What is the name of part of the Atlantic Ocean that is south of Texas, Louisiana, Mississippi, Alabama and west of Florida?

Gulf of Mexico

Explanation:

The Gulf Coast of the United States is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Texas, Louisiana, Mississippi, Alabama, and Florida, and these are known as the Gulf States.

not completely sure but i think it’s many moons, smaller in size and a ring system.

answer at the divergent plate boundary in the middle of the ocean;