How dangerous are stingrays?
It is a common opinion that Stingrays use their barb to kill their prey or to harm humans. You can hardly mention stingrays without the mention of Steve Irwin. But just how dangerous are stingrays? Mr Irwin’s death was only the third known stingray death in Australian waters, and wildlife experts agree “the normally passive creatures only sting in defence, striking with a bayonet-like barb when they feel threatened”
So stingrays really are peaceful animals and will actually try to avoid human interaction at all costs. Stingray barbs are a defence. A protective weapon against other predators. Stingrays are the ‘pussycats of the seas’. A name probably given due to their docile behaviour. That said, it is also reported that the natives of South America fear the stingray more than they do the piranha.
How dangerous are stingrays – captive vs wild
The majority of people stung by a stingray are unfortunate enough to have waded into the water and stepped on a ray.
Captive rays are generally docile and will tolerate the keepers hand being in the aquarium (such as cleaning). Take extra care to make sure that the ray does not feel trapped or scared.
In either situation, if the stingray feels threatened it can lead to defensive behaviour which may result in a tail swipe.
How dangerous are stingrays – The Spine and Venom
The Stingray Spine is its main defensive weapon and it is therefore extremely rare for a fish to use it unprovoked. The barb is a modified denticle, (same as the rays skin). The location of the barb or spine is located about 2/3 along the tail or caudal appendage of the animal. The barb usually lies flush along the topside of the tail and points in the direction of the tail tip. In rare cases the barb has changed angle and points towards the head. This adaptation has no scientific explanation.
There is a wedge-shaped area of tissue located in close contact with the barb where the spine lays flat against the dorsal surface of the ray’s tail. It is covered in a cocktail of venom and mucus.
There is a lot of confusion referring to the correct terms fish keepers use when speaking about the spine/sting and barb. Here are the correct terms
The Sting: Refers to the entire structure (the spine its sheath and venom glands)
The Spine: Refers to the ridged surface of the sting made from dentin
The Barb: Refers to the backward facing serrations along the lateral part of the spine
Stingrays are unable to raise and lower their sting however in response to a threat, but they can swipe their powerful tail to strike a predator.
How dangerous are stingrays – The Venom
All species of stingray have very similar venoms, yet some species are rather more potent than others. They all contain the same enzymes: serotonin, 5-nucleotidase and phosphodiesterase. The last two enzymes are responsible for the necrosis and tissue breakdown seen in a stingray sting.
The serotonin is the enzyme which causes the excruciating pain in the area of the wound. Therefore, if left untreated the actions of these enzymes will continue to cause pain and tissue breakdown.
The stingray’s infamous tail spines have two components: the sharp inner barb used for piercing, and a thin sheath surrounding it that contains the venom. The barb pierces the venom sac along with the victim’s skin as the spine is deployed. As a result, the poisonous slime is introduced into the wound.
The barb is extremely sharp. It can penetrate bone. Operating under the same principle as an arrowhead it slides into flesh fairly easily, but the serrated edges make it very difficult and painful to extract. The tail is very flexible and can bend pretty much any direction within a split second, inflicting serious damage.
How dangerous are stingrays – First Aid for Stings
The toxins or venom from the stingray’s spines are protein molecules. You can “denature” proteins. To do this, the most effective treatment is to immerse the wound in as hot as water as the patient can stand. Expect this to take a couple of hours. You’ll know when the treatment has worked because it wont hurt when you take the wound out of the water.
How hot should the water be? Don’t use boiling water. That will just take your skin off. Take advice from the patient or trust your own instinct if you are the patient. In our experience, the hotter the water, the less the sting hurts. Continuously top up the hot water to ease the pain. You/they will feel so much relief from keeping the wound in hot water. Now, it’s just a matter of sitting with their hand in a bowl for a couple of hours. Every so often, they might say – “its fine now”. You’ll quickly figure out that the pain will return until all the proteins are denatured.
Please seek medical attention immediately if the wound itself is severe. Especially if you consider the barb’s serrated edges could cause more damage with its removal without medical advice. Most UK doctors might not have had to treat a stingray injury before, so please let them know that untreated necrosis can result in a build-up of decomposing dead tissue and cell debris at or near the site of the cell death. A classic example is gangrene.