Cownose Rays are known to take on long migrations in schools of thousands of individuals, moving northwards in late Spring and southwards in late Autumn. It is believed that this migration is initiated by the orientation of the sun and by water temperature.
Cownose Rays migration, Gulf of Mexico © Sandra Critelli
Cownose Rays can be recognised by their unusual bi-lobed head. Under the snout are two large fleshy lobes. These are often mistaken as the entrance to the mouth. The mouth however, is on the underside the fish.
The Cownose Ray is a pelagic species of eagle ray which inhabits the open ocean but can sometimes be found in inshore waters. Unlike other stingrays, they rarely rest on the seabed and prefer to be on the move just like their well-known relatives the Manta Rays.
While migrating in groups or ‘fevers’ of up to 10,000 individuals, their migration pattern, in the Atlantic, includes a northward movement in the late spring and southward movement in the late fall. However, the southbound migration has been observed to contain larger schools than the northbound migration.
Researchers believe that the changes in water temperature, coupled with sun orientation, may initiate seasonal mass migration. Research also suggests that the southward migration might be influenced by solar orientation while the northward migration might be influenced by water temperature cooling below 22 degrees Celsius.
This species of eagle ray is restless and constantly on the move. They use their extended pectoral fins to swim, and often turn upside down, curling their fin tips above the surface of the water, leaving terrified swimmers convinced that they have seen a shark.