Ciguatoxins (CTXs) are a group of heat-stable, lipid-soluble toxins that can cause a type of foodborne illness known as ciguatera fish poisoning. These toxins are produced by microscopic marine dinoflagellates called Gambierdiscus toxicus and other related species, which grow on and around certain types of algae in warm, tropical waters.

When these dinoflagellates are consumed by herbivorous fish, the toxins accumulate in their tissues without causing harm to the fish. However, when larger carnivorous fish eat many smaller herbivorous fish, the concentration of CTXs can increase to potentially harmful levels.

Humans who consume contaminated fish may experience a range of symptoms including gastrointestinal disturbances (such as nausea, vomiting, diarrhea), neurological symptoms (such as tingling or numbness in the lips, tongue, and other parts of the body, reversal of hot and cold sensations, and muscle weakness), and cardiovascular symptoms (such as low blood pressure, irregular heartbeat).

These symptoms can be severe and may last for several weeks or even months. Currently, there is no specific antidote or treatment for ciguatera fish poisoning, and management typically involves supportive care to manage symptoms. Prevention measures include avoiding consumption of fish known to carry CTXs, such as barracuda, grouper, moray eel, and red snapper, among others.

Ciguatera poisoning is a type of foodborne illness that is caused by consuming seafood (such as fish) that contains ciguatoxins. These toxins are produced by certain types of microalgae that can accumulate in larger marine animals and become concentrated in the flesh of fish.

Ciguatera poisoning is characterized by a variety of symptoms, including nausea, vomiting, diarrhea, abdominal pain, muscle weakness, and neurological symptoms such as tingling or numbness in the lips, tongue, and other parts of the body. In severe cases, it can also cause heart problems, seizures, and even coma.

The severity of ciguatera poisoning can vary widely depending on the amount and type of toxin consumed, as well as individual susceptibility. There is no specific antidote for ciguatera poisoning, and treatment typically involves supportive care such as fluid replacement, pain management, and monitoring for complications.

Prevention measures include avoiding consumption of fish known to carry a high risk of ciguatoxins, particularly larger predatory reef fish such as barracuda, grouper, moray eel, and red snapper. Cooking or freezing the fish does not destroy the toxin, so it is important to choose fish carefully when dining in areas where ciguatera poisoning is common.

"Mercenaria" is a genus of saltwater clams, also known as the "heart cockle" or "quahog." It is a common name and does not have a specific medical definition. The clams are edible and are often used in various dishes, and the shells are sometimes used for crafts or decorative purposes. They are found in the waters of the Atlantic coast of North America, from Canada to Mexico.