Round rays (Urolophus halleri) are the most common species of stingray found within their range from Northern California south to Panama. As a result, they are also the most likely ray species to inflict stings on unsuspecting beachgoers. Completely burying themselves in the sand, as can be seen in this week's photo, round rays hide from predators, which include elephant seals, black sea bass and sharks, among others.
A relatively small ray, the maximum disk diameter is about 12 in. (31 cm) for females and 10 in. (25 cm) for males. The infamous venomous spine is found on the tail and used for defensive purposes. Spines are shed annually and regrow. While not fatal, the sting is quite painful and can easily become infected.
Female rays hold their fertilized eggs internally as they develop. As the young hatch out, they are released into the ocean looking like miniature versions of mom. Litters can range from one to six, with two or three being the average.