Lo and behold a strange amoeba: Is it Actinocoma ramosa?

[NachoBen]

We have a small amoeba with filopodia all around it. It boasts about a clear nucleus and a dark, round nucleolus. It also has a round contractile vacuole with short radial channels.



A strange thing is that this specimen goes through expansion-contraction cycles. See video.

I have not been able to get closer of an ID other than Actinocoma ramosa. However, Actinocoma 's nucleus has a thick envelope I don't see in my amoeba.


Any help warmly welcomed. Thank you!

[NachoBen]

A more careful search seem to suggest Nuclearia simplex.