Cownose Rays: Rhinoptera bonasus
Cownose rays are found in both ocean and bay environments along the east coasts of North and South America, as well as in the Gulf of Mexico. They migrate to our waters in May and stay until October. Here in Virginia, they prefer the warm, sandy, shallow waters of the Chesapeake Bay but can also be found at depths of up to 72 feet in the ocean.
The body of a cownose ray is flattened as it has adapted to a bottom-dwelling existence. The pectoral fins, or side fins, spread out from the body and look like wings. When mature, a cownose ray can weigh more than 35 pounds and these “wings” can reach a span of more than three feet. A notch in the ray’s head, when viewed from above, gives it the appearance of a cow’s muzzle, giving it the name “cownose.”
These rays form schools of hundreds of individual animals and have been seen leaping from the water’s surface, although this behavior is not clearly understood. Swimmers often mistake the wingtips of rays swimming close to the surface for shark dorsal fins.
Cownose rays are bottom feeders. Using flaps surrounding their mouth, they churn up the bottom sediment to uncover clams, oysters, mussels and other invertebrates. Powerful grinding plates in their mouths crush the shells, allowing them to feed on these animals.
Virginia Aquarium Cownose Rays
The Aquarium’s stingray habitat is one of the most popular exhibits in the Bay & Ocean Pavilion. Every day, Aquarium visitors flock to this touch pool for a chance to touch some of these graceful creatures. It is not unusual to find some rays rising to the surface to find a hand to rub against.
The Aquarium’s rays are fed twice a day. In the morning they are hand-fed by an aquarist who gets in the water with the animals. A lighter snack is distributed in the afternoon from the side of the pool. Both feedings offer guests a chance to learn more about these amazing animals and ask questions of the aquarists.
While rays are not endangered, they can sometimes fall victim to human-related activities. It is not uncommon for them to become entangled in fishing lines from both commercial and recreational fishing. Pollution is another major threat. Not only does it cause habitat destruction, but it can also harm food animals, such as clams and mussels, that rays prey on. Finally many of the popular dive and snorkel areas that highlight swimming with rays use food to attract these wild animals. Like any other wild animal, after being fed repeatedly by humans, the rays may eventually lose their natural instinct to hunt for food.
To help keep ray populations from declining, support conservation of our oceans. Participate in beach cleanups and always dispose of your trash properly. If you fish, learn the proper techniques of de-hooking an accidentally caught stingray.