Common Name: Thresher Shark

Scientific Name: Alopias pelagicus

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Lamniformes

Family: Alopiidae

Genus: Alopias

Species: A. pelagicus


You may ask, “What is Alopias pelagicus?”. Well Alopias pelagicus is a shark commonly known as the Thresher shark. The thresher belongs to the class chondrichthyes which means that it is not a bony fish; instead, its skeleton is made of cartilage. The thresher is a chordate because of its backbone. One of the very important body parts that the thresher sharks have is a very big caudal fin. If you look at a picture of a thresher the caudal fin will be the very large tail at its rear end. They use this body part to catch its prey including pelagic fish, squid, lancet fishes, herring, mackerel, and small billfishes. The caudal fin also makes up 80% of the threshers full length body! Another very important body part that the thresher shark has is its big eyes. He/she uses this body part to spot its prey. Once it has caught its prey the thresher’s small teeth and jaw come in. these 2 body parts come in real handy when the thresher has stung and killed its prey with its tail.


The thresher usually lives in warm waters, and coastal waters to the depths of 350 meters. Young threshers are found in shallow water. They usually spend most of their time in the middle and close to the surface water looking for food and trying not to get eaten or hunted by humans. Threshers try their best to not get eaten just like any other animal. Next, is why populations of these beautiful animals (thresher sharks) are shrinking and not growing? Because of shark hunting activities and demand for shark fins, livers, hides, and quality of meat there are less and less each year. The threshers’ meat is edible and so human beings who like their meat eat them.


Finally, what I learned and stood out the most as I read was how they use their tail. When I first was gathering the information I didn’t know that threshers had very large tails or caudal fin. All I thought was that it would be normal like the great white but it wasn’t. Another great thing that I learned about is where they live. I thought that threshers lived in the bottom of the ocean lurking around, but I was wrong.


Author: Lizbeth R

Published: 02/ 2009


Sources: Grubber, Samuel H. "Thresher shark." World history encyclopedia. 1998. Owen, Weldon. "Thresher Shark." Thresher sharks. 2 Feb. 2009. Trejo, Tonatiuh. "Global Population Structure of Thresher Sharks (Alopias spp.)." Moss Landing Marine Labs - Ichthyology Lab. 04 Feb. 2009 . Tricas, TC., K. Deacon, P. Last, JE. McCosker, TI Walker, L. Taylor, and Weldon Owen. "Thresher Shark." The Province of New Brunswick Canada.


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