The bag and length limits for catfish in the Trinity River depend on the specific species you are targeting, as regulated by the Texas Parks and Wildlife Department (TPWD). For Channel and Blue Catfish, there is a combined daily bag limit of 25 fish, with a minimum length requirement of 12 inches. However, within that 25-fish limit, typically only a certain number of fish over a specific length (such as 30 or 45 inches) may be kept to protect the trophy "monster" cats the Trinity is famous for. For Flathead Catfish, the daily bag limit is generally 5 fish with a minimum length of 18 inches. It is important to note that specific sections of the river, especially those near spillways or within certain counties, might have "Special Regulations" or consumption advisories due to environmental factors. Always check the most current TPWD Outdoor Annual or the official website before heading out, as regulations can change annually to ensure sustainable populations in this high-traffic freshwater fishery.