former large, commercially operated oceanarium at Rancho Palos Verdes near Los Angeles. It was opened in 1954 following the overwhelming success of Marineland in Florida. The aquarium had the world's largest holding tank, with a circumference of 76 metres (250 feet) and a capacity of close to 3,800,000 litres (1,000,000 gallons). This and other tanks housed an impressive array of fishes (4,000 specimens of 250 species) and marine mammals (more than 110 specimens of 11 species). These marine mammals, which included Pacific pilot whales, were featured in numerous acrobatic shows and were also used in behavioral research on the learning capabilities of such animals. Marineland of the Pacific closed in 1987.