Round Stingray, Urobatis halleri

Round Stingray, Urobatis halleri, Juvenile. Fish caught from coastal waters of Mission Bay, San Diego, California, December 2015. Total Length: 25 cm (10 inches). Disc: 15 cm (5.9 inches) x 17 cm (6.7 inches). Tail: 9.1 cm (3.6 inches). Catch, photograph and identification courtesy of Ben Cantrell, Peoria, Illinois.

Round Stingray, Urobatis halleri. Fish caught from shore at Los Barriles, Baja California Sur, January 2017. Total Length: 32 cm (13 inches). Disc: 8.8 cm (3.5 inches) x 10 cm (3.9 inches). Tail: 11 cm (4.3 inches). Catch and photograph courtesy of Brad Murakami, Surrey, British Columbia, Canada.

Round Stingray, Urobatis halleri. Fish caught from Fish caught from shore off Las Conchas Beach, Puerto Peñasco, Sonora, November 2022. Total Length: 38 cm (15 inches). Disc: 10.5 cm (4.1 inches) x 12 cm (4.6 inches). Tail: 13 cm (5.1 inches). Catch and identification courtesy of Steve Wozniak, Alamo, California.

Round Stingray, Urobatis halleri. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, March 2012. Total Length: 38 cm (15 inches). Disc: 20 cm (7.9 inches) x 20 cm (7.9 inches). Tail: 17 cm (6.7 inches).

Round Stingray, Urobatis halleri. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2017. Total Length: 41 cm (16 inches). Disc: 20 cm (7.9 inches) x 22 cm (8.6 inches). Tail: 17 cm (6.9 inches). Catch, photograph and identification courtesy of Kenneth Tse, Toronto, Ontario, Canada.

Round Stingray, Urobatis halleri. Fish caught from coastal waters off Mazatlán, Sinaloa, April 2013. Total Length: 58 cm (23 inches). Disc: 28 cm (11 inches) x 31 cm (12 inches). Tail: 23 cm (9.2 inches). Catch and photograph courtesy of George Brinkman, Guelph, Ontario, Canada.

Round Stingray, Urobatis halleri. Fish caught from coastal waters off Catalina Island, California, September 2016. Catch, photograph and identification courtesy of Chris Wheaton, Fullerton, California.

Round Stingray, Urobatis halleri. Underwater photograph taken in coastal waters off Puerto Vallarta, Jalisco, September 2021. Photograph courtesy of Kevin Erwin, Seattle, Washington.

The Round Stingray, Urobatis halleri, is a member of the American Round Stingray or Urotrygonidae Family, and is known in Mexico as raya redonda común. Globally, there are six species in the genus Urobatis, of which four are found in Mexican waters, one in the Atlantic and three in the Pacific Ocean.

The Round Stingray has a rounded flat body and vary in color from light brown to tan with the central portion of their discs usually featuring large circular markings superimposed on a spotted or vermiculited background. Their ventral side is off white. Their discs are slightly longer than they are deep and have a fairly straight front side margin and a pointed snout. Their eyes and spiracles are on top of their heads and their mouths, nostrils, and gill slits are on their ventral sides. Their pectoral wings are rounded. Their tails are short and stout, equal to less than half the disc length, with a large stinger and a large rounded caudal fin. Their stingers are impressive (pictured below), varying in length from 2.5 cm (1.0 inch) to 3.8 cm (1.5 inches). They have very smooth skin that is devoid of denticles or thorns.

The Round Stingray reside over and within sandy and muddy bottoms. They are occasionally found in rocky reef areas at depths up to 180 m (300 feet), however they are most abundant at depths of less than 15 m (50 feet) and move to greater depths during cold-water episodes. During breeding season, they are found in greater numbers at estuary mouths and shallow bays. The Round Stingrays reach a maximum of 58 cm (23 inches)  in length with discs having a maximum width of 31 cm (12 inches), however most have disc diameters of less than 25.4 cm (10 inches). They can weigh up to 1.36 kg (3 lbs 0 oz). As of January 1, 2024, the International Game Fish Association world record stood at 1.36 kg (3 lbs 0 oz) with the fish caught in coastal waters off Ventura, California in September 1989. 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. In turn they are preyed upon by the Northern Elephant Seal, Mirounga angustirostris and large fish such as the Giant Sea Bass, Stereolepsis gigas and the Leopard Shark, Triakis semifasciata. Reproduction occurs via internal fertilization with embryos developing via aplacental vivparity with a gestation period of 3 months. Their pups are born alive with disc widths ranging from from 6.3 cm (2.5 inches) to 10.0 cm (3.9 inches) and resemble miniature adults that are independent at birth. The Round Stiingray 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 Round Stingray is a resident of all Mexican waters of the Pacific Ocean.

The Round Stingray can mostly likely be confused with the Cortez Stingray, Urobatis maculates (spots and blotches well away from the margin of the disc) and the Reef Stingray, Urobatis concentricus (chain-like dark markings on the back).

From  conservation perspective the Round Stingray is currently considered to be of Least Concern, with stable populations found over a wide range. They are the most common ray found along the beaches of Southern California and Northern Baja generating numerous stingray injuries to waders and swimmers. From a fishing perspective, they are fairly abundant in certain locations at certain times of the year but are only retained by subsistence fishermen, being considered by most to be a “catch and release.”