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Wysłany: Czw 11:26, 07 Kwi 2011 Temat postu: jordans women A List of Small Shark air jordan wom |
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The Smallest Shark in the World
Sharks are often imagined as large and lethal predators cruising the waters for their latest meal. However [link widoczny dla zalogowanych], not all sharks are large. Although a shark’s size will depend on factors such as age and nutrition, many healthy adult sharks grow no larger than a foot long. Dispelling the myth of the large and terrifying shark, here is a list of the world’s small sharks.
Read on
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The following sharks hold the top five spots on the Discovery Channel’s list:
pale catshark (Apristurus sibogae) – 8.27 inchespanama ghost catshark (Apristurus stenseni) – 9 inchesgreen lanternshark (Etmopterus virens) – 9 inchesshorttail lanternshark (Etmopterus brachyurus) – 9.4 inchesAfrican lanternshark (Etmopterus polli) – 9.4 inchesWhere to Find Small Sharks
Small sharks in the epipelagic zone do exist [link widoczny dla zalogowanych], although they are larger than the deep water small sharks. The picked dogfish (Squalus acanthias) can grow to 160 centimeters but is only 59-110 centimeters at first maturity. This small shark generally dwells between the surface and 200 meters down. The Sarawak pygmy swell shark (Cephaloscyllium sarawakensis) of Malaysia, lives between 118 and 165 meters growing up to be 40 centimeters long.
That said [link widoczny dla zalogowanych], shark expert R. Aidan Martin believes the deepwater dogfish shark Etmopterus perryi is most likely the world’s smallest shark and the Florida Museum of Natural History agrees. This small shark was found to be 19 centimeters long as an adult. According to the Etmopterus perryi entry at Fishbase.org, this small shark lives between 283 and 439 meters below the sea in the waters around Columbia and Venezuela.
Determining the smallest shark in the world is a bit hard for marine biologists to do. At birth sharks are obviously much smaller than they are as adults. For example, the great white shark is about 120 centimeters (43 inches) at birth and can grow up to be 680 centimeters (22.3 feet) as an adult. In an attempt to standardize the measuring process, marine biologists measure animals when they reach reproductive maturity. However, determining when a shark has reached this point is not always easy.
All of the top five small sharks on the Discovery Channel list are deep water creatures living hundreds of meters up to one thousand meters below the surface according to Fishbase.org. According to Dr. J. P. Shukla’s book “Fish and Fisheries” deep sea fish often have smaller bodies than their epipelagic cousins. This is an adaptation to the increased pressure at depth and the scarcity of food sources deep beneath the sea.
More Small Sharks
Interestingly, E. perryi does not make it to the Discovery Channel’s “Shark Week: Top 20 Lists: Smallest Sharks”. The number one small shark on this list is the pale catshark (Apristurus sibogae) measuring at 8.27 inches or 21 centimeters. According to Fishbase.org however, the size of this fish was based on a juvenile specimen. Regardless, these small sharks can be found at depths of 655 meters in the waters of Indonesia.
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