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Bizarre Alien Sexes
An alien species' sex system is very bizarre in comparison to terrestrial ones. Perhaps it has two sexes that are not identifiable as either "male" or "female" in terrestrial terms, or perhaps it has three or more sexes, each of whom is indispensible for the species' reproduction process.

Of course, Earth has a few bizarre examples of its own. Some species of fungi have more than two sexes (although only two at a time are required for reproduction). There's a species of fish that only has one sex, and among seahorses, the male bears the children. But this only scratches the surface of what writers can imagine.

Supertrope of One-Gender Race. Subtrope of Bizarre Alien Reproduction. May lead to Pronoun Trouble. Compare Extra Parent Conception, Bizarre Sexual Dimorphism. Contrast No Biological Sex.


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    Comic Books 
  • Sillage has an alien species that apparently requires two "females" and a "male" for procreation, though no details are given as to how it works.
  • In Phil Foglio's Buck Godot: Zap Gun for Hire's "The Gallimaufry" storyline, a male alien Pog member named Qvakk states that he loved Oort, another male member of his race/species, and was "gonna take him home, make lots of eggs".

  • The Soft Ones in Isaac Asimov's The Gods Themselves are from a universe with different laws of physics. They have soft bodies of three sexes (rational/left, emotional/mid and parental/right), all of which are required for reproduction by "melting" (fusing their bodies together at the intermolecular level). This creates a mature solid form with the fused mind of the three soft ones, which forget this little fact after the act. The one that actually gets pregnant is referred to throughout using male pronouns.
    • Just to clarify this a bit, when a triad of Soft Ones "melt" (that is, mate), they temporarily form a Hard One, but don't remember that after they separate (the Hard One does, however, remember its previous periods of consciousness when it is formed again). Nonetheless, this fusion is related to reproduction, being the means by which new Soft Ones are conceived (one at a time) to grow to term inside the Parental of the triad. It's not said outright, but there is the implication that there is an order to the pregnancies so that each triad will produce at least one full triad of offspring before they grow out of the breeding stage and finally merge permanently as a Hard One. The Hard Ones are genderless and act in a parental/mentor advisory role to the Soft Ones (though the Parental Soft Ones act as parents to the babies when the latter are very young).
  • Known Space:
    • The Puppeteers, who are already fairly strange looking, claim to have three "sexes", one of which is non-sentient. In actuality, they're merely prudish about admitting that they're a parasitoid species—the "third sex" is a different species, and serves as a host for an embryo created by the two actual Puppeteers. Also, they have quite mixed feelings about the sacrifice of their non-sentient 'bride' for the purpose of reproduction. They positively dote upon the creatures, attracting them to their nest, dressing them up, caring for them. There is love there, ending in the heartbreak of a lethal birth, and joy for the new life.
    • Jotoki are amphibious and look sort of like starfish. They have an immature aquatic stage, and five sexes. Each limb starts as a separate non-sapient creature, which meet and join at maturity, then develop intelligence just before they breed.
  • The Player of Games by Iain M. Banks: The Empire of Azad is ruled by humanoids with three sexes, all of which contribute genes: "males" with testes and penis, an intermediate "apex" with ovaries and a "reversible vagina" that is used as an ovipositor after a male has fertilized them, and "females" with uterus and an endogenous retrovirus that modifies the implanted egg. The only non-sexual difference between the sexes is the eugenically bred-in lowered intelligence for non-apices. The apices are very much on top and exercise crushing sexual discrimination against both other sexes: sexism here sees females as passive incubators and domestics, males as workhorses and disposable soldiers. Notably, more females than males appear to compete in the Azad tournament.
  • Bruce Coville has a couple of examples:
    • The My Teacher is an Alien series mentions one species that requires "seven genders [sic] to produce an egg, and three more to hatch it". This being a kid's book, the exact mechanics of this are never explained.
    • More ambiguously, Tar Gibbons from Rod Albright Alien Adventures insists on gender neutral pronouns because referring to it as male or female is offensive to it. No details are given.
    Rod: So, is that closer to a boy or a girl?
    Gibbons: Hmm... it's closer to a pippik than anything else.
  • Venus and the Seven Sexes, a 1949 short-story by William Tenn, features a seven sexed species that passes gametes in a chain: sex "D" receives from sex "C" and transmits to sex "E." The sex of the offspring is determined by the sex of the parent which receives/completes the fully fertilized gamete. One sex is tasked with coordinating the family.
  • The Tralfamadorians from Kurt Vonnegut's Slaughterhouse-Five claim to have five sexes. Because they can see through time as well as space, they claim humans actually have seven sexes. Five of these are "only active in the fourth dimension," so humans can't perceive their contribution to the reproductive process. Three are named as examples: male homosexuals, women over sixty-five, and babies who live less than an hour after birth (though female homosexuals and men over sixty-five are not necessary for reproduction). Each human would thus have 7 individuals who contributed to the act of procreation even though we can only detect 2.
  • Bob Shaw's "Warren Peace" has the Squelchers, an alien race with no less then six different sexes, each one with its own unique appearance, and with a reproductive cycle where each sex fertilizes the others in turn. The forms look so different that, to the vast majority of the universe, the species only consists of the fourth sex, which resembles an orange haired saggy sasquatch (kind of like a blown up balloon that's developed a slow leak) with multiple eyes in a ring around its head (usually covered by its fur), oversized feet that let it wade on water, and two giant red nipple-like gamete sacs positioned one above the other on its torso. The fifth sex, the only other one mentioned, is described as being indistinguishible from a tree, except for the presence of a pair of two dual-pronged ovipositors (they look almost identical to staples) sprouting from its trunk.
  • Chanur Novels: The stsho have three sexes, called "gtst", "gtste", and "gtsto", and form mating trios instead of mating pairs. None of the sexes can exactly be called male or female, since a stsho which fills the young-bearing role in one trio can simultaneously fill a non-young-bearing role in a different trio. Nothing beyond that is known, since the stsho are an extremely private and xenophobic race which refuses to share details of their biology with any other species. For further strangeness, sufficient psychological/emotional stress can cause a stsho to undergo "phasing" and spontaneously change sex as well as personality.
  • In The True Meaning of Smekday by Adam Rex, the Boov aliens who attempt to enslave the human race have 7 sexes that translate in English to: girl, boy, boygirl, girlboy, boyboygirl, and boyboyboyboy.
  • Star Trek Expanded Universe:
    • In the TOS-era novels by Diane Duane, there is one race, the Sulamid that is described as a bundle of bright purple tentacles about six to seven feet high, topped off with a sheaf of pink-stalked and tentacled eyes with triangular pupils and a purplish, "bloodshot" look. According to Dr. McCoy, they have twelve sexes, and all of them claim to be "male," especially the ones that bear the children. The Enterprise has at least three of them among the crew, Mr. Athende in Maintenance, Lt. Meshav from Data Management, and ensign Hwa'vire from Engineering.
    • Andorians—in the Star Trek Novel Verse (Star Trek Online borrowed this)—have four sexes and need to form a telepathically bound quartet comprised of one of each sex before they can hope to conceive. "Chan" and "thaan" approximate male, while "zhen" and "shen" approximate female (the "shen" conceives the embryo while the "zhen" carries it to term in a pouch). There isn't any evidence of this within the Live-Action TV canon though: It's based on a throwaway line from TNG: "Data's Day" that Andorian marriages consist of four people, but that could just as easily imply polygamy. Since they have a low birth rate, it's a Hand Wave for why that race isn't seen much in space, despite being one of the Federation's founding species. The novels have fleshed out the four-sex biology and four-gender culture interpretation considerably. This is apparently an Enforced Trope: the authors felt that it offered more storytelling opportunities than the polygamy explanation.
    • The squales in the Star Trek: Titan novel Over a Torrent Sea have four sexes.
    • The Jelna Rigelians have four sexes too—endomale, endofemale, exomale, exofemale. Contrast with Zami Rigelians, who have the usual two sexes, and Rigelian Chelons, who are hermaphrodites but accept gender identities due to centuries of cultural imposition by the Jelna and Zami.
    • Damiani, Vissians, Bactricians: all have three sexes. In Bactricians, the third sex is a small breeding caste traded between couples of males and females, in Damiani all three sexes are equally prominent.
  • In Octavia Butler's Lilith's Brood books, there are male and female Oankali, but the third gender Ooloi does the genetic mixing.
  • In Piers Anthony's Cluster series, the Spicans have three sexes—impact, undulant, and sibilant—of which all three are required for reproduction. Whenever all three are present in the same area, mating will occur—not might, will. There are three roles that can each be assumed by any of the three sexes, and the gender of the offspring is determined by which sex takes which role.
  • One science fiction story (name forgotten) features an alien species with five sexes, all of which are involved in the conception and raising of a child in their own way. The meat of the story involved an individual of the "siring" sex taking a "nurturing" partner to court to get custody of their offspring.
  • In Last and First Men, the Last Men, our many-millions-of-years descendents, have evolved and/or engineered themselves to have several different sub-sexes.
  • In the Marsbound series, the "Martians" (who aren't actually native to Mars) don't appear to have fixed sexes. Their reproduction is described as a wrestling match with several participants—and the winner gets to be the mother.
  • The Jokka created by M.C.A. Hogarth have three genders, anadi (female), emodo (male), and eperu (neuter). They can also change genders up to twice in their lives, the causes aren't entirely clear.
  • In the novel Silent Runners, aliens nicknamed "pupfish" evolved with three sexes: males, females, and pouchers. All three are necessary to reproduce: males fertilize females, who produce underdeveloped larvae that are deposited in a poucher (like marsupials), where the larvae receive the poucher's chromosomes and continue their development. The species is also superfecund, with a female able to birth the larvae of multiple males at once, and multiple females can deposit in the same poucher. The author worked out a pretty detailed analysis of the biology behind this.
  • In William Barton and Michael Capobianco's Alpha Centauri, the "leospiders" apparently had several different sexes: males suck some sort of seed from quondam females, take more from quasimales, inseminate macrofemmes with the collection... It's confusing since the expedition learns about the process from multi-billion year old pornography.
  • In the Gor series, the alien Kurii have three (or four) sexes, or genders. They basically work out to be male, female, a "blood nurser" which the females lay their offspring in and then the babies eat their way out of, and a fourth sex which is essentially a male with low testosterone, which is shunned by the community, but in certain circumstances becomes a breeding male; hence they're not sure whether to consider it a separate sex or not.
  • There is a story by Stanislaw Lem about aliens who, among other things, have five sexes.
  • The Lo'ona Aeo in Mikhail Akhmanov's Arrivals from the Dark series have 4 sexes. Roughly translated into English, they are "full male", "half-male", "half-female", and "full female". Only the full female sex is capable of conceiving and bearing a child. A full male and half-male are required for the "mental contamination" process that kick-starts the pregnancy (no physical action required). The half-female sex is sterile and does not participate. The Lo'ona Aeo are capable of chemically altering the future sex of a child, as necessary to maintain the genetic diversity. A Lo'ona Aeo named Zantu defied her parents by allowing herself to become a full female, as originally intended by her genes, instead of the half-female her parents wanted her to be. She was exiled until such time as she reaches the Lo'ona Aeo equivalent of menopause and is no longer a threat to the genetic makeup of the species. Zantu's child is unique among the Lo'ona Aeo for having only two parents, her father being Sergey Valdez, whose Psychic Powers unintentionally triggered the process. The child is still a full Lo'ona Aeo, but he has inherited some of Sergey's adventurous traits.
  • In Mars Evacuees by Sophia McDougall, the alien Morror have five sexes: Suth-laaa, Quth-laaa,note  Ruul, Thuul and Ma-lashnath. It's rare to actually have five parents, which improves the fitness of offspring, but none have less than three. Only snippets of detail are given about the mechanics of procreation and childbirth, but suffice to say they reproduce in idiosyncratic fashion.
  • In the short story Hop-Friend by Terry Carr, Martians (or "Marshies") are mentioned to have three sexes.

    Live-Action TV 
  • Star Trek:
    • In one of the Star Trek: Enterprise episodes, the Vissians have male, female and an intermediate "Cogenitor" sex, which contributes no genetic material to the child but provides an enzyme which is required for conception. Trip develops a friendship with the third person in a trio of aliens and had a difficult time when he finds out that the cogenitor sex is treated as an inferior.
    • In Star Trek: Voyager the hostile "Species 8472" is reported to have as many as has five distinct sexes, at least according to Voyager's medical hologram but he admits they don't know anything else about their reproduction.
  • The Newcomers in Alien Nation. Tenctonese have three sexes—male, female, and "binnaum"—all three of which are necessary to have a child. Because binnaums are relatively rare, they traditionally live monastic lives, only having sex when they are asked to help fertilize an egg for a male/female couple. Once mating has happened, the egg spends sometime in the mother's egg pouch and sometimes in the father's egg pouch.
    • One episode dealt with changing social roles as the Newcomers adapted to life on Earth. A binnaum has married a female and seeks the help of "his" male friend in reproducing (IIRC the binnaum was the one to help the male and his wife produce their own children years ago). The male is at first uncomfortable with this non-traditional situation (the male being an absent parent while the binnaum will raise the child), but eventually agrees.
  • The Goa'uld in Stargate SG-1 are a two-sex race that doesn't match up with Earth norms. The majority of Goa'uld appear to be biologically male but tend take the gender identity of their host, with a very small minority being biologically female "queens" that produce larvae. While queens can reproduce asexually, fertilization by a male passes his genetic memory to the offspring; for this reason, what few queens exist are kept as trophy wives by powerful system lords.


    Tabletop Games 
  • The Droyne in Traveller have three sexes: Male, female, and enabler, the enablers being required to give off scent during a mating session. Droyne also are casted in the manner of social insects and each caste has only one sex. Droyne language focuses more on caste then on sex as that is more important in their psychological framework.
  • In Star Fleet Battles, the methane-breathing Hydrans (an Expy of the Masters from John Christopher's The Tripods trilogy) have three arms, three legs, and three sexes: male, female, and "enabler." Males take command and technical positions while females take worker, pilot and soldier professions, though rarely females will take command positions. Enablers are barely sentient and exist only for breeding and caring for young, though some sterilized enablers are used as servants on their starships. It requires all three sexesto produce more Hydrans: the male and female deposit their genetic contribution into a special pouch on the enabler, which also has a genetic contribution of its own. After a few months' gestation, it always gives birth to triplets... one male, one female, and one enabler, of course.
  • In Myriad Song Elvers have four sexes, male, female, midwife and neuter. Elvers are all born neuter and change to one of the breeding sexes at twenty based on the gender composition of the surrounding community, individuals isolated from others of their species may be neuter for life. Midwife carries fertilized eggs in a pouch and provides hormones.

    Video Games 
  • The Real-Time Strategy Achron has the Grekim, a race of Time Travelling alien cyborg squid with three sexes (octo, pharo, and sepi) and three "classes" (basic, pod, and ligo). Any two members of different sexes may "progenerate" a member of the third sex of the same class or the next one up (e.g. a pharo and a sepi can produce an octo or an octopod, or an octopod and a pharopod can produce a sepipod or a sepiligo). This is the species' primary method of producing units; although the exact details are unclear, a certain amount of proximity is needed but it does not require physical contact. Ligo cannot "progenerate", but can "split down" into two basic units of the remaining genders (e.g. an octoligo can split down into a pharo and a sepi).
  • Cthulhu Saves the World has party member Paws, a cat-like alien, explain that his species technically has every member as a unique gender. However, for sake of convenience, he allows the party to refer to him as "he".
  • Done with two different species in the X-Universe.
    • The Boron have three sexes: male, female, and Lar. The presence of a Lar during reproduction is highly valued, though not strictly necessary.
    • The Paranids have eleven genders, and while not all of them are required for any individual act of reproduction, the combination of parents will affect the development of the young.
  • In Star Trek: Starfleet Command, the Hydrans are featured again after their original appearance in Star Fleet Battles (see Tabletop Games above). For some reason, the enabler is referred to as the "matriarchal."

    Web Comics 

    Web Original 
  • One clade in Orion's Arm has four genders, three passing on a different type of tissue (plant/animal/technological), and one acting as a womb. The rest of civilized space recognizes six genders, approximately defined as male, female, hermaphrodite, female pseudohermaphrodite, male pseudohermaphrodite, and genderless.
  • The speculative alien species Triaformica has three sexes, due to being descended from fungal ancestors. Likewise, only two sexes are needed to reproduce at any one time.

    Real Life 
  • The nematode Caenorhabditis elegans consists of males and hermaphrodites instead of males and females. In the event that a hermaphrodite cannot find a male to mate with, it can self-fertilize.
  • The Iberian minnow, Squalius alburnoides, consists of two distinct but linked lineages, one consisting only of diploid males and the other consisting of triploid males and females. The diploid males mate with triploid females to produce only diploid male offspring.
  • Fungi have over 36,000 sexes, but only two are needed at any one time to reproduce.
  • The white-throated sparrow is moving towards four genders. Males and females are either white-striped or tan-striped. White-striped males are big philanderers that don't care for their young, butt into others' territory and have high testosterone. White-striped females are aggressive nymphomaniacs who palm off the child-rearing responsibility onto their mates. They're monogamous, though. They always mate with tan-striped birds and the tan-striped birds are more devoted parents, less aggressive and not as horny. And it looks like the chromosome responsible for these differences is turning into a sex chromosome.
  • The Cape honeybee reproduces by parasitically cuckolding the better known "killer bee." The Cape honeybees have a unique caste known as a pseudoqueen, which don't work like workers but don't reproduce as often as dedicated queens, which use mind control pheromones to trick the killer bees into killing their own queen and caring for the Cape honeybees. When the host colony eventually dies, the pseudoqueens fly off to find new host colonies and repeat the process.

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alternative title(s): More Than Two Sexes
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