Stone fish Synanceia Verrucosa

Photo: Stonefish disguised as a stone

The stonefish is a deadly bottom-dwelling fish with 13 sharp venomous spines on its back, which can inject extremely painful and potentially fatal poison if stepped on or handled carelessly. The stonefish has an oval body and mottled, camouflaged skin. It can modify its shape and appearance to blend into the environment. Its warty, scaleless skin is covered with bumps, nodules, filaments and growths that mimic outgrowths of algae and give it a unique appearance. It also has splashes of colour that further help it to camouflage itself.

Stonefish Description What Does a Stonefish Look Like?

Photo: Stonefish blending into its environment

The stonefish is a plump, 35–50cm long bottom-dwelling fish with thirteen venomous spines on the dorsal fin on its back and a large upward-opening mouth. It is a master of disguise and has the uncanny ability to adapt various rock-like shapes and colours to blend in with its surroundings. Its favourite camouflage is to look like an algae-covered rock. Additionally, it can partially bury itself in sand or mud to appear like a rock on the sea floor. Hidden by one of its excellent disguises, the stonefish waits motionless for prey to pass by.

Worldwide there are five species of stonefish. The two species of stonefish are found in waters around Australia and are the most venomous. The Reef Stonefish ( Synanceia verrucosa) has a deep depression between its eyes. The Estuary Stonefish ( Synanceia horrida) has elevated eyes separated by a bony ridge. The male and female stonefish are similar in appearance. However, the female is bigger and broader around the abdomen than the male and can weigh 50% more. Stonefish have a lifespan of between 5 to 10 years.

How Dangerous is the Stonefish? How Terrible is the Stonefish

Photo: Stonefish dorsal fin spines

The stone fish is variously called the most dangerous, the most venomous fish, and even the most poisonous fish in the world. But is the stonefish really that terrible, and are these names for it fair?

The terms dangerous and deadly refer to how harmful an animal is to humans. And stonefish's sting is most certainly hazardous to humans. But a stonefish never attacks a human! Most encounters between stonefish and humans are accidental. The venomous spines on the back of a stonefish are strictly for its own protection and are intended to keep the fish safe from predators. So, the stonefish is dangerous or deadly only if a human intentionally comes into contact with it, usually by accidentally stepping on it. So is a stonefish dangerous and deadly for humans? The answer is YES.

By definition, a poisonous animal's entire body or parts of its flesh contain toxic substances that are harmful if touched or eaten. Sharks and rays eat stonefish and suffer no noticeable adverse effects. Humans, too, can eat the stonefish if they remove the venom glands feeding the spines or boil the animal to destroy its toxicity. Human deaths from eating stonefish are rare to non-existent. So, is the stonefish poisonous? Technically, the answer is NO.

A venomous animal injects its toxin into another animal. Because the stonefish injects its highly toxic venom into its victim when its spins are compressed, it is the world's most venomous fish. So, is the stonefish venomous? The answer is YES.

So, in conclusion, the stonefish is the deadliest and most dangerous venomous fish in the world to humans!

• The Stonefish's Sting - Painful & Deadly

Stonefish Habitat Where Do Stonefish Live?

Photo: Stonefish Australian Location Map

The stonefish lives in shallow tropical waters of the Pacific and Indian Oceans to the Red Sea. Stonefish in Australia are found off the coastline especially in the Great Barrier Reef. It usually lurks amongst coral and rock formations and camouflages itself to look like a clump of coral or a piece of rock. Where there isn't sufficient environmental cover to disguise itself, the stonefish will use its powerful pectoral fins to dig itself into the seabed and pretends to be something most appropriate to its surroundings, typically an algae-covered rock.

The stonefish can survive out of water for up to 24 hours. This may be an adaptation to its shallow water existence, where it may get trapped in drying out rock-pools during low tide.

Stonefish Diet What Do Stonefish Eat?

Stonefish Catching Prey Video

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The stonefish eats other fish and bottom-dwelling invertebrates. It is a sit-and-wait ambush predator that stays motionless and grabs its prey when they swim close by. (See video).

The stonefish's capture technique is called ‘gape and suck’. The stonefish can expand the volume of its throat, which has extra pleated skin to allow expansion, and mouth in a split second. When it opens its powerful jaws wide open and expands its throat, it creates a significant vacuum suction pressure between the inside of its mouth and the outside environment which sucks its unsuspecting prey into its gaping mouth where it is swallowed whole. This action is so quick that it's all over in less than 1/100th of a second.

Stonefish Reproduction Stonefish Life-cycle

The stonefish is a solitary animal. The only time it actively seeks out another is during mating season for spawning. The female stonefish release a layer of large fertilised eggs on the sea-floor and the male comes along, releasing sperm over them. Young stonefish hatch within three days. They are well developed and self-sufficient from birth.

Stonefish Predators & Threats What Kills Stonefish?

The main predators of adult stonefish are sharks, stingrays, and sea snakes. Young stonefish are easy prey for other fish. Very few survive to adulthood.

Stonefish Conservation Status Is the Stonefish Endangered?

The worldwide stonefish population is not known. It is found throughout its various habitats. There is no evidence to suggest that it is threatened in anyway. The stonefish is not endangered.

Stonefish Attack Do Stonefish Attack Humans?

Stonefish do not attack humans. Its venomous dorsal fin spines are only for defence. They do what they have always done and stay hidden and motionless in their habitat with their venomous dorsal fin spines erect as a defence. Stonefish sometimes wash up near the shoreline or on beaches where humans may step on them or pick them up. So strictly speaking any injury suffered by a human is self-inflicted – You ventured into its habitat, stepped on it or touched it. You didn't leave the animal alone and got stung.

Stonefish Sting Can a Stonefish Kill You?

Photo: Stonefish dorsal spine

Photo: Human foot after stonefish sting

The stonefish is the most venomous fish in the world. Hidden beneath its dorsal fin are 13 spines with deadly spikes that act like hypodermic needles and inject highly toxic venom into any creature that comes in contact with them. The venom in these spines is only released-when pressure is applied to the stonefish’s spine, which means the venom is most often emitted when the stonefish is being attacked by a predator or stepped on by a human. Stonefish venom has both cardiovascular and neuromuscular toxicity. The pain caused by the venom is described as being immediate and excruciatingly painful and may last many days. The severity of the outcome is depended on the number of punctures suffered from these spines. Symptoms include muscular paralysis, breathing difficulties and shock. If left untreated heart failure and death may occur.

The stonefish is ranked as the 20th most venomous animal in the world. There have been no recorded human deaths in Australia as a result of an encounter with a stonefish. It is believed that several fatalities may occur in other Indo-Pacific areas, usually due to the lack of medical treatment. Stonefish antivenom is the second-most frequently administered antivenom in Australia.

Stonefish Treatment for Sting What to Do if You are Stung by a Stonefish

The best precautions against a stonefish injury are being alert, wearing sturdy footwear, and not touching or picking up these animals.

If you do step on a stonefish or are foolish enough to pick one up and get stung, wash the wound with cold water (saltwater is fine). Then apply heat to the wound for 30-90 minutes. Soaking the wound in very hot water (but not so hot that it causes burns on the victim) is one easy option. Heat may help destroy stonefish venom and provide some pain relief to the victim. Vinegar, supplied on most Australian beaches for use against jellyfish stings, is also said to reduce pain. These remedies are offer temporary relief only. Medical treatment should always be sought urgently.

Stonefish vs Scorpionfish What’s the Difference Between Stonefish & Scorpionfish

Stonefish and Scorpionfish are often confused.

The stonefish is best at pretending to be a stone and is capable of less colour-matching compared to the scorpionfish. It is also the most venomous fish in the world. Only its dorsal fin is venomous.

The scorpionfish has more prominent eyes and can change its colour to better match its surroundings, including colourful corals. It has venomous spines on its back as well as on its fins. It isn't as venomous as the stonefish.