Fishy Friday: Masters of Camouflage

A large rainbow trout hiding in a weed bed, highlighted with help from a polarizing lens filter.

While trout may seem brightly-colored–or even downright gaudy–when held out of the water, their markings provide excellent camouflage within their natural surroundings. Not only do their dark-colored backs help them to blend in with the streambed when viewed from above, but the spots on their bodies break up their distinct silhouettes into less-recognizable forms, making them harder to spot from any angle. Trout can also change their brightness and color saturation to better suit their surroundings.

This brown trout blends in fairly well with the gold-colored (tannic) water of its surroundings.

For example, trout that live primarily in large lakes or oceans will lose much of their coloration over time, because silvery sides with fewer spots help them to blend in against the still water in the background. During breeding season, these fish must seek out moving water, so they’ll swim up into rivers and creeks, where they quickly begin to darken up in order to better blend in with the shallow, stony riverbed.

On the left is a male Arctic char (relative of the brook trout) fresh from the ocean, and on the right is a male char that has spent several weeks swimming up a small river system to spawn, showing the full range of colors these fish can display.

This photo from a nearby creek shows a trout that isn’t as hidden as it might think.