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Harmful Algae & Red Tide Species Information

Map View About HAB News What Are HABs? HAB Species

What HAB species are found in California?

Alexandrium spp.

Potential Toxin Produced: Saxitoxins
Syndrome: Paralytic shellfish poisoning (PSP)
Photo courtesy of Melissa Carter

The dinoflagellate Alexandrium catanella (formerly Gonyaulax catanella/catenatum) produces saxitoxin, a highly potent neurotoxin, which, if consumed, causes paralytic shellfish poisoning (PSP). Ingestion of saxitoxin by humans, primarily through eating shellfish, can result in numbness, ataxia, incoherence, and in extreme cases respiratory paralysis and death.

This toxin was first discovered in 1927 after a shellfish poisoning event affected over a hundred of humans in central California. Saxitoxin is now recognized as one of the most deadly algal toxins.

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