Very little information is available on the biology and life history of the Cortez round stingray (1). However, like other stingrays, it is likely to be ovoviviparous, the female retaining the eggs inside the body until they hatch, and then giving birth to live young (4) (6). Reproduction in this species may be similar to the closely related U. halleri, in which mating occurs during the winter months, and the female gives birth to three to six young, after a gestation period of around three months (4). As in many ray and skate species, the male Cortez round stingray has more pointed, curved teeth than the female, an adaptation thought to allow the male to grasp the female’s pectoral fins during copulation (7).
Most stingray species spend a lot of time camouflaged on the sea bed, often partially buried in the mud or sand, but can swim rapidly when disturbed or when pursuing prey (3). The diet typically includes bottom-dwelling invertebrates, such as crustaceans, molluscs and worms, as well as small fish. Buried prey may be exposed by scooping out the sand or mud using the snout and pectoral fins (3) (4). The venomous tail spine of this and other stingrays is used in defence, and, although not fatal to humans, it can cause painful wounds (3) (4) (8).