Is female the more dominant gender?

Female guppy gender change?

• so, ive done some research on the topic of female guppy sex change. all of the answers contradict eachother. some say no, its not possible. others say it is. but i have proof that it is. i know the difference between male and female(their anal fins) i went to petsmart to get 3 females guppies to go with my other 3 females and betta at home. that was 47 days ago. now, ive noticed that 5 of the 6 females are pregnant, while the 6th isnt, and now magically appears to have the rod-like anal fin, rather than the fan-like one. so i guess my question is this....since my other 5 females are pregnant, will they be able to change their gender, the way the other one did? and also....if a female changed to a male, but then other males tried to mate with it, is it possible that it can change back to a female, and stay female, since it became pregnant?

• Answer:

  The apparently contradictory sites are all correct by their own definition of sex change. Like humans, guppies in early development all appear to be female, but after a couple months the human baby inside the womb will begin to change to male if it has the XY genes. The same time line is true of guppies, except that since they only are pregnant for a month, the apparent sex change happens a month after birth while the human baby has another seven months to go before birth. You can make the same comparison to older humans and guppies. Older females begin to reduce their production of estrogen and so the humans experience menopause while female guppies can experience something similar. Secondary sex characteristics can change so that the female begins to look masculine. So both are right by their own definitions. A genetically male guppy is always a male. A genetically female guppy is always a female. But all guppies are born looking like females and half of them change to male. So by one standard that's a sex change but as far as by actual function and genetics, it is not really a sex change. It was always going to happen. And some fish and some humans develop and mature at their own time, so a late bloomer could become a male later than every one else made their sex orientation obvious. A really old female guppy can develop masculine finnage and color and even a rudimentary gonopodium. But she is still genetically female and can't produce sperm. Because female livebears in the Poecilia kind store viable sperm inside them for six months. people sometimes assume it is this geriatric female who fathered the fry. Your new questions:The female that "became" a male was genetically male all along, just as a human male while still unborn would look female until the Y chromosome started sending some new directions to the construction team. Like I said both sides are right by their own definition of "sex change". But the side that says there is no sex change in guppies has the definition that explains everything while the other explanation is faulty in that the change is only visual. A young male looked female until the right hormones kicked in, as they were sure genetically to do. An old female could start looking male as her female hormone production drops with old age. But they only look like they have changed sex. The DNA does not change. The X chromosome is always an X chromosome and the Y is always a Y. If you started with six unsexed guppies, visually females, but with their XX or XY nature not yet expressed (visible) each would have a 50/50 chance of really being a male. Just as in flipping a coin, having one flip heads does not increase the chances of a tails next time. It stays a 50/50 chance. Female looking guppies that will turn out to be males will not get pregnant. However they can get fat. It can be hard to tell apart.