The Tampa Aquarium opened in 1995 is located in downtown Tampa. They have a great assortment of exhibits including a wetland habitat with native fish and birds also aquariums sized large and small with thousands of animals. I personally loved the sting ray zone where you were able to touch them!Admission is about $30. I think this is very much worth the price if you visit annually. This cost is also on par with other aquariums I've been to. My biggest tip on the tickets is to buy them ahead! There is an alternate line for pre-purchased tickets. Also check the site for sales and specials, they have them often.
Plan to get there early. The parking lot filled up very quickly when we went and shortly after us they were turning people away from the lot. My mother and I took our time through and we spend about 3 hours there total. We were so happy we went when that opened because we had the whole rest of the day left and missed the rush!
Links on Aquarium Information:
https://en.wikipedia.org/wiki/Florida_Aquarium
http://www.flaquarium.org/