Marshall Islands, the Phoenix Islands and Tahiti. In the eastern Pacific, it occurs from southern Baja California to Colombia, including the Cocos, Galapagos, and Revillagigedo Islands. Its presence in the Gulf of Mexico and the Caribbean Sea is unconfirmed. Silvertip sharks are found over continental and insular shelves at a depth of , occupying all levels of the water column. They are most common around isolated islands, coral banks, and reef drop-offs. Juveniles frequent coastal shallows or lagoons, while adults occur in deeper water, with little overlap between the two age groups. Description The silvertip shark is a robust and streamlined species with a moderately long, broad snout and large, round eyes. The five pairs of gill slits are short. It has 12–14 tooth rows on each side of both jaws, with one or two small teeth at the symphysis (middle of the jaws). The upper teeth are broad with oblique triangular cusps and coarse serrations near the base; the lower teeth have erect cusps with fine serrations. The first dorsal fin is large and triangular, originating above or slightly forward of the free pectoral fin tips. A ridge occurs between the first and second dorsal fins. The pectoral fins are proportionately longer than in most requiem sharks and falcate (sickle-like) in shape, with pointed tips. The coloration is blue-gray above with a bronze sheen, and white below. A subtle white band runs along the sides, with distinctive white tips and borders on all fins. Silvertip sharks can grow up to long, but typically measure in length. The maximum reported weight is . Females are larger than males. Biology and ecology Though silvertip sharks are quite mobile, they exhibit fidelity to certain areas, with reports of territorial behavior. They are usually encountered alone or in pairs. Small groups of adult females have been seen in deep water. Individual silvertip sharks behave very aggressively towards one another, and many are heavily scarred. They are also reported to dominate Galapagos sharks (C. galapagensis) and blacktip sharks (C. limbatus) of equal size when competing for food. This shark sometimes forms mixed-species aggregations with grey reef sharks. Rainbow runners (Elagatis bipinnulata) have been observed rubbing against silvertip sharks, using the sharks' rough skin to scrape off parasites. They sometimes follow marine mammals such as bottlenose dolphins (Tursiops sp.) in open water, and are themselves followed by pilot fish (Naucrates ductor). Like the grey reef