Are my black widows preggers?

Hey,
My black widows are exceptionally active, but I noticed today that three of them have started blowing up like balloons...so was wondering if they are maybe carrying eggs? If someone can tell me if they are carrying eggs or whether something else might be wrong?
Included pics of a normal fish and what the fat ones look like..If they do have eggs- advice on what I must do is needed please

 

They are carring eggs. They easy to breed. Easy way to sex, looking from above. The slim ones are male. They are egg scaters and will eat their eggs. You will need another tank to breed them. Base of tank to be lined with marbels. The eggs will fall in between the marbels and prevent them from being eaten. For best results you should use 1 male and 2 females. Worked for me. They should spawn overnight. Remove parents when you notice the female is slimmer. You might think you unsuccesful but there will be fry very small fry hard to see cos they really tiny. All the luck.

And don't feed the adults when you trying to trigger spawn. Also low water level about 15cm

 

Thanks so much