Identifying Fish That Sting and Can Maybe Kill You
Handle these common fish with extreme care and learn how to avoid and treat fish stings
If you find me close to water, chances are I’ll be catfishing. I love catching these whiskered warriors and rarely miss an opportunity to fish for them.
So I found myself casting for gafftopsail catfish on one of my first trips to the Gulf of Mexico.
My host for that trip suggested I try for “sailcats,” as he called them. “A big one might weigh 5 pounds,” he said. “They’re plentiful here. You can probably catch a dozen off the dock while I load the boat.”
What my friend failed to tell me was that sailcats sting.
When I hooked the first one, it gave a good fight before I swung it on the dock. I swung it too hard, though, and one of the fish’s needle-sharp pectoral-fin spines stabbed me in the thigh.
I didn’t think much about it at first. I’d been spined by plenty of freshwater cats, and other than some minor pain, those wounds caused no problems.
This puncture was different, though. Within seconds, burning pain shot through my entire leg. Imagine the sting of a red wasp times two. That’s how excruciating it was.
Upon examining the wound, I found my leg extremely swollen and reddened. Only when I applied a hot-water compress did the discomfort subside.
What I did not know about these saltwater cats is the fact that skin covering their serrated pectoral and dorsal-fin spines contains venom cells. The thrust of a spine into an unwary angler’s flesh ruptures the cells, allowing the venom to enter the victim’s body.
The resulting pain can be excruciating, and if not properly treated, dangerous secondary infections can result. Fortunately, my injury was minor other than the short-lived agony it caused.
Beware, though. Next time you hook a fish you’re unfamiliar with, think twice before swinging it into your boat or handling it.
Venomous Fish Outnumber Venomous Snakes
A recent study published in the Journal of Heredity by American Museum of Natural History biologists William Smith and Ward Wheeler shows there are more species of venomous fish than venomous snakes. In fact, there are more venomous fish than all other venomous vertebrates combined. The stings from some of these fish can be strong enough to debilitate or even kill a human.
The new study replaces the old estimate of 200 species with a conservative estimate of more than 1,200 species of venomous fish. DNA sequencing helped the scientists determine how known venomous species are related to other fish that might also be venomous. Some of those other fish were then examined to determine if they had venom delivery systems. They did.
“The results of this research were quite surprising,” said Dr. Smith. “They indicate that more than 1,200 fish species should be presumed venomous, and we were able to corroborate this estimate by a detailed anatomical study examining potentially venomous structures in more than 100 species.”
Snakes, scorpions, stinging insects and spiders – not fish – usually come to mind when a person thinks about venomous animals. But more than 50,000 injuries are attributed to venomous fish each year. Not surprisingly, statistics indicate that most dangerous encounters occur between anglers and the fish they catch.
We can’t examine all species of stinging fish, but here are some common ones you definitely should watch out for.
The vast majority of venomous fish are members of the catfish family. Among these are many saltwater species, all of which should be dealt with cautiously. These include the gafftopsail catfish mentioned in my opening story and the sea, or hardhead, catfish, both of which are frequently caught by anglers in portions of the Atlantic and Gulf of Mexico.
The sturdy spines on the back and side fins of these species can easily pierce the bottom of a shoe. But most stings occur when an angler carelessly handles a fish that’s being landed or unhooked.
Just a prick from one fin can cause searing pain, but most stings heal without complications. Occasionally, however, victims experience more severe symptoms such as allergic reactions, heart palpitations and loss of consciousness. Secondary infections caused by bits of skin and spine in the wound can be even more dangerous than the stings themselves.
Freshwater catfish also can sting with their sharp fins. But those most often caught by U.S. anglers – channel cats, blues, flatheads and bullheads – have little or no venom.
The same cannot be said for the miniature catfish known as madtoms. The 29 species in the U.S. rarely exceed 5 inches in length and an ounce or two in weight. But handling one is like playing with a hornet.
Glands at the base of the tiny cats’ extremely sharp dorsal and pectoral fins secrete venom that becomes incorporated in the slime and cells that make up each spine. Should you get “horned” by one of these little buggers, it’ll burn like fire.
Folks don’t catch madtoms on hook and line because these fish are so tiny. But generations of anglers have collected madtoms with seines or traps so they can use them as bait for smallmouth bass, trout and other fish.
Most quickly learn that handling a madtom carelessly is like grabbing a hot coal from a campfire. Stings rarely result in serious complications, but if you’re the one stung, you’ll think twice before handling a madtom again.
Few fish are more unusual or interesting than these weird bottom dwellers found around the world. (Tomas Willems photo via Wikipedia)
Most people know stingrays can sting. That’s why they’re called stingrays. Even so, the 22 species found in U.S. coastal waters inflict painful wounds on around 1,500 people every year.
Most injuries occur on the legs or feet when someone steps on one of these well-camouflaged bottom dwellers. Wade fishermen are particularly susceptible, as are anglers who are careless around rays brought into a boat.
Disturbing a stingray triggers a defensive thrashing of its tail, on the base of which are one to four serrated spines. The spines are sturdy enough to penetrate a wetsuit, boots or even the wooden side of a boat. If one of them penetrates a victim’s flesh, venom pours into the wound along grooves, causing pain that may leave the sufferer screaming and delirious.
Stings may take months to heal and often are accompanied by serious infections that require intensive treatment.
While unique in their appearance, lionfish have 18 venomous spines that are capable of causing incapacitating pain.
Lionfish are bizarre yet beautiful creatures with red and white stripes and long, showy fins. You’ve probably heard about them because in recent years these invasive pests, released into the wild by aquarists, have spread like locusts throughout the Caribbean and parts of the Atlantic and Gulf of Mexico. Where they have thrived, native fish populations have been reduced by as much as 70 percent.
Most lionfish encounters involve scuba divers and spear fishermen, but while these flamboyant creatures seldom take baited hooks, it’s not unheard of the catch one. If you do hook one, avoid handling it at all costs. The fish are armed with a formidable set of 18 long, sharp, venomous spines capable of inducing incapacitating pain.
A person is unlikely to die from a lionfish sting, but you might wish you had depending on how many spines penetrated the skin, the depth of the punctures, your own tolerance to pain and your body’s physical reaction to the venom.
Robson Green holding up a scorpionfish. (Photo courtesy of Robson Green)
Scorpionfish are close relatives of lionfish but have shorter, thicker spines with larger venom glands than lionfish do. As a result, they have a more potent sting as well. Because they’re delicious and commonly targeted, they’re among the fish most often indicted for their stings.
One species, the California scorpionfish, or sculpin, eagerly strikes baited hooks of anglers fishing southern California saltwater. This species lacks hollow spines for injecting its venom, but deep grooves carry a strong venom that makes itself felt right off. Many anglers call them “rattlesnakes,” because their stings cause so much misery.
The many species of rockfish popular with left-coast anglers also have the potential to put careless anglers in a world of hurt. Stepping on or being finned by some of the more venomous species can produce very painful puncture wounds that have the potential to be life-threatening.
The pain is produced when crystalline molecules of the venom excite pain receptors. Swelling, throbbing, burning and fever are commonly experienced by those unfortunate enough to suffer stings.
Some people who have previously been stung exhibit an allergy to the venom that manifests itself in rashes, swelling, hives and itching if the person is stung again.
Hospitalization and supportive treatment can be necessary with severe envenomation, so treat all rockfish stings seriously and seek medical attention promptly if necessary. Respiratory failure, cardiac problems and shock can result if you don’t.
The voracious, schooling leatherjacket, a member of the jack family, readily hits small lures and often is caught by people throwing cast nets for bait or shrimp. Common in parts of the Gulf and Atlantic, this pretty little fish, sometimes called skipjack, seldom exceeds a few inches long but packs a venomous sting that can end a fishing day early.
Little is known about the leatherjacket’s venom, which is contained in glands beneath the dorsal- and anal-fin spines. But many who’ve been stung report the pain far exceeds a sting from a catfish or even a stingray. Intense burning, throbbing and swelling can last for hours, but except in extreme cases, the stings aren’t considered life-threatening.
How to Avoid and Treat Fish Stings
Avoiding stings of venomous fish is mostly a common-sense matter.
- Learn to identify venomous species and use extra caution when fishing in waters they inhabit.
- Don’t handle fish you’re unfamiliar with or those you know can sting. Use a device like the BogaGrip when landing fish or removing hooks, or just cut the line and release the fish without landing it.
- Use great care to avoid anyone getting spined when swinging a fish into a boat. Never toss a fish to another person. And don’t leave fish on the deck or other places where they might be stepped on or sat upon.
- Shuffle your feet across the bottom when fishing waters inhabited by stingrays, or buy stingray-proof wading gaiters to wear when fishing in problem waters.
If you or someone with you is stung, follow these guidelines.
- Seek emergency medical help immediately if the victim experiences difficulty breathing, difficulty remaining conscious, chest pain, swelling around the sting site, vomiting, spasms, shock, severe bleeding or other severe symptoms.
- Soak the wound in hot but not scalding water for 30-90 minutes to reduce pain and inactivate the venom. DO NOT apply ice or cold water as this may intensify the pain.
- If necessary, use tweezers to remove any spines or bits of fish skin still in the wound. Use great care to avoid breaking the spine or getting stung by it. Removal of stingray barbs is best left to a physician.
- Scrub the wound with soap and water. Then flush the affected area with fresh water.
- Visit a physician to be sure no pieces of spine or skin remain in the wound that could cause infection. Be sure your tetanus booster is up to date.