Parasite in guppy

[jesso435]

Do you think this is a parasite? It’s long and white and has a black tip.

If it is a parasite, should I treat the whole tank, or can I get away with just removing this guppy. If I treat the tank will it crash my cycle?

Thanks

 

[NickGalante]

do you know what parasite it has? have you noticed any other guppys with the parasite?