Whitetip reef shark - Triaenodon obesus

PD Photo: Whitetip reef shark (Triaenodon obesus) off the Hawaiian Islands; the photo came to public domain from the U.S. National Oceanic and Atmospheric Administration (NOAA).

PD Photo: Whitetip reef shark (Triaenodon obesus), Guam, Mariana-Islands, from NOAA's Coral Kingdom Collection, Photo by David Burdick

PD Photo: Whitetip reef shark (Triaenodon obesus), Guam, Mariana Islands, photo by David Burdick. The slender body of the whitetip reef shark is adapted for squeezing into small holes on the reef.

PD Photo: A group of whitetip sharks (Triaenodon obesus) in the Northwestern Hawaiian Islands, photo taken in July 2004 by Dr. Dwayne Meadows, NOAA

The whitetip reef shark (Triaenodon obesus)is also known as blunthead shark, light-tip shark, reef whitetip shark and whitetip shark. It is a comparatively small requiem shark, not exceeding 1.6 meters/ 5.2 feet length and weight around 18 kg/ 40 lbs. It has slender body and short but broad head, tubular skin flaps beside the nostrils, oval eyes, and white-tipped dorsal and caudal fins.

It is one of the most common sharks found in and around Indo-Pacific coral reefs, from Indian Ocean, through Southeast Asia to Australia, central Pacific Ocean, near South Africa and off the west coast of Central America. These usually are found in/ near KwaZulu-Natal, Red Sea, Indian subcontinent, Madagascar, Mauritius, Comoros, Aldabra Group of island s, Seychelles, Sri Lanka, Chagos Archipelago, off southern China, Taiwan, Ryukyu Islands, Philippines, Southeast Asia, Indonesia, northern Australia, Melanesia, Micronesia, Polynesia, Hawaii, Pitcairn Islands, Costa Rica, Panama, and off the Galápagos Islands.

Whitetip reef sharks spend much of their day time resting inside caves. At night they hunt fishes including eels, squirrel fish, snappers, damsel fish, surgeon fish, trigger fish, parrot fish, goat fishes, octopuses, lobsters and crabs. Despite their nocturnal habits, whitetip reef sharks sometimes hunt in daytime also.

Whitetip reef shark is viviparous. Female whitetip reef sharks are followed by prospective mating males, who grasp her pectoral fin and the two of them get into positions suitable for copulation. Females give birth to 1 to 6 pups on alternative years. Whitetip reef shark pups reach sexual maturity when they grow to a length of around 1.1 meter/ 3.6 feet and an age of 8 to 9 years. On the Great Barrier Reef, males live to 14 years and females to 19 years; the maximum lifespan of may be upwards of 25 years.

Whitetip reef sharks may approach swimmers closely but are seldom aggressive unless they are provoked. They are well-suited to ecotourism diving, and with conditioning they can be hand-fed by divers. Such tourism practices can be found in some of the Carribean islands, though the sharp species may vary.

PD Photo of a swimming white tip reef shark, facing three-quarters towards the camera; whitetip reef sharks are commonly encountered by humans and pose little danger.

The International Union for Conservation of Nature (IUCN) has assessed whitetip reef sharks as ‘Near Threatened’, as its numbers have dwindled in the recent decades due to increasing fishing. Whitetip reef sharks are caught for food, though there are reports of ciguatera poisoning caused by consuming them as food. The slow reproductive rate and limited habitat preferences of this species also renders its populations vulnerable to overexploitation.