Roughtail Stingray

Fascinating facts about the Roughtail Stingray

• A 274-metre (899-ft) dive in the Bahamas makes the roughtail stingray one of the deepest-diving stingrays known, yet it usually stays in the sweet spot of 15–50 m (49–164 ft) where sandy or muddy bottoms hide its camouflaged disc.
• Weighing up to 360 kg (800 lb) and spanning 2.6 m (8.5 ft) across, this ray rivals a small car in size, and its long, whip-like tail measures about 2.5 times the length of its disc.
• From December to May the species migrates offshore along the U.S. east coast, then in spring rushes north of Cape Hatteras to Long Island and Cape Cod, keeping a clear size gradient, larger individuals stay farther south while smaller ones move north.
• Females give birth after a 9–11-month gestation to typically five pups that arrive at 34–37 cm (13–15 in) across, and both sexes don’t reach maturity until they’re over a meter wide (130–160 cm, or 51–63 in).
• Its venomous spine can pierce flesh easily, making accidental injuries a real risk for fishers, yet the ray isn’t aggressive and spends most of its time buried in sediment, only surfacing to snatch crabs, shrimp, squid or small fish that wander by.

At a glance

About the Roughtail Stingray

The roughtlay stingray, Bathytoshia centroura, glides over sandy and muddy bottoms like a dark, diamond-shaped shadow, its disc 1.2–1.3 times as wide as it is long and edged by straight to gently sinuous margins. A long, whip-like tail trails behind, tipped with a saw-toothed spine and a subtle ventral fin fold, while rows of flat-based thorns, bucklers, decorate the back once the ray exceeds about 46 cm across. Adults can span up to 2.6 m (8.5 ft) and weigh 360 kg (800 lb), making them the largest whip-tail stingrays in the Atlantic. They favor live-bottom habitats where sessile invertebrates create a rough terrain, typically at 15–50 m (49–164 ft) but diving as deep as 274 m (899 ft) in the Bahamas, and they migrate seasonally, overwintering offshore before moving into coastal bays and estuaries in summer. Their diet is a pragmatic mix of benthic invertebrates, crabs, bivalves, gastropods, squid, polychaete worms, and opportunistic bony fishes such as sand lance and scup, reflecting whatever prey is most abundant in a given locale. A surprising trait is their aplacental viviparity: embryos first draw on yolk, then switch to a nutrient-rich “uterine milk” called histotroph, a strategy that yields only four to six well-developed pups after a nine- to eleven-month gestation, underscoring their slow-reproducing nature. Although generally non-aggressive, the roughtail’s venomous tail spine can inflict severe wounds, making handling by fishers risky. Pregnant females often isolate themselves from conspecifics, and the species’ low activity level sees them half-buried in sediment, waiting for unsuspecting prey to drift by. Their predators include great hammerheads, while hitch-hiking live sharksuckers sometimes attach to their bodies. Parasites ranging from tapeworms to leeches are common, yet the ray’s robust size and thick skin provide a formidable defense against many threats, allowing it to persist in both the northwestern and southwestern Atlantic despite growing human pressures.

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