St. Louis Aquarium, to be open year round, will have fish tanks containing a combined 1 million gallons of water and display thousands of aquatic species, LHM officials said.

An exhibit with one of the largest shark collections in the Midwest will have what officials call the Shark Bridge, a rope-and-steel contraption that will suspend visitors inches above the water.

An LHM representative said that depending on final design, the shark tank will hold from 350,000 to 550,000 gallons of saltwater. The bridge over the tank will be 75 to 85 feet long. Its V shape made of steel will have rope suspension support. Rope mesh sides will allow the single-file walkers to see into the tank but will stop anyone from falling or jumping into the water, the representative said.

St. Louis Aquarium will be a member of the Association of Zoos and Aquariums, LHM said. The facility will employ marine biologists and aquarists to care for the creatures displayed and oversee water chemistry, animal nutrition, veterinary duties, education, staffing and safety.

The association, based in Silver Spring, Md., has more than 230 members. Among them is the Butterfly House, which opened in 1998 in Chesterfield and, since 2001, has been a division of the Missouri Botanical Garden.