Marine Science/ Per. 1
Sharks are one of the most feared sea animals. They live in oceans across the world but are most common in tropical waters. There are over three hundred fifty species of sharks. They can be broadly categorized into the following four groups: Squalomorphii, Squatinomorphii, Batoidea, and Galeomorphii. The shark family Sphyrnidae that includes the Hammerheads are part of the Galeomorphic classification. They are probably the most easily recognizable of all the sharks. The Hammerheads are among the strangest looking sharks. As the name indicates they have a flattened head which resembles the head of a hammer. Their eyes and nostrils are at the ends of the hammer. There are many species of Hammerheads. There are eight living species of hammerheads. The following four are the main categories:
1. Scalloped hammerhead (Sphyrna lewini)-Pectoral fins are tipped with black this grey shark. The maximum length is about 12 feet.
2. Bonnethead (Spyrna tiburo)-With a head shaped like a shovel the bonnethead rarely grows more than four feet long. This shark is commonly seen inshore.
3. Smooth hammerhead (Sphyrna zygaena)-Bronze with dusky fin tips, it can grow to thirteen feet.
4. Great hammerhead (Sphyrna mokarran)-Attaining a length of a possible 18 feet, this is the largest and most dangerous of all the hammerheads.
One of the most interesting things about the hammerheads is the unique shape of their heads. Ever since scientists started to study the hammerhead they have speculated about the use of the hammer. The hammer is a complex structure and probably serves more than one function. The most important function of the hammer according to scientists is increased electroreceptive area and it's sensory perception. This means that the hammerhead has a remarkable sensory ability to detect the small electrical auras surrounding all living creatures. Under certain conditions, such as in searching...
Bibliography: Klimley, Peter, "Hammerhead City", Natural History, Oct. 1995, pp 33-38. Martin,
Richard, "Why the Hammerhead?", Sea Frontiers, May-June 1989, pp. 142-145. Moss,
Sanford, Sharks, Prentice-Hall, 1984. World Book Encyclopedia, Sharks, World
Book Inc., 1988.
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