Adults begin to reproduce once they attain a size of 2 to 3 meters (female) or 1.5 to 1.7 meters (male). They reproduce once per year but childbirth is biennial since the females get pregnant every other year. The reproduction method is Viviparous which means the pups develop inside of the mother. There is evidence that the reproduction method is aggressive and violent since many female Caribbean Reef Sharks have been found with deep wounds on their sides during mating season. These wounds are caused by bites and heal in time leaving large and highly visible scars.
The International Union for Conservation of Nature (IUCN) has assessed the Caribbean reef shark as Near Threatened; its population has declined off Belize and Cuba from overfishing and exploitation continues in other regions. They are also threatened by the degradation and destruction of their coral reef habitat. Commercial fishing for this species is prohibited in United States waters. They are protected in the Bahamas due to their significance to ecotourism, as well as in a number of Marine Protected Areas (MPAs) off Brazil and elsewhere. However, enforcement against illegal fishing is lacking in some of these reserves, and many areas in which this species is abundant are not protected.
On the infrequent occasions when they swim in oceanic waters, grey reef sharks often associate with marine mammals or large pelagic fishes, such as sailfish (Istiophorus platypterus). There is an account of around 25 grey reef sharks following a large pod of bottlenose dolphins (Tursiops sp.), along with 25 silky sharks (C. falciformis) and a single silvertip shark. Rainbow runners (Elagatis bipinnulata) have been observed rubbing against grey reef sharks, using the sharks' rough skin to scrape off parasites.
Off Enewetak, grey reef sharks exhibit different social behaviors on different parts of the reef. Sharks tend to be solitary on shallower reefs and pinnacles. Near reef drop-offs, loose aggregations of five to 20 sharks form in the morning and grow in number throughout the day before dispersing at night. In level areas, sharks form polarized schools (all swimming in the same direction) of around 30 individuals near the sea bottom, arranging themselves parallel to each other or slowly swimming in circles. Most individuals within polarized schools are females, and the formation of these schools has been theorized to relate to mating or pupping.
Although they only grow to about 1.6 to 3 meters (5 to 10 feet) in length, these sharks are the apex predators on the very delicate coral reefs. That means, around coral reefs, they are the top of the food chain. The significants of this goes largely unnoticed, but theWorld Wildlife Fund has classified the Reef Shark as one of the most important species on the entire planet!
A reef is a bar of rock, sand, coral or similar material, lying beneath the surface of water. Many reefs result from abiotic processes (i.e. deposition of sand, wave erosion planing down rock outcrops, and other natural processes), but the best known reefs are the coral reefs of tropical waters developed through biotic processes dominated by corals and coralline algae.