No Such Thing as a “Typical” Shark—Shark Diversity, Part 3
August 13, 2009

Frilled, Leopard, Coral Catshark

Frilled, Leopard, Coral Catshark

Here’s some other shark adaptations:

  • Swell sharks can inflate their stomachs with water, increasing their diameter by up to 3 times their normal size. This sudden size increase can startle predators or  help the shark to wedge itself in a crevice on a reefbed, making it hard for predators to remove it.
  • Juvenile Nurse sharks prop themselves up on their side fins and curl the fins under themselves to create a false cave that unsuspecting crabs seek refuge in. The sharks promptly eat any tricked crabs.
  • The way an Epaulette shark’s side fins are attached to its body allow it to maneuver its fins in a type of “walking” motion over coral and rock beds.
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No Such Thing as a “Typical Shark”—Shark Diversity, Part 2
August 11, 2009

sharkdiversity2

Pajama, Bullhead Zebra, Portjackson

Here’s some more ways that sharks are diverse:

Size
Sharks come in a wide range of sizes. Dwarf Dogfish are the smallest, reaching a max length of only 8 inches. Whale sharks are the largest. The biggest one actually measured was 42 feet, though there are estimates that they reach up to 60 feet. While there are several other sharks that grow to be close to or more than 20 feet long, most reach more moderate  lengths. About half of known shark species are under 3 feet long, and eighty percent don’t exceed 9 feet.

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No Such Thing as a “Typical” Shark—Shark Diversity, Part 1
August 6, 2009

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.

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