Side Effects of Stepping on Dangerous Fish

Fish that are dangerous to step on or touch exist in all warm seas, from Australia to the Caribbean and United States. Knowing what to do before you are stung or bitten can be vital, as response time is often a factor in determining how painful or dangerous the end result will be.

Australian Coastal Waters

• Dangerous Australian marine creatures include stonefish, scorpionfish, bullrouts, the blue ringed octopus and box jellyfish. When stepped on, these fish deliver venomous stings that are painful, attack the nervous system and can even be fatal, sometimes in as little as four minutes.

Side Effects

• The venom of many Australian fish contains a neurotoxin, which can cause extreme pain, difficulty breathing and cardiac arrest. When an individual is stung by a blue-ringed octopus he will require assistance breathing until the venom is gone.

Caribbean Coastal Waters

• Closer to home, fire coral, sea urchins, stonefish and scorpionfish can be found in the Caribbean. While stingrays that swim these waters rarely attack, they will sting if you step on them.

Side Effects

• The tentacles of fire coral, when stepped on, cause mild to severe pain, nausea and vomiting but are not fatal. Sea urchin spines cause nausea, vomiting, muscle cramps, difficulty breathing, swelling, redness and numbness. Infection is the main concern with a stingray wound.

Portuguese Man of War

• In all tropical seas, including Florida and Hawaii, Portuguese Man O' Wars can make entering the water dangerous. These jellyfish-like creatures drift on the tides, sometimes in groups of thousands, and their sting is painful though not typically fatal.

Side Effects

• Side effects of a sting from a Portuguese Man of War include pain, burning, redness, long whip-like welt lines and swelling of lymph nodes. With allergic reactions, there can be problems with breathing and cardiac arrest.