Mote Marine Laboratory

Taking the Sting out of the Ray

Millions of “Crocodile Hunter” fans were shocked when Steve Irwin was killed in September 2006 by a stingray while snorkeling on the Great Barrier Reef in Australia. Internet chat rooms were flooded with condolences and disbelief that a man who had become famous for wrestling giant crocs and huge snakes on his popular Animal Planet series had died after swimming over a stingray and being stabbed in the chest by the ray’s barb. Then, about a month later, James Bertakis made headlines around the world when he was stabbed in the chest after a spotted eagle ray jumped onto his boat while he was motoring near Boca Raton, Fla. According to published reports, Mr. Bertakis was trying to get the ray off the boat when it stabbed him in the chest. He survived the encounter after undergoing surgery to remove a portion of the stingray barb that had lodged in his heart.

Unlike the International Shark Attack File kept by the University of Florida, there is no scientific record of the number of people injured or killed by stingrays. Experts believe the number of deaths is low, that fatal encounters are extremely rare and only occur when the location of the wound affects vital organs. Here, Mote staff scientist Dr. James Gelsleichter, who studies freshwater rays living in the St. Johns River on Florida’s east coast, answers some of the most frequently asked questions about stingrays and these recent stingray encounters.

QUESTION: Why would a stingray attack the Crocodile Hunter?
ANSWER: Stingrays use their tail spines only for defense. It’s likely that this particular animal perceived Mr. Irwin and other members of the film crew as a threat and its tail spine snapped up in a typical defensive response. Although many have argued that Mr. Irwin was not riding or touching the animal, it’s very important to remember that rays have an exceptional array of senses that allow them to perceive potential threats even if those threats are at a considerable distance.

Q: Why was this “attack” fatal?
A: Stingray-related injuries most commonly occur in beachgoers, who step on rays and are generally wounded on the feet or legs. That’s why stingray wounds are rarely fatal. In contrast, virtually all of the few individuals who have been wounded in or near the heart have died as a result of this event, usually due to heart muscle necrosis, loss of blood, and/or fluid accumulation in the heart cavity, which prevents the heart from beating properly. The tissue necrosis, or breakdown, can be caused by the ray toxin, which appears to possess enzymes capable of degrading connective tissue. Removing the spine itself may have also led to greater blood loss, because of the barb’s serrations. However, it’s unfair to place blame on the victim for removing the spine, because that’s a natural response to such a traumatic event.

Q: What species of stingray is responsible for the Crocodile Hunter’s death?
A: Initially, the media reported that Steve Irwin died as a result of an injury from a “bull ray” spine. This suggested that the species involved in this event was the Australian bull ray, Myliobatis australis. However, given the location of the spine in M. australis — very close to the body near the base of the tail — and the reported distance between Mr. Irwin and the animal, it’s unlikely that this species was involved in his death. Dr. Colin Simpfendorfer, a Mote scientist and former research scientist of the Western Australian Fisheries Department, has suggested that the species responsible for this tragic event may be the cowtail stingray, Pastinachus sephen, a large-bodied ray that is common in that area of Australia and possesses a tail spine better situated for striking predators because the tail spine is located further from the body, near the middle of the tail. While this species certainly appears to be a likely candidate, it is important to remember that we still don’t have confirmation of the species that killed Mr. Irwin.

Q: Why did the spotted eagle ray that stabbed Mr. Bertakis jump out of the water? Was it aiming for him?
A: We’re not sure why some rays, like spotted eagle rays, jump out of the water, but we know they do it regularly. Some scientists have suggested that it may be a way for the stingray to remove parasites, but this hasn’t been proven. We have similar questions, for instance, about why mullet or other fish jump out of the water. The incident that led to Mr. Bertakis’ being stabbed in the chest was purely an accident — a ray and a boater being in the same place at the wrong time.

Q: You’ve mentioned the bull ray and the cowtail stingray in Australia, and the spotted eagle ray in Florida. How many different kinds of stingrays are there and where do they live?
A: There are about 200 species of stingrays in the scientific order Myliobatiformes. They include the giant stingarees, sixgill stingrays, stingarees, river stingrays, whiptail stingrays, butterfly rays, eagle rays, cownose rays and devil rays. Stingrays can be found in both freshwater and marine habitats throughout the world. Most of the river stingrays of the family Potamotrygonidae live permanently in freshwater and have lost the ability to survive in marine habitats. Atlantic stingrays living in Florida’s St. Johns River, which I study, also seem to spend their entire lives in freshwater, but are capable of adapting to saltwater in controlled laboratory settings.

Q: Do stingrays shoot their spines like darts or arrows?
A: No, a stingray is incapable of using its spine as a projectile. The spine is only capable of injuring a predator or human that is within the range of its tail. However, since the tails of many stingray species are long and whip-like, rays can have a considerable striking range.

Q: Does a stingray lose its spine when it injures a predator or person?
A: Yes, a stingray often loses its spine when it injures another creature. This occurs largely due to the relatively weak connection between the spine and the tail, the often surprising force of this defensive reaction and the anchor-like teeth of the spine, which tend to lodge in tissue like a series of arrowheads or fishhook barbs.

Q: Does a stingray die like a bee when it loses its spine?
A: No, a stingray is relatively unaffected by the loss of its spine because the spine is connected to the tail by only a small amount of connective tissue. Loss of a spine usually results in spine replacement within a short period. In fact, some stingray species replace their spines on an annual basis.

Q: What about marine aquariums — like Mote Aquarium — that have stingrays in touch pools. Can those hurt me?
A: Marine parks and aquariums that display stingrays in “petting” exhibits — like the “Ray Tray” at Mote Aquarium — regularly remove or trim the spines of their animals so that visitors won’t be injured. However, to the best of our knowledge, this does not occur at popular dive or snorkeling spots that offer opportunities to encounter and/or feed stingrays in the wild. It’s likely that animals in those places are accustomed to being around humans, making it less likely the rays will exhibit a defensive response resulting in injury. But visitors on those types of excursions should still exercise caution.

Q: What kinds of stingrays does Mote Aquarium keep?
A: Mote Aquarium’s Ray Tray focuses on rays commonly found on Florida’s Gulf Coast. The Aquarium usually has cownose rays, Atlantic stingrays and yellow stingrays. These rays all have their barbs trimmed. We also have southern stingrays in the shark habitat, whose barbs are intact.

Q: Do trimmed barbs grow back?
A: Stingray barbs are made of a dentine and enamel-like material, similar to the tooth-like scales on sharks. They do grow back. These spines are found on the top side of the tail.

Q: What should I do if I step on a stingray and get stung?
A: A stingray’s venom is largely a protein-based toxin that causes great pain in mammals and may also alter heart rate and respiration. Since the venom carried on the barb is protein-based, it can be inactivated by exposing it to high temperatures. You should immerse the wound in hot water or apply a heat compress immediately. Although this should reduce the initial pain of a stingray injury, victims should also obtain medical assistance so that the wound can be properly examined and cleaned to avoid secondary infections or other complications.

Q: How can I avoid coming in contact with a stingray at the beach?
A: The best method is to “Do the Stingray Shuffle.” That means shuffling your feet in the sand as you’re walking along in the water instead of stepping normally. It’s common for stingrays to bury themselves in the sand along shore. Rays will usually sense the shuffling movement and swim off with no harm done.

Learn more about: Stingrays