What Is A Hammerhead Shark?-Members of the Sphyrnidae family-Includes eight species: Scalloped Bonnethead, Winghead Shark, Scalloped Hammerhead, Scoophead Shark, Great Hammerhead, Bonnethead Shark, Golden Hammerhead and Smooth Hammerhead.-Set apart from other sharks by their hammer shaped head
HabitatHammerhead sharks arefound in long coasts inwater up to depths of300m and also in shallow
Habitat Continued…-Migrate to cooler water during summer months frequently in large masses-Found in lagoons and continental shelves-Large gatherings found in bodies of water such as Hawaii, South Africa, Australia - studies concluded they are highly social and communicate through body movement including rituals such as shaking the head and pushing other with their bodies
Feeding Information-Prey on many different speciessuch as fish and other types ofsharks-Stingray is most valued foodsource; tail spine is evenconsumed (Flying cloud. 2008)-Invertebrate prey:crabs, squid, octopus, lobsters-Bony fish:groupers, catfish, flatfish-Great hammerheads have beenreported of eating their ownspecies (Antonio, 2008)-Feeds at dusk along floor of
Body has several distinctive features-Hammerhead of a Hammerhead-“cephlafoil”, meaning two wide flattened expansions that resemble shape of hammer-Hammer shaped extensions made up of connective tissue and supported by skeloton-Hammer shaped head varies from each type of hammerhead including great, scalloped, and smooth-Round eyes located on far regions of hammer head-very far apart-Lateral expansions also include nostrils-Dorsal fins located on shark varies in size and direction of point, all very large-Brown to light grey on dorsal side and white underside
Anatomy of A Hammer Head (Stapley, 2011)
-Hammer heads use their body form as an advantage when capturing live prey-They can control the angle of attack that their head pins down prey-Highly maneuverable and can use whole body and weight to hold onto prey- can bat down and restrain with just their head-This plays a role in the capture of sting rays which are animals that swim on an angle-Very quick and efficient at holding prey in place and then consuming it-Nostrils and eyes (36 degree view of surroundings)being spread out plays a vital role in capturing of prey; it allows
Advantages to “Hammer head”-Optic nerves in a hammerhead’s brain are reached through smell that enters each nostril individually-Hammerheads can determine direction of smell by paying close attention to which nostril the smell hits first since they are so spread apart-Nostrils spread apart allows them
Reproduction-Slow reproduction rate-Frequently mate close to surface of water-Yolk-sac placenta sustained in uterus-Live birth known as viviparity-Relies on nutrition to feed unborn pup-Birth occurs after 11 months in spring and summer- occurs in Northern Hemisphere
Specific importance to humansHammerhead sharks are highly valued for their fins, their meat is consumed by humans and they provide liver oil for vitamins
Conservation and EndangermentClassified in large coastal species group- most vulnerable to overfishingUsually not a specific target to fishers but often die when they are caught by gillnet or netsCurrently considered to be endangered by the World Conservation UnionUnder threat due to shark finning operationsPopulations are vulnerable to fishers because of slow reproduction rateAccording to the International Union
Interesting facts-Hammerhead sharks can get a sun tan from swimming close to waters surface for an extended amount of time- dorsal side will become darker when increased exposure to sun-Some members of the shark family including hammerheads exert up to 8,000 pounds of force per square inch when biting their prey-These specific sharks are wanted to make Asian fin soup that can cost between 20 and 1,000 dollars a bowl
Image ReferencesPowerdinky. Baby Hammerhead. 19 Feb. 2008. Flickr.com. Web. 20 Nov. 2011http://www.flickr.com/x/t/0098009/photos/24027902@N08/2277915531/Pertersbar. Hammer from Cocos Island, Costa Rica. 3 Jan 2010. Flickr.com. Web. 20 Nov. 2011http://www.flickr.com/x/t/0098009/photos/barrypeters/4242623174/Seamore. The depths.9 March 2009. Flickr.com. Web. 20 Nov. 2011http://www.flickr.com/x/t/0093009/photos/seamoor/3341036032/*Cris*. Hammerhead Shark. 12 June 2007. Flickr.com. Web. 20 Nov. 2011 http://www.flickr.com/x/t/0094009/photos/cristiano_deana/542916788/
Image References Continued… MaestroBen. Hammerhead. 13 Feb 2007. Flickr.com. Web. 20 Nov. 2011 http://www.flickr.com/x/t/0098009/photos/maestroben/389503682/ Erik Charlton. Hammerhead. 12 Oct 2008. Flickr.com. Web. 20 Nov. 2011. http://www.flickr.com/x/t/0095009/photos/erikcharlton/2935553971/Flying Cloud. Sea World Sting Ray. 13 July 2008. Flickr.com. Web. 20. Nov. 2011. http://www.flickr.com/photos/flying_cloud/2666292417/. Antonio, Charlie V. Giant Crab at Manilla Ocean Park Philippines. 19 April 2008. Flickr.com. Web . 20 Nov. 2011. http://www.flickr.com/x/t/0099009/photos/charlimages/2424279935/ .
Text ReferencesBester, Cathleen. “Great Hammerhead.” Florida Museum of Natural History. FLMH Icthyology Department, 2011. Web. 7 Oct. 2011 http://www.flmnh.ufl.edu/fish/gallery/descript/greathammerhead.htmlGalloway, Evan. “Sharks Follow Their Nose.” Today’s Science. Facts On File News Services, July 2010. Web. 7 Oct 2011. http:://www.2facts.com/article/s1800090Maddalena, Alessandro and Buttigieg, Alex. “The Social Lives of Hammerheads.” WorldandI.com, June 2006. Web. 1 Nov 2011. http://www.worldandi.com/subscribers/feature_detail.asp?num=25044Martin, Aiden. “Sandy Plains: No Place to Hide. Great Hammerhead Shark.” ReefQuest Centre for Shark Research. Biology of Sharks and Rays, n.d. Web. 1 Nov 2011. http://www.elasmo-research.org/education/ecology/sandy-gt_hammerhead.htm.Murray, Loiuse. “Endangered Great Hammerhead Sharks Tracked on North Atlantic.” Earth times. Feb. 2011. Web. 7 Oct 2011. http://www.earthtimes.org/nature/endangered-great-hammerhead-sharks-tracked - north-atlantic/340/.
Text References ContinuedPlessis, Amelia Du. “Sharks: The Hammerhead Sharks.” Sharks.org. 2011. Web. 7 Oct 2011. http://www.sharks.org.za/hammerhead-shark.html.SeaWorld Parks & Entertainment. “Sharks and Rays-Diet and Eating Habits.” SeaWorld/Busch Gardens: Animals, 2011. Web. 7 Oct. 2011. http://www.seaworld.org/about-us/index.html.