Tetrodotoxin poisoning

Tetrodotoxin is another potent neurotoxin, is also known as anhydrotetrodotoxin 4-epitetrodotoxin, or tetrodonic acid, is a marine biotoxin associated with certain fish species, notably pufferfish.

Although the ingestion of livers from certain species of puffer fish is the most common cause of tetrodotoxin poisoning, tetrodotoxin also appears in trigger fishes, ocean sunfishes, globefishes, porcupine fishes, some parrot fishes, a goby, xanthid crabs, sea stars and angel fish, a horse crab, a number of marine snails, a flatworm, a South Atlantic sea squirt, ribbon worms and marine red algae.

Bacteria, omnipresent organism that commonly inhabit the aquatic system, are implicated as the primary source of tetrodotoxin.

There are several microbial sources of tetrodotoxin in including Pseudomonas, Vibrio, Listonella, and Alteromonas species. It has been suggested that the puffer fish accrue tetrodotoxin as a biological defense agent. There appears to be symbiotic association between tetrodotoxin-producing bacteria and higher organism, which offer distinct advantages to both partners.

The lethal dose of tetrodotoxin is only 5 mg/kg in the guinea pig. In humans, the lethal dose is 334 mg/kg by ingestion. Tetrodotoxin affects the nervous system by preventing the propagation of the nerve impulse.
Tetrodotoxin poisoning