Bat Ray, Myliobatis californica

The bat ray is part of the eagle ray family living on the sandy or muddy sea bottom, a kelp bed, and rocky shoreline, in an estuary, bay, or slough off the Pacific coast and around the Galapagos Islands. It can be found in a group or swimming alone and will sometime bury itself in the sand.

The average length of the bat ray is 3.28 feet, but some have been recorded of reaching 5.9 feet. Wingspan of this species can reach 6 feet and weigh up to 200 lbs., but typically 20 – 30 lbs. is the average. The lifespan of the bat ray can be up to 23 years.

While feeding, this species of ray will use its wings to remove the sand from the seabed to uncover its prey, such as clams, oysters, and mollusks. Other prey in the diet of the bat ray includes crabs, crustaceans, and small fish. The teeth are flat and tightly packed in the mouth and used for crushing the prey, then it will spit out the shell fragments and consume the flesh. The teeth will fall out and be continually replaced throughout life. A spike containing venom is located on the tail near the base, but it is not considered dangerous and will only use this spike for defense when attacked or if it is frightened.

While mating the male will swim under the female with synchronized wing beats and impregnate her by using his clasper (reproductive organ) to fertilize the eggs inside her orifice. While in the orifice the embryo will feed on the egg yolk, and as it grows it will absorb protein through the uterine fluid. This is done annually during the spring or summer and the female will give birth to up to 10 young called pups. When born, the pectoral fins (wings) will be wrapped around the pup and the spike will be encased in a sheath that will fall off within hours after birth.

The bat ray is currently fished commercially in Mexico and is fished for sport in the U.S., but native tribes fished the bat ray for food off the coast of California in large numbers. However, the bat ray is not on any endangered species list at the present time, and is used frequently in marine parks as an attraction, where patrons are allowed to touch the fish usually on the wing.

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Subclass: Elasmobranchii

Order: Myliobatiformes

Family: Myliobatidae

Image Caption: Bat ray (Myliobatis californica) at the Channel Islands, California. Credit: Ed Bierman/Wikipedia (CC BY 2.0)