Fish nocturnal

Pacific Electric Ray

Tetronarce californica

The Pacific Electric Ray is the ocean's silent powerhouse, a master of ambush that uses bio-electricity to stun its prey. Found gliding through kelp forests and sandy flats, this fascinating ray is a true marvel of marine evolution.

4 Sightings

1 Habitats

Quick Identification

straighten

Size

Typically 0.6–1 m (2–3.3 ft), with large females reaching 1.4 m (4.6 ft); can weigh up to 41 kg (90 lbs).

palette

Colors

Dorsal surface is uniform dark gray, slate, or leaden brown; often features small, dark, scattered spots; the underside is creamy white.

visibility

Key Features

Circular pectoral fin disc that is broader than it is long
Two unequal dorsal fins located on a thick, muscular tail
Visible kidney-shaped electric organs on either side of the head
Smooth-rimmed spiracles (breathing holes) located behind the eyes

When You’ll See Them

schedule

Activity pattern nocturnal

brightness_5

Peak hours 10 PM - 4 AM

calendar_month

Season Year-round

restaurant

Diet A carnivorous predator that primarily eats bony fish such as Pacific herring, kelp bass, and mackerel; it wraps its fins around prey and delivers an electric shock to stun it before swallowing it whole.

park

Habitat Coastal waters along the continental shelf, ranging from sandy flats and muddy bottoms to the edges of rocky reefs and kelp forests.

bar_chart
Loading activity data...

Behavior

The Pacific Electric Ray is a solitary and somewhat sluggish predator during the day, often found resting partially buried in the sand or mud. They are famous for their specialized electric organs, derived from muscle tissue, which can discharge a powerful shock of up to 45 volts. They use this bio-electricity primarily to stun fast-moving prey and to deter potential predators like sharks or sea lions.

Unlike many other ray species that remain strictly on the seafloor, the Pacific Electric Ray is a surprisingly active swimmer. At night, they frequently leave the bottom to cruise through the water column, sometimes hundreds of feet above the floor. While generally indifferent to humans, they are known to be curious and may approach divers. They should be treated with caution, as a shock can be strong enough to temporarily disable a person.

photo_camera EverydayEarth exclusive

Camera Tips

To capture high-quality footage of a Pacific Electric Ray, you will need a waterproof action camera or a specialized underwater housing. Focus your efforts on 'edge' habitats—the areas where a rocky reef or kelp forest transitions into a sandy flat. These rays love to bury themselves in the sand just outside the cover of the reef to ambush prey drifting by. Look for a 'footprint' in the sand—a faint, circular depression that indicates a ray is buried just beneath the surface.

Placement is critical: secure your camera to a weighted sand-plate or a low-profile tripod no more than 6 to 12 inches off the seafloor. Angle the lens slightly upward to catch the ray's silhouette if it swims overhead, or parallel to the sand to capture the undulation of its thick tail as it glides along the bottom. Because these rays are most active in total darkness, you must use artificial lighting. We highly recommend using red-filtered LED lights; rays and most fish have poor sensitivity to red light, whereas bright white lights may cause them to flee the area immediately.

Motion triggers are notoriously difficult to use underwater due to floating kelp and surge movement. Instead, set your camera to a 'Time Lapse' or 'Interval' video mode, capturing a 10-second clip every two minutes. This ensures you catch the ray even if its movement is too slow to trigger a sensor. If your camera allows for high frame rates (60fps or higher), use it; slowing down the footage can help you see the subtle 'pulse' of the ray when it discharges electricity or the incredible speed of its strike when it moves from a buried position to engulfing a fish.

Similar Species

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

Round Stingray

Much smaller with a thin, whip-like tail containing a venomous spine rather than a thick tail with dorsal fins.

California Skate

Has a more pointed, triangular snout and a rougher texture on its back compared to the smooth, rounded disc of the Electric Ray.

Frequently Asked Questions

Pacific Electric Rays are primarily nocturnal. While they can be seen resting on the sand during the day, they do most of their swimming and hunting in the water column after the sun goes down, typically between 10 PM and 4 AM.

These rays are not easily attracted by traditional baits. The best way to capture them is through strategic placement. Set cameras near the edges of kelp forests or near schooling fish like anchovies, which are their primary food source. They are often curious about the low-frequency electromagnetic fields of electronic devices, which may naturally draw them toward a camera.

Their diet consists almost entirely of live fish. They are known to eat Pacific mackerel, herring, flatfish, and even small sharks. They hunt by drifting toward a fish and then delivering a sudden burst of electricity to paralyze it before consumption.

Yes, they are frequently found in shallow coastal waters, ranging from the surf zone down to 200 meters. Divers and snorkelers often encounter them in sandy patches within or adjacent to kelp forests along the California coast.

You can distinguish them by their tail and shape. The Pacific Electric Ray has a very thick, muscular tail with two distinct dorsal fins and no stinging spine. The Round Stingray is much smaller, has a whip-like tail with a sharp venomous barb, and lacks the visible kidney-shaped electric organs on its head.

Record Pacific Electric Ray at your habitat

Connect a camera to start building your own species record — AI identifies every visitor automatically.

Join free Identify a photo