I have been to the Santa Monica Pier Aquarium once and I think, for what it's worth, once was enough. It is a very, very small aquarium in comparison to the Aquarium of the Pacific in Long Beach. They do have a small touch pool though where they have a few sea urchins, star fishes, crabs and snails. Admission is inexpensive, $1 for 12 years and over, so you pretty much get what you pay for.
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