The Pokémon roster has recently surpassed 1000 unique species in the Gen IX games Scarlet & Violet. While there are 18 different types, the Water typing takes well over 150 of them. As one of the major types in Pokémon, not only is Water-type one of the starter options, but bodies of water dominate every single region, and are natural habitats for Pokémon.
Source：https://www.cbr.com/pokemon-water-stone-evolutions/
