If you’ve ever dipped your toes into the shallow ocean water along California’s coast, you may have encountered one of its secretive residents: the California Round Stingray. Though small, inconspicuous, and peaceful by nature, this ray is the single most common source of stingray injuries to beachgoers in SoCal.
Welcome to Round Stingray 101 where we take you under the sand and behind the camouflage to get an inside look into the world of the Round Stingray.
Round Stingray, by Robin Miller, Wikipedia
Identification & Characteristics of the Round Stingray
The Round Stingry’s superpower is subtlety. Spend enough time in the surf zone or shallow coastal waters and you’ll realize just how cleverly these rays blend into their surroundings.
Let’s dive into some of their unique characteristics:
Shape and size: Also known as Urobatis Halleri, or Haller’s round ray, they’re a member of the Urolphidae family with a unique disc-like body. It’s one of the smaller species of stingrays, with the pectoral disc width typically measuring between 6 to12 inches. Its eyes and spiracles—openings used to draw water over the gills—are located on the top of its head, allowing it to see and breathe and see even when it is nearly completely buried beneath the sand.
Coloration: They are typically a grayish-brown color on top, often mottled or spotted with lighter yellow or tan spots. This camouflage allows them to blend seamlessly into the sandy seafloor, often making them invisible to the human eye.
The barb: Round stingrays have a relatively short, stout tail, which is typically about the length of their body. Located about halfway down the tail is a venomous serrated spine; their weapon used purely for defense. The barb typically lies flat against the tail, but during a sting, the tail flexes back as it whips upwards, driving the barb into the perceived threat above. The barb typically only measures 1 to 2 inches, but the venom and serrations can cause surprising damage to the victim of a sting, whether it’s a great white shark or an unsuspecting beachgoer.
A fascinating little fact: Round Stingrays periodically shed and replace their spine! For the majority of the year, they carry just one primary spine, unless it is ripped or broken off. But starting around June, small secondary spines develop and eventually replace the primary again 3 to 4 months later.
Habitat and Distribution
Round stingrays are most densely concentrated along the warmer waters of Southern California and Northern Baja California beaches. Their preferred habitat is one that puts them in direct contact with beachgoers.
They favor shallow coastal waters, often less than 50 feet deep, with sandy or muddy bottoms. This includes intertidal zones, shallow bays, and estuary mouths. The stingray’s strategy is simple: bury themselves just beneath the sand to hide from predators and ambush prey. This makes them virtually impossible to detect by sight, turning your causal walk into a game of chance.
Round Stingray Buried in Sand
Stingray populations are migrational and temperature-dependent. They are most common in coastal waters from spring through fall and have been documented congregating in large numbers near warm water sources like power plant outfalls further increasing the density (and therefore the risk of injuries) in specific areas like Seal Beach, CA.
Behavior and Diet
Round Stingrays are benthic foragers, meaning they search the ocean floor for invertebrates. They feed mostly during the day, preying on worms, mollusks, small crustaceans, shrimp, and other soft-bodied organisms.
These rays are not aggressive and don’t hunt or chase humans. Their sting is strictly defensive. At rest, they rely on being undetectable. When physically disturbed (such as when stepped on or kicked by unsuspecting beachgoers), their natural reflex is either to retreat or to whip their tail upward and jab with their spine. Because their stinger is serrated, once embedded in flesh, it can be hard to remove, and parts of it can even break off in the wound, increasing the risk of infection.
Behaviorally, they may react rapidly to pressure or vibration through the seafloor or water. That’s why the “stingray shuffle” is recommended because it gives the ray a chance to sense your approach and swim away rather than reflexively lash out.
Reproduction and Lifespan
The seasonal life cycle of the California Round Stingray directly impacts the density of rays in near-shore waters and, consequently, the risk to humans.
The California Round Stingray is viviparous, meaning it gives birth to live young. They have one of the shortest gestation periods of any ray, lasting only about three to four months. In Southern California, mating season typically peaks in the spring (March to May). Between June and October, females move into warmer, shallow habitats to give birth to small litters of one to six pups.
These warm, sandy beaches and bays act as critical nursery grounds. Since the young rays remain in the shallows for protection and feeding before migrating to deeper waters, the summer and early fall months see the highest concentrations of rays in areas where humans swim and wade. This natural process may partially explain why stingray injuries skyrocket during peak beach season in the summer. Of course, there are also many more people in the water during these times, which is likely also a contributing factor.
Interaction with Humans
Stings most commonly occur when a person steps on or kicks a stingray The ray’s reflex is a tail whip upwards and the spine penetrates the foot. Because of their camouflage, tendency to bury themselves in the sand, and overall low-water visibility, the vast majority of stingrays are unseen until contact. Despite the pain, round ray stings are almost never fatal, although they can become dangerous if tendons are severed or arteries are hit, if there is an allergic reaction to the venom, or if a secondary infection sets in.
Most stingray injuries are preventable with simple caution, behavior modification and foot protection. DragonSkin stingray-resistant booties are designed specifically for you to walk, wade, and explore the water with confidence. Our booties are crafted with multi-layered materials engineered to resist punctures and penetrations, adding a buffer between your skin and any lurking spine beneath the sand.
LEARN MORE ABOUT OUR STINGRAY-RESISTANT BOOTIES
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