Actinotaenium cucurbitinumImage © Koos Meesters

Actinotaenium cucurbitinum. Notice elliptical cell outline and relatively large dimensions.

Cell dimensions (L x B): 70 x 30 µm

 

 

Desmid of the month
October 2020

Actinotaenium cucurbitinum

De name of A. cucurbitinum suggests a resemblance to A. cucurbita. Yet, there are some striking morphological differences. Where A. cucurbita is marked by about cylindrical cells, those of A. cucurbitinum are more elliptical. Where cell wall of A. cucurbita is characterized by deepened pore fields rendering the wall a somewhat coarse appearance, such pore fields are lacking in A. cucurbitinum. Finally, cells of A. cucurbitinum usually are distinctly larger than those of A. cucurbita. In the Netherlands, A. cucurbitinum is a rare species occurring in oligotrophic, acidic moorland pools.

Image © Koos Meesters

Dead cell of A. cucurbitinum (originating from the same Dutch population as the former one) at the poles of which some scattered, fine cell wall pores may be distinguished.

Image © Jan Šťastný

Dead cell of A. cucurbitiunum (from a Czech population) showing cell wall pores somewhat better.