Ultraviolet rays and food play a very important role. Turtles have large requirements for calcium and vitamins. For these reasons, it is not natural to feed tortoises exclusively with lettuce and tomatoes. They are lacking in vitamins and often treated with insecticides, resulting in various malformations and diseases.
With a natural diet, we obtain improvements in health and even recovery for sick turtles.
Tortoises appreciate corpses of animals. Schmitt and Ingu reports even the case of an Indian which knew quickly how to find corpses of drowned persons in lakes, using a gluttonous tortoise attached to a leash.
Plants: the same as for tortoises to which can be added aquatic plants (algae, watercress, water hyacinth, Spirogyra), present in and around ponds.
The same list as for terrestrial turtles.
2 - 3 times a week.
Oyster and egg shells are regularly introduced as a calcium supplement.