By: Kady Samples
Tiger sharks can grow to be about 14-20 feet in length with an average of 12 feet. They can vary in weight from 850 pounds to approximately 1,400 pounds. They were given the name because of the tiger-like pattern on their body during their youth, a pattern which slowly disappears with age and which eventually may only be faintly or no longer visible. This coloring probably serves as camouflage because the young usually stay close to the coast, directly below the water surface, and with their stripes they very much resemble the shadows of waves in the water.
Tiger sharks are noted for having the widest food spectrum of all sharks. They can eat almost anything, from turtles to birds, as well as other sharks and fish. Besides normal prey they even eat garbage like tires, nails or car license plates, as sometimes documented by examinations of their stomach contents. For this reason they acquired the reputation of being "garbage eaters" and were considered primitive.
All tiger sharks generally swim slowly, which, combined with cryptic coloration, may make them difficult for prey to detect them in some habitats. They are especially well camouflaged against dark backgrounds. Despite their sluggish appearance, tiger sharks are one of the strongest swimmers of the carcharhinid sharks. Once the shark has come close, a speed burst allows it to reach the intended prey before it can escape.
The exterior appearance of a tiger shark is relatively atypical for the family of gray sharks for its body is longer and the snout is not pointed but noticeably flat and edgy. Tiger sharks are the only species of gray sharks with suction holes. The tiger shark's teeth and jaws is also what differentiates this species from other gray sharks and generally from most other shark species. While the teeth of other sharks which hunt swimming prey as a rule are designed to cut in the upper jaw region and to grab and hold onto possible prey in the lower jaw, tiger sharks have rows of almost 24 identical teeth both in the upper and lower jaws. These teeth have both a cutting as well as sawing region.
People who are not used to these animals should avoid them whenever possible. They are very curious and may be rather persistent when encountering skin divers who chase and harpoon fish. Even though the accident rate should not be overemphasized, it cannot be denied that most accidents in the tropics are ascribed to tiger sharks. Nevertheless, the danger of being bitten by a tiger shark is still relatively small - as is the case for all other shark species. In Hawaiian waters, a region frequented by numerous tiger sharks, the accident rate does not exceed one per year. Tiger sharks are endangered because they are used for food and pills and other goods, they are also hunted for sport.
Pregnancy with tiger sharks lasts between 15 and 16 months. Normally, the young are born with a length of 50 to 70 centimeters, but depending on where they are born, the young may also be much larger. For example, in the region around Hawaii their size at birth reaches 80 to 90 centimeters. The average number of pups per litter is 41 whereby the spectrum fluctuates between 10 all the way up to 80. Females appear to bear young only every three years. It is not known if males have a similar cycle, but generally they are presumed to have more of an annual cycle. Tiger sharks are the only species of gray shark who do not bear their young live with a placenta, but reproduce aplencentally viviparous. It is unclear if this should be considered a more primitive method of reproduction.