thank you all for the replies .
one water body is really shallow and turbid
the other is really stained and has dark water
I think it may be something like mentioned before and the fish have evolved and or adapted to be better equipped to forage
interestingly enough years ago the first time I hit one of them I was trying to ketch catfish. I landed several and one in particular had a bold lateral line .
and get this .....it was hard fight and water was super warm . when I landed it its lateral line had droplets of blood coming out up and down the fish ?
Never seen that before or since on any fish .....