Sandbar shark (C. plumbeus): The sandbar shark has a snout that is shorter than the width of its mouth and a large first dorsal fin originating over the axis of the pectoral fin (the Caribbean reef shark’s first dorsal fin is further from the head than the sandbar shark). Unlike the Caribbean reef shark, the sandbar shark has widely spaced non-overlapping dermal denticles that lack defined teeth on their free edges.
Reef Ambassadors are forever just passing through, crossing borders, taking in cultures, and exploring foreign shores. And now you can follow our ambassadors more closely, as we roll out a new monthly film series for 2016, showcasing their adventures in the best waves around the globe. This 10 Episode series will bring you along with our team to far off, exotic locales to iconic surf destinations.
Socially, they are mostly loners unless living in a threatening ecosystem. These are the first and the only species of sharks that are known to “sleep” on the ocean floor or within reef caves. It is believed that these sharks are not actually sleeping but merely resting. These sharks have actually been given the nickname “sleeping sharks” because of their habit of lying motionless at the sea bottom. This is a somewhat unusual and unique behavior of these sharks.
Reef sharks play a major role in shaping Caribbean reef communities.  As the top predators of the reef and indicator species for marine ecosystems, they help maintain the delicate balance of marine life in reef environments.  Reef sharks are highly valued for their meat, leather, liver oil, and fishmeal, which make them prone to overfishing and targeting. Yet, their importance for the tourism industry makes them more valuable alive than dead. In 2011, Honduras declared its waters to be a permanent sanctuary for sharks, making fishing for these species completely forbidden.

Grey reef sharks are active at all times of the day, with activity levels peaking at night.[4] At Rangiroa, groups of around 30 sharks spend the day together in a small part of their collective home range, dispersing at night into shallower water to forage for food. Their home range is about 0.8 km2 (0.31 sq mi).[25] At Enewetak in the Marshall Islands, grey reef sharks from different parts of the reef exhibit different social and ranging behaviors. Sharks on the outer ocean reefs tend to be nomadic, swimming long distances along the reef, while those around lagoon reefs and underwater pinnacles stay within defined daytime and night-time home ranges.[26] Where there are strong tidal currents, grey reef sharks move against the water: towards the shore with the ebbing tide and back out to sea with the rising tide. This may allow them to better detect the scent of their prey, or afford them the cover of turbid water in which to hunt.[25]


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.
Every year, Reef Check trains thousands of citizen scientist divers who volunteer to survey the health of coral reefs around the world, and rocky reef ecosystems along the entire coast of California. The results are used to improve the management of these critically important natural resources. Reef Check programs provide ecologically sound and economically sustainable solutions to save reefs, by creating partnerships among community volunteers, government agencies, businesses, universities and other nonprofits.

Grey reef sharks feed mainly on bony fishes, with cephalopods such as squid and octopus being the second-most important food group, and crustaceans such as crabs and lobsters making up the remainder. The larger sharks take a greater proportion of cephalopods.[20] These sharks hunt individually or in groups, and have been known to pin schools of fish against the outer walls of coral reefs for feeding.[14] Hunting groups of up to 700 grey reef sharks have been observed at Fakarava atoll in French Polynesia.[21][22] They excel at capturing fish swimming in the open, and they complement hunting whitetip reef sharks, which are more adept at capturing fish inside caves and crevices.[4] Their sense of smell is extremely acute, being capable of detecting one part tuna extract in 10 billion parts of sea water.[13] In the presence of a large quantity of food, grey reef sharks may be roused into a feeding frenzy; in one documented frenzy caused by an underwater explosion that killed several snappers, one of the sharks involved was attacked and consumed by the others.[23]


Typically a solitary animal, juvenile blacktip reef sharks will commonly conjugate in shallow regions during high tide. Vulnerable to larger predators, they will reside in shallower areas until larger in size. Blacktip reef sharks tend to be more active during dawn and dusk, but like most sharks they are opportunistic feeders. Their diet consists of crustaceans, squid, octopus, and bony fish.
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.
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