Grayling are not native to Scotland having been introduced from England into river the Clyde in the mid 19th Century. You can see why the grayling was brought here, its such a beautiful fish providing sport through the winter when the trout fishing season is closed. A sport for hardy fly fisherman.
Grayling are salmonids, related to trout and salmon by the possession of an adipose fin however they are classed as coarse fish because they spawn in the the early summer. Over the years they have been persecuted because they are considered unacceptable competition for trout and salmon, vermin, a foolishness that has in the past resulted in them being killed out of hand.
Grayling are a great sport fish and for those who enjoy eating fish I suggest you take an occasional one for the pot, they are great eating with a smell like fresh thyme, hence the name Thymallus.
Success with grayling is not just to do with reading the water as you would do with trout. Grayling are a shoal fish and knowing where the best shoals are located is a real bonus to the grayling angler especially on the large rivers like the Tay and Tweed. Float fishing, trotting worms or sweet corn is very popular as is fly fishing and be ready for a fight, the large dorsal fin on a grayling adds to their fighting qualities allowing them to 'dig in' and fight above their weight.
When fishing in the winter for grayling you should take great care where you wade, chances are that you will be among spawning salmon at some point on most of the rivers holding grayling and it is important not to disturb spawning fish or trudge though redds with eggs.
Give grayling a go, and if you do want to take a fish for the pot but be sparing for they are a precious resource.