Just a couple of comments-
Using an old photo is fine provided it's in context with the text i.e. used to demonstrate some particular circumstance ("see how this fish took the lure"), about a particular point in time or to demonstrate some other aspect that of fishing not related to a particular trip or time frame.
Photographing a fish more than once in a number of poses and is a good habit to get into, better to put one fish through the extra stress rather than all the fish you catch. Sometimes the extra shock of pulling a fish aboard for the photo can make a difference to its survival, reduce that risk.
As the photographer I'll often hand a fish of mine to someone else for me to photo if I'm after something particular in that shot, head shot, lure positioning etc. The quicker the shot is got the better.
Have one from memory of my shots altered to remove a bit of blood, magazine policy.
My point is that pictures can be used a number of ways to enhance a story or tell one of their own and with live fish as the resource limiting a picture or fish to only one story bounded by a particular time frame can is a bit wasteful, at least as I see it. Just never allow a picture to lie because it's your reputation on the line.
Similar shots, photographer's biggest bane, the shot has to be quick, there's only so many ways you can hold a fish that's acceptable to put into print weather/light is often an issue. The good ones keep trying.
As for the text, its up the the editor to draw the line on that one, if they accept sh1t, sh1t will be submitted
PS Don't see it often see it love love when you see a few shots supposedly of a one day and someones clothes change, or their hair gets longer or shorter
PPS How you caption your photo is the critical part.