Among the most abundant sharks inhabiting the tropical coral reefs of the Indian and Pacific Oceans, this species prefers shallow, inshore waters.

The blacktip reef shark has extremely small home ranges and exhibits strong site fidelity, remaining within the same local area for up to several years at a time.

Accounts of the blacktip reef shark's life history have been variable and sometimes contradictory, in part reflecting geographical differences within the species.

Like other members of its family, this shark is viviparous, with females giving birth to two to five young on a biennial, annual, or possibly biannual cycle.

Newborn sharks are found further inshore and in shallower water than adults, frequently roaming in large groups over areas flooded by high tide.

French naturalists Jean René Constant Quoy and Joseph Paul Gaimard originally described the blacktip reef shark during the 1817–1820 exploratory voyage of the corvette Uranie.

A 1998 allozyme analysis by Gavin Naylor again yielded ambiguous results, finding that the blacktip reef shark forms a polytomy (irresolvable group) with 10 other Carcharhinus species.

[9] Although it has been reported from a depth of 75 m (246 ft),[6] the blacktip reef shark is usually found in water only a few meters deep, and can often be seen swimming close to shore with its dorsal fin exposed.

This species has also been reported from brackish estuaries and lakes in Madagascar, and freshwater environments in Malaysia, though it is not able to tolerate low salinity to the same degree as the bull shark (C. leucas).

The sharks spend most of their time swimming back and forth along reef ledges, making occasional short forays onto sandy flats.

Their average swimming speed decreases when the tide rises at night, possibly because the influx of cooler water reduces their metabolism, or the accompanying movement of prey fishes makes foraging easier.

[17] Blacktip reef sharks at Aldabra tend to be more mobile than those at Palmyra, with recorded individual movements of up to 2.5 km (1.6 mi) over 7 hours.

[17] Their known parasites include the tapeworms Anthobothrium lesteri,[18] Nybelinia queenslandensis,[19] Otobothrium alexanderi,[20] and Platybothrium jondoeorum,[21] a myxosporidian in the genus Unicapsula,[22] and the monogenean Dermophthirius melanopteri.

[24] As often the most abundant apex predator within its ecosystem, the blacktip reef shark plays a major role in structuring inshore ecological communities.

[16] Its diet is composed primarily of small teleost fishes, including mullet, groupers, grunters, jacks, mojarras, wrasses, surgeonfish, and smelt-whitings.

[3][9] Off northern Australia, this species is known to consume sea snakes, including Acrochordus granulatus, Hydrelaps darwiniensis, Hydrophis spp.

[16] Miscellaneous items that have been found inside the stomachs of this species include algae, turtle grass, coral, hydrozoa, bryozoa, rats, and stones.

[13][16] Researchers working at Enewetak Atoll in the Marshall Islands have found the blacktip reef shark can be readily attracted by splashing or striking metal tools against hard objects underwater, as well as by the scent of both healthy and injured fish.

Instead, its vision is adapted for sensitivity to movement or contrast under low light conditions, which is further enhanced by the presence of a reflective tapetum lucidum.

[13] Earlier accounts from the Indian Ocean by Johnson (1978), Madagascar by Fourmanoir (1961), and the Red Sea by Gohar and Mazhar (1964), indicated a biannual cycle in these regions with two breeding seasons per year from June to July and December to January.

After four months, the yolk sac has begun to be converted into a placental connection that attaches to the uterine wall; at this time, the embryo's dark fin markings develop.

[9][13] Young blacktip reef sharks commonly form large groups in water barely deep enough to cover their bodies, over sand flats or in mangrove swamps close to shore.

[38] Most attacks involve sharks biting the legs or feet of waders, apparently mistaking them for their natural prey, and do not result in serious injury.

[3] The blacktip reef shark is a normal catch of coastal fisheries, such as those operating off Thailand and India, but is not targeted or considered commercially important.

[9][16] Blacktip reef sharks are popular subjects of public aquarium exhibits, because of their stereotypically "shark-like" appearance, ability to breed in captivity and modest size, and are also attractions for ecotourism divers.