Professor Pierre Aronnax was a friend of both Zoticus de Lesseps and his father, who gave permission for Zoticus to be his assistant on board The Nautilus while he served in Mexico. Aronnax was a marine biologist and natural historian who joined Captain Nemo's voyage to further his knowledge. He was killed when the Nautosphere entered the Charybidis whirlpool but was able to save his book, The Oceanology Handbook: A Course for Underwater Explorers.