Love on the brink of life and death: male octopuses paralyze females so as not to become their lunch (2 photos + 1 video)

Researchers from the University of Queensland have discovered that male blue-ringed octopuses Hapalochlaena fasciata have developed a unique survival strategy during mating. To avoid sexual cannibalism, they inject females with tetrodotoxin, a powerful poison that temporarily paralyzes the female and allows the male time to impregnate her and escape.





Dangerous Approach: Why Do Males Have to Protect Themselves?

In the world of octopuses, reproduction is not only an intimate process, but also a deadly one. In many species, females are significantly larger, more aggressive, and more voracious than males. After mating, they can attack their partner, strangle and eat him, which makes an encounter with a female extremely risky.

Hapalochlaena fasciata is a species of venomous octopus, in which sexual dimorphism is not as pronounced as in other representatives of the order: females weigh only twice as much as males on average. However, this is enough to ensure that if aggression occurs, the male has no chance of survival.

Researchers from the Queensland Brain Institute, led by Wen-Sung Chang, observed these mollusks in laboratory conditions. They noticed that before mating, males bite the female in the aorta, introducing tetrodotoxin into her body.

How does the poison work?

Tetrodotoxin is a neurotoxin that causes paralysis. It is found in a number of poisonous animals, such as puffer fish. In octopuses, it is usually used for hunting and defense against predators, but in Hapalochlaena fasciata, it also plays a key role in the reproductive strategy.

After the bite, the female's breathing slows, her skin turns pale, her pupils stop responding to light, and her body becomes immobile. On average, the paralysis lasts about an hour, which is enough time for the male to complete mating and escape.



Evolutionary "arms race" between males and females

Scientists have discovered that the salivary glands of males are significantly larger than those of females - their mass is three times greater. This is due to the fact that the male needs to produce a sufficient amount of poison to temporarily neutralize the partner, since females have partially developed resistance to tetrodotoxin.

Researchers also noticed that after mating, the bite wound in the aorta area remains on females for three days. This may be an additional mechanism that reduces their activity and aggressiveness for some time after contact with the male.

In addition, observations have shown that if the male misses the aorta, the effect of the poison is weaker, and the female recovers in 35 minutes instead of an hour.

The discovery made by scientists demonstrates unique adaptation mechanisms in the animal world. Reproduction is often associated with high risks, but evolution helps to find new ways to survive.