Pond Boss Forums STOCKING A NEW POND Raising Forage and Bait Bullfrog/Leopard Frog Tadpoles Defenseless?

My ponds have an abundance of BF and LF tadpoles - and by abudance I mean literally thousands - and despite my predator heavy fishery I see no impacts on their populations nor have I ever witnessed a tadpole being hammered. My theory is that these tadpoles must possess some kind of taste that fish find disagreeable otherwise how could they swim so slowly and in wide open water with such impunity?

Bear in mind my fisheries lack LMB as species, but for HSB, YP, BG, RES, and SMB I have found that tadpoles are not preferred forage, if they are targeted at all.

I have tried to test this theory by tossing LF tadpoles into a pellet feeding frenzy and while they were initially swallowed by SMB and HSB they were soon regurgitated.

I have also seen tanks of BG and SMB overwintered back at Condello's place with LF and BF tadpoles, PK Shrimp and FHM. After a month all the FHM, shrimp and all but the biggest BG were gone. The tadpoles seemed untouched.

It stands to reason an otherwise apparently defenseless, slow swimming organism like a tadpole must have some kind of unseen deterrent enabling it to escape predation or they would have become extinct long ago.

Anyone else witnessed this reluctance to prey on tadpoles? Can someone enlighten us on whether tadpoles possess some kind of enzyme that makes them distasteful? I do surmise once tadpoles become toads or frogs they must lose this defense mechanism as frogs are definitely a preferred forage item for SMB and LMB.