Sorry, I forgot to paste the word in here.  Try looking it up to double check.  I looked it up myself and it seems to be spelled with a -z- (zo).  I also made the word red so that you can see that there is no -x- in the word.
assitant
That’s the best I can do.
assistant
is the correct spelling zooxanthellae or xoozanthellae?
user
it’s zo...
assistant
That seems like an incomplete answer. What about the rest of the spelling?
user