The maximum length for this species is 3.3 metres (10 feet). Males mature at the lengths of 2.2-2.3 metres (9-10 years of age) and grow to a lesser size than females, which reach maturity at the lengths 2.3-2.5 metres (12 years of age), however, these numbers are different among the different populations of this species. Silky sharks weigh around 350 kilograms (770 pounds).
The first specimen described was given the name "Carcharias (Prionodon) falciformis" by Johannes Müller and Jakob Henle in 1841. The genus name "Carcharhinus" comes from the Greek words ""karcharos"" which means "sharpen", and ""rhinos"" which means "nose". Other names given to the Silky shark are "Squalus" or "Prionodon tiburo", "Gymnorhinus" or "Gymnorrhinus pharaonis", "Aprionodon sitankaiensis", "Carcharhinus floridanus", "Eulamia malpeloensis", and "Carcharhinus atrodorsus".
The Silky shark is common in tropical and subtropical waters, and is found in the Atlantic, Pacific and Indian Oceans. In the western Atlantic, it ranges from the U.S state Massachusetts to Brazil (including the Gulf of Mexico and Caribbean Sea), and in the east it ranges from Spain to Angola. It is found in the western Indian Ocean and the Red Sea from Tanzania to Mozambique, including Madagascar and the Comores, and in the middle and eastern Indian Ocean in ranges from the Maldives and Sri Lanka to western Australia. It is found from China to New Zealand in the western Pacific (including the Hawaiian Islands), and Baja California to Peru in the eastern Pacific.
Although the Silky shark is mainly found in the pelagic zone, the Silky shark is not just found in the open ocean, but has also been recorded from depths as shallow as 18 meters (56 ft). It is an active, swift shark that prefers warmer waters (about 23°C). It is commonly found near the edges of continental shelves and over deep water reefs where there is a large amount of food source. It mainly ranges from the surface down to at least 500 meters (1,550 ft) but has been caught over water as deep as 4000 meters (12,400 ft). Studies show that groups of Silky sharks contain Silky sharks of different genders, but of the same size. Young Silky sharks can be found in coastal nurseries and adults are found further offshore, over deeper waters.
The Silky shark feeds mainly on bony fish such as tuna, mackerel, sardines, mullets, groupers, snappers, sea chubs, sea catfish, eels, lanternfish, filefish, triggerfish, and porcupinefish. It's diet also includes squid, paper nautilus, and swimming crabs, and there is fossil evidence of it scavenging on dead whales. Since of their good sense of hearing, and hunting tactics, these sharks are excellent hunters. They usually work together to "herd" groups of small fish to the surface, trapping the fish. When the fish are all tightly packed together, the Silky sharks attack the fish with great speed, and often consume the whole group of fish.
The Silky shark is viviparous, meaning that it gives live birth. In the western north Atlantic, females mate in the late spring (May-June), and give birth in the same time period, but in the next year, meaning that the gestation period lasts 12 months. The number of pups per litter is 6-14 in the western Atlantic, 9-12 in the eastern Atlantic, 9-14 in the western Indian Ocean, and 2-11 in the central Indian. The young spend their first few months in coral reefs, but move to the open ocean by the first winter. In the western north Atlantic, nursery areas are located along the Caribbean islands.
In english, the Silky shark is also called the "Net-eater shark" in the eastern Pacific because of the fact that it is often caught in nets used for fishing tuna. The Silky shark is also called the "Blackspot shark", "Grey whaler shark", "Olive shark", "Reef shark", "Ridgeback shark", "Sickle shark", "Sickle silk shark", and "Sickle-shaped shark". In other languages, the Silky shark is called the "cação" (Portuguese), "cazon" (Spanish), "cazon de playa" (Spanish), "cazón-tiburón" (Spanish), "haukkahai" (Finnish), "jaqueta" (Spanish), "jaqueton" (Spanish), "kanhaai" (Dutch), "karcharinos lios" (Greek), "kurotogarizame" (Japanese), "lombo preto" (Portuguese), "malie" (Samoan), "mandi sravu" (Malay), "mangeur d'hommes" (French), "marracho sedoso" (Portuguese), "marracho-luzidio" (Portuguese), "mbamba menyo" (Swahili), "moosi" (Gujarati), "mungsing" (Javanese), "mushi" (Marathi), "papa" (Swahili), "papa bunshu" (Swahili), "pating" (Tagalog), "requin soyeux" (French), "seidenhai" (German), "suga sura" (Telugu), "syhaai" (Afrikaans), "tiburón" (Spanish), "tiburon jaqueton" (Spanish), "tiburón lustroso" (Spanish), "tiburón sedoso" (Spanish), "tinterero" (Spanish), "tollo" (Spanish), "tollo mantequero" (Spanish), "tribon berde" (Papiamento), "tubarão-luzidio" (Portuguese), "yu jereh" (Malay), "yu pasir" (Malay), and "zijdehaai" (Dutch).
Silky sharks are considered dangerous to humans because of their aggressive nature and size. Silky sharks have been observed with their head raised, back arched and tail lowered, a posture believed to be a form of threat display.
Silky sharks are important to longline and gillnet fisheries in many parts of the world. In the Gulf of Mexico they are often caught with tuna catches, but are also caught by shark fishery. In the Caribbean they are sometimes fished, usually by longline, but they are not a common catch. In the Maldives and Sri Lanka, they are the most important shark species, making up 70-80% of the catches made in the pelagic zone. In Japanese waters, Silky sharks are a common target species of the shark fishery and are also caught with swordfish and tuna fisheries. In the mid-Atlantic waters of the U.S.A, the Silky shark is fished on a limited basis, but not in significant numbers. The meat, oil, and fins of the Silky shark are sold commercially. The Silky shark is also fished by recreational fishermen. Like other sharks, the Silky shark is in danger due to overfishing, because of its long gestation period, low number of offspring, and slow growth rate.
Other than its importance to various fisheries, Silky sharks have been used in various scientific studies to investigate the sensory biology of sharks.
Hairpin turn
A hairpin turn (also hairpin bend, hairpin corner, or just hairpin), is a very tight corner. It makes a vehicle turn almost 180° to continue on the road. It gets its name from the way it looks like a hairpin or bobby pin. Hairpin turns may be called switchbacks in American English.
Hairpin turns may be built when a road or path climbs up or down a steep slope. This allows the path to travel the slope with a smaller slope. Hairpin turns may be used in race tracks to slow down the race cars after a long, fast straight.
Sepang International Circuit
The Sepang International Circuit (SIC) is a racing circuit in Sepang, Selangor, Malaysia. It is near the Kuala Lumpur International Airport, about 60 km south of the capital city Kuala Lumpur. It is the venue used for the Formula One Malaysian Grand Prix, A1 Grand Prix as well as the Malaysian MotoGP. The circuit was designed by German designer Hermann Tilke.
The main circuit is 5.54 km long. It is raced in a clockwise direction. It is noted for its sweeping corners and wide straights. The layout is unusual, with a very long back straight separated from the pit straight by just one very tight hairpin corner.
The circuit may be set-up with other configurations. The north circuit is the first half of the main circuit. The course turns back towards the pit straight after turn 6 and is 2.71 km long.
The south circuit is the other half of the circuit. The back straight of the main circuit becomes the pit straight. It joins onto turn 8 of the main circuit to form a hairpin turn. This circuit is 2.61 km in length.
Sepang International Circuit also features kart racing and motocross facilities.
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