80% of the time yes ,but theres always the ones who fool your experiance by impersonating a different fish .if you hold your rod with a tight line still after you've set the hook and watch your tip you can usually tell not only the species from how the tip behaves ,but get a indication of its size ,again through experiance you learn too interpret these things more accurately .now this is all only really possible if your rod & set up is balanced ( sensative enough ) as you can only read the signs if you can see them .
the easy ones most people can tell are EELS ,perch ,grayling & gudgeon because of the way they react to being caught (they deon't like it ,too the point of being quite annoyed) ,other fish just seem too accept the inevitable sooner or later .
by experiance you do get too learn the charictoristic's of how perticular species tend too fight once caught