How Can I Sex My Columbian Tetra?

[mbsqw1d]

Was hoping someone could help with some tips on how to sex this fish. . I have five that are maturing and starting to chase each other a bit, (although my Dwarf Gourami keeps them in check ) and thought it could be a sign that there's a female present..?

thanks

 

[The-Wolf]

There is no physical difference between m/f,
when the female is egg laden she will appear plumper.