Oceanic Whitetip shark
The famous shipwreck shark
The Oceanic Whitetip shark (Carcharhinus longimanus) is a large pelagic requiem shark inhabiting tropical and warm temperate seas. It is most distinguished for its long, white-tipped, rounded fins. It is a slow-moving but aggressive shark that dominates feeding frenzies, and is a danger to shipwreck or air crash survivors.
Recent studies show steeply declining populations because its large fins are highly valued as the chief ingredient of shark fin soup, and as with other shark species, the Oceanic Whitetip shark faces commercial fishing pressures.
It is considered one of the most dangerous sharks to humans.
Photo: © 2018, Harry Stone, Planet Shark Divers, all rights reserved.
Family: Carcharhinidae – Requiem sharks
Common Name– Ground Sharks
Common Name– Requiem Sharks
Status: IUCN Red List Vulnerable . The Federal Government announced that on March 1, 2018, the Oceanic Whitetip shark would be listed as threatened under the Endangered Species Act. The decision comes in response to a 2015 petition filed by Defenders of Wildlife and includes provisions for protecting the sharks and their critical habitat.
Average Size and Length: The Oceanic Whitetip shark can grow to large sizes 11-13 feet, but are typically less than 10 feet in length. Females are larger than males.
Average Weight: The maximum recorded weight of an Oceanic Whitetip shark is 370 pounds.
Current Rare Mythical Sightings: Known as the “Lesser White Shark”, the Oceanic Whitetip sharks are likely to be the predominant sharks that plagued the crew of the U.S.S. Indianapolis after it was sunk by a Japanese submarine near the end of World War II. It is known as the worst shark attack in history.
“One of the most interesting anecdotes about the behavior of oceanic whitetips has nothing to do with shipwrecks or divers, though. In the 1950s, fishery researchers in the Gulf of Mexico were surprised when they opened up the stomachs of whitetips and found five- and 10-pound tuna in them, because the sharks aren’t fast enough to chase down small tuna. Then one day they saw a large group of whitetips swimming through a school of tuna, at the surface, with their mouths open. “No attempt was made by the sharks to chase after or snap at the hundreds of tuna,” the researchers reported. “The whitetips were merely waiting and ready for those moments when tunas would accidentally swim or leap right into their mouths.”
The author of Jaws, Peter Benchley claims to have observed the Oceanic Whitetip shark swimming with Pilot whales and eating their faces!
Prior to the 16th century, the Oceanic Whitetip shark was known as the “sea dog” by sailors and ship bearing folk because of their dog-like behaviors including following ships, and when it is attracted to something that appears to be food, its movements become more enthusiastic and it approaches cautiously but stubbornly, retreating and maintaining a safe distance if driven off, but ready to rush in if the opportunity presents itself. Very similar to that of a dog.
Teeth and Jaw: The Oceanic Whitetip shark has unique jaws and teeth. In the lower jaw (mandible) the teeth are serrated and have very thin tips. They are small, and triangular. The teeth in the upper jaw are larger and more spread apart, broad, triangular and are fully serrated. An Oceanic Whitetip shark upper tooth measures between 18-23mm. The arrangement of the teeth is 14 or 15 on each side of the symphysis of the upper jaw and 13-15 teeth on either side of the lower jaw symphysis. Bull and Dusky sharks have similar teeth.
Head: The head of the Oceanic Whitetip shark includes a short and bluntly rounded nose and circular eyes.
Denticles: The dermal denticles of the Oceanic Whitetip shark lie almost flat resulting in a smooth-to-the-touch skin. The denticles overlap only slightly with some skin exposed. Usually having 5, but sometimes 6 or 7, ridges, the denticles are broader than long.
Demographic, Distribution, Habitat, Environment and Range: The Oceanic Whitetip is found globally in deep, open oceans, temperatures greater than 64 degrees F, and no colder than 59 degrees F. They typical temperature is between 68–82 °F. They typically withdraw from areas when temperatures fall outside of these limits.
The Oceanic Whitetip shark is found between 45 degrees N and 43 degrees S latitude. Most of the time, the Oceanic Whitetip shark is found from the surface down to a depth of about 490 feet. However, research via longline capture data suggests that there is a correlation between population and distance. The greater the population of sharks, the greater the distance from land tends to be. On occasion, they are found closer to land and in shallow water.
Diet: The main diet of an Oceanic Whitetip shark is made up of bony fish like lancetfish, oarfish, barracuda, jacks, dolphinfish, marlin, tuna, and mackerel, and pelagic cephalopods. However, they will eat just about anything else, especially if it is wounded and in a submissive and compromising state.
Oceanic Whitetip sharks are also known scavengers. If it is dead and floats, they will find it.
Ram-Suction Index: For ventilation, they are ram and therefore must always keep moving. They are ram-feeding by biting into groups of fish and swimming through schools of fish with an open mouth.
Aesthetic Identification: The Oceanic Whitetip shark is stocky and somewhat flattened looking with a hump-back. The Oceanic Whitetip shark has a large rounded first dorsal fin and very long and wide paddle-like pectoral fins. Oceanic Whitetip sharks have a distinctive pattern of mottled white markings on the tips of their dorsal, pectoral, and tail fins. These markings are why they are called “whitetip” sharks. They are generally grayish bronze to brown, while their undersides are whitish with some individuals having a yellow tinge, but can vary depending on location. Juvenile sharks may even have black markings.
Biology and Reproduction: Oceanic whitetip sharks live up to 19 years, although it is thought that individuals may live to be much older (up to 36 years).
Female Oceanic Whitetip sharks reach maturity between 6 and 9 years of age (depending on geographic location) Oceanic Whitetip sharks are viviparous, and have a gestation period of 10 to 12 months. The reproductive cycle is thought to be biennial, meaning that the sharks are giving birth on alternating years. Litters range from 1 to 14 pups with an average of 6. There is also a likely correlation between female size and number of pups per litter, with larger sharks producing more offspring.
Mating season is in early summer in the northwest Atlantic Ocean and southwest Indian Ocean, although females captured in the Pacific have been found with embryos year-round, suggesting a longer mating season there.
Females reach sexual maturity at 80 inches, and males at 69 inches.
Behavioral Traits, Sensing and Intelligence: Non-diurnal. They are active both day and night.
Most of the time, the Oceanic Whitetip is solitary, except when there is a large amount of prey present. When feeding with other species, it becomes aggressive, competitive and opportunistic. This is how feeding frenzies occur.
It is mostly a very slow-moving shark, but when it is attracted to something that appears to be food, its movements become more enthusiastic and it approaches cautiously but stubbornly, retreating and maintaining a safe distance if driven off, but ready to rush in if the opportunity presents itself.
Research suggests that Oceanic Whitetip sharks are goal-oriented. They are motivated by achieving a set task, and therefore validates their determination. The crew of the U.S.S. Indianapolis unfortunately endured this behavior.
Speed: The Oceanic Whitetip shark is a known slow-moving shark.
Oceanic Whitetip Shark Future and Conservation: Once found all over the world in large numbers, the Oceanic Whitetip shark is still found all over the world, but in much declined numbers. The Oceanic Whitetip is a commercially important species for its fins, meat, and oil. It is the main ingredient of shark fin soup. It is eaten fresh, smoked, dried, and salted and its hide is used for leather. It is more often taken as bycatch than by design, since it is drawn to longline bait that is intended for other species.
88% decline in the Gulf of Mexico and 80-95% decline across the Pacific since the 1990’s.
Oceanic Whitetip Shark Recorded Attacks on Humans: Notoriously known for being one of the most dangerous sharks to humans. The number is large.