Bitten by an octopus is dangerous

Injuries caused by jellyfish, fish and co .: Treat bites and stings correctly

The bathing and diving season is just around the corner, and with it the risk of injuries from springs, fish and other marine animals. We show which animals are really dangerous, give first aid tips and explain how to properly handle bites and stings.

When there is nothing exciting to report, the tabloids like to put horror stories of shark attacks on the "colorful side" in order to increase circulation. Some scars from alleged ray or moray attacks are also often diver's Latin. In fact, accidents while diving are extremely rare and can be almost completely prevented if you stick to a few rules of conduct. No animal attacks for no reason, but uses its weapons, be it teeth, stings or poison, exclusively for self-defense - with the exception of accidents with jellyfish.

Giant triggerfish defend their territory very tenaciously (Photo Wolfgang Pölzer).

Fish bite attacks

Non-divers or beginners think of sharks first and foremost when talking about dangerous marine animals, but barracudas and moray eels also have a downright bad reputation. However, incidents are extremely rare and often provoked themselves or by third parties. In fact, most of the bite attacks are on divers, and especially on the legs, on the account of large ones Trigger fishing. These fish are considered to be extremely aggressive, especially during brood care, and defend their territory with impetuous attacks on the intruder. A bite of the four conical teeth of a titanium pusher usually only creates bruises under 5 mm neoprene, but unprotected wounds that bleed heavily. If, despite all caution, severe bite injuries occur, pain, fright and blood loss in many cases result in symptoms of shock, so that in the worst case there is a risk of drowning. Rapid recovery from the water is therefore the most important rescue measure. The wounds must then be treated immediately, i.e. by bandaging or even applying a pressure bandage in the case of heavily bleeding wounds.

The strangest marine animals in the world

Doctor fish wear a razor-sharp scalpel at the root of their tail (photo Wolfgang Pölzer).

Cuts from rays, fish and corals

Teeth aren't the only defensive weapons on the reef. In addition to the bite wounds, cuts also lead to deep, sometimes heavily bleeding wounds, which have to be treated in the same way as the bite wounds shown. Surgeon fish for example, have one or more razor-sharp bone spurs at the root of the tail, which either stick out constantly, or - as with some species, can be folded out for defense. Deep cuts can also produce various types of rays, with poison glands additionally complicating wound care.

You shouldn't get too close to fire urchins (photo Wolfgang Pölzer).

Wounds from stings without injection of venom

Most vacationers already have painful experiences with Sea urchins collected. The problem is that the brittle limestone spines, which are covered with sharp flakes, easily break off in the wound. It is largely unknown that the hooks are against the direction of impact. So these are not barbs, but rather “fragmentation bombs”. If there are sting remains above the skin level, you can try to free the sting in the sting canal by carefully shaking it with splinter tweezers and then pulling it out. Medical, surgical care is only necessary in difficult cases and with injuries near the joint. Since tiny fragments almost always remain in the wound, it is often worth trying to loosen and dissolve them overnight with vinegar packs. A final disinfection of the puncture sites with alcohol solution is definitely advisable. With some tropical sea urchin species it gets even worse: These animals carry poison in their spines and grasping tongs, which results in very severe pain symptoms. Nevertheless, the measures to be taken do not differ for these sea urchins.

Stingrays can be dangerous when cornered (Photo Wolfgang Pölzer).

Injuries from injected poison stitches

The eponymous bone-like sting of the Stingrays is flat, pointed, barbed at the edges and can be up to 30 centimeters long, depending on the species. It has two longitudinal grooves on the underside, in which the poison glands are located as spongy tissue. These bony swords are covered with a thin layer of skin. In defense, the ray often whips its tail over its back like a "scorpion". The spread sting makes deep wounds. When you pull back, the edges of the saw enlarge the wounds. Since glandular tissue is definitely torn or stripped off, poison also gets into the wound. The composition of the protein-based toxin differs depending on the species. In several species, the poison appears to affect the cardiovascular system. No specific antidote is known.

Lionfish have poison glands on many of their fin rays (Photo Wolfgang Pölzer).

Members of the family of Scorpion fish are represented in all oceans and equipped with poisons of various strengths. Many species are ground dwellers who are well camouflaged, often buried, waiting motionless for prey. For their defense, they have spines provided with poison glands in their back, pelvic and anal fins, which can be erected. They trust this protection so much that some do not flee or flee very late if one accidentally or intentionally approaches them. Scorpionfish and lionfish have a complex protein-based poison that leads to tissue necrosis, i.e. to destruction and death of the affected layers. Depending on the type, the consequences of the application of the poison are pain of varying intensity, which is initially localized at the puncture site, but can spread and increase. A strong development of edema on the affected area can be observed regularly. Larger amounts of poison also lead to nausea, palpitations, sweats and a feeling of weakness. It is not uncommon for the accident victims to be strikingly pale. As with all poisoning with proteins, allergic reactions are also possible here, which can dramatically worsen the condition of the casualty. Overall, the symptoms can therefore range from mild to severe, with therapy primarily only being symptomatic.

The sting by you is particularly dangerous, especially with large amounts of poison Stonefish. Very severe, persistent pain, nausea, vomiting, palpitations, and feeling weak are common symptoms. The patient is at risk of circulatory collapse or pulmonary edema. While lidocaine injections are only pain-relieving for a short period of time, there is an antiserum that is able to alleviate the patient's symptoms, which are often still severe, even several days after the accident. Unfortunately, due to its short shelf life and high price, it is not always available everywhere in holiday countries.

Weever males can hardly be seen on the sandy bottom, which is why they are very dangerous for beach holidaymakers (photo Wolfgang Pölzer).

Those native to European seas Weever Every year thousands of wading tourists sting on sandy beaches. Fortunately, its sting is extremely painful, but rather harmless. The poison is extremely thermolabile: a slight warming of the puncture site to 40 to 50 degrees Celsius immediately after the bite usually quickly relieves the symptoms. In many writings, local heat treatment is recommended as an immediate measure, especially for weever, scorpion and stone fish. This is based on the assumption that proteins are quickly destroyed at 50 degrees Celsius or more. Especially in situations without quick access to the doctor or hospital, the poisoning with glowing cigarettes or with steam-saturated compresses was "treated" by laypeople themselves. However, because of the often rapid swelling of the tissue, the associated rapid reduction in heat to body temperature, and not least because of the rapid distribution of toxins in the lymph or blood, this heat therapy is usually without sufficient effect. Instead, at the necessary high treatment temperatures, it will even lead to additional tissue damage through burning or scalding. It is undisputed, however, that moderate hyperthermia of 40 to a maximum of 50 degrees Celsius leads to pain relief in all poisonous sting injuries, often especially if the heat is applied alternately with cold over ice cubes every 5 minutes.

The nerve poison of the cone snail is highly concentrated and also very dangerous for humans (photo Paul Munzinger).

Conical snail poisoning

The shells of snails are among the most popular souvenirs from tropical coastal regions. The apparently empty housing turns out to be one Cone snail but if you touch it as still inhabited, this can - depending on the species - lead to a life-threatening accident. Because: cone snails hunt and defend themselves with tiny, hollow poison arrows that contain a mixture of neurotoxins. They fire these from the gullet at close range. Easily and often unnoticed at first, they penetrate human skin. The pain that soon sets in is followed by a spreading numbness around the puncture site and a general feeling of exhaustion. Muscle weakness sets in, uncoordinated movements, difficulty swallowing, slurred speech, shortness of breath, blurred vision, unconsciousness and even coma. If left untreated, the poisoning can lead to death due to the complete paralysis of the respiratory muscles.

Important to know: there is no antiserum for cone snail venom! Therapy therefore primarily consists of the introduction of a ventilation tube into the windpipe (endotracheal intubation) and ventilation until the toxicity has subsided after 24 hours at the latest. Similar symptoms are shown by patients who receive a Blue ring octopus were bitten. The salivary gland toxin of this Indo-Pacific reef inhabitant is produced by bacteria and is identical to that of puffer fish, the highly effective neurotoxin tetrodotoxin. However, since this substance is not a protein, it defies any heat therapy or pharmacological attempt to produce an antiserum.

Practical first aid tips

A heat treatment like the "bite away" can help in an emergency.

General procedure for poison injuries

  • Leave the water immediately
  • Reassure affected divers and do not leave them alone
  • Quickly immobilize the relevant extremity
  • Prophylactic shock positioning in the conscious patient
  • Stable lateral position in spontaneously breathing but unconscious patients
  • Constant observation
  • Remove rings and bracelets (risk of constriction in the event of severe swelling)
  • Identification of the poisonous animal (pay attention to self-protection!)
  • Quick transport to the nearest doctor
  • Constant control of the vital functions
  • In case of accidents with Weever, Scorpionfish and Lion fishing:
  • The fastest possible moderate warming of the puncture site to 50 degrees for ten seconds
  • See a doctor
  • Wound cleansing


Contact with the luminous jellyfish threatens with bruising (photo Wolfgang Pölzer).

Treating bruises: General procedure for jellyfish contact

In the case of severe bruising by Portuguese galleys and box jellyfish, it is important to act particularly cautiously, because: Poisoning can be life-threatening. The unprotected skin contact with the tentacles causes extremely severe pain, which often causes the victim to pass out. The mild symptoms include reddening of the skin, swelling and the formation of wheals. In almost all cases, nausea and vomiting as well as poor circulation are further consequences, as well as shortness of breath and shock. There is a risk of respiratory paralysis and cardiac arrest. Chronic consequences are muscle cramps, circulatory and pigmentation disorders, tissue loss and scars. One of the most important first aid measures is getting out of the water immediately and saving the person affected. It is important to remember that the jellyfish may still be there. Rescuers must protect themselves with a diving suit with a hood! Remove any tentacles that have remained on the skin - think of self-protection here as well. Household vinegar deactivates remaining nettle cells. Scatter dry sand on the skin regions, let it dry and scrape off with the back of a knife. Then medical care takes place. Antisera exist for various box jellyfish! Monitoring your breathing, heart and circulation is important - cardiopulmonary resuscitation may be necessary!

  • Rescuers always pay attention to self-protection!
  • Do not exert any pressure on the contact mucus, first carefully remove any remaining nettle threads with disposable gloves
  • Rinse with salt water or, better still, household vinegar
  • Immediate heat stimulation of a maximum of 50 degrees Celsius for ten seconds on the affected skin areas; Heat stimulus repeatable after the skin has cooled down
  • Long-term heat baths at 40 degrees Celsius can alleviate more severe pain
  • Coat the affected areas with antihistamine gel and cortisone ointment
  • In case of contact with box jellyfish: Rinse the affected areas with vinegar for at least 30 seconds; necessarily seek medical help; there is a special antiserum for box jellyfish!
  • In case of contact with luminous jellyfish: Rinse wounded areas immediately with concentrated magnesium sulphate solution, salt water or vinegar; Heat stimulation of up to 50 degrees Celsius for ten seconds
  • In case of hairy jellyfish contact: coat injured areas with ammonium bicarbonate paste or shaving foam, after drying carefully scrape off with a spatula. Alternatively, rinse with salt water or vinegar; Heat stimulation of up to 50 degrees Celsius for up to ten seconds.


In this way, injuries from marine animals can be prevented

  • Never corner animals and, if possible, respect the territories
  • Always keep your distance to the bottom / reef and do not touch anything
  • Do not touch or catch any animals
  • Never reach into caves or crevices
  • Do not feed marine animals

Our medical experts

PD Dr. Claus-Martin Muth

PD Dr. Claus-Martin Muth Muth is a specialist in anesthesiology and emergency medicine, he works in Ulm.

PD Dr. Tim Piepho

PD Dr. Tim Piepho The specialist in anesthesiology and emergency medicine works at the University Clinic in Mainz.

Uli Erfurth

Uli Erfurth The qualified biologist is a diving instructor trainer, speaker for marine biology seminars and lives in Weimar.