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 whi ...

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) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...

has rated it as being of "

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

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 (electrical) potential difference, electric pressure, or electric tension, is the difference in electric potential between two points. In a Electrostatics, static electric field, it corresponds to the Work (electrical), ...

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 () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

, and in the coastal waters of the western

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

from northeastern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

North Carolina North Carolina ( ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, South Carolina to the south, Georgia (U.S. stat ...

. It is also found in the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

and the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

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 constituting the order (biology), order Actiniaria. Because of their colourful appearance, they are named after the ''Anemone'', a terrestrial flowering plant. Sea anemone ...

s, small bony fish and various

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

Status

The lesser electric ray is caught as

in coastal shrimp fisheries and in

seine net Seine fishing (or seine-haul fishing; ) is a method of fishing that employs a surrounding net, called a seine, that hangs vertically in the water with its bottom edge held down by weights and its top edge buoyed by floats. Seine nets can be de ...

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