C+limbatus

Class: Elasmobranchii Order: Carcharhiniformes Family: Carcharhinidae

//__ Endangered Species Act __//

· ** Year Assessed : 2000 ** · ** Carcharhinus limbatus is presently protected by the Endangered Species Act because it is highly vulnerable to the inshore fishing industry and its habitat is threatened by humans. Carcharhinus limbatus is frequently caught by fisheries and its meat and fins are prized. Additionally, the meat of this shark is sold fresh, fresh frozen, or dried and salted. The hides are used for leather and its liver oil is used for **** its vitamin content. **



//__ Location of Ecosystem: __// //__ Physical Habitat features __// ** Pacific Ocean **
 * Frequenting the waters along shores of **** North America ****, **** South America **** , **** Africa **** , **** Southern Europe **** , **** Southern Asia **** , and **** Northern Australia **** , Carcharhinus limbatus ranges from 30°S to 45°N. Specifically, Blacktip sharks are pelagic and reside in tropical to subtropical coastal, shelf, and island waters. The Blacktip shark inhabits inshore and offshore waters. It is often seen near the shoreline around river mouths, bays, and estuaries. While it is most common to see the Blacktip shark in these areas, they can be seen offshore and over deeper waters. For the most part, they stay in the upper 100 feet of waters they inhabit. **
 * 2. Annual temperature: 10 - 25 C **
 * Annual Salinity - 33.0 **
 * Latitude - 30 - 60 N **
 * 3. Geologic Processes in the **** Pacific Ocean **** : **
 * - Earthquakes **
 * - Volcanoes and ring of fire **
 * - Subduction **
 * - Sea floor spreading **
 * - Meteorites **
 * 4. Currents **
 * Alaska **** current **
 * North pacific current **
 * California **** current **
 * 5. Tides **
 * 0- 5.6 = 5.6 **

//__ Migration Patterns/Population Estimates __// //__ Appearance of the Blacktip shark __//
 * The migration patterns of the Blacktip shark are consistent in that during winter months, the Blacktip will migrate in schools to warmer waters. For example, in **** Florida ****, the Blacktip is frequently seen in **** Florida **** ’s bays, estuaries, and coastal waters. When sensing colder water conditions, it swims southward to the open, warmer waters of the **** Caribbean **** . **
 * We have no set number of Blacktip sharks left in the waters. We only know that they are decreasing rapidly due to the mass amount of fishing. **
 * While the current estimated population of the Blacktip shark is unknown, it is known that it continues to be the victim of fisheries intentionally seeking it and those who catch it in their nets as an accident. With a gestation period of 10 to 12 months and the constant hunting of this species of shark, the population trend appears on the decline. **
 * The Blacktip shark's average size is approximately 150 cm and 18kg.Their upper body is grayish brown and they have a white ventral surface with two white stripes up and down the sides. **

//__ Reproduction __// ** Blacktip Sharks are viviparous. Their litters usually include 1 to 10 pups per litter, but more commonly 4 to 7 pups per litter. The Blacktip shark is about 40 to 70 cm. at birth and its Gestation period is 10 to 12 months. Males and Females mature to different sizes. Males are between 135 and 180 cm and females are between 120 and 190 cm. The Blacktip sharks life span is about 12 years. ** //__ Anatomy __// //__ Feeding __//
 * - Streamlined body **
 * - pointed snout **
 * - Small eyes **
 * - Lateral line that senses pressure and assists the shark with position. **
 * - Five pairs of gill slits **
 * - Fifteen tooth rows on both sides **
 * - The first dorsal fin is tall with a short rear tip. **
 * - Large pectoral fins are pointed. **
 * - The teeth have serrated edges **
 * - Jaws have 2 central teeth in the upper jaw and 1 in the lower jaw. **
 * The Blacktip shark diet is 90% fish. For the most part the Blacktip shark feeds on small schooling fish. Some of these include herring, sardines, and anchovies. The Blacktip shark also eats larger fish including catfish, grouper and grunts. Black tip sharks are also known to eat some stingrays, skates, and dogfish. Blacktips use a method for predatory success. They breach out of the water spinning three to four times. This behavior assists the sharks' predatory success while feeding near the surface. The sharks attack at high speed and then snap at the fish as the shark passes through through the school. The velocity and momentum the shark reaches propels them out of the water. The main predator of the Blacktip shark is humans, but for baby Blacktip sharks they must be careful around larger sharks. **



//__ Economic importance __// ** The Blacktip shark is caught by commercial fisheries. The fisheries use equipment such as longlines, fixed bottom nets, bottom trawls, and hook-and-line. The meat of a Blacktip shark is of high quality. The meat can be sold fresh, frozen, or dried and salted. The fins are sold to make shark fin soup and the skin of the shark is for leather. It seems like the fisheries are using the entire shark, but there is more. They use the liver oil for vitamins and the shark's carcasses for fishmeal. **

//__ Reason for Endangerment __// //__ Conservation __// //__ Solutions __//
 * The Blacktip shark is endangered for one major reason and that is fishing. The meat of a Blacktip shark is considered to be high quality and the flesh is considered to be better than the sandbar shark. The Blacktip shark is also significant to Indian and Mexican fisheries. Fisheries that specialize in selling the Blacktip shark are located in the **** Mediterranean ****, **** South China Sea **** , and northern **** Australia **** . **
 * The Blacktip shark is managed by the National Marine Fisheries Service. **** U.S. **** rates have had their ups and downs in the past couple years. In 2000 it reached a peak in commercial landings in the **** Southeast Atlantic **** shark fishery. Most of the catch has been of adult sharks above the minimum reproductive size. This indicates that the Blacktip shark species is being managed more than it has in the past. **
 * They can ban the selling of Blacktip shark. **
 * They can keep some Blacktip sharks in captivity. **
 * Keep an eye on the amount of sharks and protect them to the best of their ability **.

//__Scavenger Hunt Questions__

1. What is the Blacktip's biggest threat? 2. When was it assessed? 3. What does the Blacktip Shark eat?

__Citations__ // [|http://i.pbase.com/u49/la_mer_blue/large/34894509.MooreaBlackTipSharkcopy.jpg][|http://blog.bioethics.net/blacktip.jpg] [] [] [] []