Are amphoteric species zwitterionic?

Yes, amphoteric species are zwitterionic. The term zwitterionic is derived from zwitterions, which are dipolar molecules. They have two functional groups - one having a positive charge and the other having a negative charge. Each zwitterion is capable of behaving both as an acid and as a base, depending on the solution it is put into. 

Amphoteric species are species that have the potential to behave both as an acid and as a base, which means they are zwitterionic.