Robert l davis

I believe it is smell. 60yrs ago i use ro use softshell crawfish for trout all summer when we could find them. One time i was tired and just threw my line out with a softshell on it and let it rest on the bottom at a tailout of a hole. I watched two sea run cutthroat come swimming up river moving in a sigsag pattern and they were searching for my crawfish the closer they got to my bait they started swimming directly to were my bait was laying in water. One of them took my bait and i caught the fish. These two trout came upstream fifty yds or more. Softshell crawfish is so much better than peeled crawfish tail, no comparison, like someone mentioned before about softshell crab working so well for sheephead. It is same for black drum soft shell out perform hardshell 10 to 1. We use to turn rocks over and catch softshell rock crab under the rocks. This was in florida mid 50's