I found Plationus patulus in 1996 and 2005 exclusively in Simmlried. In my other finding areas I have been unableto detect the species. After 2005 I have not found any other specimen. Plationus patulus is easily recognized by the 10 spines on the front edge of the lorica (s. fig. 2). In contrast to species of the genus Brachionus the foot of Plationus patulus is not curled but jointed (s. figs. 1 and 3b).
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: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. 3 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. 4:Plationus patulus. Ventral view with with the large red eyespot. Obj. 40 X.
Fig. 5:Plationus patulus. The trophi in a strongly squashed specimen. Obj. 100 X.