It takes two … or does it? Charlotte the single stingray pregnant with pups

US stingray with no male companion expected to give birth to up to four offspring via rare phenomenon of parthenogenesis

Charlotte, a rust-colored stingray the size of a serving platter, has spent much of her life gliding around the confines of a storefront aquarium in North Carolina's Appalachian Mountains.

She's 2,300 miles (3,700km) from her natural habitat under the waves off southern California. She hasn't shared a tank of water with a male of her species in at least eight years.