In most anurans the males deposit sperm onto the females as they are being laid however the male "Ascaphus truei" possesses an intromittent organ and internal fertilization occurs in a few other genera including "Nectophrynoides", "Mertensophryne", and "Eleutherodactylus".
In most anurans the males deposit sperm onto the females as they are being laid, however males of the genus "Ascaphus" possess an intromittent organ, unique among anurans, for internal fertilization. Internal fertilization does occur in a few other genera, including "Nectophrynoides", "Mertensophryne", and "Eleutherodactylus".