There’s a specific life history strategy called semelparity, which is what you’re describing (breeding once then dying). To my understanding, this is incentivized if the chances of getting a second attempt to breed are too low, and so it becomes more evolutionarily advantageous to simply go all out on the first attempt
A bit similar process in sea-dwelling salmons: migrating from salt water into fresh water (quite a big metabolic challenge in itself), traveling up rapids to suitable spawning places (often a long and arduous journey)… after they’ve accomplished that, their chances of returning alive are quite low. So they mostly die. But their close relatives, river-dwelling trouts spawn many times in life, because their migration isn’t as costly.
I would suspect that something in how octopuses reproduce has an element of “return being costly” - it could be a metabolic return to the feeding and growing state instead of a physical return.
To be clear, it’s still an advantage and for the ones that it isn’t they don’t die after mating. Most cephalopods are both predators and prey that life cycle results in a very high mortality rate. If you don’t hunt enough, you fail and if you get eaten you fail. The deep cold water ones though, tend to have to live longer due to less prey and have fewer predators so they tend to not die after mating.
There’s a specific life history strategy called semelparity, which is what you’re describing (breeding once then dying). To my understanding, this is incentivized if the chances of getting a second attempt to breed are too low, and so it becomes more evolutionarily advantageous to simply go all out on the first attempt
A bit similar process in sea-dwelling salmons: migrating from salt water into fresh water (quite a big metabolic challenge in itself), traveling up rapids to suitable spawning places (often a long and arduous journey)… after they’ve accomplished that, their chances of returning alive are quite low. So they mostly die. But their close relatives, river-dwelling trouts spawn many times in life, because their migration isn’t as costly.
I would suspect that something in how octopuses reproduce has an element of “return being costly” - it could be a metabolic return to the feeding and growing state instead of a physical return.
Thanks, one solid answer! It could be that it used to be an advantage at some point and now it’s just perpetuated
To be clear, it’s still an advantage and for the ones that it isn’t they don’t die after mating. Most cephalopods are both predators and prey that life cycle results in a very high mortality rate. If you don’t hunt enough, you fail and if you get eaten you fail. The deep cold water ones though, tend to have to live longer due to less prey and have fewer predators so they tend to not die after mating.
Semelparity: “Fuck it, I’m gonna nut to death”