Male blue-ringed octopuses inject venom during mating to prevent themselves from being eaten by females.
by
The Blue-lined Octopus is a species of octopus famous for its highly toxic tetrodotoxin , and inhabits the shallow waters and coral reefs of the Western Pacific Ocean from the Ogasawara Islands and the Ryukyu Islands of Japan to Australia. It has been discovered that males of the Blue-lined Octopus inject tetrodotoxin into the bodies of larger females to immobilize them during mating in order to avoid being eaten by them.
Blue-lined octopus Hapalochlaena fasciata males envenomate females to facilitate copulation: Current Biology
https://www.cell.com/current-biology/abstract/S0960-9822(25)00057-0
Male octopus injects female with venom during sex to avoid being eaten | New Scientist
https://www.newscientist.com/article/2471120-male-octopus-injects-female-with-venom-during-sex-to-avoid-being-eaten/
Male blue-lined octopuses inject females with venom during sex to avoid being eaten, study shows | Marine life | The Guardian
https://www.theguardian.com/environment/2025/mar/11/blue-lined-octopus-sex-venom-tetrodotoxin
Many people may think of praying mantises when they hear that the female eats the male after mating, but cannibalism after mating is also common in cephalopods such as squids and octopuses. The same is true of the Blue-lined octopus, which is common in Japan. After laying eggs, the female goes without food or drink for about six weeks, so she may eat the male after mating to replenish her energy before that.
In octopus mating, the male uses an arm called a coccygeal arm to transfer sperm to the female, but some species have tactics to avoid being eaten by the female after mating. For example, the shelled octopus, Takobune , has an ecology in which the male 'cuts off the coccygeal arm after transferring sperm,' and there are also octopuses that have long, thin coccygeal arms to keep distance from the female.
However, the short copulatory arms of the blue-ringed octopus mean it cannot mate at a distance from the female. In this study, a research team from the University of Queensland in Australia observed blue-ringed octopus mating in the laboratory to determine how male blue-ringed octopuses avoid being eaten after mating.
As a result, it was found that male blue-ringed octopuses bite the female near the aorta during mating, injecting the highly toxic tetrodotoxin, a highly potent neurotoxin also found in pufferfish, and that bites by blue-ringed octopuses can be fatal to humans.
by Klaus Stiefel
About eight minutes after being injected with tetrodotoxin by a male, the female blue-ringed octopus stopped breathing, turned pale, and her pupils became unresponsive to light, allowing the male to avoid being eaten while in close proximity to the female during mating, which can last between 40 and 75 minutes.
'Mating ended when the female regained control of her arms and pushed the male away. None of the females that were injected with tetrodotoxin died during the experiment, and they resumed normal feeding behavior the next day, suggesting that female blue-ringed octopuses are resistant to tetrodotoxin.'
The study also reported that the posterior salivary glands that contain tetrodotoxin in male blue-ringed octopuses are about three times heavier than females, presumably because males need to carry more venom than females for mating.
The female blue-ringed octopus is about the size of a golf ball, and at the time of mating, the female is about 2 to 5 times larger than the male. 'As the females got bigger and stronger, the males eventually needed a special strategy to ensure that they could pass on their genes to the next generation,' said Wen-Sung Chung , a postdoctoral researcher at the University of Queensland and lead author of the paper.
Related Posts:
