Nocturnal and solitary, the marbled electric ray can often be found lying the sea floor buried except for its eyes and spiracles. This slow-moving predator feeds almost exclusively on small bony fishes, which it ambushes from the bottom and subdues with strong electric bursts. It defends itself by turning towards the threat, swimming in a loop, or curling up with its underside facing outward, while emitting electric shocks to drive off the prospective predator. Its paired electric organs are capable of producing 70–80 volts of electricity. This species is aplacental viviparous, with the developing embryos sustained by yolk and histotroph ("uterine milk") produced by the mother. Mating takes place from November to January, and females bear litters of 3–32 pups every other year after a gestation period of 9–12 months. The newborn ray is immediately capable of using electricity to hunt.