In the coral reefs of Eastern Australia, the males of octopus with blue lines (Hapalochlaena bandaged), minutes and vulnerable, they developed a surprising tactic for survive the love encounter: inject poison into females. This act is not cruel, but an evolutionary necessity. The females, in fact, are larger and they represent a threat to their companionsof which they often feed on.
To reveal the details of this ritual is a study published on Current Biologyaccording to which this kind of octopus during mating uses the Carthotossine (TTX), a powerful neurotoxin. The TTX, present in many animals, from dishes with fish dishes, is used for predation and defense.
The blue striped octopus seizes the TTX from symbondic bacteria in its rear salivary glands (PSG). When he died, the saliva full of TTX immobilizes large prey e It can be lethal for humans.
The octopus with blue lines are about double males, a risk for the latter during reproduction. The researchers found that the PSG of the males are three times heavier than those of the females. Using mating experiments in the laboratory, they showed that males use a bite aimed at the aorta of the female to inject TTX at the beginning of the copulation, immobilizing it.
This technique allows males to complete the mating without the risk of being devoured. Sex cannibalism is common in cephalopods (as cuttlefish and squid), and octopus females, especially during the hatching, they need a lot of energy. The males, therefore, are exposed to a high danger.
To counteract this threat, male octopus have developed this strategy. Rather than sacrifice a limbas some species do, or lengthening an organ, resort to a chemical weapon. The poison injection temporarily paralyzes the female, allowing the male to transfer his seed.
Scientists observed that the females, after injection, show signs of paralysis. Breathing slows down, the skin pales and the pupils do not react to light. However, this effect is temporary and No female dies during the process.
This evolutionary “armaments” race, as it defines it Wen-Sung Chungauthor of the research and Postdoctoral Research Fellow at Queensland Univereesity, shows how nature suitable for extreme situations suitable.
