Northern Mountain Swordtails

[jonnyf84]

Hi all, i should of really posted this in the rare section but its not the most active forum. Well after months of searching i finally got my NMS', 2 males and 3 females. They are very shy but last night i got a good look at one of them, it has a 'sword' but it doesn't the vertical stripes as all male NMS' have, it was basically a female with a 'sword'. My question is will this new male develope the vertical stripes and will he become fertile and able to inpregnate the females?

Now my platies have done this on numerous occasions but to be honest i'm not bothered if they are able to inpregnate as they breed like nothing else, also there is no colour/marking variation between the males and females and therefore i have never taken much notice.

Any opinions will be much appreciated.

Jonny.

 

[dunchp]

Many Xiphophorus have two morphs of males, one which is often far larger than the other and one which is often far more colourful. Xiphophorus nigrensis and Xiphophorus milleri do this. Almost all Xiphophorus also have early and late developing males, the late developing males look like females but are actually males, sometime the sexing out is linked to an event like the death of another male. It is possible that this is a mechanism to avoid being bullied by a more dominant male. In Xiphophorus, there is also the issue of an Alpha Male which will be brightly coloured, there will also be Subordinate Males which will either not sex out (as above) or will stay less brightly coloured (again probably a mechanism to avoid being bullied).

Whenever I get hold of new Xiphophorus species, I always try and get hold of six or more (like you have done) for this reason as occasionally, if you get an apparent pair, the female will be a latent male.

So, the short answer to your question is that the dull male could either be: -

1./ A late developing male which will develop colouration in due course.
2./ A subordinate male which will possibly not develop much more until the alpha male is removed.
3./ A lesser coloured morph which will not develop more colouration whatever you do (I have not heard of Xiphophorus nezahualcoyotl doing this, but I don't have much first hand experience of them).

If you are worried then you could split the dull male from the other males for a while and see what happens.

 

[jonnyf84]

That was just the kind of reply i was looking for, thankyou. They are still only about 4cm long so i'm guessing they are 6-7 months old in which case i will hope that it is a very late developing male, i'm not going to seperate as they just arrived 3 days ago and as you probably know they are quiet, shy fish so they will need a few weeks at least to settle. Thanks again.

Jonny

 

[dunchp]

That was just the kind of reply i was looking for, thankyou. They are still only about 4cm long so i'm guessing they are 6-7 months old in which case i will hope that it is a very late developing male, i'm not going to seperate as they just arrived 3 days ago and as you probably know they are quiet, shy fish so they will need a few weeks at least to settle. Thanks again.

Jonny

No problem, as long as it doesn't look scrawny, you will be fine.

 

[kribensis12]

Pics?

 

[jonnyf84]

Not a chance just yet i'm afraid - i do wish though . These guys are seriouslly shy, i only see them twice a day when i feed, they come to a small plant opening in the back corner of the tank and wait for any food that drops there way, all other food gets left which is very frustrating . For them to come out of the plants I have to sit about 5 feet back from the tank with no room lights on so they dont't see me . One did actually come into the opening at the front last night which is a great sign, they have only been in there since Sunday though so i expect they will get more confident.

He's not scrawny i dont think, slightly bigger than the natural male but very healthy looking, i thought i noticed some vertical stripes developing on him last night - that could just be my wishful imagination though!!!

They are such beautiful little fish. I will post pics as soon as i can.