Giant Electric Ray, Narcine entemedor: The Giant Electric Ray is a rather easy fish to identify due to its uniform brown coloration with the rear margins of the fins being narrowly white.
The disc of this fish species is oval and very flat. It has enlarged pectoral fins that cover the front margin of the pelvic fins. The mouth is small and the nostrils on each side are single non-portioned openings (as pictured below).
The Giant Electric Ray reaches a maximum size of 30 inches with the young being just under 5 inches at birth.
It is found over sandy bottoms in the first 300 feet of the water column and in Mexican fishing waters ranges south of Guerrero Negro along the Pacific side of Baja California, throughout the Sea of Cortez, and along the coast of the Mexican mainland south to Guatemala.
The Giant Electric Ray is a member of the Narcinidae Family, which includes electric rays and numbfish, known in Mexico as rayas eléctricas. The Electric Rays are sluggish fish found in sandy and muddy areas, often buried under the substratum. They all have an elongated, oval disc with soft, flaccid edges, and two large similarly sized dorsal fins. They have soft and loose skin that lacks dentricles or thorns.
Each has a pair of kidney-shaped electric organs that are visible as mounds on either side of the head and are used as a defense mechanism to stun prey. They also have an accessory electric organ that produces low voltage discharges that may function in intra-specific communication. Young are born alive and arrive as miniature adults ready to fend for themselves. There are 24 global members of the family from 9 genera, of which the Narcine genus has 20 species, two of which are found in Mexican waters.