Ad

Are there any sharks without countershading?

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmailFacebooktwittergoogle_plusredditpinterestlinkedintumblrmail
The wobbegong shark is one of the shark species that doesn’t use countershading to camouflage itself, instead it blends into its environment thanks to parts of its body that look like plants.

By Blaise Jones

Countershading is a very important part of what make sharks such efficient predators. However, not every shark shares this advantageous color pattern. Many species opt for a different approach.

Bottom Dwellers

Sharks that spend their time on the bottom do not need countershading because they don’t swim around in the water column while hunting. These sharks rely more on matching the top of their body to the colors of their environment. Examples include the nurse shark, carpet sharks, angel sharks, and the wobbegong shark. Wobbegong sharks go a step further by having tassel-like growths hanging from their head, which breaks up their silhouette and helps them blend in with the bottom more effectively.

Leopard shark.

Splotches and Camo-patterns

Wobbegong sharks aren’t the only species that rely on a unique color pattern to blend in. Many species exhibit unique colorations that might make them stick out to us, but to their prey it makes them almost invisible.

Sharks like the tiger shark, leopard shark, and whale shark exhibit a mottled pattern, with stripes or splotches of lighter colors mixed with dark. In the case of the leopard shark, its colors blend in with the swaying kelp stalks of its habitat. As for tiger and whale sharks, their color patterns resemble the way light shimmers as it passes through water.

Most marine animals are colorblind and can only tell the difference between shades of a color, not the actual color itself. The dark base color of the animal will absorb all downwelling light while the light, rippling splotches will reflect it, making them appear as rippling beams of light in the water column.

White-tip reef shark.

Eye-catching Colors

While sharks are by no means colorful, some sharks have highly contrasting colors seemingly on display. Sharks like the blacktip, blacknose, and the whitetip reef shark all have contrasting splashes of color on their bodies. While it might seem like a bad idea to draw attention to oneself like this, this splotches do have some advantages.

In the case of the blacktip, these dark spots are located on, you guessed it, the tips of their fins. Therefore, they probably function as distractions. A predator hunting a smaller blacktip will see these tips first and attack them, allowing the blacktip to potentially escape and grow the fin-tips back.

Sharks with splotches of white probably use them for hunting. White is the most reflective color and stands out in the ocean. Sharks such as the oceanic whitetip could use this to lure in their prey, which see the white splotches and think they are small prey item.

Dwellers of the Abyss

Finally, we have the deep-water sharks. These sharks are mostly completely dark, though some are pale and pallid, like the goblin shark. Most animals that have evolved to live in darkness end up this pale color, which is caused by the lack of a need to protect the skin from ultraviolet light.

The dark color, as exhibited by sharks such as the dwarf lantern shark and the megamouth shark helps them blend in with an environment of complete darkness. However, some sharks have evolved to use their darkness even further. Bioluminescent sharks, such as the spined pygmy shark, have special organs that produce bright blue lights. These stand out vividly in the inky darkness of the abyss, and the dark coloration helps the rest of the shark blend in while their prey approaches the shiny object only to learn at the last second that the small prey they thought they were going to eat is actually attached to a larger shark that is going to consume them.

SOURCES:

“Sharks: The Animal Answer Guide” by Gene Helfman and George H. Burgess

“The Encyclopedia of Sharks” by Steve Parker

“The Pigmentation of Cavernicolous Animals” by Ernest Baldwin and R.A. Beatty, from the Biochemical and Zoological Laboratories of Cambridge, 1941

-TSF-

#sharks #countershading #camouflage #TSF

Facebooktwittergoogle_plusredditpinterestlinkedintumblrmailFacebooktwittergoogle_plusredditpinterestlinkedintumblrmail

FacebooktwitterpinterestFacebooktwitterpinterest