This Fish’s Eyes Turn Black When It Gets Mad Guppies have silver eyes, but when they’re ready for a fight, their irises go dark. An experiment with robots shows why.

Just using your other, hard-earned fish. It’s a nice feature that will save you some dough. For 10 Gold Fish, you can get 250 Silver Fish, and for 500 Silver Fish, you can get 10 Gold Fish.

Meet Methuselah: The world's oldest known aquarium fish is at least 92, DNA shows The 4-foot long, 40-pound fish first arrived at San Francisco's Steinhart Aquarium in 1938 and was thought to be ...

One of the tasks with an aquarium business is managing the breeding, since far more of the eggs and new fish will survive in tanks than in the wild. He highlighted a pair of Midas fish that he ...

The fish can live up to 40 years, but the longest Kraul said he has been able to keep one alive is 42 days — a whole month and a half before they even develop their distinctive yellow color.