It's probably not what you think

How these male octopuses avoid becoming dinner during sex

Wild as it may seem drugging sexual partners happens in the animal kingdom. 

Talk about lack of consent. A study has shown that there’s an octopus out there that injects the female with paralysing venom during sex, mind you this has a twist – they do it to avoid being eaten. Wow.  

If you’ve followed us at Sex in Space for a while, you’ll know by now that some animals have some pretty interesting mating behaviours - from constructing elaborate love dens, to being able to continue to mate after being decapitated – animals have some weird courting behaviours.  

This one might be the wildest we’ve come across so far. It’s the love life of the blue-lined octopus, which if you don’t know already are a tiny, but very dangerous cephalopod that is often found in shallow reefs and tide pools.  

Full sized females are only about the size of a golf ball, and that’s around 2-5 times bigger than their male counterparts. These ladies are also prone to eating their mates, something called sexual cannibalism, which apparently is very common in cephalopods.  

All male octopuses have a specialised arm for mating, which transfers a sperm capsule into the female’s oviduct, which is part of their reproductive system. Male octopuses have come up with some very creative strategies to avoid becoming their mate’s next snack during sex –  argonauts will sacrifice their mating arm and let it drop off afterwards, while other species have evolved an extra long mating arm.  

But since the blue-lined octopus doesn’t have a very long mating arm, it’s not able to do long distance mating, so it needs to try something more dangerous – mounting its partner. This is where the paralysing venom comes in. The researchers of this study saw male octopuses immobilising females during mating sessions that lasted between 40-75 minutes. They use their very potent neurotoxin called tetrodoxin, the same stuff they use to immobilise their prey. As the neurotoxin takes effect, the females even stopped breathing after eight minutes, they went pale and their pupils no longer responded to light. The mating would end when females regained control of their arms and pushed the male off. As you would.  

None of the females died during this process and they fed normally the next day, which suggests that they have natural resistance to tetrodoxin. Interestingly, blue-lined octopuses, like a lot of octopus species, die very soon after mating anyway – this is something called ‘semelparity’ a breeding strategy where an organism dies after it reproduces once. The females die after their larvae hatch.  

So, there you have it – one more example of how nature evolves some very interesting and unexpected quirks. Let us know if you have any questions in the comments, and make sure to subscribe to Sex in Space to keep up with more wild and woolly sex facts like this.   

Read the article in the Guardian here.