Cownose Ray, Rhinoptera bonasus

The cownose ray is found in the western Atlantic from the coast of Maine to southern Brazil. In the fall schools of 10,000 or more will migrate south to the warmer water of Yucatan, Mexico. The cownose ray is a bottom dweller at depths of up to 70 feet, in brackish (salty) water. As a territorial act the cownose will leap out of the water and land with a loud smack.

An adult cownose has a brown body with a yellowish white belly, has an average wingspan of 45 inches and can weigh 50 lbs, but larger ones have been recorded. The wingspan of the young at birth range from 11 – 18 inches; a pair of wide-set eyes are on a very broad head, with a pair of lobes underneath.

Dental plates along with canine teeth hidden behind are inside the mouth, used for crushing food. The stinger of the cownose ray is on the tail close to the body with teeth along the lateral edges, which are coated with venom and used to defend itself from a predator. The sting is comparable to a bee sting and could be harmful if allergic to the venom.

Diet of the cownose consists mainly of clams, crustaceans, and oysters. Using the lobes like a vacuum, it will suck the food into the mouth and crush it with the dental plates. Searching for food in groups, the cownose will flap its wings to remove the sediment from clams, and oysters, and then it will feed on the uncovered invertebrate.

Inside the female the embryo will have the wings folded around the body and are nourished by the egg yolk, later by absorption of uterine secretion. Length of the gestation period has been disputed and no exact length of time has been concluded. The litter will be born live and exit the female tail first.

Cownose are often kept in zoo aquariums where visitors can actually touch and pet this species. The barb has been removed making it safe when the cownose is placed in one of these touch tanks.

On the endangered species list, the cownose ray is rated near threatened.

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Myliobatiformes

Family: Myliobatidae

Image Credit: Citron/Wikipedia (CC BY-SA 3.0)