The Stonefish really has to be one of the ugliest fish I have ever seen, it is exceptionally poisonous, and has a truly evil countenance

Stonefish from off the Borneo coast

Stonefish (Synanceja horrida), is a member of the Scorpion fish family (Scorpaenidae).

As with many of the fish we are covering here, it is considered the most venomous of fish in the world and probably if we differentiate between Fish, Jelly Fish and Octopus this may well be an accurate statement.

The fact of the matter is – the Stonefish is a creature you keep your distance from and while in areas they are known to inhabit, take appropriate precautions like wearing shoes when wading in the water, or if scuba diving don’t put your hand on any rocks!

On the dive I took this photograph of the stonefish, it took my wife at least a minute to convince me 1) that I was looking at a fish and 2) where it was!


The Stonefish is found in the shallow waters of the tropics and ranges throughout the Pacific and Indian Oceans, The Red Sea and the Great Barrier Reef.


  • This is a particularly unattractive looking animal with a skin that is difficult to distinguish from rocks or old growth encrusted coral.
  • They tend to be 30 to 50cm in length and is usually a mottled green or brown colour.
  • Their diet consists of Fish, Shrimps and other small crustaceans.
  • For obvious reasons it tends to inhabit coral reefs around plants and rocks which suit its dull colouring. It also can be found (looking like a rock….) on mud or sanded areas.

  • In China and Japan they are eaten – in Japan they are served in restaurants as an expensive Sashimi plate called Okoze.

  • The Fish is able to survive for up to 20 hours out of water.
  • The Stonefish has 12-13 dorsal spines, 2 pelvic spines, and 3 anal spines. Each spine is is linked to a pair of venom glands. A loose sheath covers each spine. The sheath is pushed down the spine during poisoning (when someone stands on it), causing the venom glands located at the base of the spines to be squeezed and release their poison up the spines and into the wound.
  • The Venom is a very potent but heat labile (readily destroyed by heat). It is collectively myotoxic (affects muscles), neurotoxic (nerves), vaso permeable (causes swelling), and cardio toxic (heart).

Basically the poison causes severe pain, possibly shock, paralysis and tissue death, also giving rise to other complications if treatment is not quickly received.

It is said the pain is so severe that patients are known to beg for the offending limb to be amputated.

They are of the same family as scorpion fish and lionfish amongst others.

Scorpion fish

Scorpion fish

Scorpion fish

Scorpion fish

A Lionfish from Aliwal Shoal


First Aid

The poison can be destroyed by heat so immersion in hot water – not scalding – goes a long way to neutralizing the pain as well as the poison. In order to minimize the extent to which the poison enters the body, a tourniquet or constrictive bandaging may be applied above the wound.

The wound should be cleaned to remove any debris and the affected limb or body part should be raised above the rest of the body. If available a 5% solution may be used to wash the wound out.

It is recommended patients should receive high dose of oral and intravenous antibiotic prophylaxis for vibrio prevention -

Vibrio vulnificus causes an infection often incurred after eating seafood, especially oysters; the bacteria can also enter the body through open wounds when swimming or wading in infected waters, or via puncture wounds from the spines of fish such as tilapia.

Symptoms include vomiting, diarrhea, abdominal pain, and a blistering dermatitis that is sometimes mistaken for pemphigus or pemphigoid

In people with compromised immune systems such as in chronic liver disease, a cut infected with Vibrio bacteria can quickly become worse and spread into the bloodstream. Severe symptoms and even death can then occur.

Poisoning by this fish can at times result in a fatality, but this is comparatively rare.

The majority of reported cases of poisoning by Stonefish happen to be on land or at least away from the sea – Aquarium owners while handling Stonefish they have as pets account for the highest incidence!

Click here to read about more dangerous sea creatures like the Stonefish

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