Including the extended period of diapause, the gestation period lasts around 11–12 months, with 1–6 young being born in mid to late May. In 1941, in a shallow channel between Chincoteague Island and Cape Charles, Virginia, several large bluntnose stingrays were observed repeatedly breaking the surface and swimming rapidly in straight lines, some with their tails thrashing in the air; others were seen rising slowly to the surface and "hanging" for several minutes. One of the rays was hooked and the shock of capture caused it to release five near-term fetuses, suggesting that this activity may have been related to parturition. The aborted young were pale with small yolk sacs, and a swelling in the place of their tail spines. Females begin ovulating a new batch of eggs immediately after giving birth, indicating that they have an annual reproductive cycle. Newborn rays measure across and weigh . Males mature sexually at disc width of and a weight of , while females mature at a disc width of and a weight of .