hoenter image description hereHow to make an reproductive system where the males have 100% guarantee of their paternity and make cuckoldry and sperm competition impossible similar to seahorses,where the males get pregnant and can give birth instantaneously with no pain or discomfort; also let the males store the females ovum like ova banks?


Males are also polygynous and predominant over females and are bigger stronger and taller and smarter than females and if a female isn't around he will reproduce by androgenesis.

Melding (also sometimes known as 'the joining') is a process by which males can create a state of synchronicity between their nervous system and that of an indefinite amount of partners. Melding allows participants to share thoughts, emotions, and experiences; the process also serves to 'map' the genome of a partner to see which females has the best genes for reproduction. allowing them to intuitively know who would be the best partner to be able to get together with a desired partner in order to spawn a child with the ideal or desired characteristics that the male wants in their own child.this ability allows males to be so skilled in genetics and males to instinctively know their paternity.

Females have an ovipositor identical to the human penis if a female can't find a male to carry her children she will carry her own children like a human female would females can also produce over 50 billion ovum and fresh eggs and don't have menopause or periods and can reproduce parthenogenesis when no male is around


Males are more altruistic and cooperative so males alliances are far more developed and advanced than females and bond by melding making male competition non existent and peaceful, female's are far more aggressive and solitary only forming groups between sisters and other female relatives and will attack and kill any non related female's baby's on site if left unprotected females are also cooperative breeders with the alpha female being the main breeder and females will also kill and swap children of other females with her own,Due to the polygynous mating behavior of males, a female cannot be sure which offspring are hers unless she reproduces by pathogenesis or she carries her own babies.

  • 2
    $\begingroup$ Speaking of "new to the site" -- Welcome to Worldbuilding.SE! Please take the tour and read over the FAQ to better understand how this site works. $\endgroup$
    – Zeiss Ikon
    Jul 22, 2022 at 15:24
  • $\begingroup$ This seems like an open ended question asking for brainstorming, and idea generation, such questions are not permitted on this site. There are tons of species who don't engage in sperm competition, including primates. We're not here to discuss the totality of possible solutions, but help you with your particular worldbuilding species. What can you tell us about their biology and behavior? Can you try brainstorming a solution on your own, and ask us for solving any specific problems that you encounter? $\endgroup$
    – sphennings
    Jul 22, 2022 at 15:55
  • $\begingroup$ Does this answer your question? Can there be a society where competition is impossible? $\endgroup$
    – JBH
    Jul 22, 2022 at 17:48
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    $\begingroup$ No I just looked at this question this talks about environmental competition my question ask for how to eliminate reproductive competition among males $\endgroup$
    – Kirari
    Jul 22, 2022 at 19:03
  • $\begingroup$ @Kirari If you don't believe these are duplicates, then you need to better explain why they're not. Sperm competition (whether yours or the other Q) is always an environmental issue. I couldn't discern enough difference between your Q and the other, which is why I VTCd as a duplicate. Note that when you wrote your question, the system automatically listed similar questions for you to review. The other Q was on that list, probably in position #1. I may be wrong, but I bet you didn't bother to look at it. When you write questions, you need to look at that list. $\endgroup$
    – JBH
    Jul 23, 2022 at 3:33

3 Answers 3


Reversing the roles already does half of the job.

You see, fertility can be selected for in biology: if you are guaranteed to fertilize the female you had sex with, it all becomes a matter of reaching her first. Being very fertile is not exactly always good for the sake of having better offspring genetically, however, as seen in whales where the female will travel long distances and the last male to fertilize her has undoubtedly more stamina and physique than the competitors that had to bust their load and dip first due to not being able to keep following, and thus would have "inferior" genes.

In your case, very high fertility may not be exactly necessary in males to begin with, because you're asking for an essential reversal of the sexual roles, with the male carrying and nurturing the developing babies/eggs rather than the female. If sea horses and pipefish are anything to go by, the first big difference is that this would also switch the competition members: in normal species, cuckoldry and sperm competition happen because there's more than one male wanting a single female to carry their child. In this situation however we have more than one female wanting the male to carry their eggs.

The 2 main changes to this inversion as far as nature shows us are:

  • the ones developing traits meant to impress the sexual partners, such as vibrant colors and patterns, are the females rather than the males.

  • the males have a special brood pouch in order to house the babies, while females have ovipositors meant to place their eggs inside the pouch.

The ova banks you ask for aren't that hard. Methods for storing and nurturing sperm cells exist in females of various species, and so it's far from absurd that your reproductive males could have something like that. Females with eggs that can last longer being selected is also anything but crazy to see happening.

The seahorse method does mean there's no sperm competition, but only because the males are the ones doing the pregnancy part. They Don't need to compete for the females, the females are the ones who need to compete for them.

As for your instantaneous development/painless childbirth, sorry but forget it. Even in sea horses the babies are expelled through powerful (and potentially painful) muscle contractions and the babies, despite minuscule to a human, still take over a week until they're ready to be born. This is also something essentially every animal species would like (you usually want your baby to grow and be born fast, because that means both you and them are vulnerable to predators for a shorter period), but sadly cells can only divide so quickly without devolving into tumors.

Essentially, is it possible for there to be a species where the males handle the childbirth and there's no cuckoldry? Yes, we see it happens in nature and the males being the ones who make the children means the females would be the ones competing and that they'd probably be the ones to have penis-like Structures meant for penetration (hopefully they're pretty fertile). The best method to avoid extended competition is having them mate for life. Storage of egg cells is plausible enough as similar processes are shown to happen in nature. Painless childbirth with instant baby growth is a no go however, even with brood pouches the release of the baby is still tied to muscle contractions unless your species' newborns can instinctively teleport out of the pouch.


This may have unintended consequences

For seahorses, the reason they define the males and females the way that they do, is because technically, the fertilization step happens externally. If this were not the case, then arguments could be made that what we currently call "males" would be called "females" and vice versa. Biologists might say that seahorses gametes are unique in that the "sperm" are much larger than the "eggs" in this case.

For this reason, such a society might develop in such a way that what you are calling "males" are actually considered the female and what you are calling "females" are considered the males.

Aristotle's defined females as those who could produce life inside themselves and males as those who could produce life in others.

So you'll need to be careful because what you are proposing might be indistinguishable from humans for a large portion of their history.

It would only be later in your species development, when they found out that their biology was different then that of other organisms that they would realize that their males are really females, and that their females are really males.


What about it is some kind of amphibian/marsupial hybrid? The female would inject her "goo" of tiny shell-less eggs inside the male's internal 'bag' so it would be fertilized in a pool of sperm.

The offspring would eat the residual eggs for nutrition and develop inside the paternal bag like marsupials.

There is also a species of sea slug that literally swordfights with their penises. The first one to be 'stabbed' is fecundated and have to carry the opponent's eggs. I believe it would mean your species is hermaphrodite or something like that.


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