Why is Parasyte spelled with a y in the title? It is my understanding that the word parasite is spelled with an i and not a y. However, the title of the anime and manga, when translated into English, uses a y in the spelling.
However, this only seems to apply to the title, since the species is referred to as "parasites" (at least throughout the wikipedia article) and Uda Mamoru calls his parasite as Parasite in episode 7:  



Is there a reason for this misspelling?
Or is there maybe a difference between "parasyte" and "parasite"?
According to Wikipedia user Doceirias who translated the Del Rey version of the manga:


  Essentially, the word kiseiju1 is consistently translated as Parasyte, while the word kiseichu2 is translated literally as parasite. The creatures themselves are referred to either as kiseichu or parasaito. The word kiseiju only appears one time (if memory serves) and is used to refer to human beings. I decided the distinction was an important one, and that the word Parasyte actually referred to mankind.


As with writing byte instead of bite, Parasyte is a deliberate respelling of parasite for distinction purposes.



1 kiseijuu 寄生獣: parasite beasts
2 kiseichuu 寄生虫: parasite bugs