Bat ray

Bat rays feed on mollusks, crustaceanCrustacean

The crustaceans are a large group of arthropods , usually treated as a subphylum ....
s and small fish on the seabed, using their winglike pectoralPectoral

Pectoral, from the Latin pectoralis, 'pertaining to the breast/chest', can refer to:...
 fins to move sand and expose prey animals. They may also dig trenches up to 20 cm deep to expose buried prey, such as clams. Bat ray teeth are flat and pavementlike, forming tightly-packed rows that are used for crushing and grinding prey--the crushed shells are ejected and the flesh consumed. As with all elasmobranchs, these teeth fall out and are replaced continuously.

While the bat ray, like other stingrayStingray

Dasyatidae is a family of rays, cartilaginous marine fishes, related to skates and sharks....
s, has a venomous spine in its tail (near the base), it is not considered dangerous and uses the spine only when attacked or frightened.

Currently, the bat ray is fished commercially in MexicoMexico

The United Mexican States, generally known as Mexico is a country located in North America, bordered at the north by t...
 but not the United StatesUnited States

The United States of America, also known as the United States, the U.S., the U.S.A., and America, is...
. However, it is sometimes fished for sport for its fighting characteristics. Prehistorically, native tribes on the California coast (probably OhloneOhlone

The Ohlone are an ethnic group of Native American people whose members lived in what is now the San Francisco Bay Area and M...
), especially in the San Francisco BaySan Francisco Bay

The San Francisco Bay is a shallow, productive estuary through which water draining approximately forty percent of Californi...
 area, fished bat rays in large numbers, presumably for food.

Commercial oysterOyster Overview

The name oyster is used for a number of different groups of molluscs which grow for the most part in marine or brackish wate...
 growers have long believed bat rays (which inhabit the same estuarine areas favored for the industry) prey on oysters, and trapped them in large numbers. In fact, crabs (which are prey of bat rays) are principally responsible for oyster loss. Bat rays are not considered endangered or threatened.

Bat ray reproduction is ovoviviparousOvoviviparity

Ovoviviparous animals develop within eggs that remain within the mother's body up until they hatch or are about to hatch....
. They mate annually, in the spring or summer, and have a gestation period of nine to twelve months. Litter sizes range from two to ten — pups emerge with their pectoral fins wrapped around the body, and the venomous spine is flexible and covered in a sheath which sloughs off within hours of birth. Bat rays live up to 23 years.

Bat rays copulate while swimming with synchronized wingbeats--the male under the female. The male inserts a clasper into the female's cloaca, channeling semen into the orifice to fertilize her eggs.