|Re: what sex is my swordtail and are they pregnant|
Subject: Re: what sex is my swordtail and are they pregnant
by finnipper on 7/10/2013 1:56:35
There is a lot of rubbish going around when it comes to sexing swordtails because they are unique when it comes to gender.
Late developing fish which appear to be female but which can turn out to be male, old females which develop a sword and what appears to be a gonopodium and so appear to be male along with a females ability to store sperm and give birth to several broods from a single mating lead people to believe that the fish is capable of changing sex. This is not the case, a functioning female (one which has given birth)cannot change in to a functioning male and a functioning male i.e one which has fathered offspring cannot become a functioning female. Sexing these fish is therefore a little hit and miss to be honest.
Gravid spots aren't always very obvious either, in some fish they are very dark and in others almost invisible. If the fish is very fat there is a reasonable chance that it is pregnant especially if it is in a mixed sex tank.