Male blue-lined octopuses inject a powerful neurotoxin into the hearts of females before mating to avoid being eaten, according to a new study.

In the perilous world of cephalopod romance, male blue-lined octopuses have evolved a shocking strategy to survive mating.

Scientists have found that male blue-lined octopuses inject venom and paralyse females during sex to avoid being killed and cannibalised by their much larger partners.

While unfortunate for the males, becoming a post-sex meal offers the females vital nutrients needed to sustain themselves and their soon-to-be hundreds of gestating offspring. This practice is especially common in animals exhibiting female sexual dimorphism,

Male blue-lined octopuses inject females with venom during mating to avoid being eaten by their partners, observations suggest 1. Blue-lined octopuses (Hapalochlaena fasciata) have paralysing venom that can kill a human.

Male blue-lined octopi (Hapalochlaena fasciata) have been found to use venom on their sexual partners, as well as for the usual reasons of defense against predators and subduing prey. Killing the females would be counterproductive,