Hi Dave,
The very same thing happened to me mid september, I went up the Don for a week, caught my first salmon and chapped it cos it was very fresh, and it was my first. I actually thought it was a cock fish because it had a wee hook in the bottom jaw, which I didn't think hens developed. Wrong. I discovered they obviously can do, but much smaller than that of a cock fish.
My first Salmon, fresh hen, definately the good looking member of the photo.....
I too felt guilty when I found it was a hen with eggs inside, but when I told another angler about it the next day he said, "Never feel guilty about killing them!" (Salmon in general) He made the interesting point that when we hook, play, land the fish, and then release them, they are using up vital energy reserves which they need for swimming up river and for the process of spawning.
I think his general point was that you should never feel guilty about taking the odd fresh fish for a nutritious meal, considering that whether we kill them or not we are still fishing for them, and if we catch them, we are seriously "screwing up their day" either way. So after all that I ended up feeling a wee bit guilty about fishing for them at all!
I was lucky enough to go on and catch and release a further 4 fish over the next couple of days and found it became more obvious which sex was which when you see them close up in the flesh, but here's some more pictures for you to compare anyway! (Sorry to anyone whos against spinning, I tried hard with the fly everyday but river conditions weren't right for it.)
Fresh cock fish
Small cock fish starting to colour up (not a great pic)
Coloured hen fish
Hen fish starting to colour up
(Also sorry to anyone whos seen these photos already in the don reports pages, I just thought it'd be clearer to stick these here....)
The only takeable one of those four is the 1st one, which would have been the one I should have taken in hindsight cos it's definately a cock fish, but thats the beauty of hindsight. Plus when I got my first ever the day before I didn't expect to be catching anymore!
Anyway, basically I don't think either of us should feel guilty for killing our first salmon, and if we manage to keep catching them we should release pretty much all of them and certainly try not to kill any hen fish in future!
cheers
Adam