The body musculature is usually free of poison. The highest concentration of the toxins is found in the viscera (gonads, especially the ovaries liver and intestine) and skin. There are reports of a distinct relationship between gonadal activity of the fish and its toxicity, the fish being most lethal for consumption immediately prior to and during their reproductive periods.
Ingestion of the flesh, viscera, or skin of toxic tetraodontiform fishes can cause poisoning. In Taiwan, more than 100 cases were reported from 1998 to 2008, and the mortality rate was about 10%. Despite this, reports of up to 50 deaths annually occur in Japan from puffer fish poisoning. Įven with its long history of toxic effects, the fish is considered a delicacy in Japan especially and is prepared by licensed puffer fish cooks only in Japan. They are relatively uncommon in the temperate zone and completely absent from cold waters. Also referred to as Fugu (meaning “river pig” in Japanese), balloonfish, blowfish, bubblefish, globefish, Patka fish, swellfish, toadfish, toadies, honey toads, sugar toads, and sea squab, the puffer fish is commonly found in coastal regions of the tropics such as the Indian Ocean and in the South Pacific.
TTX poisonings have been reported in Japan, Taiwan, Hong Kong, Cambodia, Bangladesh, and the United States. TTX is one of the most potent and oldest known neurotoxins, and puffer fish poisoning is common along the coasts of Asian countries. We report a case of mild poisoning and suggest observation for such cases.
TTX poisonings have been reported in Japan, Taiwan, Hong Kong, Bangladesh, and the United States (Haque et al. Severe cases may present with respiratory depression, circulatory failure, and death. Puffer fish poisoning may cause a constellation of symptoms, such as giddiness, numbness and tingling sensation of the mouth, paresthesia, and muscle weakness. Puffer fish contains tetrodotoxin (TTX), a potent poison affecting the neural pathway. The fish is gaining popularity in Singapore and can be found in quite a few restaurants now. However the larvae pick their poison, the tiger puffer fish is declining in the wild for unknown reasons, and overfishing may make matters worse, Itoi says – showing that even the most fearsome of fish needs protection from humans.Although many Asians regard puffer fish as a delicacy since ancient times, puffer fish (Lageocephalus scitalleratus) is also a well-known source of possibly lethal food poisoning. Itoi rejects the criticism, pointing to factors that make it unlikely the poison comes from bacteria. Perhaps the larvae get the TTX from bacteria or from their fathers as well as their mothers. It's also possible that the larvae aren't getting the TTX from their mothers, says chemical ecologist Richard Zimmer of the University of California, Los Angeles. "I suspect tetrodotoxin is defensive" for the puffer larvae, Williams says, but "additional research needs to be done to verify that." In her own studies, predators spit out the larvae of the deadly blue-ringed octopus, which also contain low levels of TTX, but those same predators will happily eat baits spiked with higher amounts of the poison. The predators might reject the larvae because of a chemical other than TTX, says chemical ecologist Becky Williams of Utah State University.
The larvae are armed with the chemical deterrent in their mothers' ovaries, the researchers argue.īut other scientists say the new study doesn't close the case. Itoi and his team think the bigger fish can taste the baby puffers' dose of TTX. But when the scientists placed puffer larvae in front of young flounder, sea bass and other fish, the bigger fish gulped the tiny larvae – and quickly spit them out, the researchers report in an upcoming issue of the journal Toxicon. They found that the larvae of tiger and grass puffers contain very small amounts of TTX, far less than would be lethal to a bigger fish looking for a meal. Japanese researcher Shiro Itoi of Nihon University and his colleagues set out to unravel the puffer's secrets.