Does Size Matter?

[Yanks15]

My guppy dropped her fry a month ago. Of the remaining fry (born in community tank) about half are twice the size of the rest. My question is.....as far as sexing, are the females bigger, males bigger, or just different sizes because they are differant sizes? I've try to visually sex them and they all look like females but I'm no pro. This is my first batch and at this age they are too difficult for me to tell. The larger ones are almost an inch long(head to end of fins) the smaller are half the size.

Thanks.

 

[OldMan47]

At a month old they do all look like females. At 2 months some will be showing that they are not females but newborn guppies all look female for much of their growing time. Once the growth slows down, the secondary sex characteristics and the colors seem to start to come out.

 

[Haych]

it sounds like you have two batches there

 

[Yanks15]

I'm pretty sure it's only one batch because there was only one female. It was the first time she birthed (in a breeding trap) and unfortunately she died after birth. They are showing color already and look exactly like the mother- blueish leopard on tail fin. The interesting thing is that some of the larger ones appear to have a gravid spot, or at least something similar around their anal fin. Would that prove that they are females?

Thanks

 

[Haych]

that always confused me, how they look like theyre born pregnant.

couldnt help you on if that can help sex them though.

maybe some are larger as theyre stronger, smaller ones less developed etc like twins/triplets in humans

 

[Yanks15]

I kind of chaulked it up to genetics. Maybe the father was really big and some take after him and the rest take after mom. I honestly don't know if it works the same for fish as it does for people but it sounds good.lol I can't be certain what dad looked like because she was probably pregnant when I got her. I know what the males looked like that I had so maybe as they get older I can tell if one of mine is dad.

 

[Haych]

exactly

 

[OldMan47]

Genes are genes whether it is fish or people. The things controlled by genes varies with the species as does the things controlled more by environment. Size seems to be genetic in most fish but fish never seem to truly stop growing. The growth just slows a lot as they get older.

 

[WhatTheJack]

When that little, I think you should see a black dot on the females already.

My female guppies like have a black dot from very early on and they're like there permanently!

 

[Yanks15]

I do have a few that appear to have a gravid spot already but I guess I'll wait to ID them when they get a little older and I can really see the anal fins developed.