The Caribbean reef shark is a viviparous species, meaning its developing embryos are nourished via a placental connection. The litters average four to six pups. Although this shark’s reproduction has not been studied in the northern hemisphere, but to the south, parturition occurs during the Amazon summer of November to December. Pregnant females are often found to have biting scars from males on the sides of their bodies, due to the aggressive behaviors of males during mating. Gestation is believed to take approximately one year. A pregnant female with biting scars and wounds on the sides of her body, taken off the coast of north-northeastern Brazil, carried four near-term embryos. One was a 27.5 in. (700 mm) long male and three were females measuring 27.0 in. (685 mm), 27.4 in. (697 mm), and 27.7 in. (704 mm) in length. Because she was carrying near-term embryos, it is postulated that this area may be a pupping ground. Although such captures have shed light on the topic, relatively little is known about the reproduction of the Caribbean reef shark. Much information has been obtained from a pregnant female carrying four near-term embryos off the coast of northeastern Brazil. This female had scars and wounds on her side. Because the shark carried near-term embryos, it is postulated that this area may be a pupping ground.
Along with the blacktip reef shark (C. melanopterus) and the whitetip reef shark (Triaenodon obesus), the grey reef shark is one of the three most common sharks inhabiting Indo-Pacific reefs. They actively expel most other shark species from favored habitats, even species larger in size. In areas where this species co-exists with the blacktip reef shark, the latter species occupies the shallow flats, while the former stays in deeper water. Areas with a high abundance of grey reef sharks tend to contain few sandbar sharks (C. plumbeus), and vice versa; this may be due to their similar diets causing competitive exclusion.
These biotic reef types take on additional names depending upon how the reef lies in relation to the land, if any. Reef types include fringing reef, barrier reefs, as well as atolls. A fringing reef is a reef that is attached to an island. A barrier reef forms a calcareous barrier around an island resulting in a lagoon between the shore and the reef. An atoll is a ring reef with no land present. The reef front (ocean side) is a high energy locale whereas the internal lagoon will be at a lower energy with fine grained sediments.