QuestionI have a red ear slider and a box turtle in the tank there is an egg. Who's is it and how is this possible?
AnswerOK, some Asian box turtles are semi-aquatic- but how do you have these two species sharing a habitat?
Turtles often lay infertile eggs when stressed. if the egg is not buried in a nest, it is a 'stress egg' and could have come from either turtle.
Try http://www.austinsturtlepage.com for more help.