Množina: aquaria

ETYM Latin See Aquarius, Ewer.
Tank filled with water for keeping fish and underwater animals; SYN. fish tank, marine museum, vivarium.
Tank or similar container used for the study and display of living aquatic plants and animals. The same name is used for institutions that exhibit aquatic life. These have been common since Roman times, but the first modern public aquarium was opened in Regent's Park, London, in 1853. A recent development is the oceanarium or seaquarium, a large display of marine life forms.

Množina: aquarium fish