The Electric Ray Family – Narcinidae
There are two members of the Electric Ray or Narcinidae Family currently presented in this website:
The Electric Ray or Narcinidae Family are known in Mexico’s fishing areas as rayas eléctricas. Members of the family are found in the Atlantic, Indian, and Pacific Oceans in temperate and tropical waters. The family has thirty global members placed in four genera. Four members are found in Mexican waters, one in the Atlantic and three in the Pacific.
The Electric Rays, also known as the numbfish, are small to medium sized bottom dwelling fish with flat oval discs that have convex front profiles and soft edges. They vary widely in color dorsally and are typically off-white ventrally. Most also have numerous spots, blotches, bars or lines, including ocelli spots. Their head has small eyes and their snout is short to moderately elongated. They have a straight mouth with a highly protrusible jaw and prominent lip furrows around the periphery. Their nostrils are located just forward of the mouth and are connected to it with a broad groove. Their nasal flaps are short but merged into a broad nasal curtain that overlaps the mouth. They have small teeth with a single moderate cusp; their teeth and tooth bands are exposed when the mouth is closed. They have large kidney-shaped electric organs on either side of their head and are able of producing an electric shock up to 37 volts that is utilized as a defense mechanism and to stun and capture prey. They also have an accessory electric organ behind the main electric organ that generates currents and is believed to aid in communication. They have a large caudal fin, two prominent dorsal fins of equal size, and a stout tail that is equal to or longer than the length of the disc. They are covered with soft loose skin that is smooth and without denticles or thorns.
The Electric Rays are slow-swimming bottom dwellers that feed on small fish and invertebrates, the majority of which are found on the ocean floor. They are a shallow water species found over sandy beaches, enclosed muddy bays, and estuaries adjacent to coral reef and in river mouths at depths up to 1,000 meters (3,300 feet). Reproduction is ovoviviparous with each female giving birth to approximately twenty fully formed young annually. The young develop internally from eggs which hatch and then grow inside the uterus; eventually the pups are born live as miniature adults. Due to their formidable electric shocking capabilities they have few natural predators. They are a rare and poorly studied species and as such very limited information is available about their behavioral patterns.
The Electric Rays are part of folklore with reports that the ancient Greeks and Romans used their electric currents to treat aliments such as gout and headaches. They are routinely caught as a by-catch by trawl fisheries and normally discarded as there is virtually no commercial interest in them. Their long-term viability is of concern due to long maturation periods for females and low reproductive capacities. They do not survive trawl net capture and are prone to loss of the inshore habitat they reside in due to activities such as dredging. Population trends are lacking making an assessment of the stability of the population difficult. They are not used as aquarium fish due to their size and the fact that they do not survive long in captivity. Caution: divers are warned to avoid contact with these rays. Some give electric shocks that are powerful enough to knock down an adult human. They are also known to be very confrontational and will swim directly towards divers if harassed.