What is Lionfish, Scorpionfish, and Stonefish Toxicity?
Venomous fish pose a significant danger to divers around the world. Out of all the venomous animals with backbones, more than half are fish. The family of fish known as Scorpaenidae, which includes the most venomous fish in the ocean, are responsible for most injuries caused by marine venomous creatures each year, second only to stingrays.
The Scorpaenidae family is categorized into three main types based on the shape of their venomous spines: lionfish, scorpionfish, and stonefish. All of these fish have spines on the top (dorsal), bottom (pelvic), and back end (anal) fins. Each spine is covered by a skin-like sheath that produces venom, and this venom is released when the fish is touched, piercing the skin of the victim.
Lionfish are often kept in aquariums and usually hurt people when they’re being handled, especially the fingers and hands. Scorpionfish are usually encountered by divers or fishermen and tend to injure hands when touched. Stonefish, which are bottom-feeding fish, often cause injuries when people accidentally step on them. This often happens in the coastal waters of Australia, Indonesia, and India.
Knowing where these fish are found, what they look like, the type of injuries they cause, and how to manage their venomous stings is important for both doctors and those who are at risk.
What Causes Lionfish, Scorpionfish, and Stonefish Toxicity?
The lionfish is a type of fish native to the coastlines of the area around the Indian and Pacific Oceans but is also found in home aquariums across the United States. Aquarium owners are often attracted to their striking colors and unique fins and rays that have spines. However, lionfish are considered as one of the fast spreading and harmful intruders in the Atlantic Ocean. One of the most notorious of these harmful species, the red lionfish, likely began spreading off the coast of Florida about 25 years ago. Now, two of the 15 species of lionfish, including the common lionfish, are well-established along the eastern coast of the US, threatening life on Caribbean coral reefs.
It’s important for divers in these areas to avoid touching lionfish due to the damaging effect of their venom. Many divers actively hunt lionfish to protect the health of the reef, but it’s vital to wear protective gloves and gear to avoid being injured by their spines.
Scorpionfish, like the lionfish, are native to the Indian and Pacific ocean coastal waters, but they can also be found along the coastlines of California to South America, and the coast of North Carolina extending to Brazil. Unlike the lionfish, scorpionfish are less aggressive but they are much better at blending in with their environment. Although they’re often kept in aquariums, they can cause injuries when caught by fishermen or encountered by divers.
The stonefish, a member of the Synanceinae family, is most commonly found in the region around the Indian and Pacific Oceans. A few species can also be spotted in the Caribbean Sea and Florida Keys. The stonefish, like the scorpionfish, is quite good at camouflaging but is perceived to be less attractive. Unlike the scorpionfish and lionfish, the stonefish often inflicts injury without even being spotted, as it lies flat on the ocean floor. Most injuries happen when someone accidentally kicks or steps on their rigid dorsal spines. Notably, the stonefish is regarded as the world’s most venomous fish.
Risk Factors and Frequency for Lionfish, Scorpionfish, and Stonefish Toxicity
In a 2015 review of past cases, researcher Diaz found that envenomation, or poisoning, by Scorpaenidae fish tends to affect young adult men on vacation in areas where the fish are natural inhabitants. These individuals are often putting themselves at higher risk by participating in activities like surf wading, wade-fishing, beachcombing, or tide pool exploring.
Lionfish, a popular aquarium pet, pose an additional threat. According to records from the San Francisco Bay Area Regional Poison Control Center, 82% of 45 reported lionfish injuries between 1979 and 1983 happened in homes with saltwater aquariums, while 18% took place in tropical fish stores. These injuries typically occurred while people were handling the fish to feed them or move them.
Signs and Symptoms of Lionfish, Scorpionfish, and Stonefish Toxicity
If you’ve been bitten or stung by a venomous animal, it’s crucial to give a detailed account of the event to the doctor. This can help identify what caused the problem. Most people who experience this type of injury usually seek medical attention within 2 hours. This is often due to the onset of various body-wide symptoms, a visible puncture wound, severe pain that might also be felt in adjacent areas, or swelling related to the injury.
The wound area might show signs of redness, paleness or bruising. Alongside the intense pain, patients might experience loss of sensation or abnormal sensations, like tingling or numbness. Swelling is especially likely if the injury is on the lower leg from a stonefish sting. In these cases, lymph nodes might also become inflamed. The doctor might also notice symptoms like low blood pressure, sweating, trouble breathing, stomach tenderness, and a decrease in physical strength.
Testing for Lionfish, Scorpionfish, and Stonefish Toxicity
If you have an infected puncture wound, doctors may take a sample from your wound to culture, or grow, in the lab. The sample is placed in an environment that encourages the growth of certain bacteria, such as Vibrio species which are found in saltwater. The sample can also be stained to look for types of bacteria called aquatic mycobacteria. The wound will also be thoroughly cleaned with warm sterile saltwater. If necessary, doctors can numb the area around the wound with a local anesthetic to search for any foreign bodies, like spines, that may be stuck in the wound.
Just like you would get an x-ray for a broken bone, doctors may want to take further pictures to see if anything else might be lodged in the wound. They can use x-rays or ultrasound imaging depending on whether the object is visible or invisible to x-rays.
If you have blisters, these can contain active venom which could result in the death of skin cells if not treated by removing the blister. This is why if you have a wound with blisters, the doctor may remove them.
Treatment Options for Lionfish, Scorpionfish, and Stonefish Toxicity
Many people who get stung by marine creatures like fish, starfish, or sea urchins are effectively treated using a method called hot water immersion therapy. This is considered the best approach as it takes advantage of the fact that the venoms are heat sensitive. Ordinarily, the affected limb is immersed in hot water, approximately 42 to 45 degrees Celsius or as hot as the patient can comfortably tolerate, for about 30 to 90 minutes. This process is repeated until the pain doesn’t recur after removing the limb from hot water.
If this therapy isn’t enough to manage the pain, anti-inflammatory medication might be given for mild discomfort, while stronger painkillers may be required for more intense ongoing pain. Sometimes, when the limbs swell up and become painful, compression dressings might be applied. If a person has been severely envenomated by specific species like scorpionfish and stonefish, a special antidote can be given, either as an injection into a muscle or through an IV drip. This could neutralize toxins from certain Indo-Pacific and Atlantic fish species. Doctors need to watch out for severe cases, especially if the victim starts showing signs of whole-body symptoms since there have been instances of fatal outcomes. However, the cause of death in these cases might have been severe allergic reactions rather than venom poisoning.
Patients should also get a tetanus shot if needed. In most cases, other than minor ones, prophylactic antibiotics should be given to prevent infections. Broad-spectrum antibiotics tend to be recommended to cover a range of bacteria typically found in marine environments, such as Vibrio, Aeromonas, Mycobacterium marinum, and Erysipelothrix rhusiopathiae. A single antibiotic may be sufficient for patients with a healthy immune system and minor wounds. If a wound gets infected acutely, doctors should guide the antibiotic therapy based on the results of laboratory tests to see which bacteria are present and what drugs they’re susceptible to.
What else can Lionfish, Scorpionfish, and Stonefish Toxicity be?
If you get stung or bitten in the sea, it may be difficult to figure out the type of marine creature responsible for the injury because the resulting wounds could look similar. Here are some marine creatures that could potentially cause harm:
- Stingrays: They cause the most marine injuries in the United States every year. If you’ve stepped on a flat diamond-shaped fish hidden in the sand, a stingray may be responsible.
- Coral: Stepping on sharp coral debris is a common injury and can cause skin redness and irritation at the injury site.
- Sea urchins: Stepping on these can cause many small puncture wounds that often contain dark, brittle spines.
- Jellyfish: If you’ve been stung by a jellyfish, your skin will usually show a whip-like pattern of redness and irritation.
- Cone snail, sea anemone, starfish, catfish, blue-ringed octopus, and weeverfish: Though these creatures don’t account for as many injuries, they should also be considered as potential culprits for marine injuries.
Knowing the source of the injury can help in providing the right treatment. So, it’s crucial to remember the details of the incident.
What to expect with Lionfish, Scorpionfish, and Stonefish Toxicity
Patients can suffer from long-term health problems due to injuries from marine life, which can lead to serious illness. There are many documented cases where injuries, especially ones involving the hand, can lead to the inability to fully extend or bend joints. In more severe cases, these injuries can cause a condition called compartment syndrome, an issue often resulting from extreme pressure build-up in muscles that can damage nerves and blood vessels.
Marine life injuries can also cause wounds that heal slowly or turn into dead tissue ulcers. In addition, if any spines or stingers remain lodged in the body, it can lead to ongoing pain and long-term nerve damage.
Preventing Lionfish, Scorpionfish, and Stonefish Toxicity
The best way to deal with injuries from scorpionfish, lionfish, and stonefish is to avoid them. Divers all around the world should know where these fish live and what they look like. People who work with these fish in aquariums or go fishing for them should never touch the fish with their hands. If they must handle the fish, they should use gloves that can’t be punctured. It’s important to know that Scorpaenidae fish, which is the family these fishes belong to, can still sting and release venom up to 48 hours after they die.
People who walk in coastal waters can minimize the risk of getting stung by moving their feet in a shuffling motion or using a walking stick to clear a safe path. This helps to scare off the fish, reducing the risk of unexpectedly coming across one. Wearing protective shoes and leg guards can also help prevent injuries from these fishes. But keep in mind that the spines of a stonefish are very sharp and can even pierce through a regular tennis shoe.
