WAIKIKI, Oahu, Hawaii -- The Waikiki Aquarium is asking for help finding seven colorful clams that were stolen over the weekend. Officials suspect the clams are now in someone's private fish tank.

The seven stolen clams are about an inch to four inches wide and very colorful.

"These clams were truly spectacular the colors on them. They were so iridescent, turquoise blue," Waikiki Aquarium Director Andrew Rossiter said.

The stolen clams were the prettiest of those on display. The aquarium director suspects the clams were stolen by a collector or someone hoping to sell to collectors for personal aquariums. There is hope the clams are still alive and the thief willing to avoid prosecution by bringing them back.

Officials asked for the thieves to have a change of heart.

"That they please return them no questions asked, a complete amnesty," Rossiter said.

Some of the clams have the capability to grow to giant size. The aquarium planned to breed them, but the stolen ones were years from breeding age.

After the theft, the aquarium put the other 37 clams into hiding. They won't be put out again until the display can be rebuilt so it is more secure. Unfortunately it will be less accessible to children whom the display was built to serve.

"The exhibit which is the only one of its kind in the whole of America was built at a low level, especially so children could have access to it," Rossiter said.

"They should be returned here. They're looked after and children can see them. Adults can see them. We can all learn from them," aquarium visitor Leanne Mercado said.

The stolen clams are a threatened species. You need a license to own them.