Fish
Stingray
Myliobatoidei · also called stingrays, whiprays
A stingray is a shark that lay down flat. It swims by rippling the edges of its disc, glides just above the sand, and hunts buried clams and worms by sensing their faint electric fields and crushing them with pavement-like teeth. The famous tail spine is a defensive tool only — a ray never attacks with it, and uses it just when something steps on or grabs the animal.
Overview
Stingrays are a large group within the batoids, the flattened branch of the cartilaginous fish that also contains sharks, skates, and sawfish. There are well over 200 species in tropical and warm-temperate seas worldwide, on sand, seagrass, and coral flats, plus the fully freshwater river stingrays of South America. All are carnivores of hard-shelled and buried prey.
The sting
The tail carries one or more serrated, venomous spines — modified scales with a groove of venom tissue and backward-facing barbs. A struck stingray whips its tail up and over the disc to drive the spine home; it is pure defence. Stings are agonising and infection-prone but rarely fatal. On stingray coasts the advice is to shuffle your feet so buried rays swim off before you tread on one.
Live birth
Stingrays give live birth. Eggs hatch inside the mother and the young are fed on a rich uterine “milk” called histotroph before a small litter of fully formed miniature rays is born.
Status
Stingrays as a group are Not Evaluated, trend decreasing. Some coastal species stay common, but many larger marine rays and the river stingrays are threatened. Rays mature late and bear very few young, leaving them highly exposed to targeted fishing, trawl bycatch, the aquarium trade, and loss of the estuaries where they feed and pup.
Stingray: common questions
How dangerous is a stingray to people?
For most people a stingray is harmless as long as it is not stepped on or handled. Stings do happen, usually to the ankle or foot of someone wading, and they are extremely painful, prone to infection, and slow to heal, but they are rarely life-threatening. Serious harm comes when the spine strikes the chest or abdomen, which is very unusual and generally involves a large ray and a person leaning over it or falling on it. Standard first aid is to immerse the wound in water as hot as can be tolerated, which breaks down the venom, remove any visible spine fragments, and seek medical care because of the infection risk and the chance of a retained barb. The death of the wildlife broadcaster Steve Irwin in 2006 was a rare case of a spine penetrating the heart.
Why do stingrays sting, and can they aim at a person?
The spine is purely a defensive weapon against predators such as sharks and large fish, and a stingray gets no food and gains nothing by using it on a person. A ray resting on the bottom that is suddenly trodden on or grabbed reacts by lashing its tail up and forward, which can drive the spine into whatever is pinning it. It is a reflex, not aimed hunting, and a ray that has room to flee will almost always just swim away. This is why shuffling your feet through the shallows works so well; the vibration warns buried rays and they leave before contact.
What is the difference between a stingray and a manta ray?
They are close relatives but live very different lives. A stingray is a bottom-dweller that lies on or in the sand, feeds on buried shellfish and worms crushed by flat teeth, and carries a venomous tail spine. A manta ray is a giant open-water filter feeder, up to seven metres across, that cruises near the surface with its mouth open straining plankton, has no functional sting, and never rests on the bottom. Mantas and their smaller cousins the devil rays are essentially stingrays that abandoned the sea floor for the plankton-rich open ocean, in the same way that whale sharks and basking sharks did among the sharks.
Do stingrays live in fresh water?
Some do. The river stingrays of the family Potamotrygonidae live entirely in the rivers and lakes of tropical South America, mainly the Amazon and Orinoco basins, and they cannot survive in the sea. They are true freshwater animals, give birth to live young in the river, and are a genuine hazard to people who fish and bathe, since a river-ray sting in a remote area is a medical emergency. Separately, a handful of large marine stingray species, such as some whiprays in Africa, Asia, and northern Australia, can tolerate fresh water and travel hundreds of kilometres up rivers, but unlike the South American river rays they still return to estuaries and the sea.