Oceanic Whitetip Shark

The oceanic whitetip shark (Carcharhinus longimanus) is a large pelagic requiem shark found in tropical and warm temperate seas. It is characterized by its stocky body and long, white-tipped fins. While typically solitary, these sharks may gather in large numbers where food concentrations are high. Their diet primarily consists of bony fish and cephalopods, and females give live birth.

The oceanic whitetip shark is known to be opportunistic and aggressive, making it potentially dangerous to shipwreck survivors. Unfortunately, the species is critically endangered according to the IUCN Red List, with populations declining rapidly due to the harvesting of fins and meat. Like other shark species, the oceanic whitetip faces increasing fishing pressure across its range.

These sharks can be found worldwide between 45°N and 43°S latitude and prefer deep, open oceans with temperatures greater than 18 °C (64 °F). They thrive in temperatures above 20 °C (68 °F) and up to 28 °C (82 °F), but are capable of withstanding temperatures as low as 15 °C (59 °F) while avoiding anything lower.

The oceanic whitetip shark's most distinctive features are its long, wing-like pectoral and dorsal fins, which are larger than those of most other shark species and have rounded tips. The shark has a rounded snout and circular eyes with nictitating membranes.

As a robust, large-bodied shark, the oceanic whitetip can reach lengths of over 4 m (13 ft) and weigh up to 150 kg (330 lbs). However, the average length is around 3 m (10 ft) and the females tend to be slightly larger than males by about 10 cm (3.9 in).

In terms of appearance, the shark has a gray-bronze color on its dorsal side and white on its ventral side. As the name suggests, most of its fins have white tips. The fins may also have mottled patterns, and young sharks can have black markings. A saddle-like patch may be visible between the first and second dorsal fins. The shark has two types of teeth, with those in the lower jaw being thinner and serrated and those in the upper jaw being larger, wider, and entirely serrated. The shark has a unique pattern of denticles, which are nearly flat and wide with five to seven ridges and very little overlap.

Oceanic whitetip sharks are typically solitary but can gather in groups when food is abundant. They are slow-moving and tend to swim near the top of the water column in open water. During the summer, when the water surface is warmer, they may swim faster and at deeper depths. These sharks have been observed breaching out of the water.

The species primarily feeds on pelagic cephalopods like squid and bony fish such as lancetfish, oarfish, barracuda, jacks, mahi-mahi, marlin, tuna, and mackerel. However, their diet can be more varied and less selective, including threadfins, stingrays, sea turtles, seabirds, gastropods, crustaceans, and carcasses of marine mammals. Their feeding methods involve swimming through schools of frenzied tuna with an open mouth, waiting for the fish to swim in before biting down. In the past, oceanic whitetip sharks were commonly found scavenging on floating carcasses during whaling. They often compete with silky sharks for food, which may explain their leisurely swimming style combined with aggressive behavior. They have also been observed trailing pilot whales since both species feed on squid.

The oceanic whitetip shark may be followed by pilot fish, dolphinfish, and remora. Sucker scars on the skin of an individual filmed off Hawaii (🇺🇸 United States) suggest that the species may dive deep enough to battle with giant squid. In the past, mariners referred to sharks as "sea dogs," and the oceanic whitetip was the most frequently seen shark following ships. They often form groups when there is an abundance of large bony fish, such as in Cat Island, 🇧🇸 Bahamas during winter and spring.

The mating and birthing of oceanic whitetip sharks appear to occur in early summer in the northwest Atlantic Ocean and southwest 🌊 Indian Ocean. However, females captured in the Pacific have been found with embryos year-round, suggesting a longer mating season in that region. These sharks are viviparous, with embryos developing in utero and being nourished by a placental sac. The gestation period lasts from nine months to one year. Both males and females reach maturity at around 180–190 cm (71–75 in) in length between the ages of six and seven. Growth continues at a rate of 9.10 cm (3.58 in) per year. The average length of maturity for females in the greater equatorial and southwestern Atlantic is 170 cm (67 in), and 170–190 cm (67–75 in) for males. In the Pacific, sharks appear to mature at four to five years old. One oceanic whitetip shark was estimated to have lived for 22 years.

Renowned oceanographic researcher Jacques Cousteau once described the oceanic whitetip shark as "the most dangerous of all sharks," while author and big-game fisherman Ernest Hemingway portrayed them as aggressive opportunists in The Old Man and the Sea.