Whitetip Reef Shark

Triaenodon obesus - Whitetip Reef Shark

Whitetip reef shark. Photo © George Ryschkewitsch

Triaenodon obesus

This smaller, shy shark has a long, thin frame and a frowning, almost grumpy look on its face. It has distinct white tips on its dorsal and caudal (tail) fins, but otherwise is a dark gray-brown that fades to light on its underside. This is one of the few requiem sharks that doesn't have to keep swimming to breathe, and during the day it rests still on the sandy reef bottom or in caves, usually in groups. At night, the whitetip reef shark comes out to hunt sleeping fish, easily picking them out of crevices. Although it is curious around humans, it is considered a low threat, only becoming aggressive when provoked or when feeding.

Order - Carcharhiniformes
Family - Carcharhinidae
Genus - Triaenodon
Species - obesus

Common Names

Triaenodon obesus - Whitetip Reef Shark

Whitetip reef shark cruising coral reef waters. Photo courtesy NOAA

English language common names include whitetip reef shark, blunthead shark, blunt-head shark, light-tip shark, reef whitetip, reef whitetip shark, white tip reef shark, white-tip reef shark, whitetip shark, and white-tip shark. Common names in other languages include aileron blanc de lagon (French), arava (Tuamotuan), cazón (Spanish), cazón coralero trompacorta (Spanish), daaha (Somali), endormi requin (French), eno-eno (Gela), faana miyaru (Maldivian), gursh (Arabic), ikan yu (Malay) libaax (Somali), maog (Niuean), malu (Samoan), mamaru (Tahitian), manô lâlâ kea (Hawaiian), marracho de covas (Portuguese), miyaru (Maldivian), mweshar (Carolinian), nemuribuka (Japanese), pako korak (Marshallese), papa (Swahili), papa sarawanzi (Swahili), pating (Tagalog), peu (Carolinian), requin à pointes blanches (French), requin corail (French), riffhai (German), stompkophaai (Afrikaans), te alabafrnua (Tuvaluan), te bakoa (Kirabati), tintorera punta aleta blanca (Spanish), valkoevähai (Finnish), weißspitzenhundshai (German), and witpuntrifhaai (Dutch).

Importance to Humans

Triaenodon obesus - Whitetip Reef Shark

Whitetip reef shark in waters off the coast of Borneo. Photo © George Ryschkewitsch


Danger to Humans





> Check the status of the whitetip reef shark at the IUCN website.


Geographical Distribution

Triaenodon obesus - Whitetip Reef Shark, map

World distribution map for the whitetip reef shark





Triaenodon obesus - Whitetip Reef Shark

Whitetip reef shark. Illustration courtesy FAO Species Catalog, Vol. 4 Part 2 Sharks of the World

Distinctive Features
This small shark is relatively slender with a broad flattened head. The snout is broadly rounded and eyes are horizontally oval. Along with a down-slanted mouth, the prominent brow ridges give this shark a permanent "disgusted" expression to its face. The first dorsal fin originates well behind the free rear tips of the pectoral fins. The second dorsal fin is large, but smaller than the first dorsal. The pectoral fins are broad and triangular in shape. The anal fin is about as large as the second dorsal fin. There is no interdorsal ridge and lateral keels on the caudal penduncle are lacking.


Triaenodon obesus - Whitetip Reef Shark

Whitetip reef shark: note the distinct white tips on the first dorsal and upper caudal fins. Photo © Jeremy Stafford-Deitsch


There may arise some confusion between the whitetip reef shark and the silvertip shark (C. albimarginatus). The silvertip shark is a much heavier species with a large first dorsal and a much smaller second dorsal fin. Also, its caudal fin is lined with white rather than tipped as in the whitetip reef shark.

The tricuspid teeth each have one large triangular cusp in the middle along with two smaller ones on either side.

Triaenodon obesus - Whitetip Reef Shark

Whitetip reef shark dentition: upper and lower teeth. Image courtesy FAO Species Catalog, Vol. 4 Part 2 Sharks of the World

Size, Age, and Growth
The whitetip reef shark grow to a maximum length of just under 7 feet (2.13 m), however individuals are rare at lengths over 1.6 m (5.25 feet). Males mature at about 3.4 feet (1.05 m) and generally reach 5.5 feet (1.68 m) in length. Females reach maturity at 3.4-3.57 feet (1.05-1.09 m) and grow to at least 5.18 feet (1.58 m). This species is known to reach a maximum age of at least 25 years.

Food Habits

During mating, the male whitetip reef shark lies next to the female, using his mouth to hold on to her pectoral fins. This is followed by the male inserting one of his claspers into her genital opening, releasing sperm. Fertilization occurs internally, resulting in 1-5 embryos. These embryos are nourished via a placenta-like attachment to the mother during gestation. After an approximately 5 month gestation period, a litter of 1-5 pups is born with each pup measuring 20.5-23.6 inches (52-60 cm) in length. Mating and birth occur during varying seasons and is dependent upon location. At Enewetak Atoll, birth occurs during autumn and winter while in French Polynesia it occurs during the summer months.

Triaenodon obesus - Whitetip Reef Shark

The whitetip reef shark feeds during the night on benthic prey. Photo © George Ryschkewitsch


The copepod Paralebion elongatus is a parasite reported from whitetip reef sharks caught in Hawaiian waters.


Rüppell originally described this shark as Carcharias obesus in 1837. This name was changed to the currently valid scientific name of Triaenodon obesus (Rüppell, 1837) later that same year. A synonym referring to this species that has appeared in previous scientific literature is Triaenodon apicalis Whitely 1939.

Prepared by: Cathleen Bester