Southern Stingray (Hypanus americanus): Facts and Habitat

What does a southern stingray look like?

A southern stingray is built for life on the sea floor. Its head, body and huge pectoral fins are fused into one flat disc that is more angular than in most rays, with sharp outer corners that give it a diamond or kite shape. The disc is roughly 1.2 times as wide as it is long.

The upper side is dark gray, olive or brown, often matching the color of the local sand, and young rays tend to be grayer than adults. The underside is white. A row of small, thorny bumps called tubercles runs down the middle of the back of larger animals.

The eyes sit on top of the head, and just behind them are two openings called spiracles. The mouth, nostrils and five pairs of gill slits are on the underside, out of sight of the eyes. The mouth holds rows of flat, plate-like teeth for crushing shells.

The whip-like tail can be up to twice as long as the body. Near its base sits a long, stiff spine with saw-tooth edges, covered by a thin sheath of skin and venom-producing tissue. A low fin fold runs along the underside of the tail behind the spine.

How big do southern stingrays get?

Southern stingrays show one of the biggest size differences between the sexes of any ray. Large females have a disc about 1.5 m (5 ft) across, and the biggest ever reported reached about 2 m (6.6 ft) and 97 kg (214 lb). Males are much smaller and rarely exceed about 67 cm (26 in) in disc width.

Like other rays, they are measured by disc width, from wingtip to wingtip, because the tail is often damaged. Including the tail, a big female can be well over 2 m (6.6 ft) long. Newborn pups are about 20–34 cm (8–13 in) across.

Southern stingrays are large for stingrays but far smaller than manta rays, which reach about 7 m (23 ft) across. The differences are explained in manta ray vs stingray.

Habitat and range

The southern stingray lives in tropical and subtropical waters of the western Atlantic Ocean. Its range stretches from New Jersey in the United States, where it is an occasional summer visitor, south along the coast to Florida, around the Gulf of Mexico and through the Bahamas and the Caribbean to southern Brazil. It is most abundant around Florida and the Bahamas.

It is a bottom-dweller of shallow, warm water. Typical homes are sand flats, seagrass beds, lagoons, bays, estuary mouths and sandy patches between coral reefs, often in water only 1–5 m (3–16 ft) deep. Southern stingrays have been recorded down to about 53 m (174 ft). They avoid steep reef walls, where there is little soft sand to dig in.

What do southern stingrays eat?

Southern stingrays are carnivores that feed mainly on animals hidden in the sand. Their diet includes shrimp, crabs, mantis shrimp and other crustaceans, clams and other bivalves, marine worms and small fish such as gobies and wrasses. One study of a single stingray’s stomach found prey from 15 different families.

Because its eyes are on top and its mouth is underneath, a southern stingray cannot see what it is eating. Instead, it finds prey with a keen sense of smell, touch and electroreception. Pores on the underside of the head, called ampullae of Lorenzini, detect the faint electric fields produced by the muscles and nerves of buried animals, the same sense that sharks use.

To dig prey out, a stingray flaps the edges of its disc to stir up the sand or blows strong jets of water from its mouth into the seabed, leaving shallow pits behind. It then traps the prey under its body and crushes shells with its plate-like teeth. Bar jacks and cormorants sometimes follow feeding stingrays to snatch small fish that are flushed out of the sand.

Behavior and senses

Southern stingrays are usually seen alone or in pairs, though they gather in groups to mate, rest or feed, and young rays can be very numerous in nursery areas. In many places they are most active around dusk and at night, but they forage at any time of day when food is available.

They swim by rippling the edges of the disc in waves from front to back, a slow but very maneuverable style that lets them hover, turn on the spot and settle gently on the bottom. When resting, a stingray flicks sand over its back until only its eyes, spiracles and tail are visible. Because it breathes in through the spiracles on top of its head rather than through the mouth, it can lie buried for long periods.

This habit of hiding in shallow sand is the main reason people get stung: a wader may step on a ray that it cannot see. Simple ways to avoid this are explained in what is the stingray shuffle?

Reproduction and life cycle

Like all stingrays, the southern stingray mates by internal fertilization. Males have a pair of claspers, extensions of the pelvic fins used to transfer sperm. During courtship, one or more males follow a female closely and grip the edge of her disc with their teeth. Mature males grow teeth with small, pointed cusps that help them hold on. Females can mate again soon after giving birth.

The young develop inside the mother without a placenta. At first they feed on the yolk of their egg, and later on a protein-rich fluid called histotroph, or uterine milk, made by the wall of the womb. Pregnancy lasts several months, with estimates from about 4 to 11 months, and wild females are thought to breed about once a year.

A litter usually holds 2–10 pups, with an average of about four, and bigger females have more young. The pups are born fully formed, with their tail spine sheathed so that it cannot harm the mother, and they receive no care after birth. Males mature at a disc width of about 51 cm (20 in) and females at about 75–80 cm (30–31 in), when they are several years old.

Lifespan, predators and threats

Little is known about how long southern stingrays live. In one study, the oldest males were aged at about 12 years and the oldest females at about 13 years, and some may live longer. Rays in public aquariums have lived for many years, but long-term records are scarce.

The main natural predators are large sharks. The great hammerhead is a stingray specialist that uses its wide head to pin rays to the sea floor before biting them, and tiger and bull sharks also eat rays. Many hammerheads are found with stingray spines stuck in their jaws, showing that the barb is not always enough to stop a determined predator.

People are the other major threat. Southern stingrays are caught in shrimp trawls, gillnets and on longlines across their range, often as bycatch, and in some areas they are landed for meat. Coastal development and the loss of seagrass beds and mangrove nurseries also reduce the shallow habitat that young rays depend on.

Conservation status

The IUCN Red List classifies the southern stingray as Near Threatened (assessed in 2020). The species is still widespread and common in many places, especially in protected waters of Florida, the Bahamas and the Caribbean. However, heavy fishing pressure in parts of Central and South America is thought to have caused declines.

Like most rays, southern stingrays grow slowly, mature late and have few young, so populations cannot quickly replace animals lost to fishing. Marine protected areas, limits on trawling and well-managed ecotourism all help them.

Southern stingrays and people: Stingray City

The southern stingray is one of the most watched rays in the world. At Stingray City and the nearby Sandbar in the North Sound of Grand Cayman, dozens of rays gather in water only about 1 m (3 ft) deep to meet boatloads of snorkelers. The habit began decades ago, when fishermen cleaned their catch in the calm water and rays learned to come for the scraps. Similar sites exist in Antigua and the Turks and Caicos Islands.

The rays at Stingray City are protected by law. Research there has shown that regular hand-feeding changes their behavior: fed rays become active by day, stay in a small area all year and may be in poorer condition than wild rays. Many guides now limit feeding and handling.

Southern stingrays are not aggressive and, if disturbed, almost always swim away. Injuries happen when a ray is stepped on, cornered or grabbed. The sting is extremely painful but rarely life-threatening; if someone is stung, seek emergency medical help immediately or call 911 in the US. More details are in are stingrays dangerous?

Myths and facts

Myth: Stingrays attack people. Southern stingrays never chase or attack humans. The tail barb is a defensive weapon, and it is used only when a ray is pinned, stepped on or grabbed.

Myth: The barb always breaks off in a wound. Stingray spines can break, and rays regularly shed and regrow them, but in a US hospital review of 119 stingray injuries, no spines or fragments were found left in the wounds.

Myth: Stingrays are a kind of flat shark. Rays and sharks are close relatives with skeletons made of cartilage, but rays are a separate branch of the family tree, not flattened sharks. The relationship is explained in are stingrays related to sharks?