TF are delicate little things. But yes, you can catch them and transport them in your round tank.
I have been doing it for years. Here is what I have learned.
Use a longggg seine are they will swim around the ends.
Don't lift the seine out of the water, use a small mesh net to take them out.
If you can't go immediately in to your tank then a 5gal bucket half full of lake water can be used.
A tranquilizer solution can be used for long hauls to help with survival.
It takes me about 20 minutes to get them to my pond and I get 95% survival w/o tranquilizer.
If you have any further questions. I will be glad to try and help you. I live in Central Texas and so far, my TF have survived. Sooner or later we will have a hard winter and I will loose them but the last 5 years have been ok. They are cool to have in a pond. I love it when they start running the banks in April. The bass will tear a white buzz bait up.
