Tropical Fish Forum

Tropical Fish Keeping Help and Advice => General Fishkeeping advice => Topic started by: werp on August 21, 2013, 10:40:01 PM

Title: this is not meant to be a stupid question
Post by: werp on August 21, 2013, 10:40:01 PM

ok, this is not meant to be a stupid question but it probably is.
can sword tails change sex?
i bought 3 large green sword tails 1 obvious male and 2 what looked to be obvious females. i have had them a month. i spend a great deal of time watching my fish and yet yesterday i noticed one of the so called females is growing a sword. any ideas or is it just a late developer?
thanks

Title: Re: this is not meant to be a stupid question
Post by: ColinB on August 22, 2013, 08:37:33 AM

Not a silly question at all as there seems to be some confusion over this with lots of different opinions as there always is on t'interweb. I put 'swordtail sex change' into google and got a zillion different posts, but the main idea seems to be that some males can be late developers so a bigger male doesn't bully them.

Title: Re: this is not meant to be a stupid question
Post by: Sue on August 22, 2013, 08:41:10 AM

You will read that they can, but the truth is that they can't. Male swordtails can take up to a year to show male characteristics. They are one of the slowest livebearers in this respect. It is this slowness that has led to the myth about them changing sex.

I don't know if the same applies to swordtails as other fish. For example, I have cockatoo cichlids (Apistogramma cacatuoides) and juvenile males will take on female appearance to avoid bullying from the dominant male. I saved what I though was a 1 male 2 female trio from a batch of fry. The females both showed the typical bright yellow of a female in breeding condition. They had reached maturity and one female had already spawned with the male several times before the other female suddenly grew his fin extensions and changed colour. This is such a common occurance that in cockatoos it has a name - sleeper males.
I do know that male swordtails can be aggressive towards each other, more so than in other common livebearer species, which is why I flag this up as a possibilty.


Colin beat me to it!

Title: Re: this is not meant to be a stupid question
Post by: ColinB on August 22, 2013, 08:54:04 AM

I've had a lot of coffee - it's the only way to beat Sue to an answer ;D

Title: Re: this is not meant to be a stupid question
Post by: Resa on August 22, 2013, 11:31:41 AM

Morning Werp!

The forum gurus have sorted your question out....I'm just here saying, Welcome to the madhouse ;D