Toxins #2 – Fish Biotoxins

Ciguatera Poisoning:

Can occur when various marine finfish (barracuda, red snapper, grouper, amberjack, sea bass, triggerfish, or other reef fish) are consumed. 

Because they are high up on the food chain, they can accumulate a great deal of the biotoxins in their digestive organs.

The risk is in eating any large fish from tropical and subtropical waters of the West Indies, Caribbean, Pacific, and Indian Oceans between the latitudes of 35N to 35S.

In these waters the filter feeders have been consuming small dinoflagellets (algae), in particular, Gambierdiscus toxicus, and these algae contain ciguatoxin (CTx-1).  As the ciguatoxin progresses up the food chain, it becomes concentrated in the intestinal tracts of the fish. 

If they have not been cleaned properly, eliminating the contents of the bowel, consuming them can be toxic due to ciguatoxin.

Signs & Symptoms of Ciguatera Poisoning:

Ciguatera can cause gastrointestinal, neurological, or cardiovascular symptoms.

History – the patient has recently eaten fish, from a species of marine finfish.

Onset of symptoms is typically in about 6 hours but can occur in 10 minutes – 24 hours after eating the fish.


Gastrointestinal – usually mild:




Numbness & tingling about the mouth and extremities (paresthesias)

Neurological – can be severe:


Muscle pain – myalgia, arthralgia

Dizziness & vertigo


Sensation of temperature reversal: hot feels cold and cold feels hot

Cardiovascular – can be severe:

Dysrythmia – Arrhythmia



Decreased BP (hypotension)


Is strictly supportive care: rest, liquids, and treat the symptoms.

There is no antitoxin.

It may take days to weeks to recover.  

Deaths are rare; they are secondary to respiratory and cardiovascular failure.

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