Completely Cartilaginous! An Educator s Guide to the Program

Transcription

1 Completely Cartilaginous! An Educator s Guide to the Program GRADES: 1-3; multi-age PROGRAM DESCRIPTION: This educator s guide provided by the Oklahoma Aquarium will teach students all about the different sharks, skates and stingrays that call our oceans home. The program will address how cartilaginous fish differ from bony fish such as tuna and salmon. Completely Cartilaginous will show why sharks are so important to our ecosystem and why they need to be protected. *Before your class visits the Oklahoma Aquarium* This guide contains information and activities for you to use both before and after your visit to the Oklahoma Aquarium. You may want to read stories about sharks, skates and rays, present information in class, or utilize some of the activities from this booklet.

2 Completely Cartilaginous Table of Contents Completely Cartilaginous Abstract 2 Educator Information 3 Vocabulary 6 Resources/Reference Materials 8 PASS/OK Science Standards 9 Accompanying Activities - Sharkometre 11 - Shark Label me 17 - Tooth Match 19 - Fin Match 22 - Shark Link 24 - Shark Search 25 1

3 Completely Cartilaginous: Abstract Sharks are one of the most misunderstood animals on our planet. They are feared by many as man-eaters, but in reality, sharks have no desire to eat humans. Sharks, like their cousins the skates and rays, are fish, more specifically, cartilaginous fish. The skeletons of cartilaginous fishes are made up of the same material as the tips of our noses and our ears; unlike most fish which have bony skeletons. The lightweight skeleton gives sharks an advantage as a predator, they are faster and lighter. Cartilaginous skeletons are just one of the different adaptations that sharks have which make them perfect apex predators. Sharks are responsible for approximately 5 deaths per year, and most are the case of mistaken identity. Humans however, are responsible for over 100 million shark deaths every year. Many sharks are killed for nothing more than their fins, or they are caught as by-catch. The health of our oceans and therefore our planet is dependent on maintaining a healthy balance in our oceans. Sharks play a vital role in maintaining balance in the ocean. As an apex predator, they hunt weak and sick animals, helping to prevent the spread of disease. It is our responsibility to learn all we can about sharks and share that knowledge with our friends and families so that we can hopefully dispel the myths that have plagued sharks. Not only are they a vital part of our ecosystem, but they are also an extremely fascinating animal. There are over 450 different species of sharks and they have remained virtually unchanged for millions of years. 2

4 Completely Cartilaginous: Educator Information Shark Anatomy Sharks come in all sizes and shapes. One of the smallest sharks is only 6 inches and the largest shark can grow to more than 40 feet long. Sharks are different from other fish in the way that their bodies are made up. Bony fish have skeletons made of bone, but sharks have skeletons made of cartilage, the same flexible material in your nose and ears. Cartilage is tough like bone, but it is much lighter. This keeps sharks lightweight, so they do not sink in the ocean, sharks also have a very fatty liver so they do not need a swim bladder like bony fish to keep them afloat. Sharks have a different skin texture than fish. They do not have scales; instead they are covered with dermal denticles. These tough, protective denticles are small and tooth-like in shape. They are designed to minimize drag due to friction while the shark is moving through the water. Sharks breathe by taking in dissolved oxygen from water. The water enters through the shark s mouth, passes through the gills and is pushed out through the gill slits behind the head. In bony fish, the slits are covered by an operculum, but in most sharks the gills are visible. Sharks fins on the sides of their body are called pectoral fins and pelvic fins. The shark uses these fins positioned at different angles, to change the path of the water moving around them. When the fin is tilted up, the water flows below the fin creating an upward lift. When the fin is tilted down, the water flows above the fin and pushes the shark downward. Sharks have one or two vertical dorsal fins on their back and some sharks have a vertical anal fin on their underside. 3

5 These help the shark keep from rolling as it moves through the water and they help turn the shark left and right. The shark's nose is one of its greatest features and it can detect even the slightest traces of blood in the water. Another thing about a shark's sense of smell is that it is directional. This means that smell coming from the left of the shark will arrive at the left nasal cavity just before it arrives at the right nasal cavity. This way, a shark can figure out where a smell is coming from and head in that direction. Sharks also have a great sense of hearing. Sharks can follow sounds for many miles, listening for wounded prey. Eyesight varies in different sharks. Sharks that stay near the top of the water's surface do not have good eyesight, but sharks that stay at the bottom of the ocean have large eyes that let them see in murky darkness. Since their eyes are positioned on each side of the head, as opposed to on the front, sharks have a good field of view. Sharks rely heavily on their sense of taste. Before they eat, they will take a sample to taste their prey. They reject prey that is not part of their diet, such as people. That s right; sharks don t really find us very tasty! The ampullae of Lorenzini detect small electrical impulses that allow sharks to feel the weak electrical fields generated by all living organisms. The range is limited to a few feet in front of the shark's nose, but it is enough for the shark to seek out fish hiding on the ocean floor. Shark Teeth Shark teeth are similar to human teeth in their consistency, but that is where the similarities end. Humans only have two sets of teeth in a lifetime whereas sharks lose and replace about 30,000 teeth during their lifetime. When shark teeth become broken or dull, they fall out of the tooth bed and are replaced with a sharp new tooth. Shark s teeth are arranged in several rows in their jaw and move forward like a conveyer belt. Sharks can detach their jaws when catching prey, allowing them to throw their mouth forward to get a good bite. 4

6 Conclusion Sharks are very difficult to study because they are fast travelers and move over long distances in waters that are not very accessible to humans. Sharks are solitary animals that usually live and hunt by themselves. They do associate with other sharks in certain circumstances, such as mating. Sometimes sharks will swim in schools but not because they need protection from predators. When sharks hunt, they like to surprise their prey. This is never done in schools. For the most part, sharks live a solitary life. 5

7 VOCABULARY: Adaptation Ampullae of Lorenzini Anal Fin Apex Predator Benthic Cartilage Caudal Fin Counter Shading Dermal Denticles Dorsal Fin(s) Elasmobranches Fins a characteristic body part, shape or behavior that helps a plant or animal survive in its environment a network of jelly filled sacks which detect the small electrical signals that all animals release the fin closest to the tail, which provides stability in species where it is present; not all sharks have an anal fin a predator that is at the top of the food chain living on or near the sea bottom a tough, flexible material, of which the skeleton of sharks, rays, and skates are composed, also supports the ears and noses of human beings also known as the tail, it propels the shark forward a type of camouflage where the top of the animal is dark and the bottom is light skin teeth tiny teeth-like structures on the skin of a shark fin or fins on a shark s back which stabilize the shark while swimming cartilaginous fish, including sharks, skates and rays rigid appendages supported by cartilaginous rods in sharks and their relatives 6

8 Lateral Line Nictitating Membranes Pectoral Fins Pelvic Fins Predators Prey Spiracle Swim Bladder located on each side of the shark's body; a row of small holes connecting an internal canal that is sensitive to movements shark s eyelids; sharks are the only fish that have eyelids paired fins off the sides of a shark s body; they lift the shark as it swims paired fins lower on the shark s body and more towards the tail than pectoral fins, they stabilize the shark while swimming animals that eat other animals animals that are eaten by other animals a small opening located behind the eye used to bring water to the gills; more prominent in bottom dwelling elasmobranches such as skates and stingrays an air filled bladder used for buoyancy in many bony fishes 7

9 RESOURCES: Internet Resources: Books and References: Musgrave, Ruth A., Doubilet, David, Hayes, Jennifer (2011) National Geographic Kids Everything Sharks: All the Shark Facts, Photos and Fun That You Can Sink Your Teeth Into. National Geographic Castro, Jose (2011) The Sharks of North America. Oxford University Press. Skomal, Greg Dr. (2008) The Shark Handbook: The Essential Guide for Understanding the Sharks of the World. Cider Mill Press book Publishers Parker, Steve and Jane (2002) The Encyclopedia of Sharks.Firefly Books Ltd. Sabuda, Robert, Reinhart, Matthew (2006) Encyclopedia Prehistorica Sharks and Other Sea Monsters. Candlewich Press. 8

10 PASS STANDARDS MET: All education programs and their accompanying materials at the Oklahoma Aquarium will meet several Oklahoma PASS objectives in various disciplines. The following list is not all inclusive. SCIENCE Science Processes and Inquiry: (Grade 1-3) Process Standard 1: Observe and (Grade 1-3) Process Standard 2: Classify (Grade 1-3) Process Standard 3: Experiment Physical Science: (Grade 1-3) (Grade 1-3) Standard 1: Properties of Matter and Energy Standard 2: Life Cycles and Organisms Life Science: (Grade 1) (Grade 2) (Grade 3) Standard 2: Characteristics and Basic Needs of Organisms Standard 2: Life Cycles and Organisms Standard 2: Characteristics and Needs of Organisms and Environments Earth/Space Science: (Grade 1-3) Standard 3: Properties of Earth Materials 9

11 OKLAHOMA ACADEMIC STANDARDS FOR SCIENCE MET: LS1-1 1-LS1-2 1-LS3-1 1-ESS3-1 2-LS4-1 3-PS2-3 3-LS1-1 3-LS2-1 3-LS3-1 3-LS4-1 3-LS4-2 3-LS4-3 3-LS4-4 10

12 For more resources visit: Make your own Sharkometre! The Sharkometre is a great way to introduce people to the sizes of sharks, be it the magnificent Whale Shark (56 ft) or the tiny Pygmy Lantern Shark (7 in) that can fit in the palm of your hand. Materials: You will need: 1 length of rope approx 56 feet either find an old length or visit your local chandlers and ask to buy the end of a reel. Hooks/cable-ties to attach the labels to the rope. Shark Labels - Print the labels below or create your own. Then simply laminate or mount them on some card and affix to your rope. 11

13 Spined Pygmy Shark Image Natural History Museum Bluespotted Ribbontail Ray Image Cat Gordon Squaliolus laticaudus Taeniura lymma 2 ft 3 in long 11 in long Tropi cal waters Lives deep in the ocean Small but poisonous One of the smallest sharks in the world Smallspotted Catshark Image David Peake Epaul ette Shark Image Alex Mustard Scyliorhinus canicula Hemiscyllium ocellatum 2 ft 6 in long 3 ft 3 in long Temperate waters in the UK The most common catshark, lays eggcases Tropical waters Walks on the seabed with it s fins 12

14 Starry Smoothhound Image Hans Hillewaert Port Jackson Shark Image Anonymous Mustelus asterias Heterodontus portusjacksoni 4 ft 6 in long 1 ft 7 in long Found in Northeast Atlantic & the Mediterranean Sea Subtropical waters of South Australia Eats crab, lobster and shrimp Powerful jaws to crunch prey Angel shark Image Simon Rogerson Bull Shark Image Alexander Safonov Squatina squatina 8 ft 2 in long Temperate waters, UK too! A sneaky predator who hides in the sand Carcharhinus leucas 11 ft 2 in long Tropical & sub tropical seas Can tolerate long periods of time in freshwater rivers connected to the ocean 13

15 Tasselled Wobbegong Image Alexanda Safonov Common Skate Image Davey Benson Eucrossorhinus dasypogon Dipturis batis 4 ft 3 in long 9 ft 8 in long Western Pacific, coastal Temperate waters, in the UK Highly camouflaged, can you see it? Britain s biggest skate but not so common Bl ue Shark Image Linda Pitkin Shortfin Mako Image Andy Murch Prionace glauca Isurus oxyrinchus 13 ft long 13 ft long Distributed globally, UK too! Can swim 1,000s of km in one trip Worldwide distribution, UK too! Fastest shark, bursts of more than 35km/h 14

16 Tiger Shark Image James Wiseman Galeocerdo cuvier 18 ft long Great White Shark Image Sean Sequeira Carcharodon carcharias 20 ft long Worldwide in tropical waters Worldwide on continental margins Eats everything! Called a garbage can with fins Warm blooded for extra acceleration Thresher Shark Image John van Lent Great Hammerhead Image Gary J. Wood Alopias vulpinus Sphyrna mokarran 20 ft long 20 ft long Temperate seas worldwide, UK too! Tropical & warm waters close to coasts Long tail to stun prey Likes to eat stingrays 15

17 Green Sawfish Double-decker Bus Image Doug Perrine Pristis zijsron 24 ft long Tropical waters but rare Thrashes saw from side to side to catch fish 33 ft long Found in London and rest of UK Basking Shark Whale Shark Image Charles Hood Image Gareth Millson Cetorhinus maximus 39 ft long Temperate seas worldwide, UK too! Largest fish in the UK & feeds on plankton Rhincodon typus 46 ft long Tropical seas Biggest fish in the ocean 16

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20 Tooth Match Some sharks have teeth like strainers suited to eat tiny shrimp such as krill. Some sharks have teeth like forks that help them eat small f ish such as sardines. Some sharks have teeth like pliers that help them crush hard food such as crabs. Some sharks have teeth like saws to eat large fish such as tuna. 19

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22 Tooth Match Key 21

23 Fin Match Match the words in the first column to the best available answer in the second column. caudal fin 1) used for balance to prevent rolling dorsal fin pelvic fin anal fin 2) used for stabilization, not all sharks have this fin 3) used for stabilization, keeps shark swimming upright 4) used for maintaining speed pectoral fin second dorsal fin 5) used to steer and slow down, also provides lift 6) provides forward thrust in swimming, helps shark steer 22

24 Fin Match Key Fin Match 6 caudal fin 3 dorsal fin 1 pelvic fin 2 anal fin 5 pectoral fin 4 second dorsal fin 23

25 Shark Link Predators, prey, and environment are interdependent on one another, even when the predator is a shark! The following activity will show students how each depend upon the other for a healthy ecosystem. If one member becomes extinct, watch what happens! Have students write a brief synopsis about what they learned at the end of the activity. 1. Have students stand in a circle and count off by three s. 2. One s are sharks. 3. Two s are prey. 4. Three s are environment. 5. Have students step forward into the circle until they are standing shoulder-to-shoulder in a tight ring. 6. Have students turn to their left so that all students are facing the back of the head of the person in front of them. 7. Have students, gently, bend backwards until they are sitting on the lap of the person behind them and the person in front of them is sitting on their lap. 8. Once the link of sitting students is stable, tell the students that they have formed a stable ecosystem with predators, prey, and environment all working together. 9. Have the ones, the sharks, fall out. The system collapses. Explain to the students the significance that each member of the ecosystem has for example, what would have happened if the prey fell out or if the environment had fallen out? 24

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