Grey reef sharks are often curious about divers when they first enter the water and may approach quite closely, though they lose interest on repeat dives.[4] They can become dangerous in the presence of food, and tend to be more aggressive if encountered in open water rather than on the reef.[13] There have been several known attacks on spearfishers, possibly by mistake, when the shark struck at the speared fish close to the diver. This species will also attack if pursued or cornered, and divers should immediately retreat (slowly and always facing the shark) if it begins to perform a threat display.[4] Photographing the display should not be attempted, as the flash from a camera is known to have incited at least one attack.[3] Although of modest size, they are capable of inflicting significant damage: during one study of the threat display, a grey reef shark attacked the researchers' submersible multiple times, leaving tooth marks in the plastic windows and biting off one of the propellers. The shark consistently launched its attacks from a distance of 6 m (20 ft), which it was able to cover in a third of a second.[14] As of 2008, the International Shark Attack File listed seven unprovoked and six provoked attacks (none of them fatal) attributable to this species.[29]
The Caribbean reef shark is found throughout tropical waters, particularly in the Caribbean Sea. This shark’s range includes Florida, Bermuda, the northern Gulf of Mexico, Yucatan, Cuba, Jamaica, Bahamas, Mexico, Puerto Rico, Colombia, Venezuela, and Brazil. It is one of the most abundant sharks around the Bahamas and the Antilles. Although Caribbean reef sharks are found near reefs in southern Florida, surveys using long-line gear off the east coast of Florida reveal that Caribbean reef sharks are extremely rare north of the Florida Keys.
The Caribbean reef shark has an interdorsal ridge from the rear of the first dorsal fin to the front of the second dorsal fin. The second dorsal fin has a very short free rear tip. The snout of C. perezi is moderately short and broadly rounded. It has poorly developed, low anterior nasal flaps and relatively large circular eyes. Caribbean reef sharks also have moderately long gill slits with the third gill slit lying above the origin of the pectoral fin. Comparison to similar sharks:
In California, Reef Check helps ensure the long-term sustainability and health of the nearshore rocky reefs and kelp forests. Reef Check California volunteers are divers, fishermen, kayakers, surfers, boaters, and a wide range of Californians who take a proactive role in making sure that our nearshore ecosystems are healthy and well managed. We monitor rocky reefs inside and outside of California's marine protected areas (MPAs). We work with marine managers, researchers and the public to provide the scientific data needed to make informed, science-based decisions for the sustainable management and conservation of California's ocean environment. We would love your support, volunteer today!
The Reef story started 25 years ago when two brothers from Argentina Fernando and Santiago Aguerre acted on an idea to produce high quality, comfortable yet stylish sandals. Inspired by their love of the California lifestyle and surfing culture, the brothers moved to California in the early 80's and found Reef sandals. With a tiny amount of start up capital of $4000 and after lots of hard work Reef is now widely considered to be the number one sandal brand in the world.
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.
Social aggregation is well documented in grey reef sharks. In the northwestern Hawaiian Islands, large numbers of pregnant adult females have been observed slowly swimming in circles in shallow water, occasionally exposing their dorsal fins or backs. These groups last from 11:00 to 15:00, corresponding to peak daylight hours.[28] Similarly, at Sand Island off Johnston Atoll, females form aggregations in shallow water from March to June. The number of sharks per group differs from year to year. Each day, the sharks begin arriving at the aggregation area at 09:00, reaching a peak in numbers during the hottest part of the day in the afternoon, and dispersing by 19:00. Individual sharks return to the aggregation site every one to six days. These female sharks are speculated to be taking advantage of the warmer water to speed their growth or that of their embryos. The shallow waters may also enable them to avoid unwanted attention by males.[10]
The Caribbean reef shark is found throughout tropical waters, particularly in the Caribbean Sea. This shark’s range includes Florida, Bermuda, the northern Gulf of Mexico, Yucatan, Cuba, Jamaica, Bahamas, Mexico, Puerto Rico, Colombia, Venezuela, and Brazil. It is one of the most abundant sharks around the Bahamas and the Antilles. Although Caribbean reef sharks are found near reefs in southern Florida, surveys using long-line gear off the east coast of Florida reveal that Caribbean reef sharks are extremely rare north of the Florida Keys.
There is little evidence of territoriality in the grey reef shark; individuals will tolerate others of their species entering and feeding within their home ranges.[27] Off Hawaii, individuals may stay around the same part of the reef for up to three years,[28] while at Rangiroa, they regularly shift their locations by up to 15 km (9.3 mi).[27] Individual grey reef sharks at Enewetak become highly aggressive at specific locations, suggesting they may exhibit dominant behavior over other sharks in their home areas.[3]
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]

Barcode of Life ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History Ichthyology Department ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species Database ~ WoRMS

Measuring up to 3 m (9.8 ft) long, the Caribbean reef shark is one of the largest apex predators in the reef ecosystem, feeding on a variety of fishes and cephalopods. They have been documented resting motionless on the sea bottom or inside caves, unusual behavior for an active-swimming shark. If threatened, it may perform a threat display in which it frequently changes direction and dips its pectoral fins. Like other requiem sharks, it is viviparous with females giving birth to 4–6 young every other year. Caribbean reef sharks are of some importance to fisheries as a source of meat, leather, liver oil, and fishmeal, but recently they have become more valuable as an ecotourist attraction. In the Bahamas and elsewhere, bait is used to attract them to groups of divers in controversial "shark feedings". This species is responsible for a small number of attacks on humans. The shark attacks usually happen in spring and summer.


Blacktip reef sharks, Carcharhinus melanopterus (Quoy and Gaimard, 1824), are small sharks measuring up to 1.8 m with short, bluntly-rounded snouts, oval eyes, and narrow-cusped teeth. They have 2 dorsal fins and no interdorsal ridges. Juveniles (< 70 cm) are yellow-brown on their dorsal (upper) sides, white on their ventral (under) sides; adults are brownish-gray and white, respectively. All their fins have conspicuous black or dark brown tips, and posterior (rear) dark edges on their pectoral fins and their upper lobe of their caudal (tail) fins. The prominent black tips of their first dorsal fin contrasts with a light band below it; a conspicuous dark band on their flanks which extends to their pelvic fins. Maximum weight: 24 kg; frequents depth ranges from the surface to 75 m.
Blacktip reef sharks are regularly caught by inshore fisheries and are vulnerable to depletion because of their small litter sizes and long gestation periods. Traumatogenic. May become aggressive to spear fishers and are reported to bite people wading in shallow water. Generally marketed fresh (as fillet), may be dried, salted, smoked or frozen. Fins are valued for shark-fin soup; a market that is decimating shark populations worldwide. They are also sought for their liver as source of oil.
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.
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