The two turtles, Cuff and Link, starred in the 1976 film Rocky and made a comeback appearance in Creed II, released in 2018.
Stallone, who is 72 years old, shared a photo with the turtles on his Instagram account earlier this month.
He said the turtles are now 44 years old.
In Rocky, Stallone referred to the turtles as “the exotic animals I was telling you about. These are my friends, Cuff and Link” when he introduced them to his love interest in the film.
Cuff and Link are alive and appear to be living a life of “relative peace and splendor,” the news outlet reports.