Fish genders?

[Fishlover142]

Hi I'm new here I was wondering on how I could tell the gender of my common gold fish and what size I'll be able to tell gender I currently have four two are about an Inch and a half the other a little under an inch thks in advance.

 

[the loach]

Your goldfish are just babies, still impossible to tell. Once they are over 3 to 4 inches females may get thicker and males may develop little white breeding tubercles on their gills. But still hard to tell, when they are over 10 inches it is easier.