Terrapin

A terrapin is a turtle that lives in fresh or brackish water. In British English, the species most commonly referred to as terrapins are members of the family Emydidae which includes the red-eared slider and the slider, but not the terrestrial box turtle. The name "terrapin" is used for the diamondback terrapin in both British English and American English; the name originally being used by early European settlers in North America to describe these brackish water reptiles that inhabited neither freshwater habitats nor the sea. However, in American English the name is not routinely applied to other semi-aquatic or freshwater turtles, unlike the situation in British English where any such turtle might be called a terrapin.