By Water Volume:
* Chimelong Ocean Kingdom in Zhuhai, China, holds the title of largest aquarium by water volume, boasting over 48 million gallons.
By Number of Species:
* Georgia Aquarium in Atlanta, USA, holds the title of largest aquarium by number of species, housing over 500 different species of aquatic life.
By Size of Exhibit:
* Dubai Aquarium and Underwater Zoo in Dubai, UAE, holds the title of largest aquarium tank, with a 10 million gallon tank housing a variety of sharks, rays, and other marine life.
By Total Area:
* Oceanário de Lisboa in Lisbon, Portugal, holds the title of largest aquarium by total area, covering over 10,000 square meters.
So, depending on what you consider "biggest", there are different contenders for the top spot.