- Broad angular disc (body shape) brown to olive, with no spots or markings
- Pectoral fins ("wings") are long and pointed
- Snout is projecting, squarish, with an indentation at center (almost bi-lobed)
- Two small cephalic lobes or flaps protruding from front of head
- Mouth small, sub-terminal
- Tail is whip-like with one to two spine(s) at the base just behind a small dorsal fin
Spotted Eagle Ray, Aetobatus narinari (many spots on back); Brazilian Cownose Ray, Rhinoptera brasiliensis (very similar in appearance, has 9 series of tooth plates compared to R. bonasus which typically has 7); Bullnose ray, Myliobatis freminvillei (snout without a central indentation)
Wingspan (disc width) common up to 4 feet and can weigh up to 50 pounds.
A pelagic species found in bays, estuaries, river mouths, and open ocean. Present in some estuaries year-round.
Non-aggressive species of little danger to humans with the exception of their defensive venomous barb located near the base of the tail.
Known to form large schools containing 100s or 1,000s of individuals. Migrates seasonally in the Gulf of Mexico and along the U.S. Atlantic coast (north is spring/summer, south in fall/winter).
They are opportunistic benthic feeders. Their diet consists mainly of bivalve mollusks, crustaceans, and various other benthic invertebrates (i.e., clams, oysters, shrimp, marine worms).
Internal fertilization. The female carries eggs inside her body until they hatch, after which, she gives live birth to the hatched pups (aplacental viviparity or ovoviviparity); Normally just one pup per litter though litters containing 2 pups have rarely been observed.
Males can be identified by the presence of paired claspers on the inner margin of the pelvic fins. The breeding period is considered to be June through October.