 牛鲨 牛鲨
Cow shark (carcharhinus leucas) because of its sturdy as a bull's shape, wide flat nose, and with aggressive behavior and name, scientific name of white sharks (bull shark carcharhinus leucas), also known as the bull shark, bull shark English name bull shark. In India, cow sharks are generally known as the Sundarbans, the Ganges shark, or shark, fish curry dishes in Bangladesh. In Africa, commonly referred to as the Zambezi shark (zambezi). Its wide distribution and different habitats make it in different places have different names, such as Nicaragua shark and so on.
Named person (müller et henle, 1839)
Category:
The animal kingdom - chordates door - Pisces cartilage - sharks Head - sharks suborder - Carcharhinidae - sharks are - cow sharks.
Range:
Cow shark activity in the fresh water, they are in warm coastal areas of the ocean, reefs, sand mud, rivers, estuaries and lakes are common in fresh water or salt water. Cow shark can reach the depth of 150 meters in places, but generally not deeper than 30 meters.
Cow shark located in Western Australia to Brazil from any of the tropical and subtropical coastal waters. In the Atlantic Ocean east and west sides of the Pacific east and west sides, the Indian Ocean are distributed the West Bank, roughly in the range between 40 degrees latitude north and south, the South China Sea, too.
In the Atlantic, from Massachu_set_ts to southern Brazil, from Morocco to Angola, one can see traces of them. In the Indian Ocean, they come and go in South Africa to Kenya, India, Vietnam to Australia. An estimated 500 head of cattle more than the shark in the Brisbane River in Queensland, Australia, and more cattle located in Gold Coast shark.
In the Pacific, they are living in Baja California to Ecuador. They also have the population living in the Amazon, and the farthest reaches record is about to reach the Mississippi River, Illinois location. Lake Nicaragua, India, West Bengal and Assam, Bangladesh, the Ganges and Brahmaputra, are they haunt. They can live in any waters, including South Africa, salt Lake St Lucia. However, cattle are not true freshwater sharks shark. Hurricane Katrina swept across the United States in 2005 after the Lake Pontchartrain also found a large number of cattle one shark.
Scholars have recently considered the cattle in the Lake Nicaragua shark should be another species, because the lake has no outlet. While others think they will skip like a salmon-like rushing streams, because scientists have a shark in the lake were some of the cattle identification, the shark was in the sea cow was found. Although the level of protection cow shark in iucn (International Union for Conservation of Nature and Natural Resources) in the still relatively low, but because of human over-hunting, cow shark is about to enter the ranks of endangered animals.
Characteristics:
Cow shark smaller body than other sharks is relatively broad, thick trunk, the whole body was fusiform. Showed a dark gray dorsal side, ventral to gray. Male cow shark can grow to 2.1 meters long, 90 kg. Females are larger, up to 3.5 meters long, 230 kilograms in weight.
Cow shark's head wide and flat, the long tail above and below the base has a concave depression. Cow shark eyes, very round, instant film developed. Nose was wide and triangular flap; no nose and mouth ditch or tentacles.
Cow shark most appalling is that it's a big mouth, that mouth disproportionately large, was split arc, round and short snout is very wide, thick with sharp teeth. Cow shark tooth upper flat and wide, margin serrulate long, sharp teeth straight or slightly oblique, not a small sharp teeth; mandibular teeth narrow jaw and vertical or slightly oblique, serrated edges and long, near the base is smooth. Cow shark's upper and lower teeth also have division of labor: a sharp lower teeth to facilitate and nm prey, firmly grasp the prey; triangular serrated like the teeth, for to devour, cutting food, the prey, piercing, tearing the flesh of prey . Cow shark mouth closed tight when the upper and lower jaws together, do not grin.
Cow shark has two dorsal fins, there is no ridge between dorsal fins, the first dorsal fin large, starting with the rear base of pectoral fin relative, concave trailing edge, bottom corner tip protrusion; the first one the second dorsal fin small, starting before the starting point in the anal or relative , trailing edge into the pit, after the sudden sharp angle; pectoral fins large, was sickle-shaped, posterior margin concave, outer corner of blunt tip, obtuse angles, side fins extending up to the first one back-end of a dorsal fin base; caudal fin width to length, tail vertebral axial rise, the front of the lower lobe was significantly triangle prominent, central low-lying extended between the long and the rear has a deep notch, the rear of the small triangle prominent, blunt tip end. Baby shark fin at the top of the block in black marker, grow up will disappear.
Feeding:
Shark infested cattle hunt alone, they generally hovered in the shallow water. Cow shark is a regular sneak in shallow water feeding sharks. It is highly offensive, the scientists see it as the best fight of the sharks. Cow shark is an ambush predator, it can cause fatal wounds, no matter what game it is fearless.
Food:
When cow shark predation Xiude accurate, quick bite, eat more, and never picky eaters, it is mainly to include other sharks (even great whites), including fish for food, animals eat rays, dolphins, sea turtles, dolphins , sea birds, molluscs, echinoderms, crustaceans, Amon, and even dogs. Cow shark often in the river mouth upstream to prey hippos, rhinos, crocodiles and other aquatic animals. For some things can not eat, such as plastic bags, broken fishing nets, according to swallow cow shark is not wrong, and even shark's stomach was found in cattle over coal and car number plates.
Propagation:
Cow shark to viviparous reproduction. Pregnancy a year, a litter 1-13. Cattle eating shark eggs have a very strange behavior, the strongest of the embryos in the womb unfertilized eggs or eat less of the embryo. Therefore, their hunting skills in the mother's belly cow when Shark began to trained, finally, only the strongest, most ferocious, can have a chance to survive. Cow shark summer in estuaries the general production. Pups at birth is about 70 cm, about 10 years to reach maturity, when the cow shark is still relatively weak. Immature female shark pups will bring coastal waters have been to childhood, to avoid being the other shark attacks. Cow shark life in general in 12 years.
Brutal killer:
Cow shark in about 4 billion years ago, had been cruising in the sea, than it is now also home to the other as early as 100 million sharks, is the most ferocious sharks in the family, one of the most fearsome of the sharks. Cow shark and great white shark, sand tiger sharks with the most aggressive as the most ferocious, most shark attacks on humans, aggressive second only to the great white shark. Were often highest for the "sea wolf" "Human killer", "mysterious marine killers" "Wreck butcher." Studies have shown that the underwater environment and geographical changes, enough to cause it to attack.
Researcher believe that many of the attacks attributed to great white sharks may have as cattle. Wounding in the annual report and the impact of shark boats incident, the accident record of cow shark scared people even more than the great white shark. Foreign case of "breaking the yacht" "Swimming attack," "Brokeback wins shark mouth" and other events is the cow shark's "masterpiece", and many of these events had been considered by the great white shark.
Meek cow sharks can be expressed, but can suddenly excited. They are highly aggressive. They have extreme regional, will attack other invasive organisms, including humans. It is very much like cow shark attack living objects. Cow shark testosterone levels are higher than any other animal, so it is very fierce, swift and fierce, aggressive, and difficult to catch, hard to tame. However, it is infested waters, it is difficult to find them, their whereabouts hidden.
Curious cow shark, even if the man has no aggressive moves, they will be driven by curiosity, attack each other. Global seventeen of them have been shark attacks on humans, cattle shark is not only the list, and among the best, the great white shark attacks on humans need more than records. Cow shark attack people most vulnerable time is the time at night and the water turbidity, swimmer, or if the body if blood stains on the sparkling decorations, very easily lead to sharks, and became the object of attack at any time.
Fortunately, the cow shark attacks on humans do not like to take the initiative, most of the cattle when the sharks attack people often just a bite on the go, this is probably because it is in the muddy waters of the victim as a threat to , only bite out of misunderstanding. Such as swimmer inadvertently disturb its courtship chasing, or violation of its site, or cut off its escape routes.
Highly flexible labor force:
Into the river, the cow shark as the secretion of hormones and other changes will become fierce brutal nature, and thus more dangerous. People in the Amazon at 3,000 km upstream of cattle seen sharks, the Ganges in India, the Americas, the Gulf of Mexico, Africa, the Zambezi River, Mississippi River and other rivers near the sea have been found in cow sharks. Whether in Lake Nicaragua in Central America, or the Saint Louis, Mississippi, wounding both cattle shark incident.
Because cattle can enter the freshwater shark, and in these fresh waters, it is usually not equipped with shark nets, which gives access to fresh water shark cow provides an excellent opportunity to hurt. Therefore, other than a dangerous shark species, people are more likely to encounter with them, so its greatest threat to mankind.
Cow shark's vision is not good, but their abnormal sense of smell is sensitive, can sniff out 10 million liters of water diluted in a drop of blood in the taste, and can track a few kilometers in the sea by virtue of blood found. Also by virtue of vibration and sound of the sea, track located within one kilometer of the prey. Shark feeding cattle is very complex and is known to not picky eaters, in their stomach, he discovered cattle, dogs, hippos and even the bodies of people, sometimes, even the cow sharks eat other sharks.
In addition, most sharks need adequate rest, and the cattle seemed to sharks wandered around the clock. Cow shark does not swim bladder, which can be surfaced to inflate the stomach in order to maintain buoyancy.
FISHERIES:
Mainly induced bovine shark cage, gill net and longline catch, high economic value. Good meat, processed into various meat products; fins can be made into shark fin; thick skin, can be processed into leather; liver can be processed into vitamin or cod liver oil; residues can be made into fish meal.
Artificial feeding:
Cow shark as fierce, Puma fierce, aggressive, and difficult to catch, hard to tame, domesticated breeding is not easy. At present, only in the United States and Canada, only a few countries cow shark aquarium, 2002, Shenzhen Sea World's Shark Aquarium is considered that a cow shark blacktip shark, which became China's cock The first cattle shark aquarium. In 2006, the Shanghai Ocean Aquarium also found mixed with other sharks in the middle of the four cattle shark, when Christmas was on display, and, the aquarium has already begun to rare beef shark "marriage birth" to prepare. |
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