Male Blue-Lined Octopuses Use Venom to Paralyze Females During Mating

Researchers discovered that males inject tetrodotoxin to immobilize larger females, preventing sexual cannibalism and ensuring reproduction.

Male blue-lined octopuses inject tetrodotoxin, a potent neurotoxin, into females' aortas to paralyze them during mating.
This strategy prevents females, who are up to twice the size of males, from cannibalizing their mates post-copulation.
The venom, produced by symbiotic bacteria in the males' salivary glands, causes temporary paralysis without killing the females.
Mating sessions last up to 75 minutes, and females regain mobility after the effects subside, often pushing males away afterward.
Despite sustaining bite wounds, all females in the study survived and successfully laid eggs within weeks of mating.