Greece
Men: Arkadios Aspougalis, Stergios Bilas, Apostolos Christou, Konstantinos Englezakis, Kristian Gkolomeev, Evangelos Makrygiannis, Dimitrios Markos, Apostolos Papastamos, Apostolos Siskos, Konstantinos Stamou, Andreas Vazaios
Women: Anastasia Boutou, Georgia Damasioti, Theodora Drakou, Maria Drasidou, Zacharoula Kalogeri, Eleni Kontogeorgou, Anna Ntountounaki, Artemis Vasilaki, Maria Zafeiratou
I am not 100% sure but I think this is the largest team we've ever sent to the World Championships. Definitely by far the largest in the last decade at least.
Pleasant surprise that we will have a women's 4x200 freestyle relay team, with Boutou, Kalogeri, Vasilaki, and Zafeiratou. For all four girls, that is the only event they are competing in. They are all 2006 or 2007 born except Kalogeri. I'm sure they won't do much, but a national record is likely. They will have a great future I think!