Southern Stingray, Hypanus americanus
The Southern Stingray, Hypanus americanus, whose common Spanish name is raya látigo blanca, is a species in the Whiptail Stingray or Dasyatidae Family, known collectively as rayas látigo in Mexico. This fish has very recently been reclassified from Dasyatis americana. Globally, there are 38 species in the genus Dasyatis, five of which are found in Mexican waters, three in the Atlantic and two in the Pacific.
The Southern Stingrays have flat diamond-shaped discs that are about 1.2 times wider than they are long. Their disc is angular at the front with a 135o angle. They vary in color from uniform gray to brown or olive with no markings dorsally and are off-white ventrally with gray or brown disc edges. They have an irregular row of short spines on the dorsal surface along the center of their back and a low dorsal keel on the tail which can be up two times longer than the disc. Their head is elevated. Their eyes, mouth, large spiracles, and gills are on the dorsal side. Their mouth is equipped with multiple rows of equally sized flat teeth. Their tail is long and slender and has a large rounded venomous spine mid-length used for defense; this venomous spine is about the same length as the distance between the outer margins of the eyes, has 52 to 80 serrated teeth on the sides, and ends in a point. They have a single row of tubercles along the midline of the back running from the nape to the caudal fin base and a short row on each shoulder. They have a central band of denticles that runs from behind the eyes to the base of the tail.
The Southern Stingrays are a coastal demersal species found over sandy bottoms, in seagrass meadows and lagoons, and around reefs at depths up to 170 feet. Females are larger than males and have a maximum disc width of 1.5 meters (4 feet 11 inches) and weight of 97 kg (214 pounds); males have a maximum disc width of 67 cm (26 inches). They are known to frequent bays and estuaries in waters with temperatures between 28oC (82oF) and 32oC (90oF). They are found as solitary individuals and in pairs or occasionally in small groups. They remain half-submerged in the substrate during daylight and emerge at night to prey on a variety of fish, including scorpionfish, surgeonfish, and toadfish, as well as clams, crabs, shrimps, and worms. They locate benthic invertebrates via electroreception utilizing rows of sensory cells known as “Ampullae of Lorenzini” that locate the weak electric fields generated by prey, including buried prey. They also have a keen sense of smell and touch. They have a limited number of predators, which include large sharks such as hammerheads. Reproduction is ovoviviparous, with embryos being sustained by a yolk sac initially then being nourished by uterine milk secreted by their mother. Two to ten miniature adults with a disc width of 17.0 cm (6.7 inches) to 34.0 cm (13.4 inches) are released after a four to eleven-month gestation period. Communication is based on pheromone signaling. They are known to be cleaned of parasites by various fish including the Bluehead Wrasse and Hogfish. They are a poorly studied species and very little is known about their behavioral patterns.
The Southern Stingrays are found in all Mexican waters of the Atlantic.
The Southern Stingray can be confused with the Atlantic Stingray, Hypanus sabina (long pointed snout with rounded disc margins), the Bluntnose Stingray, Hypanus say (rhomboidal disc with rounded edges), and the Longnose Stingray, Hypanus guttatus (projecting snout with concave front disc margins).
The Southern Stingrays are not fished commercially but are a fairly common by-catch of trawlers. From a conservation perspective they are currently classified as Data Deficient. Their population levels have been historically unmonitored and are unknown at present and they are currently unprotected. The loss of coral reef habitat would have a significant impact on their long-term viability. In general they are not considered dangerous to humans, but can be harmful to humans if they are stepped on accidentally. In some locations within their wide range they are very common and are an important ecotourism resource throughout the Caribbean. Their tail spines have been used by indigenous people to make knives, spears, and other tools.
Southern Stingray, Hypanus americanus. Fish caught from Edisto Beach, Botany Bay, South Carolina, June 2011. Total Length: 1.11 meters (3 feet 8 inches); Disc Width: 44 cm (17 inches); Disc Length: 37 cm (14 inches); Tail: 74 cm (28 inches). Catch, photo, and identification courtesy of Josh Leisen (lifelistfishing.com), Gaylord, MI.
Southern Stingray, Hypanus americanus. Fish caught from Edisto Beach, Botany Bay, South Carolina, June 2011. Total Length: 1.65 meters (5 feet 5 inches); Disc Width: 66 cm (26 inches); Disc Length: 55 cm (22 inches); Tail: 1.14 meters (4 feet 9 inches). Catch, photo, and identification courtesy of Josh Leisen (lifelistfishing.com), Gaylord, MI.