Reef Stingray, Urobatis concentricus
Reef Stingray, Urobatis concentricus, Juvenile. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, February 2014. Total Length: 13.5 cm (5.3 inches). Disc 8.4 cm (3.3 inches) x 8.3 cm (3.3 inches). Tail: 6.5 cm (2.6 inches).
Reef Stingray, Urobatis concentricus. Underwater photograph taken in coastal waters off Buena Vista, Baja California Sur, June 2017. Photograph courtesy of Bob Hillis, Ivins, Utah.
Reef Stingray, Urobatis concentricus. Underwater photograph taken in coastal waters off Puerto Vallarta, Jalisco, May 2023. Photograph courtesy of Kevin Erwin, Seattle, Washington.
Reef Stingray, Urobatis concentricus. Fish caught from shore at Km 26, Cerro Colorado, Baja California Sur, July 2005. Total Length: 32 cm (13 inches). Identification confirmed by Dr. Ross Robertson, Smithsonian Tropical Research Institute, Panama.
Reef Stingray, Urobatis concentricus. Fish caught from shore at Los Barriles, Baja California Sur, January 2017. Total Length: 34 cm (13 inches). Catch and photograph courtesy of Brad Murakami, Surrey, British Columbia, Canada.
Reef Stingray, Urobatis concentricus. Underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2018. Photographs courtesy of Ron Woheau, Zihuantanejo.
Reef Stingray, Urobatis concentricus. Underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2018. Photographs courtesy of Maude Jette, Dive Zihuantanejo, www.Divezihuatanejo.com.
The Reef Stingray, Urobatis concentricus, is a member of the American Round Stingray or Urotrygonidae Family, that is also known as the Concentric Ray and in Mexico as raya redonda de arrecife. Globally, there are six species in the genus Urobatis, of which four are found in Mexican waters, one in the Atlantic Ocean and three in the Pacific Ocean.
The Reef Stingray has a rounded flat body and varies in color being various shades of light gray with blackish lines or blotches and dark spots arranged in concentric rows on their discs giving them a “chain-like bullseye” appearance when viewed from above. Their discs are longer than they are deep and have fairly straight front side margins. Their snouts are rounded and their tails have two notable appendages that are approximately half the disc length. Their stingers are impressive (pictured above) being 2.5 cm (1.0 inch) in length. They feature a rounded caudal fin with very smooth skin that is devoid of denticles or thorns.
The Reef Stingray is a demersal species that resides over and within rubble bottoms adjacent to reefs at depths up to 395 feet. They reach a maximum total length of 48 cm (19 inches) with the discs have a maximum width of 28 cm (11 inches). They seek food by stirring the bottom sediment with their pectoral fins to dislodge small crustaceans, small fish, mussels, and worms on which they feed. Reproduction occurs via internal fertilization with embryos developing via aplacental viviparity with a gestation period of 3 months. Their pups are born alive and resemble miniature adults that are independent at birth. The Reef Stingray is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Reef Stingray is a resident of Mexican waters of the Pacific Ocean but has a limited distribution being found from Cedros Island, Baja California, southward along the central and southwest coasts of Baja, throughout the Sea of Cortez, and along the coast of the mainland south to Acapulco, Guerrero.
The Reef Stingray is most likely confused with the Cortez Stingray, Urobatis maculatus (spots and blotches well away from the margin of the disc) and the Round Stingray, Urobatis halleri (dense dark brown spotting with circular markings).
From a conservation perspective the Reef Stingray is currently classified as Data Deficient. When caught that are normally considered to be a “catch and release” and they are only retained by subsistence fishermen.