Crayfish Claw

Rather a surprise to find this on the towpath of a local canal, as I was walking past. To give some perspective it is probably 3-4 inches long. I was wondering whether it was fro the American Signal Crayfish, an invasive species that is adversely affecting our only native species, the white clawed crayfish.

I decided to test my achilles, walking out from home with no set route. In the end I walked about 10 miles and although it did ache as the walk progressed, it didn't hurt as much as in recent times. I'm exercising regularly, mainly loading the leg to improve the strength of the muscles, tendon and ligaments around the joint. Recovery was also quicker than in recent times.