This benthic fish inhabits rocky reefs, seagrass beds, and sandy and muddy flats in shallow to moderately deep waters.

It can be identified by the long, finger-like projections on the rims of its spiracles, as well as by its dark brown mottled color pattern, though some individuals are plain-colored.

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.

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 impact of fishing on its population is uncertain, and thus International Union for Conservation of Nature (IUCN) has listed this ray as Vulnerable.

[9] Bottom-dwelling in nature, the marbled electric ray inhabits rocky reefs and seagrass beds, as well as nearby areas with sandy or muddy bottoms.

[7] During warm summer months, pregnant females are known to migrate into Arcachon Bay in northwestern France, where they are commonly found in very shallow, muddy pools near oyster beds.

The thick pectoral fin disc is nearly circular and comprises about 59–67% of the total length; the paired kidney-shaped electric organs are visible beneath the skin, outside of the small eyes.

Immediately posterior to each eye is a large, oval spiracle, which bears 6–8 long, finger-like projections on the rim that almost meet at the center.

[5][12] The short, robust tail has skin folds running along either side, and terminates in a large caudal fin shaped like a triangle with blunt corners.

[10] It is highly tolerant of being deprived of oxygen (hypoxia), allowing it to cope with deoxygenated bottom waters or being stranded in small pools by the falling tide.

It deals with extreme hypoxia by coupling anaerobic glycolysis to additional energy-producing pathways in its mitochondria, which serves to slow down the accumulation of potentially harmful lactate within its cells.

[5][9][12] Cephalopods such as European squid (Loligo vulgaris) and elegant cuttlefish (Sepia elegans) are a minor secondary food source.

There is a single record of an individual that had swallowed a penaeid prawn, Penaeus kerathurus,[27] and a study of captive rays found that they reject live Macropodia crabs.

In the "jump", the ray pulls back its head and then thrusts its disc upwards, reaching about two or three times as high as the prey fish is from the bottom.

The initial electric burst is very short, containing only 10–64 pulses, but is still strong enough to cause tetanic contraction in the body of the prey fish, often breaking its vertebral column.

As the ray glides forward, the motion of the jump sweeps the now-paralyzed prey beneath it, whereupon it is enveloped by the disc and maneuvered to the mouth.

A ray touched on the disc will quickly turn toward the threat while producing electric shocks; this is followed by it fleeing in a straight line, after which it may re-bury itself.

[28] The marbled electric ray exhibits aplacental viviparity, in which the developing embryos are nourished initially by yolk, which is later supplemented by nutrient-rich histotroph ("uterine milk") produced by the mother.

[12][16] The electric organs first appear when the embryo is 1.9–2.3 cm (0.75–0.91 in) long, at which time it has distinct eyes, pectoral and pelvic fins, and external gills.

The embryo's pectoral fins enlarge and fuse with the snout at a length of 2.8–3.7 cm (1.1–1.5 in), giving it the typical circular electric ray shape.

The ancient Greeks and Romans applied live rays to those afflicted with conditions such as chronic headaches and gout, and recommended that its meat be eaten by epileptics.