Modelling body details

[TasV]

I've been playing with modelling a trout with the intention of converting it to a mould (injection mould) and using it to cast soft plastic fishing lures. I made different model the other day, printed it, shot some plastic through it and it worked really well so am going to make some more It's going ok (see attached)... but I was wondering how people would go about adding the detail work such as scales and the gill plates (better than I have... first try at this kind of surface detail work). Is there some way to make the textures with relief to 'wrap' around an object?

---