Cownose Rays reach sexual maturity between the age of 4 and 5 years, with a life expectancy of 16 to 18 years. These rays breed from April through October in large schools, with females willing with the edges of their pectoral fins sticking out of the water while the males follow closely behind trying to grasp the fins to mate. The male will insert one or both claspers and rest on one another, with the female on top of the male. Mating can last from 30 seconds to a minute.

Cownose Rays are ovoviviparous, meaning that their eggs will develop and hatch within their own bodies and will continue eating from the egg yolk until the mother gives birth. The gestation period is different in different species of rays, but for the Cownose Ray the gestation period is usually between 11 and 12 months. When ready, the mother will give birth to live pups, exiting tail first.

There are 5 stages in the life cycle of a Cownose Ray.

Stage 1: The Egg - This starts when the egg is inseminated by sperm and an embryo begins developing into a fetus. The duration of this time period is currently unknown, but when combined with Stage 2 it is an accumulative 11 to 12 months.

Stage 2: Ovoviviparity - This starts when the fetus hatches from the egg within the mother's uterus. It will continue to grow here. The duration of this time period is currently unknown, but when combined with Stage 1 it is an accumulative 11 to 12 months.

Stage 3: Newborn - This starts after the pup is born. Most Rays give birth to Juvenile pups that are capable of taking care of themselves, however it is currently unknown if Cownose Rays are the same.

Stage 4: Juvenile - This starts anywhere from after the pup is born to a few months up to a year after birth. This is the second longest period of the Ray's life, as it will spend the next 4 to 5 years growing till it reaching full Sexual Maturity.

Stage 5: Sexually Mature - This starts between four to five years after the initial birth of the pup. Once a female ray reaches this stage, she is capable of giving birth once a year. The average female lives to about 18 years of age, while the average males' lives to around 16 years of age.