A surprise jolly guest dressed in red and white can be found swimming within the 120,000-gallon Window on Washington Waters habitat at the Seattle Aquarium throughout the month of December.

The freshwater exhibit includes more than 5,000 fish and 50 plant species, including some that stretch over 7 feet tall. More than 1,500 reef fishes are being displayed on the saltwater side.

That’s the saltwater side of the Shedd Aquarium’s new “Wonder of Water” centerpiece beneath its rotunda — part of $250 ...

Climate change warms waters near the poles, enabling larger migratory fish like salmon to flourish. Equatorial populations ...