No Such Thing as a “Typical” Shark—Shark Diversity, Part 1

sharkdiversity1

Basking, Zebra, Ornate Wobbegong

There are over 500 different types of shark. Each has evolved with a specific tooth structure, skin pattern, body type and other traits to suit them to living in a specific niche and hunting a certain range of prey. Here’s a quick overview of some sharks and their adaptations to give you an idea of how diverse they are:

Tooth Structure
Some sharks, like Makos, have pointy teeth that are perfect for impaling and trapping fast, slippery fish. Others, such as Whites, have serrated teeth for tearing through and removing chunks of meat from blubbery sea mammals. Bottom dwelling sharks, like Port Jacksons, sport flat teeth that can crush shells or exoskeletons. The three filter feeding sharks—Whale, Megamouth and Basking—have minuscule teeth that are essentially useless for catching prey, but the spongy tissue along their gills can sieve tons of zooplankton from the ocean as they swim with their mouths open. White Spotted Bamboo sharks have extra versatile teeth—not only are they pointed to pierce and grasp fish, but the ligaments that attach the teeth to the jaw are unusually flexible to allow the teeth to fold back under pressure, becoming a flat surface that can crush hard shelled creatures. The small, parasitic Cookie Cutter shark attaches itself to large fish or marine mammals using its suctorial lips, and then removes a plug of flesh by vibrating its jaws and twisting its body.

Skin Patterns
Many deep-sea sharks are solid colors, mainly black, brown, grey or white. Most pelagic species are a single color on their upper body—usually a shade of blue, grey or brown—with a lighter underbelly. This counter-shading makes them inconspicuous if viewed from below (white belly against a lighted surface) or above (dark upper body against darker depths). The majority of bottom dwelling sharks have more complex skin patterns—from spots to stripes to blotches or a combination thereof—that camouflage them against coral or rocks. Wobbegongs even have irregular flaps of loose flesh around their mouths that resemble fonds of seaweed. Some sharks use their appearance to attract prey. Oceanic Whitetips have broad fins with white blotches on the ends that, under certain light and water conditions, are clearly visible while the rest of the shark becomes indistinct. Their whitened fin tips appear to be a small school of fish, which lures larger prey fish. Some deep-sea sharks, like Pygmy sharks, entice prey with bioluminescent patches of skin.

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