidia heterostyla
Sampling location: Pond of the convent Hegne, Spechtensee (Styria, Austria), Sima Moor (Austria)
Phylogenetic tree: Heterolepadella heterostyla
Diagnosis:
- lorica rhomboidal, edges curving slightly upwards
- lorica dorsally convex, ventrally flat
- length of lorica 78–82 µm, width 70–82 µm
- anterior collar dorsally and ventrally stippled
- foot groove U-shaped
- terminal segment of foot longer than basal foot section
- pointed toes of different lengths
I found Heterolepadella heterostyla in the Spechtensee in Styria/Austria in June 1999 and 25 years later in June 2024 in the Sima Moor (Austria). This species can easily be confused with the rhombic form variant of Lepadella triptera. However, Heterolepadella heterostyla has toes of different lengths (s. figs. 1 b, 2 a and 5). The right toe is always the shorter one. The lorica has a rhombic shape and the lateral corners are slightly bent forward (s. fig. 2 a). A triangular-shaped rostrum can only be seen in an outstretched specimen (s. fig. 2 b). On the ventral side of the lorica of specimens from the Sima Moor I could recognize 7 humps, which are not described in the literature (s. fig. 3).
More images and information on Heterolepadella heterostyla: Michael Plewka-Freshwater life-Heterolepadella heterostyla
Fig. 1 a-d: Heterolepadella heterostyla. L = 85 µm (of the lorica). A slightly squashed specimen from ventral. Obj. 40 X.
Fig. 2 a-b: Heterolepadella heterostyla. L = 85 µm (of the lorica). The slightly squashed specimen as shown in fig. 1 a-d in detail. Note the different lengths of the toes (TO) and the granulated collar (GC). RO = rostrum. Obj. 60 X.
Fig. 3: Heterolepadella heterostyla. L = 85 µm (of the lorica). Focal plane on the 7 humps (1-7) visible on the ventral side of the lorica. Obj. 60 X.
Fig. 4: Heterolepadella heterostyla. L = 82 µm (of the lorica). Ventral view of a slightly squashed specimen found in June 1999 in the Spectensee (Austria). Obj. 40 X.
Fig. 5: Heterolepadella heterostyla. The three segments of the foot (FT) and the toes (TO) of different length in a squashed specimen. Obj. 100 X.
Fig. 6 a-b: Heterolepadella heterostyla. Two focal planes of the trophi in a strongly squashed specimen. Obj. 100 X.