The passive cownose ray is a common summer visitor to the Chesapeake Bay. As it glides through the water, the ray’s wing tips break the surface, resembling the dorsal fins of a shark.
Rays are elasmobranches - their skeletons lack true bone and are composed entirely of cartilage. This group also includes sharks and skates, and all are characterized by the lack of a swim bladder – an organ that helps true fish float. Elasmobranches have a tendency to sink if they stop moving.
Mature cownose rays are brown with a whitish belly, and can grow to be 45 inches wide and weigh 50 pounds or more. They possess a toxin-laden stinger (or spine), located high on the tail close to the body. Cownose rays take their name from their notched head, which resembles a cow muzzle. They use their “wings” to churn the Bay’s bottom sediments to uncover hidden clams and oysters, which they then crush in their powerful jaws.
Cownose rays arrive in the Chesapeake in May and stay until early fall. Once in the Bay, large schools of up to 200 individuals move northward in search of food, arriving in the Upper Bay by early June. Cownose rays give birth to live young, or pups, in mid-June.
Stings from cownose rays are extremely uncommon. If stung by a ray, the wound should be cleaned and immersed in extremely hot water, which seems to deactivate the toxin.
In 1608, Captain John Smith had a near fatal encounter with a ray while spearfishing in the Virginia’s Rappahannock River. The story has become Bay lore – and the spot where Smith was stung is still known as Stingray Point.
Photo of cownose ray (Rhinoptera bonasus)