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The Ultimate Encounter - The Great White Shark (Carcharodon carcharias) is the one shark that seems to strike fear and terror in many people. Also called the White Pointer, White Death, White Shark and other names, this is the largest flesh eating shark in the ocean today.
Despite being a true apex predator, with few, if any natural enemies in the ocean, the Great White Shark is very vulnerable to over-fishing and today it is generally recognized as an endangered species. Indeed, the species is officially protected in South Africa, Australia, Maldives and the United States.
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- Shark Anatomy & Physiology
- Protection & Conservation
- 2005 Expedition - Guadalupe Island
Isla de Guadalupe, Mexico
2005 Guadalupe White Shark Season Synopsis (pdf)
Courtesy: Great White Adventures
- 2002 Expedition - Farallon Islands
2002 Field Notes
Farallon Islands San Francisco, California
- Diving Schedule & Registration
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The Great White Shark is found worldwide along continental edges of all temperate seas and will occasionally enter tropical waters as well. The most abundant and well-known populations appear off the southern coast of Australia (Jan-May), near South Africa (Dec-Feb), and along the western coast of North America, including California and Mexico (Aug-Nov).
Adult White Sharks feed on Pinnipeds such as sea lions and seals. The largest individual observed is said to have been 21 ½ feet in length, weighing 7300 lbs. These sharks have symmetrical tail fins; the upper and lower lobes are equal in size indicating that these sharks swim constantly and can achieve fast bursts of speed. The teeth of these sharks are a symmetrical triangular shape with serrated edges. This enables the shark to tear flesh very efficiently.
Females give birth to between seven and nine live pups and are thought to produce only four to six litters in an entire lifetime. They reach sexual maturity after 12 years. This slow rate of growth and reproduction make them extremely susceptible to fishing pressures.
Great White Sharks are cautious hunters. Despite their ferocious reputation, these sharks will often stalk their prey silently and without notice before taking a preliminary bite to test their prey. After inflicting an initial wound, the shark will often retreat and wait for the victim to weaken or die. Often humans who are attacked, by mistaken identity in most cases, will survive because this bite and retreat tactic allows them to reach help before the shark returns.
Since the release of the movie “Jaws” in 1975, the Great White Shark has been a much maligned animal. Demonized in the movies and feared the world over, these sharks have been pursued and killed with reckless abandon for decades. Now, as populations are in serious decline this shark is finally coming under some protection. SCUBA Divers are traveling to remote sites to witness these animals in their natural element and biologists are attempting to study them with ever more sophisticated techniques and tools.
Recently, a juvenile specimen was put on display in the Monterey bay Aquarium. This was the first Great White Shark ever to be held in captivity successfully for any length of time. It was released into the wild on March 31, 2005 after 198 days in captivity. More...
At Eco-Photo Explorers, we hope that through better education and understanding, this magnificent predator of the oceans will remain a part of our marine environment for generations to come.
Shark Anatomy & Physiology
What is a shark?
A shark is a fish, and like other fish, it has a backbone, lives in water, and breathes through gills. Unlike other fish, a shark has a skeleton made of cartilage, the same material that makes up the end of your nose. Cartilage is strong, flexible, and lightweight.
Are sharks warm or cold blooded?
Most sharks are cold-blooded (ectothermic) which means their inner body temperature matches the temperature of the water around them. However, some sharks like the great white are warm-blooded (endothermy) and can elevate their body temperature above that of their surroundings.
Basic Body Shape: The Great White Shark belongs to a group of sharks that share the same body shape, known as the Mackerel Sharks. These sharks are robust and torpedo shaped with a cone shaped snout. The upper and lower lobes of the tail (caudal) fin are almost equal in size, indicating the ability to swim at rapid speeds and the need to swim constantly.
Internal Skeleton: Sharks are Cartilaginous animals, with an internal skeleton comprised of cartilage, an elastic tissue higher in water content than bone. This gives the shark great flexibility, provides greater support and protection for the internal organs and lowers the shark’s overall body mass.
Jaws & Teeth: The jaws of the Great White Shark are protrusable, which means they can detach from the skull and be thrust forward, enabling the shark to gain a better grip on its prey. The teeth are symmetrical and triangular in shape with serrated edges. Like all sharks, the Great White produces replacement teeth which are located in rows inside the jaws and are bent backwards until it is necessary for them to move forward to replace worn or detached teeth.
Skin: The shark’s body is covered with scale-like structures called denticles. These give the shark’s skin a rough, sandpaper like feel. Denticles resemble teeth and it is speculated that these structures make the shark hydronamically quiet.
Fins: The caudal fin, or tail, provides the forward thrust with wide, side to side movements. The dorsal fin provides stability by preventing the body from rolling to either side during forward motion. The pectoral fins are used for lift and control of movements.
Size: The white shark is the world's largest predatory fish, reaching 21 feet (7m) in length and weighing up to 4,800 pounds (2,177kg). The size of a pup when born are approx. 3.6 feet (1.1m). On average, a fully grown mature Great White will be in the 12ft - 16ft (3.7m - 4.9m) range and weigh between 1,500 and 4,000 pounds (680kg - 1814kg). Male and female great white sharks grow at different rates. Males become adults in about 9 - 10 years. Female great white sharks usually grow larger than males. They become adults in about 14 - 16 years.
Coloring: The White Shark is really only white on its belly. The top part of its body is actually gray or blue/gray in color. This dual color pattern is a deadly combination -- the dark-colored upper back makes it difficult to see the shark while looking down from the surface. Where as, its white-colored underside makes it hard to see while looking up from the bottom. This type of camouflage makes the shark blend easily into its surroundings which allows it to sneak up and attack its prey without warning.
Vision: The eyes are located on the sides of the head, providing an excellent field of vision and have the ability to function decently in low-light conditions as well as bright light situations.
Great Whites, like humans have two basic types of retinal cell: rods and cones. There are more rods than cones in the eyes, which helps the shark in low light conditions. Rods are straight slender stick-like shaped photosensitive receptors, while cones are gently tapered and relatively squatty photosensitive receptors that resembles a cone-in-shape. Rods are particularly adept at detecting contrast and movement and responsive to faint light conditions - but are not very good at discerning fine detail. Where as, cones surpass Rods at discerning fine details, which includes color - but require well illuminated operating conditions to function well.
The Tapetram Lucidim is a mirror-like structure behind the retina which functions like a biological photomultiplier and helps the shark see in murky or dim situations. Great White Sharks do not have a Nictitating Membrane, which helps some species of sharks better protect their eyes while attacking. To protect its eyes from injury, the Great Whites have no recourse but to roll its eyes tailward in their sockets just before they strike their prey.
Smell: There are two olfactory sacs under the snout, each covered with a flap of skin that helps channel water into these chambers. Some sharks have been found to detect fish extracts at concentrations as little as 1 part per 10 billion parts of water.
Taste: Great White Sharks have taste receptor cells on small taste buds covering small bumps inside the mouth. These are stimulated by direct contact with food and are used to determine whether a food item is actually palatable or desirable.
Touch: There is a network of nerve endings beneath the shark’s skin, which react when the skin is depressed by as little as 0.0008 inch. Sharks also possess a "Lateral Line", a set of sensory hair cells arranged in tiny clusters of 1/30 inch or less known as nueromasts. These are distributed along the sides of the body and can detect water movements relative to the body movement. Sharks use this system to detect erratic movements of possible prey.
Hearing: Great White Sharks have two internal ears, known as the macula neglecta. These are very sensitive and can detect sounds in the range of 10 HZ to 800 HZ (Human hearing is in the range of 25-16,000 HZ). Sound pressure waves are channeled down tiny cartilaginous tubes in the top of the skull to the inner ears.
Electrosensory System: Named for the 17th century anatomist who fist discovered them, the Ampullae de Lorenzi are used by the Great White Shark to detect small bioelectrical fields in the water. Living organisms in the water generate small electrical impulses and electrical fields and sharks are especially adept at sensing these. The organs are located in the snout, and consist of small chambers lined with hair cells and lined with a conducive jelly.
The tubes radiate to pores on the skin, and can sample voltage potentials at various locations across the head. Sharks can detect electrical fields as weak as 0.01 microvolt. Since these weak fields diminish quickly, the effective range is only about 1 foot or so. The shark uses this sense to calibrate its attack as it nears its prey and is the reason why sharks are often confused and bite into the metal bars of shark cages.
Great white sharks are ovoniparous and reproduce Aplacental Viviparity which means they hatch from an egg and develop inside the females body for one to two years. There is no placenta to nourish the pups so they must eat the unfertilized eggs or eat their siblings to stay alive. The female will give birth to live young, unlike many sharks that lay eggs. After birth, the shark pups will swim away immediately and find food for themselves. The mother does not give any maternal care.
Females may give birth to 2 - 14 live pups per litter and are thought to only produce 4 - 6 litters in an entire lifetime. Young sharks do not sexual maturity until they reach the age of 10 - 12 years old.
Additional Information - Detailed information about Great White Shark Biology can be found at the ReefQuest Centre for Shark Research website which is dedicated to shark and ray conservation through its scientific research and public education programs.
Protection & Conservation
Despite its fearsome reputation, Great White Shark populations the world over are threatened. Over-fishing, habitat destruction and other environmental factors combine with the shark’s slow reproductive rate to create severe problems for this apex predator.
Recently, the shark has come under closer scrutiny by the scientific community. Research efforts are now showing that Great White Shark populations are in serious decline. Through better field research and the use of more sophisticated technology such as real-time tracking devices, more is known about this creature than ever before. Its migratory patterns, once little understood, are now becoming more apparent.
Recently, a victory for those trying to help protect this often vilified predator was achieved. At the 13th meeting of the Convention on International Trade in Endangered Species of Flora and Fauna (CITES), participants voted to adopt a proposal to improve management and monitoring of trade in jaws, teeth and fins from the world’s largest predatory fish. The governments of Australia and Madagascar led the push to list the Great White Shark in Appendix II, which will provide for greater control over the trade in Great White Shark body parts. The proposal was approved by a wide margin (87 in favor of listing, 34 opposed and 9 abstentions). At CITES, two-thirds of those voting need to approve a proposal before it is adopted.
The inclusion of the Great White Shark in the CITES is noteworthy because CITES has rarely included fish in its listing in the past. Only two other sharks have thus far been listed: The Whale Shark and the Basking Shark, both filter feeders whose populations are at risk from over fishing.
Great White Sharks are now protected by a growing number of countries as an endangered or threatened species. Concerns over a decrease in numbers led South Africa to institute protective legislation in 1991 (the first country to do so). Namibia, Maldives, Malta, Florida and California, US, and Australia soon followed this unprecedented effort.
At present the white shark is classified as "Vulnerable" on the International Union for Conservation of Nature (IUCN) Red List Assessment.
Status in the IUCN
Red List (1994)
Main Criterion: VU (Vulnerable)
Sub Criterion: A1cd A2cd
In the United States, some progress in providing protection for this species is being made. For example, on August 2, 1997 California Governor Pete Wilson signed Senator Mike Thompson's bill (SB 144) into law prohibiting the deliberate take of white sharks in state waters. However, the species does not appear on the Federal list of Endangered Species.
The future of the great White Shark remains uncertain. Japan recently rejected the CITES publication of the species and in other parts of the world, including the United States, it remains legal to hunt these animals.
Great White Cage Diving Schedule
Great White Shark Expeditions - The Great White Shark (Carcharodon carcharias) is the one shark that seems to strike fear and terror in many people. There’re many tour operators that can take you to Guadalupe Island, but the one we use is Great White Adventures/Shark Diving International, a leading US owned adventure and educational travel company that specializes in taking small groups of people to remote and exciting destinations. Great White Adventures/Shark Diving International is an efficient and professional operator for this type of demanding trip. The expedition vessel used is called the Searcher, a state of the art 96-foot long range dive vessel that will transport you to one of the most amazing locations in the world.
- Diving Schedule & Registration (Guadalupe Island, Mexico)
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- The Shark Foundation has been committed to the protection and research of sharks since 1997 and sees itself as the sharks' lobby.
- The ReefQuest Centre for Shark Research is dedicated to shark and ray conservation through its scientific research and public education programs.
Inside the Cage: Shark Cage Diving in North
Join Eco-Photo Explorers as they venture inside the cage right here in North America to dive with Blue Sharks in California, Rhode Island and New York. This program will conclude with heart-stopping action from Mexico’s Isla de Guadalupe, home to some of the largest Great White Sharks in the world.
Gifts & Apparel
These high quality postcards are printed on glossy, 12 point paper, and come in a package of eight. All postcards are in full dynamic color and come with a standard white border. The cards measure a standard 6" x 4" and are ready to send. Guaranteed. Will ship in 2-3 business days. Price: $8.50 - Package of 8
Diving Ceramic Mugs
Our 11 oz. ceramic mug will keep your favorite beverage hot. Large handle for easy grasping. Dishwasher and microwave safe. Printing is full of color and detail. Guaranteed. Will ship in 2-3 business days. Price: $14.99
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