This species cant be differentiated by "hair" - odontodes, head shape is a dead give away come maturity page 15 Back to Nature Guide to L-Catfishes Ingo Seidel, Very good reference to sexing.but the probable female is a bit hairy down the body so a side-on could shed some more light...
I agreeToo young to say, the head shape is far to similar to differentiate the two