Belonging to the family of requiem sharks, gray reef sharks are mostly found in the shallow water of the Indo-Pacific region; in the vicinity of coral reefs. They are round and stout, with broad fins and large eyes. Their first dorsal fin, which is white-tipped, is the distinguishing feature of the species. The other fins have a darker tip, while the tail fin is broad and black. Moreover, the dorsal fins have no ridges in between.
Gray reef sharks are fast-swimmers and are extremely quick predators, feeding especially on cephalopods and bony fish. In spite of their size, they dominate the marine world due to their aggressive behavior. These sharks are social creatures and have a specific area to which they return after roaming around for food. While hunting, they hunt individually, especially in the evenings. During the day time, they roam about in groups of 5 to 20.
Facts on Gray Reef Sharks
The underside of these sharks is white in color, with white patterns on the edges of the dorsal fin. In most of them, a black margin can be found on the caudal fin. At times, they are confused for blacktip reef sharks owing to the similarity in their appearance. The only distinguishing feature in the comparison of these two species, is that blacktip reef sharks have a distinct black tip on their dorsal fin.
The longest known specimen had a length of 255 cm, while the heaviest specimen weighed 33.7 kg. On an average, these sharks have a lifespan of 25 years. They give birth to live offspring, just like humans, and their embryos get their food from the placenta inside the womb of the female shark. At a time, the female gray reef shark can give birth to one to six young ones.
Usually, they live in warm subtropical and tropical waters. They are mostly found around coral reefs and lagoons, and are also found swimming around the outer edges of coral reefs. The depth at which these fish are found ranges from about 10 to 900 feet, but then they are also known to dive deeper to more than 3,000 feet.
Ordinarily, they are highly active at night, but there are times when these fish form schools and hunt during the day time. When in groups, they swim at the bottom of the sea and sometimes, are found to form loose aggregations. Individual reef sharks can be found around shallow reefs or lying motionless for long periods at the sea bottom. These fish are also found near insular and continental shelves.
Gray reef sharks prefer clear water with rugged areas. The water current should be flowing towards the leeward sides of the reefs. Studies have shown that those sharks that live near reefs do not stay there for a long time and travel continuously. On the other hand, those which live in lagoons are found to return to the same site.
These sharks are mostly found in the Pacific―along the coasts of New Zealand, northern parts of Australia, southern China, Indonesia, and Philippines, and the Indian Ocean―where they inhabit waters of Maldives and Madagascar. Besides these regions, they are also found in the seas surrounding the Indian and South African peninsula, and the Red sea.
In several regions, gray reef sharks are hunted extensively, which has resulted in them becoming endangered. Moreover, continuous depletion of their habitat and late age of maturity also put tremendous pressure on their population. Conservation methods have yielded results, but more needs to be done.