Editing Guide to Taming and Raising Pets (section)

=== Water ===
Of the tamable water monsters, water-based undines and Celestial Plumpfish are the most common, however turtles and a few strains of fish are also common water pets. These pets are less common than land pets, and can only be used for underwater combat. Water pets cannot be summoned until the player is already in water, and as soon as the player reaches dry land or mounts aerogear, water pets are automatically stowed to the pet bag.