Cownose ray

Anatomy

This ray’s eyes and spiracles (breathing openings) are on its brown upper body, while its mouth is on its white or yellowish underbelly. The cownose ray has large, flat, tile-like teeth on both jaws that it uses to crush hard-shelled prey. The ray spits out crushed shells and eats the soft body parts.

Diet

A cownose ray uses electroreception to search sandy seafloors for burrowed prey, like clams. Once the ray locates its prey, it uses its pectoral fins to stir up sediment, while at the same time sucking water and sediment out through its gills and away from the seafloor. This creates a steep depression in the sediment. When the cownose ray uncovers its food, it seizes it with its mouth. While foraging, schools of rays can stir up huge clouds of silt over a large area.

Predators

Cobia, sandbar sharks, and bull sharks prey on cownose rays.

Cownose rays and humans

The cownose ray has a venomous spine located directly behind the base of its dorsal fin. But even in large groups, the cownose ray is shy and not threatening. They generally swim at the surface, posing minimal risk to humans who might accidentally step on their spines, which is the cause of most ray injuries.

Conservation

The cownose ray matures relatively late and has few offspring. Though these rays are not commercially fished, they are often captured accidentally as bycatch. The cownose ray is considered “Near Threatened” by the International Union for the Conservation of Nature and Natural Resources (IUCN).

There was concern in Chesapeake Bay that an increase in the number of these rays was harming the already declining oyster population.  Current scientific research disputes whether the cownose rays were actually causing the decline.

Cool facts

• The cownose ray is known for its long migration in large schools. It’s a strong swimmer, able to cover long distances. In the Atlantic Ocean, its migration is northward in the late spring and southward in the late fall. The population in the Gulf of Mexico migrates in schools of as many as 10,000 rays, clockwise from western Florida to the Yucatan in Mexico.
• In 1608, Captain John Smith, an East Coast settler and explorer, learned about the nature of a cownose ray’s sting firsthand. While Smith was spearing a ray with his sword near the Rappahannock River, the ray defended itself by stinging Smith in the shoulder. The pain was so terrible that the crew were convinced Smith was dying, so they dug a grave for him. But John Smith overcame the pain and felt well enough that evening to eat the ray for supper. The place where this happened is still known as Stingray Point.
• As this ray swims through the ocean, its wingtips often break the surface, resembling the dorsal fin of a shark, which sometimes causes undue alarm for swimmers and divers. Occasionally, it jumps out of the water and lands with a loud smack. This behavior could be a territorial display, or a cownose ray’s way of dislodging parasites.