Male or Female Peacock Gudgeons

[Biglog]

I have three peacock gudgeons, 2 I am pretty sure are female but the third I'm not sure. The black stripe tells me female but the head tells me male. Its the first one in the pictures.

 

[Colin_T]

fish in left picture is male
fish in middle picture is a deformed female (has a bent back)
fish in right picture could be a young male

males get a rounded forehead when they mature and are well fed.

 

[Biglog]

They are all the same age so that's why I was also thinking male. However, everything I read said that only females have the black stripe so I was confused.