The apex predator of warmer waters
The Tiger shark (Galeocerdo cuvier) is a species of requiem shark and the only extant member of the genus Galeocerdo belonging to the order Carcharhiniformes. It is a large apex macropredator, growing to lengths over 16.5 feet long, and is the largest member of its family. They are found in temperate waters, especially around the central Pacific islands. We are lucky to have them here in Jupiter, Fl for part of the year. They can be curious and aggressive and should be respected when in their habitat. The Tiger sharks’ stripes tend to fade as the shark ages. The Tiger shark is also primarily a nocturnal hunter.
Common Name– Ground Sharks
Common Name– Requiem Sharks
Status: IUCN Red List NEAR THREATENED
Average Size and Length: 10-13 feet, with the occasional large female reaching 16 feet and the larger males reaching 13 feet.
The Tiger shark is dimorphic. There are some papers even claiming Tiger sharks reaching over 24 feet long, but this is not confirmed.
Average Weight: 849-1,400 pounds. Large females could reach 2,000 pounds.
Current Research, Rare, Mythical Sightings: The Tiger shark was first described by Peron and Lesueur in 1822 and was given the name Squalus cuvier. Müller and Henle in 1837 renamed it Galeocerdo tigrinus. The genus, Galeocerdo, is derived from the Greek galeos, which means shark, and kerdo, the word for fox.
Largest recorded was 18 feet long. We have some famous Tiger Sharks here in between Jupiter, Florida and Tiger Beach, Bahamas by the names of DJenny, Emma, and Patrick.
There is talk that some fishermen have had sightings of Tiger sharks reaching 20-25 feet in length at a whopping 1900 pounds!
Old Hawaiians gave the same name to both the tiger shark and white shark: “Niuhi”. Many shark species found in Hawaiian waters were honored as being sacred and were even considered reincarnations of dead family members. Check out or vlog “The Mythical Shark” on our YouTube channel.
Norfolk Island is located in the South Pacific Ocean – an area called Oceania. The island lies on the Norfolk Ridge which runs from New Zealand to New Caledonia. It lies 500 miles SSE of Noumea, 700 miles NW of Auckland, 900 miles east of Brisbane and 1,100 miles NE of Sydney. This island has a rich history of outcasts and prisoners, and a cemetery sits just beyond the beach. Recently, a team led by Riley Elliot (and joined by Andy Casagrande) discovered something special, unique, and maybe a little strange about this island. For decades the local farmers have been dumping organic waste, in the form of fresh cow carcasses, into the surrounding bay (dubbed Headstone Bay), intentionally to feed the Tiger sharks. The farmers of Norfolk Island have to consistently get rid of their old cows, and instead of burying them on the island, contaminating the land, they thought a natural disposal system would be better for all. The humans need to dispose of the meat, the sharks are hungry, nothing is wasted. In fact, this has worked out since the beginning; in turn, there have been zero incidents among Tiger sharks and humans, even being a local surfing hot spot. Unfortunately, the island is under Australian law, and the Australian government wants to end the dumping. This could (and will be) a disaster, because once sharks expect a food source and it is eliminated, they are forced to find a new food source. The team identified and tagged over 40 sharks (female and male) in one area, making this the largest aggregation globally. This high density of Tiger sharks in a small range could suggest a breeding ground. Scientists are actively studying and collecting more data currently.
Teeth and Jaw: Wide, square, terminal mouth. The sharp, primary cusp extends down. Along the primary point, are tiny serrated edges like a saw and pointed sideways. They have cutting and sawing capabilities. The upper and lower jaw are identical. Tiger sharks have rows of almost 24 identical teeth both in the upper and lower jaws. The jaws are calcified. The flatter, rear tooth component protects the large saw from the tooth pressure which amounts to three tons per square centimeters. The dentition of a Tiger shark is naturally designed to slice through flesh, bone, and other tough substances such as turtle shells. Like most sharks, its teeth are continually replaced by rows of new teeth throughout the shark’s life.
Head: Its head is somewhat wedge-shaped, which makes it easy to turn quickly to one side, with a blunt, wide square looking snout. The eyes have nictitating membranes.
Denticles: Tiger sharks have dermal denticles that are shaped like a spade.
Tail: Their long upper tail delivers bursts of speed.
Demographic, Distribution, Habitat, Environment and Range: Down to 1,000 feet by day and moves inshore to shallow water by night. Most habitats worldwide along the coast. Subtropical to tropical and moderate coastal regions. They are typically steered by warmer currents and stay closer to the equator throughout the colder months. Habitats include coasts, estuaries, harbors, bays, inlets, offshore reefs, open oceans. They have a preference for murky waters. Two hot spots are Jupiter, Florida during fall-spring, and Tiger Beach, Bahamas. Some other island groups are the Marshall Islands, Galapagos, Hawaii, and Tahiti. Tiger Sharks venture into warm temperate regions in the summer with warm ocean currents. They can travel long distances between islands. In the western Pacific Ocean, the shark has been found as far north as Japan and as far south as New Zealand. It has also been recorded in the Mediterranean, but so far only on two occasions, firstly off Spain and then off Sicily (my family heritance). They can be spotted in the Gulf of Mexico, other parts of North America and parts of South America. They are common amongst the Caribbean. Other locations where Tiger sharks are seen include off Africa, China, India, Australia, and Indonesia. There have been some reports of Tiger sharks as deep as 3,000 feet. Tiger sharks in Hawaii have been observed in depths as shallow as 10.0 feet and regularly observed in coastal waters at depths of 20 to 40 feet.
Diet: Because of their unique jaws and teeth, Tiger sharks can eat just about anything and are nicknamed the “Garbage Cans of the Sea”. They can eat birds and fish, and literally eat trash. Stomach contents typically show license plates to rubber tires and many other oddities. Their favorite food and preference are sea turtle found in 20.8 % of all specimens studied), dugong, Blue shark, other shark species, and even some accounts of cannibalism. Tiger sharks are special because they feed on a broad spectrum of prey rather than being specialized on specific prey. They are versatile in that they will hunt turtles, but also are known scavengers. They will eat dead meat of almost any animal from sea lions to reptiles, fish and sea snakes.Young tiger sharks are found to feed largely on small fish, as well as various small jellyfish, and mollusks including cephalopods. Around the time they attain 7.5 feet, or near sexual maturity, their selection expands to much larger prey.
Due to high risk of predation, dolphins often avoid regions inhabited by Tiger sharks. Injured whales may also be attacked and eaten. A group was documented killing an ailing humpback whale (Megaptera novaeangliae) in 2006 near Hawaii. They have been documented alongside Great White sharks, scavenging on whale carcasses.
Terrestrial mammals, including horses (Equus ferus caballus), goats (Capra aegagrus hircus), sheep (Ovis aries), dogs (Canis lupus familiaris), cats (Felis catus), and brown rats (Rattus norvegicus), are fairly common in the stomach contents of Tiger sharks around the coasts of Hawaii. In one case, remains of two flying foxes were found in the stomach.
Ram-Suction Index: Ram
Aesthetic Identification: Tiger sharks are called and known for their distinct stripe and spot patterns vertically down their bodies, like a tiger. These stripes are apparent when they are born through their youth and disappear as they age. It is a clever, counter-shaded, coastal camouflage of wave shadows. They are grey-green or grey-blue shading to black above, and under on the belly side light grey, to cream or muddy yellow. Tiger sharks are the only species of requiem sharks with suction holes (Spiraculi).
The Tiger shark’s dorsal fin will have the same camouflage stripes. A tiger shark generally has long fins to provide lift as the shark maneuvers through water. Its high back and dorsal fin act as a pivot, allowing it to spin quickly on its axis, though the shark’s dorsal fins are distinctively close to its tail. They have prominent interdorsal ridge and low caudal keels.
Biology and Reproduction: Male Tiger sharks reach sexual maturity at 8 feet and females at 10 feet. They mate during the spring. Tiger sharks are ovoviviparous. They produce eggs but retain them inside the female body until hatching occurs, so that “live” offspring are born. Gestation is just over 12 months (but possibly up to 16), and a Tiger shark litter can be between 10-82 young at an average of 20-30 inches. They usually give birth once every three years. One pregnant female caught off Australia reportedly measured 18. 1 foot long and weighed 3,360 pounds.
The male uses his teeth to hold the female still during copulation, often causing the female considerable discomfort. Mating in the Northern Hemisphere generally takes place between March and May, with birth between April and June the following year. In the Southern Hemisphere, mating takes place in November, December, or early January.
A Tiger shark’s recorded life span is around 25 years.
Sensing and Intelligence: Like all sharks, Tiger sharks rely heavily on sensing electrical currents through their Ampullae of lorenzini and their lateral lines. In addition, Tiger sharks have excellent sight and smell.
Behavioral Traits: Tiger sharks are primarily nomadic and solitary wanderers but may aggregate in small numbers to feed. They are primarily nocturnal. Tiger sharks are naturally inquisitive, curious and persistent (sometimes called aggressive) and therefore that is why humans should exercise caution when Tiger sharks are around. The way a Tiger shark investigates is with its jaws. Because of their bite strength and sharp teeth are what will come in contact with anything around, Humans can easily become injured or result in death.
Like all sharks, they have small pits on the snout which hold electroreceptors called the ampullae of Lorenzini, which enable them to detect electric fields, including the weak electrical impulses generated by prey, which helps them to hunt. Tiger sharks also have a sensory organ that detects vibrations around them, called a lateral line, which extends on their flanks down most of the length of their sides. A reflective layer behind the tiger shark’s retina, called the tapetum lucidum, allows light-sensing cells a second chance to capture photons of visible light. This enhances vision in low-light conditions. Their sense of smell is quite acute.
Speed: Bursts up to 20 mph. The tiger shark normally swims using small body movements, and moves slowly.
Tiger Sharks Future and Conservation: The Tiger shark is captured and killed for its fins, distinct skin, flesh, and liver. It is caught regularly in target and nontarget fisheries. Several populations have declined where they have been heavily fished. Continued demand for fins may result in further declines in the future. They are considered a near threatened species due to excessive finning and fishing. In 2010, Greenpeace International added the Tiger shark to its seafood red list, which is a list of fish commonly sold around the world, and which have a very high risk of being sourced from unsustainable fisheries.
Tiger Shark Recorded Attacks on Humans: It is extremely rare for sharks to bite humans, and usually is a cause of trying to identify if we are a prey item or mistaken identity. However, the Tiger shark is reported to be responsible for a large number of fatal shark-bite incidents and is regarded as one of the most dangerous shark species. Tiger sharks can readily be found in the marine environments we like to enjoy, including river mouths. Human interactions with tiger sharks in Hawaiian waters have been shown to increase between September and November, when tiger shark females are believed to migrate to the islands to give birth. It ranks second on the list of number of recorded bites on humans, behind the Great White shark. The bite rate is low.
Between 1959 and 2000, 4,668 tiger sharks were removed in an effort to protect the tourism industry. Despite damaging the shark population, these efforts were shown to be ineffective in decreasing the number of interactions between humans and tiger sharks. Feeding sharks in Hawaii (except for traditional Hawaiian cultural or religious practices) is illegal, and interaction with them, such as cage diving, is discouraged.