Why do modern public aquariums use tanks with different shapes and sizes?

Modern public aquariums utilize a variety of tank shapes and sizes primarily to move away from the "boxes of fish" aesthetic found in older, formal institutions. By grouping tanks of different dimensions together, designers can better illustrate the natural environments of the specimens on display.1

These design choices serve several functional and aesthetic purposes:

• Habitat Recreation: Modern exhibits aim to replicate natural settings, such as coral reefs or rainforests, which requires custom-built enclosures that accommodate the specific biological and spatial needs of the animals.12
• Visual Illusion: Architects often incorporate dry dioramas at the rear of tanks to create an illusion of distance, helping spectators feel as though they are entering an underwater world.1
• Specimen Requirements: The size and shape of a tank are dictated by the needs of the organisms housed within, including mammals, birds, reptiles, and various aquatic species, while also accounting for visitor traffic flow and acoustics.3

By varying these structures, aquariums can create a more immersive experience that emphasizes the natural beauty of the specimens while maintaining a clear distinction between the water and the viewing space.1