Silvertip Shark - Biology and Ecology

Biology and Ecology

Though silvertip sharks are quite mobile, they exhibit fidelity to certain areas and there are 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 shark, silvertip sharks sometimes perform a stereotypical threat display if pursued by divers, warning that it is prepared to attack. The display begins with the shark accelerating away to a distance of 15 m (50 ft), before turning and charging towards the perceived threat. At a distance of two body lengths, the shark brakes, turns broadside, drops its pectoral fins, gapes its jaws, lowers the posterior two-thirds of its body, and "shivers". The last two elements of this display are unique to this species; the "shivering" may serve to emphasize its white fin markings. If the diver persists, the shark may rapidly close in and slash with its upper teeth.