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Among aquarium enthusiasts who keep bettas, it is usually the male fish that are known as the "colorful ones." Oftentimes the males are favored over the females not only for their color, but also ...

The rose-veiled fairy wrasse is the first Maldivian fish to be described by a local scientist. Pictured: a male rose-veiled fairy wrasse Yi-Kai Tea/Californa Academy of Sciences Deep in the waters off ...

A lingcod, location unknown; blue lingcod fillets. From red to white to orange to blue, fish flesh can land almost anywhere on the color spectrum. What's behind this huge variation? A lot of things — ...

You can see right through this little aquarium fish from Thailand: Its skin is almost completely transparent. But when the light hits it just right, its body flickers with shimmering rainbow colors.