Sharks The Animal Answer Guide

62 Sharks: The Animal Answer Guide

ted Ratfish was caught not far from Seattle, Washington. An adult male

albino skate (mislabeled as a stingray in the posting) was captured by a fish-

erman in British waters in 2011. Albino Cownose Rays (Rhinoptera bonasus)

show up often enough that SeaWorld Orlando has a live one on display. A

few albino Short-Tail Stingrays (Dasyatis brevicaudata), perhaps the world’s

largest stingray, have been seen and photographed. Some other photos ap-

pearing on the web include an albino Zebra Shark (size not given) pho-

tographed at East Wallabi Island, Western Australia. A presumed albino

juvenile hammerhead shark in the Cebu Zoo, Philippines, turned out to be

a pangasiid catfish.

What causes the different colors of sharks?

Sharks have skin coloration of two types. Most common are skin col-

ors due to pigments in the skin cells. Melanin pigment results in grades of

black; guanine results in grades of white. The color-containing cells are

called chromatophores (literally, “color bodies”), defined by the pigments

they contain. For example, melanin is concentrated in color cells in the

skin called melanophores. Color change occurs when the shark expands or

contracts its chromatophores. When melanophores contract, those regions

of the shark become lighter in color. Pigments are either produced by the

shark itself or somehow transferred from colorful food organisms.

Less common are structural colors that cause iridescent (shiny, glowing)

color. Iridescence results from light passing through and reflecting from

Yes, Virginia, there really is a white shark. This 1. 7 -m-long ( 5. 6 -ft) albino White Shark was caught off Boknes in East-
ern Cape Province, South Africa, in 1996. It is the only known albino White Shark and in fact the only known albino
member of the family Lamnidae. Normally colored White Sharks get their name from their very white bellies. Photo by
Gene Helfman

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