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Cownose ray
NOT ON EXHIBIT
At the Aquarium
Natural History
Cownose rays have a unique feature—long, pointed pectoral fins that separate into two lobes in front of their high-domed heads. A crease in the lobes and a notched head create a cow-nose likeness that gives these rays their name. Cownose rays use their flexible fin lobes to probe the seafloor for prey, like clams. After detecting buried prey, they dig deep depressions in the sand by flapping their pectoral fins and, at the same time, sucking sand through their mouths and out their gill slits. As they forage, large schools of rays can stir up huge clouds of silt over a large area.The rays’ eyes and spiracles are on their brown upper bodies, and their mouths are on their white or yellowish underbellies. The rays have large, flat tooth plates on both jaws that they use to crush hard-shelled prey. The rays spit out crushed shells and eat the soft body parts.
Conservation
Cownose rays aren’t threatened. There is concern in Chesapeake Bay that an increase in the number of these rays is harming the already declining oyster population. One proposed solution is to allow commercial fishing for the rays, but it’s difficult and expensive to catch and process these rays. Cownose rays mature relatively late and have few offspring. Even though they have caused problems for the oyster fishery, cownose rays are an important part of the ecosystem.
Cool Facts
Cownose rays are known for their long migrations in large schools. They are strong swimmers, able to cover long distances. In the Atlantic Ocean, their 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.
Cownose rays have poisonous stingers, but even in large groups they’re shy and not threatening. In 1608, Captain John Smith, an East Coast settler and explorer, learned about the nature of a cownose’s sting. 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, they jump out of the water and land with a loud smack, a behavior thought to be a territorial display.
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Animal Facts
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ON EXHIBIT
- Scientific Name:
Rhinoptera bonasus
- Habitat:
Open Waters
- Animal Type:
Fishes
- Diet:
clams, large snails, lobsters, oysters, crabs
- Size:
to 7 feet (2.1 m) from wingtip to wingtip
- Range:
Western Atlantic: southern New England to northern Florida and throughout the Gulf of Mexico, migrating to Trinidad, Venezuela and Brazil
- Relatives:
bat rays, manta rays, stingrays, spotted eagle rays; Family: Myliobatidae
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