In Texas, you will need a fishing license with a saltwater or freshwater endorsement in order to take fish, clams, crayfish, mussels, or other aquatic wildlife from public waters and federal waters. Texas offers several licensing packages as well as a few exclusions. For example, residents under 17 and residents born before September 1, 1930 do not need fishing licenses to fish in public waters. One day licenses as well as yearly licenses are available.
Learn more about Texas Fishing Licenses and packages by visiting: http://www.tpwd.state.tx.us/publications/annual/general/fish_licenses/