The TRUTH about Swordtails

[Mickael]

Ok. I have to start with asking the questions.

1.) How exactly can you tell the difference between a male and a female? I have had 2 different pet stores sell me 2 female swordtails that wound up sprouting the mail tail. Does someone have a large picture of a young male and young female? Maybe I can print it out and show these professional clowns.

2.) Is it true or just an old wives tale that females and/or males can change sex? Cause even if it was true. Why would a female change into a male if there is already a male flirting with it? I was convinced that it was a female since the male was trying to do its business to it. Then a week later she becomes an obvious he.

3.) Can a swordtail mate with a platty? Is this too uncommon to hope for? Ugh, and for that matter, how would one tell the difference between a male and female platty? ...again, if anyone has decent pictures, that'd be awesome.

I really like swordtails. They are very active and healthy in water with a high Ph...which comes out directly of my tap. And I love the fact that I have a healthy red male that I helped breed and I'd love a few second generation babies if all my females didn't turn out to be males.

 

[pbecot01]

had the same thing happen to me... bought 2 female mollies to go with my male, and he chased both of them for a while... then one female got sick and died

a couple weeks later i bought one more female to even things out... but the "female" in my tank had changed into a male and they both harried her to death. The two males have been constantly chasing each other ever since... I think I have 2 *** fish. But he definantly looked female when I got him.

 

[Blinky]

Sexing livebearers isn't hard, if you know where to look
Males have a modified anal fin, called a gonopodium, used for injecting sperm. Females have a rounded, triangular anal fin.
Sometimes it's difficult to sex very young fish - they all start out looking the same, then the males' gonopodiums develop and what looked like a group of all girls turns out mixed. Some females grow tail extensions - use the anal fin to sex the fish and you'll never go wrong.
To keep harassment to a minimum, it's a good idea to keep livebearers in a 2:1 or 3:1 female to male ratio.
AFAIK, swords and platys can cross, but it's important to know you may have trouble finding homes for fry - crosses aren't always wanted.

 

[chinnp]

I've heard of swordtails changing sex, but don't know if there's much to it. Also, swordtails will mate with platies. Very common occurence.

 

[johnnyxxl]

many species of animal can and have changed sex they are normally short lifespan lower species ie fish, amphibs and the sort. the live bearing fish all can I believe to some degree other than guppies

 

[twdockery3]

swordtails in my experience do not change sex. some are just late bloomers. also with swordtails the early showing males are much smaller, like less than an inch in body size while some of the larger 4+ inch males do not grow their swords out until a year or more. i believe that swords do know who is an immature male and who is a female, but their "fussing" with other males and mating "dance" is quite similar. The only way to get a for sure female from the LFS is to get one with a gravid spot. Also as an aside, the first batch of fry i ever got; 30 fry, 30 males.

 

[Kissofthegorami]

Sexing livebearers isn't hard, if you know where to look
Males have a modified anal fin, called a gonopodium, used for injecting sperm. Females have a rounded, triangular anal fin.
Sometimes it's difficult to sex very young fish - they all start out looking the same, then the males' gonopodiums develop and what looked like a group of all girls turns out mixed. Some females grow tail extensions - use the anal fin to sex the fish and you'll never go wrong.

I have had swords grow to almost adult hood, over 2" with a completely triangular, female anal fin, then begin to develope into a male. Its actually not always easy with swords.