| Get to know this ferocious creature that spans | | | | entire range humans can. A hammerhead's ear |
| the world's waters. Learn its secrets and find out | | | | controls its balance and enables it to detect |
| why the hammerhead shark is an effective | | | | motion. It picks up low frequency vibrations much |
| hunter. | | | | like sounds from wounded fish. Despite these |
| Hammerhead sharks are aggressive and effective | | | | abilities, hammerhead sharks have small mouths. |
| hunters. These creatures are carnivores, feeding | | | | Drawn to schools of over a hundred in daylight, |
| on squids, octopuses, smaller fishes, and | | | | these ferocious-looking creatures are lone hunters |
| crustaceans. There are nine known species of | | | | at night. |
| hammerhead sharks today and all have | | | | Hammerhead sharks reproduce once a year. On |
| hammer-like projections on each side of the head, | | | | average, each reproductive cycle results to |
| hence the name. Its eyes and nostrils are on the | | | | anywhere from 20 to 40 pups. Male sharks |
| tips of these extensions. | | | | violently force females into coupling. Embryo |
| The hammer provides the shark with the needed | | | | develops in a placenta and is fed through an |
| lift, as these species are negatively buoyant. It | | | | umbilical cord and stays there from 10 months to |
| also allows for correct turns. Hammerhead sharks | | | | a year. Once born, young hammerheads are left |
| range from 3 to 20 feet long and can weigh up | | | | to fend for themselves. |
| to 1,000 pounds. Of the nine species identified, the | | | | In May 2007, scientists astounded the world with |
| scalloped, smooth and the great hammerheads | | | | the discovery that hammerhead sharks are |
| are most dangerous to humans. The | | | | capable of asexual reproduction. |
| hammerhead sharks are not known to actively | | | | Hammerheads can be found in temperate and |
| seek out human prey but will attack when | | | | tropical waters around the world. Summers |
| provoked. | | | | means mass migrations for hammerheads as |
| The hammerhead sharks appear to be closely | | | | they head for cooler waters. They appear |
| related to a mid-Tertiary period evolution, the | | | | olive-green or gray-brown on top and have |
| carcharhinid shark. The hammerhead's teeth | | | | off-white undersides. |
| resemble that of some carcharhinids but | | | | Today, both the great and the scalloped |
| determining the hammerhead's first appearance is | | | | hammerhead sharks are listed as endangered |
| difficult. Geneticist Andrew Martin studied all | | | | species. Over-fishing to fill the continued demand |
| hammerhead species and concluded the winghead | | | | for its fins, an expensive delicacy, has vastly |
| shark was where the hammerhead species began. | | | | decreased the scalloped hammerhead's population. |
| As in most sharks, hammerheads have sensory | | | | Scientists have voiced their concerns about these |
| receptors that it uses to hunt for preys. The | | | | great creatures and the Conservation Union has |
| hammerhead's receptors are distributed in a wide | | | | classified them as endangered species. |
| area. With eyes set at the tips of its hammer-like | | | | Sharks are great ocean creatures that are of |
| extension, have wider visual fields and longer | | | | advanced evolutionary stage. Scientists continue |
| ranges than most sharks. This greatly improves | | | | to study these ferocious giants and recent |
| its prey-sweeping ability. | | | | reports indicate a probably tenth species of the |
| The projection on its head also provides the | | | | hammerhead sharks. This probable additional |
| hammerhead shark wider nasal tracts that allow | | | | species springs from the discovery that the |
| hammerheads to spot preys or particles in the | | | | scalloped hammerheads may actually be two |
| water about ten times as effective as other | | | | species - the result of more genetic testing rather |
| sharks. Hearing is highly developed in hammerhead | | | | than a discovery of new physical characteristic. |
| sharks. Hammerheads are able hear sounds in the | | | | |