By Dana Sackett
Many TV shows and nature guides have been dedicated to educating the public on the most poisonous and venomous spiders, snakes and even frogs, but what about fish? Unlike spiders or snakes, we rarely hear about which fish are the most poisonous (or venomous). This week we are dedicating our blog post to these hazardous fish.
 |
|
(Cooney)
|
First though let’s clarify some terminology. Poisonous and venomous are terms often used interchangeably but they have different meanings. A venomous animal has a means of injecting their toxin into another animal, whereas a poisonous animal can only deliver their toxin in a more passive manner (by being touched or eaten). A common example given to clarify this difference is that frogs are poisonous while snakes are venomous. It is also important to note that the affects from a venomous fish sting can often be relieved by immersing the wound in hot water (~105–115F) because these toxins are heat labile (meaning they can be destroyed or altered by heat).
1. Pufferfish (some species are also called toadfish) have been given the title ‘Most Poisonous Fish’ and have also been labeled the second most poisonous vertebrate in the world. The toxin responsible for ranking this fish so high in the “danger zone” is called tetrodotoxin. Tetrodotoxin is neurotoxic and inhibits neural transmission leading to weakness, paralysis, and even death at relatively low concentrations (~2mg). This toxin is found in the fish’s liver, ovaries, intestines and skin, leaving muscle tissue with relatively low and somewhat safe levels to eat. However, only highly trained and certified chefs are allowed to prepare this fish for consumption; a common practice in Japan where pufferfish are considered a delicacy.
|
|
|
|
2. Stonefish have usurped the title of ‘Most Venomous Fish’ in recent years. They often resemble encrusted stones (hence the name), blending into their natural environment with ease. They deliver their venom through a row of spines on their back that can be extended when threatened (or stepped on). Venom is involuntarily expelled when pressure is placed on the fish and the more pressure the more venom. They reside in the Indo-Pacific region and northern Australia. A sting from one of these fish can cause excruciating pain, rapid swelling, tissue death, muscle weakness, temporary paralysis, and in very rare cases death.
|
|
3. Lionfish were thought to be the most venomous fish until recent years when stonefish stole the title. These conspicuous fish have venomous dorsal, anal, and pelvic spines covered by a loose sheath that moves down and compresses venom glands when the spine punctures tissue. A sting from these fish can cause extreme pain, swelling, and in very severe cases, cardiovascular collapse. Most lionfish naturally reside in the Indo-Pacific but they have become an invasive species in recent years; most notably along the Atlantic coast of the United States where they are having a major impact on Atlantic coral-reef communities. Lionfish were likely introduced along the Atlantic coast through aquarium releases.
 |
| Lionfish (Source) |
4. Stingrays are one of the most common groups of fish responsible for human envenomations; largely because many rays bury themselves on the seafloor where people unintentionally step on them. Stingray venom is generally cardiotoxic. The Bluespotted (native to the Indo-Pacific) and Southern (native to the southeastern US) stingrays are some of the most venomous of all stingrays. As a form of warning others, the Bluespotted stingray generally displays its bright blue colored spots as a warning to predators of its highly venomous sting.
 |
| Bluespotted stingray (Source) |
5. Boxfish and trunkfish are closely related to pufferfish. While these fish are not nearly as poisonous as puffers, they do have an impressive way of defending themselves with poison. When threatened or stressed, they excrete a toxin from specialized skin cells into the water, poisoning marine life in their vicinity. The Hawaiian boxfish in particular excretes a toxin called ostracitoxin or pahutoxin that is known to breakdown or destroy red blood cells.
 |
| Boxfish (Source) |
Some other venomous fish to check out are other scorpionfish (besides the stonefish and lionfish mentioned above), stargazers, which have two venomous spines in addition to organs near their eyes that cause electric shocks, and striped eel catfish.
 |
| Stargazer (Source) |
If you know of any other venomous or poisonous fish not mentioned here or have experience with a species listed here please share your knowledge and experience below.
Be sure to like The Fisheries Blog on Facebook and follow us on Twitter (@FisheriesBlog).
References:
Auerbach PS. 2007. Marine envenomations. Adapted from the 5th edition of the textbook wilderness Medicine by Mosby-Elsevier.
Barss P. 1984. Wound necrosis caused by the venom of stingrays: pathological findings and surgical management. Med J Australia. 141: 854-855.
Boylan DB, Scheuer PJ. 1967. Pahutoxin: a fish poison. Science. 155:52-56.stingrays
Diaz JH. 2008. The evaluation, management, and prevention of stringray injuries in travelers.
Fenner PJ. 1998. Dangers in the Ocean: the traveler and marine envenomation. II. Marine Vertebrates. J Travel Med. 5:213-216.
Gwee MCE, Gopalakrishnakone P, Yuen R, Khoo HE, Low KSY. 1994. A review of stonefish venoms and toxins. Pharmacology and Therapeutics. 64:509-528.
Vetrano SJ, Lebowitz JB, Marcus S. 2002. Lionfish envenomation. The Journal of Emergency Medicine. 23:379-382.
Yang CC, Liao SC, Deng JF. 1996. Tetrodotoxin poisoning in Taiwan: an analysis of poison center data. Vet Hum Toxicol 38:282-286
http://ocean.nationalgeographic.com/ocean/photos/toxic-sea-creatures/
The Fisheries Blog 
Great article! There are a few freshwater catfish species (the Madtoms) that have low levels of anti-predatory venom delivered via pectoral spines.
In the Southern California waters I've had run-ins with Sculpin. Those guys have dorsal spines with venom. A friend of mine some how had one of those spines jab him under the big toe nail. Yeah, it hurt.
We got him in the truck and drove up the 405 to UCLA Med Center. His toe was very swollen and multi-colored. He told me it felt like molten lead was injected under his nail. After several hours we took him home and bar-b-q'd that Sculpin fish and made really delicious tacos.
They’re actually scorpionfish… true sculpin are not venomous
Stone fish and puff fish, they are most deadliest in my sense as most of the people die due to them. Japanese eat puff fish and they die due to food poisoning.
Yes in japan they do eat puffer fish but you have to be very careful when cooking it if you cook it right you’ll be fine but if you don’t the poison will still be in the fish they have professionals
I do agree with all the ideas you have offered on your post. They’re really convincing and will definitely work. Still, the posts are too brief for novices. May you please extend them a little from next time? Thanks for the post.
Excellent article you have here! Luckily, I have not had a poisonous fish encounter yet. Makes me more cautious on exploring areas I’m not familiar with. Thanks!
It’s awesome designed for me tto have a site, which is helpful
in support of my knowledge. thanks admin
Are catfish poisonous
Are catfish poisonous
See my comment below
Good .. am interested
thanx for the post i never heard this this before keep up letting us know
I think that stargazer is a bit scary
And poisonous
Striped eel catfish Plotosus lineatus have the venomous spikes in their fins. Incidental injection inflicted burning pain. The injured person can lose consciousness.
The flesh of the Greenland shark is toxic if eaten, unless it is left to be fermented. People in Iceland sometimes eat the fermented meat.
I have been in this hobby for almost 35 years in that time I have been stung jabbed and inadvertently impaled by all the above for me the worst was the catfish I thought it was dead but it was not going out without it having its way first. I reached in to remove it with my hands dumb really dumb. It thrashed and impaled it’s pectoral fin into my index finger. It does not pull out instead the poison is released slowly and the movr it moves the more is released. Got water and a trip to the er where my finger had to be cut open to remove it. Then left open so it would not burst. With every beat of my heart I wished I would stop. Never again wiki handle one of these not do I recommend it to anyone.
the wasspfish has really poisonous spines on its back and I feel that the longspine waspfish should’ve been on the list.
You are correct, waspfish are very venomous. They are another species in the group scorpionfish.
While this is a good compilation of information, and happy to see sources cited, a bit of credibility is lost with the choice of title. Of the 5 marine species listed, only 2 are poisonous. Even though you explain the difference, laymen reading this will remember the title and not necessarily the details, and thus perpetuate the use of ‘poisonous’ inappropriately to refer to the 3 that are venomous. Title selection is just as important as the text.
saya sudah melakukan tips poin 2 dan 3 untuk point 1 menyusul , Aerona
I would suggest you clarify the comments made regarding pufferfish. There are various species which, if one peruses the literature, have little or no presence of the toxins described in your article. According to what I have read so far, the Northern Pufferfish – Sphoeroides maculatus – has been consumed by many people along the Atlantic coast with NO reports of toxicity regardless of whether the fish is privately or commercially harvested and prepared. The incomplete presence of the facts can lead readers to stereotype groups of fish based upon what is stated instead of what is actual.
my dad has been up close and personal with the PUFFERFISH YYAY!!!
OH ALSO MY MOM 🙂
I’d agree that the article, as fine as it is, needs to be more specific re. scope. If it is to cover the main venomous and poisonous fish, it should include the Box Jellyfish which does have a track record of fatalities and the Irukandji – not so deadly but causes serious injury.
You are correct that box jellyfish are very poisonous but they are not actually fish (despite their name). Maybe this blog could do a top ten most poisonous and venomous aquatic invertebrates.
Jeslly fish is one of the most poisonous fish
is aga eaters poison to to bass fish
what about the blue ringed octopus
hey do u like fishing what is your biggest fish you have caught
why haven you replied yet
hay $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
Also there is Cone Shell , it knows as venomous and as predator.
We have Toadfish here in Md. We are on the East coast. They might be related to the Pufferfish.
Also, we have the Snake fish everywhere now and they breed worse then roaches 10’s of thousands twice a year. They do have teeth and they can go days out of the water, they crawl on land. They prefer fresh water and eat other fish, insects, frogs ect;I personal think they would bite humans, but I don’t know. You tube has some video’s of them and they get big up to 3feet long. They I’ll eat fish devalue them like its nothing I saw one in captivity in an aquarium, the other fish was about half the size of him. They are fierce hunters, a predator to other aquatic, wild life.Thats all folks, lol 🙂 bye, bye Suzie Snow
Great article you have there and quite educational too.
There’s one thing i want to point out. It’s the picture you’ve used for Pufferfish (inflated). I think it’s not Pufferfish, I am pretty sure it’s Porcupine fish. Just want to add to that, it’s edible!
This is awesome
It was a belief here in Barbados when I was growing up in the 60s that if you got stung by a Stone fish which we called a lion fish although they say Lion fish only been around a decade or so ,(and are causing havock on our reefs so we eat them now ) that you had to get an antidote , now from here I am learning that you just threat with heat , and maybe some pain killers .
seems they been around a few decades since the 80s .
The poisionois fish, is it eatable?
I live in PR and the last two times I have been snorkeling I have found three stonefish. They are not pretty fish and did not see to be intimidated. In our Island we have the longish as an invasive species, but fortunately I have seen any yet when snorkeling, probably because they are being captured to be eaten by people.
I live in PR and the last two times I have been snorkeling I have found three stonefish. They are not pretty fish and did not see to be intimidated. In our Island we have the lionfish as an invasive species, but fortunately I have not seen any yet when snorkeling, probably because they are being captured to be eaten by people.
I’ve seen the result of a stonefish sting, was not a pleasant sight!
The two pics of the stone fish are not stone fish, but scorpion fish. And as somebody else wrote, the puffer fish pic is a porcupine fish.
nice work, even if some picture’s name is not right.
New Form of Nanorobots To Clear Blood of Toxins
The bullhead catfish it is a freshwater fish and it has venomous spines on both of the pectoral fins and the dorsal fin. The venom is very mild it might feel like a bee sting for a couple of days unless you are allergic of course.
my bro died from bofish
loved reading your article. it was really informational for me. wish to see more in the coming days.
During a holiday in Mauritius, I went for a snorkeling dive around the north coast of Ile aux Cerfs (a natural island with a golf resort on it) given teenage skills as a professional swimmer and free diver. I was told by the resort’s staff to be careful with the several urchins (the size of a small coconut) present at sea bottom but after reaching a distance of 800 meters from the shore, the tide changed and I was swimming in 150 cms of water when I suddenly felt like I had kicked a piece of broken glass. Remember, I was wearing goggles and I had seen nothing but sand plus I tend to avoid stomping on stuff while at sea so I figured I had probably kicked something while swimming. While trying to understand how the hell I had injured myself I realized the pain was escalating to excruciating levels, unbearable without beginning to swear in languages I didn’t know few moments before. With stamina and all sensorial alerts going off in my brain I started rushing for survival even before I knew what happened. I went from “what was it just now?” to “I have to save my foot” and then “I’m probably loosing my left leg”. To try to give you an idea, the feeling is like a square bedside cupboard was somehow pushed into your feet by the toes and start to navigate through your calf, your knee and then your quadricep. By the time I could see other tourists on the beach I luckily remembered that people in bad situations at sea tend to die of heart failure before anything else: I was right, although hyper lucid thanks to stamina, my heart was going off. I reached the shore with zero feelings or control of my left limbs, shouting for help I managed to get the staff to look at my foot only to give me a dim look and a “C’est poisson pierre, Mon Dieu”. What follows, I’m not too sure of cause the pain had gone beyond control, I was shaking, half crying, half laughing while transported by the first available boat for the mainland (in my memory it was the slowest of the fleet). Once at the pier’s parking lot my car was of no use given that the pain chills would have driven me against the first tree along the road, due to the brand new public hospital in Flac (the closest town) I was dropped onto a taxi that rushed me along country road at the speed of 150 km/h. At the hospital I realized why everyone looked at me like a zombie since I got out of the sea: “Sir are you with us, your situation is critical and very serious, we need your full focus”. Translated: before you faint or leave this planet we need your passport, the details of your next of kins and everything else you may want to leave written. I was administered two doses of antidote (one on the injury, one by my buttocks), got a X shaped incision to let any remaining amount of venom out of my toe (by that time it had gone white-blueish) and after being hospitalized in the orthopedic ward for 24 hours of observation a nice dose of petidine (just look that up and you’ll know how pleasant). If you’re as lucky as I was to be bitten in your lower limbs the risk to die of this is now way lower than before antidotes were discovered, but:
1) In a private clinic, each dose can be as expensive as 5K USD (In Mauritius, thanks to public health I paid nothing);
2) Although stonefish are endemic in Mauritius, not all the beaches, excursion boats, resorts or hotel have antidotes ready to use at the spot;
3) Ambulances are not the best solution to reach the closest hospital as they wouldn’t be as fast as a nimble taxi and you need to wait for them to arrive first;
4) Treating the toxin isn’t the hardest part or anyway the only challenge after you survived the sting, it took my toe 3 months of daily dressing with Betadine (Povidone-iodine) gel before it went back to a bad scar with remaining tissue;
5) after the first month, the areas around the inner tissues that came in touch with the toxin are going to die and decay so you’ll be left with a nice hole projecting through any muscular tissue/bones (I have pictures but we’re not on rotten).
6) It’s good to help blood circulation around the injured part by getting Micronized purified flavonoid fraction (diosmin, hesperidin) via Daflon, a common remedy available everywhere.
7) My foot and toes were getting better in mornings and back to swollen at nights for the whole 3 months (forget any sport beyond walking with a slipper cause shoes were a no go).
I leave this for anybody else who, left alone in his hospital bed on the first night after a stonefish sting wonders if his personal hell is just gone with the antidote, it is not. Some fishermen hospitalized next to me for fractures and motorcycle accidents showed me their toes that even if treated 10 years before were gone hard and numb as a stone and would need amputation down the line. You’ll find that online they describe pain on the very same scale as labor at the end of pregnancies but I guess I’ll never know if it’s true. Needless to say I was never so afraid to be gone like on that day and had never felt anything like that before (I remember saying out loud “If I got shot with a gun, it wouldn’t hurt this way). I won’t go useless and tell you to use precautions while in the stonefish endemic habitats, the usual rubber shoes for snorkeling won’t spare you the misery if you get unlucky. What you can do is be aware of the dangers and know that you won’t probably spot our deadly friend, so enjoy your holiday, the beautiful beaches and reefs but know that sometimes, lucky individuals as myself do pay a price.
Peace to you all and God bless the kind nurses and doctors of Ile Maurice 😉