Post pictures of the YP you catch please! or of the perch you caught int he past? You catch them in Georgia near you this time of year? How do you catch them? Is there any skin of ice on the pond/lakes where you go? Do they look much like the northern strains of YP?
I know when our YP are kept in a fish tank they really don't like light and will hide in any dark corner, under or behind plants or any structure in the tank and try never to be seen. If you have a big pool that is well lit you may want to include some 'cover' or maybe some some plastic containers that they can swim into where it is dark and feels 'safe'. They probably don't like constant daylight or artificial light either.
