Alopias+vulpinus

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 Thresher Shark


**Thresher Shark**  Genus: Alopias Species: Alopias Vulpinus Class: Chondrichtynes Order: Lamniformes Family: Alopiidae

**Endangered Species Act:** Thresher sharks were put on the endangered species list in 2002.

The cause of their endangerment is because the thresher shark is an important economic specie in many areas. It has been taken in large numbers as a targeted specie and is brought in as bycatch.

**Habitat** · Thresher sharks are found all over the world and are mostly found in oceanic and warm, coastal seas · Young thresher sharks are often close in shore and in shallow bays · Found mainly in the Indian, Atlantic and Pacific Ocean ·Latitude
 * Ecosystem**
 * Physical Habitat: The Atlantic Ocean**

· Temperature · Salinity · Geological Processes · Currents · Tides
 * Ranges from 15-25°C (annually)
 * Ranges from 33-35 PPS (annually)
 * Submarine Ridges – are risen between the continental shelves an the Mid-Atlantic ridge
 * Basins – there are three major basins… American Basin, the Brazilian Basin and the Argentina Basin
 * Islands
 * Largest are on the continental shelves
 * Newfoundland is the main island along with the British and the Falkland islands
 * There are two main circular current systems – one in the North Atlantic and one in the South Atlantic
 * These currents are wind driven but are also effected by the earths rotation
 * North Currents – North Equatorial Currents, the Canaries Current, an the Gulf Stream
 * South Currents – Brazil, Benguela, and South Equatorial Currents
 * The average tidal range is a low of 0 feet to 5 feet

**Migration Patterns:** · Thresher sharks are a highly traveling specie · They are pelagic · They usually migrate in very small groups 
 * Ranging widely from the upper ends of the oceans and usually ends up traveling over the entire ocean basin

**Survival Trends:** Population Estimate of the Thresher Shark: Unknown · Over 85% of the common thresher sharks that were caught were from the Pacific Ocean. · Only about 15% of fisheries were caught from the Atlantic Ocean

**Appearance and Anatomy:**



·  One of the most recognizable sharks ·  Small, curved teeth without serrations ·  Maximum length: 5.5 meters ·  Maximum weight: 230 kg    ·   2 dorsal in front of the pelvic fins ·  Caudal Fin - extremely large that may be up to 50% of the body length ·  Dorsal side varies from metallic brown to brown ·  Ventral side is white ·  Moderate-Sized eyes placed forward on the head

**Reproduction:** ·  This shark is ovoviviparous · This means that the egg is hatched inside the female · 2 to 6 live pups are delivered at a size of 1.1-1.5 meters and weigh between 5-6 kg. ·  During their development young may be cannibalized by their siblings while still in the mother

**Adaptations:** · Thresher sharks’ strength and endurance is a result of physiological adaptations ·  Their ability to retain body heat explains why can reach such low depths (365 meters). 
 * They have a strip of red muscle along each of its sides that is able to use oxygen efficiently so that it can contract for a long period of time
 * This muscle has a tight grouping of tiny blood vessels that transfer metabolic heat, so it can retain body heat

· Young prey mostly on schooling fish (herring, mackerels, bluefish, sardines, needlefish, etc.) · Adults also feed on cephalopods such as squid, octopuses and pelagic crustaceans · The large caudal fin is used to slap the surface of the water forcing fish to form tighter schools · Then the caudal fin is used as a whip to stun or kill prey · Hunt in small, loose groups 
 * Food Chain:**

**Economic Importance** · Thresher shark meat is highly priced when fresh for human consumption when it is eaten smoke or dried and salted · Fins are valuable for shark fin soup · Hide is also usable for leather and the liver oil can be processed for vitamins ·  Fisherman rely on thresher sharks in the Pacific, Chile, the Atlantic, Caribbean, Amazon, Argentina, the Mediterranean, Africa, Madagascar, Arabia, India, Asia, Australia, New Zealand and Japan


 * Human Threats and Reason for Endangerment**



·  Human threats · Reasons for endangerment
 * Are very minimal, but their tail is large and powerful which can do the most harm
 * SAF lists only four boat attacks and one provoked attack
 * Divers encounter small thresher sharks near rocky reefs swimming near the bottom or the surface of the ocean, but they aren’t aggressive at all
 * Highly vulnerable to “overfishing” in a short period of time… SAF has estimated that over 50% of the population has decreased in the past three generations
 * Exploitation by unmanaged fisheries (mainly the expensive fins)

· Vessel Monitoring Systems are required on U.S. Atlantic pelagic long line boats to enforce closures and monitor the fisheries · Circle hooks are also required by fisherman to increase post-release survival of thresher sharks and other fish that have been caught on hooks · U.S. Atlantic pelagic long line fisherman must attend a workshop where they learn how to properly the sharks · NOAA Fisheries Services pass create many acts that are thriving to protect the thresher shark specie - 1997 : reduces fishing recreation limit for large coastal and pelagic sharks, including the common thresher shark, from 4 to 2 - 2004 : ICCAT is concerned in the consservation of sharks caught by fisheries; ban of shark finning and live-release that are caught
 * Conservation Efforts**

**Solutions** · The thresher shark is a specie that is very vulnerable to overfishing. We could prevent this from becoming worse we could keep a strict restriction against finning for fin soup and to limit catches. Over time this could help the extinction of the thresher shark. <span style="display: block; font-weight: normal; font-size: 12px; color: black; font-family: 'LiSong Pro'; text-align: center;">

· Florida Museum of Natural History o  [] · Atlantic Ocean History o  [] · Atlantic Common Thresher Shark o  [] · Thresher Shark o  [] · ADW: Alopias vulpinus: Information o  [] · Just the Facts: o  [] · Biology of the Common Thresher o  []
 * SOURCES**

Scavenger Hunt 1. What year were the Thresher Shark put on the endangered list? 2. What is the maximum height and weight the Thresher Shakr can grow to? 3. What do the young sharks mostly prey on?