The Color of a Crayfish

When I’m tying flies, I’m always conscious of material colors. Sometimes it doesn’t really make a difference, but sometimes it does. Present a strange color (or size) to a pressured fish and they’ll likely bolt in the opposite direction. When I fish crayfish patterns, I typically have the best results with shades of green. But why?

Hudson's Mud Bugger

If you were to ask the average person to draw and color a crayfish, you’d probably end up with something that looked like a bright red dwarf cooked lobster. In fact, the only red crayfish I’ve ever seen was a cooked one at a Cajun crayfish boil. So why are there so many crawfish dubbing colors offered in the shade of red and/or orange? Most of the mud bugs I see in the wild are various shades of brown, rust, green, and even blue.

A 1901 article in The American Naturalist  sheds some light on the color of the crayfish…

“It was first noticed, while studying the habits of crayfish by observations in field work, that the color of itzulmunis in nearly all cases closely resembled the color of the environment. In one small pond of water, where the soil at the bottom was a blue clay, the crayfish were all blue in color. In another pond with a black, muddy bottom they were all black, and in still other places of different colors. But in nearly all cases they were of the same color as the environment”

Blue Crayfish

Crayfish can adapt their color to their surroundings. Here a crayfish blends in with the blue gravel of an aquarium.

Crayfish can adapt their color to their surroundings. Here a crayfish blends in with the blue gravel of an aquarium.

The article also explains the occasional red or rust color observed in a few crayfish…

“One exception to this was found with those which were red. These were confined entirely to the shallow water in the small streams, and the color was not always similar to the color of the environment. The crayfish in all colors except red were found almost entirely in the ponds with deeper water and muddy bottoms. But it was discovered later that this red color in crayfish may be caused by exposure to sunlight.”

So, in addition to environment, it appears color variations in crayfish can be attributed to age, size, molting stage, and migratory pattern. Next time you see a crayfish note its color and the color of the surroundings. It might help you become a better fisherman.

Source: W. J. Kent, The Colors of the Crayfish, The American Naturalist, Vol. 35, No. 419 (Nov., 1901) (pp. 933-936)