Went fishing for fry!

[Botanica]

Hello all! The other night we were visiting my brother and sister-in-law and noticed the HUGE amount of breeding that the live bearers have been doing! I just so happened to have a fully cycled 20g sitting on my kitchen counter waiting for fish...so I went fishing! . I have no idea what they all are...who cross bred with who...or even how many total I ended up with! They are all different shapes and sizes and colors and ages. I took a large clump of his massive hornwort that they were hiding in (my brothers tank is a 220g with angels, gouramis, rainbows and rams...not exactly fry friendly) to float in my tank for the tiny ones to feel at home. My tank has black gravel...not great to find the fry in...but there isn't anything trying to eat them so I guess it will be fine.

Here are my questions....first of all...do I need to worry about genetic defects in these fry because of the mass in/cross breeding going on in my brothers tank? His tank has 2 kinds of swordtails, 5 kinds of platies, and 3 female Dalmation mollies that seem to be always pregnant and huge even tho there is no male Molly. Can these guys cross with mollies?

Another question is how big do they have to be to sex them? The ones who seem large enough to tell all look female. Could I have gotten all female?? How early will I be able to tell the swordtails from the platies? And how soon can they breed with each other? I'd like to separate them if I can...

Here are some pics of what I could get...giving you an idea at the diversity of size, color, age etc. Thanks everyone for any advise!

 

[Samzter]

All I know is that the Molly babies are gonna get big. Then for sexing all livebearers fry are born female. Then some turn male.

 

[Botanica]

All I know is that the Molly babies are gonna get big. Then for sexing all livebearers fry are born female. Then some turn male.

Wow...they are all born female? I did not know that...wow. I know these fry will get big and not be able to live in this tank...but I have two more builds in the works and a 135 I could put them in.

 

[eduguy]

Livebearers breed lots. I have only had my platy for 1 week and it already gave birth.

 

[Botanica]

Right...but how old...or I guess I should say how big do they have to be to breed? I'd like to grab out the males but an still getting their tank ready...

 

[Calypso77]

Some say 3 month old is the youngest they will start.

 

[Aron]

I have just had a swordtail develop its sword and male organs and it was about four month old.

And to answer your question about in/cross breeding. In breeding is fine for four or five generations, cross breeding between the swordtails and platys is possible as they are both xiphophorus. A lot of fish you see sold as swordtails may already have been crossed with platys at some point to obtain desirable traits (patterns and colours, etc).

A Molly can only be crossbred with platys and swords under scientific conditions as their reproductive organs just do not work together. The reason for them staying so large is due to the fact they can store sperm for three to four month and thus impregnate themselves several times with no males present.

 

[Botanica]

I have just had a swordtail develop its sword and male organs and it was about four month old.

And to answer your question about in/cross breeding. In breeding is fine for four or five generations, cross breeding between the swordtails and platys is possible as they are both xiphophorus. A lot of fish you see sold as swordtails may already have been crossed with platys at some point to obtain desirable traits (patterns and colours, etc).

A Molly can only be crossbred with platys and swords under scientific conditions as their reproductive organs just do not work together. The reason for them staying so large is due to the fact they can store sperm for three to four month and thus impregnate themselves several times with no males present.

Thanks!! That will help me guess their age if they get swords.... As for my brothers Dalmation mollies...they have been in the tank since March...3 female...and they've looked pregnant since about April. I posted a thread asking when one might deliver back in April or early May...and no molly fry have ever been spotted. I know they could have been eaten...but these mollies are HUGE still. The tank is a jungle because I haven't had the time to go trim it for him....not really my job...so the fry are there in what I think are alarming numbers! The water test I ran showed his levels allograft the...so I guess the plants are doing their job. I just wonder about these mollies...is something wrong with them? I'll try to get my niece or sister in law to send me a recent pic I can post. Sorry...I went a bit off topic...but none of the fry I caught are mollies...that's for sure.