The Black-tip Shark (Carcharhinus melanopterus) is a species of shark of the family Carcharhinidae, easily identified by the black tips of its fins, especially on the first dorsal fin and the caudal fin. It is one of the most abundant sharks in the tropical coral reefs of the Indian Ocean and Pacific Ocean. This species prefers shallow coastal waters and frequently exposes its first dorsal fin in these areas. Most Black-tipped Sharks live on reef margins and sandy bottoms, but they are also known to support brackish or freshwater environments. This species generally reaches a length of 1.6 m. Black-tip Sharks are sedentary and live in very small areas and may remain in the same area for several years. They are active predators of small bone fish, cephalopods and crustaceans, and are also known to feed on marine snakes and seabirds. The data collected concerning the life cycle of the Black-tip Shark are sometimes contradictory and there appear to be significant differences depending on the geographical location within the range of the species. Like other members of its family, this shark is viviparous and females give birth to between two and five young babies every two years, every year or sometimes twice a year. Indeed, according to its habitat the gestation period of this shark can be 7-9 months, 10-11 months or 16 months. Newborns live in coastal waters and in shallower waters than adults, often forming large groups in areas flooded by high tides. Shy and capricious, the Black-tip Shark is difficult to approach and rarely represents a danger to humans, unless it is excited by food. However, bathers in shallow waters can sometimes have their legs bitten by mistake. This shark is fished for its meat, fins and liver oil, but is not considered to be a commercially important species. The International Union for Conservation of Nature assessed the near threatened species. Although the species as a whole remains widespread and relatively common, overfishing of this shark and its slow rate of reproduction has led to its decline in a number of localities.
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. 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. Hunting groups of up to 700 grey reef sharks have been observed at Fakarava atoll in French Polynesia. 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. Their sense of smell is extremely acute, being capable of detecting one part tuna extract in 10 billion parts of sea water. 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.
The Caribbean Reef Shark, also called the Carcharhinus Perezi in the scientific community, is a member of the requiem shark species. They are mostly found on the East coast of America (Atlantic coast) and southwards. The structure of this shark is streamlined and robust and can be easily confused with other sharks in its family. When you look up close, they have an extra rear tip on the second dorsal fin. The first dorsal fin is slightly angled or curved and the gills slits are also longer than most other varieties of sharks.
Based on morphological similarities, Jack Garrick in 1982 grouped this species with the bignose shark (C. altimus) and the sandbar shark (C. plumbeus), while Leonard Compagno in 1988 placed it as the sister species of the grey reef shark (C. amblyrhynchos). A phylogenetic analysis based on allozyme data, published by Gavin Naylor in 1992, indicated that the Caribbean reef shark is the sister taxon to a clade formed by the Galapagos shark (C. galapagensis), dusky shark (C. obscurus), oceanic whitetip shark (C. longimanus), and the blue shark (Prionace glauca). However, more work is required to fully resolve the interrelationships within Carcharhinus.
At Reef Dispensaries, our core philosophy is to put people first, extending to both our customers and our team. Our mission is to inspire hope in a healthy community, enhancing everyday life through a wide variety of products for every level of patient. Our unprecedented, innovative cultivation and production facilities ensure consistent quality of flower and concentrates. We value knowledge, trust, respect and a sense of urgency.
But another potential cause is that these sharks are skittish around people. So when too many people move into the area, the reef sharks flee to other coral reefs. Indeed, the researchers found far more sharks at small, isolated reefs than they expected. But this in itself is a danger to the reef sharks. With so many sharks concentrated in a small area, “if you really wanted to, you could fish out a few hundred sharks very easily,” said Friedlander.
Like many sharks, the Caribbean reef shark mainly eats bony fishes. The shark uses six keen senses to locate its prey: olfactory, visual, tactile (including water vibration sensitivity through a lateralis canal system), auditory, gustatory, and electric reception. The Caribbean reef shark is especially adapted to detecting low frequency sounds (indicative of a struggling fish nearby).
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. Off Hawaii, individuals may stay around the same part of the reef for up to three years, while at Rangiroa, they regularly shift their locations by up to 15 km (9.3 mi). 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.
Most observed displays by grey reef sharks have been in response to a diver (or submersible) approaching and following it from a few meters behind and above. They also perform the display towards moray eels, and in one instance towards a much larger great hammerhead (which subsequently withdrew). However, they have never been seen performing threat displays towards each other. This suggests the display is primarily a response to potential threats (i.e. predators) rather than competitors. As grey reef sharks are not territorial, they are speculated to be defending a critical volume of "personal space" around themselves. Compared to sharks from French Polynesia or Micronesia, grey reef sharks from the Indian Ocean and western Pacific are not as aggressive and less given to displaying.
Anchialine pool Archipelago Atoll Avulsion Ayre Barrier island Bay Baymouth bar Bight Bodden Brackish marsh Cape Channel Cliff Coast Coastal plain Coastal waterfall Continental margin Continental shelf Coral reef Cove Dune cliff-top Estuary Firth Fjard Fjord Förde Freshwater marsh Fundus Gat Geo Gulf Gut Headland Inlet Intertidal wetland Island Islet Isthmus Lagoon Machair Marine terrace Mega delta Mouth bar Mudflat Natural arch Peninsula Reef Regressive delta Ria River delta Salt marsh Shoal Shore Skerry Sound Spit Stack Strait Strand plain Submarine canyon Tidal island Tidal marsh Tide pool Tied island Tombolo Windwatt