Plationus patulus Müller, 1786
Most likely ID: n.a.
Â
Synonym: Brachionus patulus, Platyias patulus
Â
Sampling location: Ulmisried, Simmelried
Â
Phylogenetic tree: Plationus patulus
Â
Diagnosis:Â
- lorica almost rectangular, dorso-ventrally flattened
- length 165–265 µm (with foot)
- anterior end of lorica with 10 spines
- posterior end of lorica with 4 spines
- dorsal side of lorica fielded and granulated
- foot three-segmented
- 2 slender toes with pointed ends
- one eyespot
- foot tube surronunded by short spines
I found Plationus patulus in 1996 and 2005 in the Simmlried and again in 2021 in a shallow pond on a flooded meadow. In my other collection sites, I was not able to detect this species and a after 2021, I have not found another specimen.
Â
Plationus patulus is easily recognized by the 10 spines on the anterior margin of the lorica (s. fig. 3). Unlike species of the genus Brachionus, Plationus has a segmented foot rather than a ringed one (s. figs. 1 and 4 b).
Â
More images and information of Plationus patulus: Michael Plewka-Freshwater life-Plationus patulus
Fig. 1: Plationus patulus. L = 288 µm (with foot). Ventral view of a slightly squashed specimen with a fully extended foot. Obj. 20 X.
Fig. 2 a-d: Plationus patulus. L = 272 µm (with foot). Ventral view of a second, slightly squashed specimen. Obj. 40 X.
Fig. 3: Plationus patulus. L = 275 µm (with foot). Ventral view of a slightly squashed specimen in brightfield illumination. Note the 10 spines at the anterior end of the lorica (1-10). Obj. 20 X.
Fig. 4 a-b: Plationus patulus. Two focal planes of the short spines surrounding the foot opening (arrows). FT = foot, LA = lateral antennae, TO = toes. Obj. 40 X.
Fig. 5: Plationus patulus. Ventral view with with the large red eyespot. Obj. 40 X.
Fig. 6: Plationus patulus. The trophi in a strongly squashed specimen. Obj. 100 X.