For pufferfish, motherly love means slathering babies in deadly toxins
IF YOU’VE ever heard of fugu — that fish so dangerous to eat that Japanese sushi chefs need special certification to prepare it — then you know that some pufferfish use seriously deadly toxinstoprotectthemselvesfrom predators.
But according to a new study, these fish might benefit from their species’ predilection for poison long before they’re mature enough to produce it for themselves. A nice coating of deadly toxins might be Mom’s parting gift to her babies.
Writing for her blog Science Sushi at Discover Magazine, Christie Wilcox explains that pufferfish poison is no joke:
“Pufferfishes in the genus Takifugu are known for their poisonous nature. Any predator that messes with these toxic fish learns the hard way that their tissues are loaded with tetrodotoxin, one of the most deadly poisons on the planet. It can kill a wide diversity of species, from fish to mammals, becauseit’sapotentparalyticthat shuts down ion channels vital for nerve functioning. Humans are not immune: tetrodotoxin killed 179 people and poisoned another 467 in Japan alone from 1974 to 1983, where the flesh of these fish, fugu, is considered a delicacy perhaps because of the danger involved.”
In fact, the toxin is 120,000 times deadlier than cocaine — deadlier even than cyanide. Just a few milligrams can kill a human adult. That’s why preparing the fish for human consumptionissuchadangerous game: Patrons often want to taste just the tiniest tingle in their mouths from the poison to remind them how adventurous their meal is, but it only takes a small miscalculation to wipe your customers out before they can get to dessert.
By all appearances, however, larval pufferfish are just as helpless as any other baby fish. Quickly abandoned by their parents, they’re not able to puff themselves up to visually intimidate predators quite yet, and they haven’t accumulated enough toxins in their body to deter anyone who takes a bite.
Inapaperpublishedthismonth in Toxicon, researchers showed that larval pufferfish have more tetrodotoxin than they should. But it’s not coming from the inside out; it’s spread all over the surface of their skin. It turns out that extra tetrodotoxin is stored wherefemalepufferfishkeeptheir eggs.Whenshelaysthem,shealso releases some of the toxin — and it sticks to the babies once they hatch.— WP-Bloomberg