The lesser electric ray (''Narcine bancroftii''), also known as the Brazilian electric ray, small electric ray, spotted torpedo ray, torpedofish or trembler, is a species of numbfish in the family

Narcinidae Narcinidae, or numbfishes, are a family of electric rays (order Torpediniformes). They are bottom-dwelling cartilaginous fishes with large, rounded pectoral fin discs and long tails. They can produce an electric discharge for defense, from whic ...

found on the western coastal fringes of the Atlantic Ocean and Caribbean Sea. It is a small slow-moving fish, living in the surf zone of sandy or muddy beaches. Here it is easily caught as

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

by shrimp fisheries and seine netters. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has rated it as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

Description

This species of ray has a near-circular body and a short tail. It grows to approximately long, and wide, with colouration ranging from dark brown to reddish orange. It has irregular rings, sometimes oval in shape. The ventral surface ranges from white to greenish. It has tooth rows that vary in number from 17 to 34 in each jaw. This depends on the size of the specimen. It has two electric organs, elongate in shape, that run from the front of the eyes, down to the rear end of the disc. These organs can generate a peak

voltage Voltage, also known as electric pressure, electric tension, or (electric) potential difference, is the difference in electric potential between two points. In a static electric field, it corresponds to the work needed per unit of charge to m ...

of about 14 to 37 volts, which they use to stun prey and to defend themselves. Narcine bancroftii SI.jpg Narcine bancroftii SI2.jpg Narcine bancroftii upper teeth.jpg, Upper teeth Narcine bancroftii lower teeth.jpg, Lower teeth

Distribution

This species is found in the

Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an oceanic basin, ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of ...

, and in the coastal waters of the western

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

from northeastern

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and So ...

. It is also found in the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

and the

West Indies The West Indies is a subregion of North America, surrounded by the North Atlantic Ocean and the Caribbean Sea that includes 13 independent island countries and 18 dependencies and other territories in three major archipelagos: the Greater A ...

Habitat

The lesser electric ray is most commonly found under sand or mud, in intertidal shallow waters, but has been found at depths of up to .

Behavior

This species is nocturnal. It remains motionless during the daytime, and forages for food in the substrate at night. It is a sluggish swimmer and maintains a territory in the surf zone of the beach. Females mature at the age of two and produce as many as twenty live young at a time.

Diet

Lesser electric rays feed mainly on polychaete annelids. They also eat benthic worms, juvenile

snake eel Ophichthidae is a family of fish in the order Anguilliformes, commonly known as the snake eels. The term "Ophichthidae" comes from Greek ''ophis'' ("serpent") and ''ichthys'' ("fish"). Snake eels are also burrowing eels. They are named for their ...

sea anemone Sea anemones are a group of predation, predatory marine invertebrates of the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemones are classifi ...

s, small bony fish and various

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

Status

The lesser electric ray is caught as

in coastal shrimp fisheries and in seine net fisheries. Its population in the Gulf of Mexico has decreased to about 2% of what it was in 1972, and similar catastrophic declines have been experienced elsewhere. In July, 2016 the US National Marine Fisheries Service (NMFS) conducted a thorough review of the status of the lesser electric ray because the original study used to justify the critically endangered designation was based on a very small sample size. This updated status review conducted by NMFS incorporated fisheries dependent and independent data and concluded that the population is "not currently in danger of extinction throughout all or a significant portion of its range and is not likely to become so within the foreseeable future". The

has rated it as being of "

References

External links

Image showing teeth
* https://www.floridamuseum.ufl.edu/discover-fish/species-profiles/narcine-bancroftii/ * {{Taxonbar, from=Q5016476 lesser electric ray Fauna of the Southeastern United States Fish of the Caribbean Fish of the Dominican Republic Fish of the Western Atlantic lesser electric ray lesser electric ray Taxa named by Charles Hamilton Smith