I found these specimens in a sample taken from shallow waters, in the Northern Adriatic Sea (Italy). Average width around 16 um and length around 24 um. Asymmetric, with pores scattered on the valve surface. Presence of a pyrenoid.

However, I'm uncertain whether they are P. borbonicum or another species...

Does anyone have an idea?

Here attached are some images taken by LM, in bright field and a couple of short video in Epifluorescence, corresponding to Z acquisition, since the valve pores are more evident.

Thanks in advance.