This dinoflagellat had a very strong red colour. I dont know the species. Maybe the genus is Protoperidinium?
Stack with 11 pictures
Obj. 40x DIC, projection eyepiece 2,5x
date of the photo: 26.9. (the temperature of the water was still higher as now)
I've seen similar "dinos" in my marine samples, but have never been able to get a shot anywhere near as nice as this. They generally seem to come to rest in a position where you really can't get a photo that shows the wonderful shape.