Marine life  /  Sharks & rays  /  Giant electric ray
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Species entry

Giant electric ray

Narcine entemedor

A heavy-bodied electric ray that lies half-buried in sand and can deliver a shock strong enough to be felt through a glove.

Size
To 100 cm
Depth
5–25 m
Habitat
Sand pockets between boulders
Active
Night
Range
Eastern Pacific
Rarity
Islas Revillagigedo
4 stars of 5, two or three a season
SP-01
giant electric ray · full body · habitat
4:3 · min 2400px

To about 1 m. A heavy, rounded, soft-bodied ray, plain brown to grey above, usually lying half buried in sand with only the outline and the eyes showing. The electric organs are the paired kidney-shaped structures either side of the head, visible as two darker patches through the skin on a clean animal.

It hunts at night over sand, taking worms and small crustaceans, and spends the day buried. The discharge is defensive and repeatable and is strong enough to be felt clearly through a wetsuit glove. It is not dangerous to a healthy diver but it is a genuine surprise, and the way people get one is by putting a hand down on sand without looking. That is the whole of the practical advice: on a sand patch between boulders, look before you steady yourself.

Where to find:

LocationRarity Best monthsDepthHabitat
Islas Revillagigedo Mexico editorial estimate
4 stars of 5, two or three a season
Year-round
5–25 m
Sand pockets between boulders

Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.

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