Bullseye Electric Ray, Diplobatis ommata
The Bullseye Electric Ray, Diplobatis ommata, whose common Spanish name is raya eléctrica diana, is a species in the Electric Rays or Narcinidae Family, known collectively as rayas eléctricas in Mexico. Globally, there are only four species in the genus Diplobatis, one of which, this species, is found in Mexican waters of the Pacific.
The Bullseye Electric Rays have elongated oval discs that are slightly longer than they are wide and have a convex front margin. They are light brown with profuse leopard-like spotting and diffuse dark crossbars with a large “bullseye” ocellated spot on the center of their disc’s dorsal side. Some fish are uniformly brown while still displaying the large “bullseye”. Their head has small eyes, nostrils with two openings, and a protractile and tubular mouth. They have prominent well developed electric organs that are visible as kidney-shaped mounds on both sides of their head and that are capable of delivering strong jolts to stun prey. They have two rounded dorsal fins of equal size. They have stout, triangular, rounded, and well developed caudal fins with a narrow side fold; both lobes of the fin are continuous around the tip. Males have claspers that are stand alone and not continuous with the pelvic fins.
The Bullseye Electric Rays are a demersal species found over sandy and rubble terrain at depths up to 500 feet. They reach a maximum length of 25.0 cm (9.8 inches). They seek food by stirring bottom sediment with their pectoral fins and dislodging small crustaceans, small fish, mussels, and worms on which they feed. Pups are born alive as miniature adults and are independent at birth. They are a rare and poorly studied species and as such very limited information is available about their behavioral patterns.
In Mexican waters the Bullseye Electric Rays are found in all waters of the Pacific with the exception that they are absent from north of La Bocana along the central and northwest coasts of Baja.
Due to its small stature and large ocellated spot on its back, the Bullseye Electric Ray cannot be confused with any other species.
The Bullseye Electric Rays are caught fairly frequently as a by-catch of shrimp trawlers off the southwest coast of Baja and are normally discarded. Due to their size, they are of limited interest to most.
Bullseye Electric Ray, Diplobatis ommata. Fish provided by the commercial fishermen of the greater Los Cabos Area, Baja California Sur, February 2010. Length: 12.5 cm (5.0 inches). Disc Width: 5.2 cm (2.0 inches).