The size of the bat ray is dependent on many factors, such as habitat alterations and different oceanographic and environmental conditions.

There has been a record of an abnormal cephalic horn formation in a juvenile male on the coast of Baja California Sur, Mexico.

Cephalic horns are a flexible projection from the front of the head and can be described as a modified aspect of their pectoral fins.

[12] The Bat Ray can be found in both tropical and temperate oceans from central Oregon in the USA to Mexico in the Gulf of California.

[14][15] The bat ray (Myliobatis californica)[3][4][5] is found in muddy or sandy sloughs, estuaries and bays, kelp beds and rocky-bottomed shoreline.

This species can typically be found in flat sections of water with a sand patch in between rocks or with a rocky bottom.

Litter sizes range from two to ten — pups emerge tail first 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.

The male inserts a clasper into the female's cloaca, channeling semen into the orifice to fertilize her eggs.

[17] The sexual maturity size of the female Bat Ray (Myliobatis california) is often greater than the male one.

Histotrophic viviparity is when the embryos inside the oviduct get their nutrition from uterine secretions instead of a yolk sac in order to grow throughout gestation without the need of a placenta.

[12] For males, sexual maturity occurs at a disc width of 622 mm and a weight of about 3.7 kg around 2–3 years of age.

These rays will have an abrupt transition in the clasper and disc width relationship once reaching sexual maturity.

For females, full sexual maturity is reached when at 63% of the asymptotic disc width at approximately 5–6 years of age.

In these areas, young are born in the late summer/early fall and subadults are most abundant during the summer close to the shore.

The male moved repetitively back and forth in order to get closer to the underside of the female to insert the clasper into her cloaca.

Oil-clearing utilizes a dissection microscope and fiber optic light to examine a prepared centrum face in order to view the bands.

[19] Bat rays feed on mollusks, crustaceans and small fish on the seabed, using their winglike pectoral fins to move sand and expose prey animals.

[23][24] Bat rays create pits by excavating the substrate in order to feed upon invertebrates and small fish.

Prehistorically, native tribes on the California coast (probably Ohlone), especially in the San Francisco Bay area, fished bat rays in large numbers, presumably for food.

[27] Commercial 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.

[9] The holes that bat rays leave behind after digging with their snouts allow smaller fish to eat the organisms hidden in the sand that they otherwise would not be able to retrieve themselves.