A terrarium adapted to be immersed in an aquarium containing water, the terrarium comprising a shaft means having a first end and second end and a receptacle defining at least one wall, the at least one wall having a length, presenting at least one opening, an air exhaust and an interior wherein the receptacle is connected to the shaft means at the first end wherein the shaft means at the second end is adapted to anchor the receptacle in the aquarium and wherein the interior of the receptacle is adapted to receive air from an air supply means so as to define a dry zone in the interior.