Fish Active at night

Giant Electric Ray

Narcine entemedor

iNaturalist Wikipedia

Meet the 'Intimidator' of the Pacific shallows—a master of camouflage that carries its own biological batteries. The Giant Electric Ray is a fascinating nocturnal neighbor for those living along the Eastern Pacific coast.

0 Sightings

0 Habitats

Quick Identification

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Size

Typically reaches a total length of 60–90 cm (24–35 inches), weighing between 2–5 kg (4.4–11 lbs).

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Colors

Uniformly tan, grayish-brown, or sandy brown on the upper surface; creamy white or pale yellowish on the underside.

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Key Features

Circular or oval pectoral disc
Two prominent dorsal fins of nearly equal size
Thick, muscular tail without a stinging spine
Kidney-shaped electric organs visible through the skin on either side of the head

When You’ll See Them

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Activity pattern Active at night

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Peak hours 10 PM - 4 AM

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Season Year-round

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Diet Small bottom-dwelling invertebrates including polychaete worms, small crustaceans, and occasionally tiny squids or buried fish.

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Habitat Shallow coastal waters, sandy seafloors, and the margins of rocky or coral reefs.

public Geographic range

Where Does the Giant Electric Ray Live?

The Giant Electric Ray is a signature species of the Eastern Pacific Ocean, with a native range that spans from the southern Gulf of California down through the tropical waters of Central America to Panama and occasionally as far south as Peru. This ray thrives in the coastal shelf environments of Mexico, Costa Rica, and Colombia, favoring the warm, nutrient-rich shallows near the shore. While it is a marine specialist, it is frequently found in bays and estuaries where sandy substrates provide the perfect environment for its ambush-style lifestyle.

Basemap © OpenStreetMap contributors

9 Countries

1.2M km² Range

Least Concern Conservation

MX Mexico CR Costa Rica PA Panama CO Colombia EC Ecuador GT Guatemala SV El Salvador HN Honduras NI Nicaragua

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iNaturalist / Verified observation data

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Behavior

The Giant Electric Ray is a sluggish, bottom-dwelling species that spends much of its day buried under a thin layer of sand. By pumping water through spiracles on top of its head, it can stay oxygenated while remaining almost entirely hidden from both predators and prey. Despite the intimidating name, these rays are generally non-aggressive toward humans, though they will deliver a significant bio-electric shock if stepped on or handled, which they use as a primary defense mechanism.

As nocturnal hunters, they become much more active after sunset. They use their specialized electric organs—composed of modified muscle tissue—to emit low-voltage pulses for navigating and locating prey in the dark, and high-voltage bursts to stun small fish or invertebrates. Unlike stingrays, they lack a venomous barb, relying entirely on their 'battery power' and camouflage for survival. In social terms, they are mostly solitary but may congregate in high-quality feeding grounds or during mating seasons.

photo_camera EverydayEarth exclusive

Camera Tips

To capture a Giant Electric Ray on camera, you will need a specialized underwater housing or a dedicated marine trail camera. Since these rays are nocturnal and spend much of their time buried, your best bet is to position the camera at the interface where a rocky reef meets a sandy flat. This 'ecotone' is a high-traffic highway for rays moving between their daytime hiding spots and nighttime hunting grounds.

Standard PIR (passive infrared) motion sensors rarely work effectively underwater. Instead, set your camera to a time-lapse mode—taking a photo every 30 to 60 seconds—or use a camera with 'pixel-change' detection if the water is clear. Because the Giant Electric Ray is active in near-total darkness, high-quality infrared (IR) LEDs are essential. Ensure your IR lights are angled slightly away from the lens to avoid 'backscatter,' where light reflects off suspended sand particles, creating a snow-globe effect in your footage.

Placement is key: mount your camera on a heavy, low-profile weighted base or a sand-screw about 12-18 inches off the seafloor, angled slightly downward. You can entice a ray to stay in front of the lens longer by using a 'scent bag' filled with crushed shrimp or squid secured just out of the frame. This won't necessarily make them 'attack' the bait, but the scent will cause them to linger and forage in the area, giving you much better opportunities for a clear ID.

Similar Species

Species that look similar or are commonly confused with Giant Electric Ray.

Bullseye Electric Ray

Much smaller with a prominent, target-like spot (ocellus) in the center of its back.

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Frequently Asked Questions

Giant Electric Rays are strictly nocturnal. While they spend their days buried in the sand to avoid predators, they emerge after dark to forage for worms and crustaceans along the seafloor.

The best way to attract these rays is by placing a mesh bag of crushed shellfish or squid near your camera setup. The scent will draw them in, and they will often linger in the area to investigate the substrate for food.

Their diet consists primarily of soft-bodied invertebrates like polychaete worms and small crustaceans. They use their sensitive snouts to detect prey buried in the sand and can stun them with electric pulses.

Yes, they are frequently found in shallow bays and near public piers within their range. Because they prefer shallow, sandy bottoms, they often live in very close proximity to human beachfronts and marinas.

Look at the tail and the shape. Electric rays have a thick, muscular tail with two distinct dorsal fins and no stinging barb, whereas stingrays have thin, whip-like tails usually equipped with a sharp, venomous spine.

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