Silver, Gold and Platinum are each one fare per person from age 2; children under 2 enter free, and none of the three has a separate child price.
Each quantity step on the aquarium's site prints "Excludes charges and fees" under its fares, so every venue fare quoted here is before whatever charges and fees apply. The site does not say what they come to, and we have not found a page that does.
Silver, AED 199, covers the Aquarium Tunnel, the Underwater Zoo and Penguin Cove, plus an AED 20 voucher for the shop. UAE residents are offered 15% off Silver, shown at AED 169. That is an offer on the aquarium's own site, not a standing fare, and we do not sell it.