This is a young adult Green Frog. It is much smaller than the old blue-faced males in the ponds, but it is still an adult and reproductively active, capable of laying a clutch of several hundred eggs in a night:
Tadpoles Swimming in Tank 6
The tadpoles shown here are Green Frogs (Lithobates clamitans) in tank 6. As of tonight, all eight experiment tanks have many tadpoles and eggs, with the past week seeing many clutches of eggs being laid by Cope’s Gray Tree Frogs (Hyla chrysoscelis).