So I assume you are fishing for a species that actually has a "legal limit" in the body of water you would be fishing. If the regulation hasn't changed and I remember correctly it doesn't matter if you fish for one night or a week straight. If the "possession" limit is 6 per licensed angler then you better not have more than 6 in your sole possession. Fillets in the cooler at the lake need to have a piece of skin attached in order to identify species and those count towards your possession. I am sure someone else will chime in and tell you if I am wrong as well as post the actual regs off the G&F site. Don't quote me.