It seems, fungi often infect animals, while plants it seems, never. Is it because the cellulose cell walls make them incompatible with animal tissue?
Acrochaetium spiculiphilum is an marine endozoic parasite on sponges.
It is a Biliphyte algae and thus a plant.
Yes! Here's a paper published August 2018 https://www.sciencedirect.com/science/article/pii/S0960982218308157