In British and Australian English this would be called a "tortoise", whereas the amphibious variety of this animal is a "turtle". The Americans use "turtle", as in the translation.
Well, turtles and tortoises are both reptiles, and they form the order Testudines, along with the terrapin.
According to my dictionary schildpad is a tortoise and a turtle would be a watershildpad or seeschildpad - Duo thinks the Dutch use the same word for tortoise and turtle but the dictionary doesnt
In Dutch, we don't make a distinction between 'tortoise' and 'turtle'. Otherwise, 'tortoise' would be 'landschildpad' and 'turtle' would be 'zeeschildpad' and/or 'zoetwaterschildpad'. But really, we use for both just 'schildpad'.