At certain times of the year, various species of fish and shellfish contain poisonous biotoxins, even if well cooked. Certain fish--groupers, barracudas, snappers, jacks, mackerel, and triggerfish--cause ciguatera fish poisoning and should always be avoided, according to the Centers for Disease Control and Prevention. Other types of fish which may contain the toxin at unpredictable times include sea bass, and a wide range of tropical reef and warm-water fish.

The risk of ciguatera poisoning exists in all tropical and subtropical waters of the West Indies, the Pacific Ocean, and the Indian Ocean, where these reef fish are eaten.

Two other forms of poisoning can occur from naturally occurring toxins in fish: tetrodotoxin, sometimes called pufferfish poisoning or fugu poisoning, and scombroid poisoning.

Where is the risk of ciguatera poisoning the greatest?

Reef fish from the tropical and subtropical waters of the West Indies, the Pacific Ocean, and the Indian Ocean pose the greatest threat. Cases have been reported in the United States in California, Hawaii, Texas, Guam, Puerto Rico, Vermont, U.S. Virgin Islands, and Florida, and a few isolated cases of ciguatera poisoning have even been noted along the eastern seaboard of the United States.

More than 400 species of fish, particularly reef fish, are thought to contain the toxin for ciguatera poisoning.

What are the symptoms of ciguatera poisoning?

Symptoms of ciguatera poisoning generally appear within two to six hours after the toxic fish has been eaten. The following are the most common symptoms of ciguatera poisoning. However, each individual may experiences symptoms differently. Symptoms may include:

  • Nausea

  • Vomiting

  • Watery diarrhea

  • Numbness and tingling about the mouth and extremities

In more severe cases, the person may suffer muscle pains, dizziness, and sensations of temperature reversal, where hot things seem cold and cold things seem hot. The symptoms of ciguatera poisoning may resemble other medical conditions. Always consult your doctor for a diagnosis.

Treatment for ciguatera poisoning

Treatment for ciguatera poisoning involves relieving the symptoms and treating any complications. Generally, recovery takes from several days to several weeks. Specific treatment for ciguatera poisoning is based on:

  • Your overall health and medical history

  • Extent of the disease

  • Your tolerance for specific medications, procedures, and therapies

  • Your opinion or preference

What is tetrodotoxin?

Tetrodotoxin, also called pufferfish poisoning or fugu poisoning, is a much rarer form of fish poisoning, but it is potentially very serious. This is almost exclusively associated with the consumption of the pufferfish from waters of the Indo-Pacific regions, but there have been several reported cases of poisonings, including fatalities, from pufferfish from the Atlantic Ocean, Gulf of Mexico, and Gulf of California. Pufferfish poisoning is a continuing problem in Japan.

What are the symptoms of pufferfish poisoning?

Symptoms generally appear between 20 minutes to three hours after eating the poisonous pufferfish. The following are the most common symptoms of pufferfish poisoning. However, each individual may experience symptoms differently. Symptoms may include:

The symptoms of pufferfish poisoning may resemble other medical conditions. Always consult your doctor for a diagnosis.

Treatment for pufferfish poisoning

Treatment for pufferfish poisoning consists of limiting the body's absorption of the toxin, relieving symptoms, and treating life-threatening complications. There is no known antidote for tetrodotoxin. Specific treatment will be determined by your doctor based on:

  • Your overall health and medical history

  • Extent of the disease

  • Your tolerance for specific medications, procedures, and therapies

  • Your opinion or preference