The advice above is best - find out before you go. But If you are not sure of the fish you have caught, try my method (I'm sure i'm not alone)...
This can work with plenty of fish - inc Huss/doggies, which can cause small cuts on your hand/arm as they writhe about, Bass with seemingly spines all over, even Ray etc, not to mention our weaver fiend... Try lowering your catch onto an old damp hand towel, it is easy to wrap it up and you just hold the spare (quite tightly) with a slight pressure on the ground, I have found that you dont lose grip of the fish (and drop it! - which cant be good), you maintain much more control, with a little practice its easy - mine seem to go back OK, that dont end up on the plate anyway

I cant see how the spines of anything can touch you.
Not rocket science but it works until you know more about your quarry, and that towel will come in handy all night Stinks the day after though so stick it with your rods under the hose after fishing trip. (And dont let the missus find it as it _will_ go missing! lost a few like that)