The Stonefish

The Stonefish, scientifically known as the Synanceia verrucosa, is a small marine fish native to the Indo-Pacific. The stonefish can be found from as far west as the East Coast of Africa to as far east as French Polynesia. Few people have probably seen a Stonefish in person. They sometimes show up in personal aquariums or in sushi restaurants in eastern Asia.

Here's a map of the distribution of the Stonefish:

The Stonefish makes its habitat in the shallow waters of coral reefs. The Stonefish received its name because of its brownish color that helps it to camouflage itself among rocks and coral. Stonefish are very small (30-40 cm) and therefore their prey usually consists of other small fish as well as shrimp, while their primary predators are sharks and stingrays. Stonefish feed by camouflaging themselves next to rocks and staying very still. When prey venture too close, they strike with a surprising amount of speed. Their ability to camouflage is a huge help in their hunting and their ability to hide from predators.

Here's a camouflaged Stonefish:



The stonefish is debatably the most venomous fish in the world. However, they are not aggressive creatures as they only release their venom as a defense mechanism. In fact, it’s an involuntary reaction to detected pressure. When a predator such as a shark or a human foot comes into contact and applies pressure on a Stonefish, it’s thirteen dorsal spines extend (as seen in the video) from it’s back and transfer venom into its victim. After a stonefish uses its venom, it must wait a period of a few weeks until more venom is produced and ready to be utilized. The venom of the Stonefish is extremely dangerous. The venom is called verrucotoxin or VTX. It is a mixture of several protein-based venoms such as stonustoxin, cardioleputin, and trachynilysin. Scientists aren’t quite sure how the venom actually works. Contact with Stonefish venom is extremely painful and comes with dangerous health implications. The severity of the injury depends on how deep and how many of the venomous spines reach into the victim. The venom can cause “respiratory weakness, damage to the cardiovascular system, convulsions and paralysis” In serious cases, Stonefish venom can lead to death. Luckily, there is antivenom. If medical attention isn’t reached within a couple of hours of the injury, there is a serious risk of fatality. Survivors of stonefish encounters often times suffer from nerve damage as well as joint and muscle pain in the areas surrounding the spines entrance point. Thankfully, encounters with the Stonefish are rare and there are very few fatalities each year.

Here's a video of Steve Irwin extracting venom from a Stonefish:

Sources:

http://library.thinkquest.org/C007974/2_1sto.htm
http://www.ncbi.nlm.nih.gov/pubmed/17572694
http://lifestyle.iloveindia.com/lounge/facts-about-stonefish-8120.html
http://fishbase.org/Summary/SpeciesSummary.php?id=10752
http://www.youtube.com/watch?v=PGqUE4T2hPo
http://australianmuseum.net.au/Reef-Stonefish-Synanceia-verrucosa-Bloch-Schneider-1801