I have a few in an aquarium now, if they live long enough maybe they will grow and will become more obvious. When they get 3-4" long they will develop a dark tail. Last year caught a bunch of small ones on tiny 1/64 oz jigs. I could see them swimming near the bank and target them with the jig. They would attack it. They were easy to identify by the dark tail.
That would make sense that the SMB already got a spawn off. I think it is still too early for the RES.
My SMB have had good spawns. Have caught lots and transferred to other ponds.
