The pool frog (R. lessonae) is the other species of European aquatic frogs. They may interbreed with marsh frogs to produce a hybrid form called the European edible frog (R. esculenta). Male and female edible frogs may breed with males and females of either R. ridibunda or R. lessonae to produce viable offspring; however, breeding between male and female edible frogs results in infertile eggs or offspring incapable of surviving.