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Sharks. Shy Ocean Creatures?. Sharks are Cartilagenous Fish. What parts of the human body are made of cartilage? Ears Tips of nose Covering at the end of bones Front parts of the ribs Tendons and ligaments Growth plates in children and adolescents. Anatomy of a Shark.
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Sharks Shy Ocean Creatures?
Sharks are Cartilagenous Fish • What parts of the human body are made of cartilage? • Ears • Tips of nose • Covering at the end of bones • Front parts of the ribs • Tendons and ligaments • Growth plates in children and adolescents
Anatomy of a Shark • Sharks belong to a family called Chondrichthyes. The members all have cartilage rather than bones.
Members • Sharks, skates and the rays • There are approximately 700 species.
Cartilage not Bones Cartilage is lighter than bone and helps the shark to float.
Unique Characteristics • Placoid Scales – tiny teeth embedded in skin that point towards the back to the fish. • Prevent fish from being eaten from the tail • Ventral gill slits with no covering • Very vulnerable area • Spiracles are breathing holes on the dorsal side of the head behind the eyes • Mouth is ventral and used for bottom feeding • Pectoral fins help give the fish lift like the wings of a plane.
Stingrays and Skates • Most are bottom dwellers in the sand of the Gulf of Mexico and on the Atlantic Coast from the Carolinas to Brazil. • Their tail is used for stabbing prey and enemies. • Stingrays have a spine on their tail, skates do not.
Sharks Comes in all Sizes – about 350 species Whale Shark Dwarf Dog Shark 6.5 in up to 59 ft.
Mermaid Purses? • Shark egg sacs
Great Whites • Ocean Acrobats
Tiger Sharks Garbage Cans of the Ocean They eat anything they can and help keep the ocean clean
The Real Jaws • Meet the bull shark
Bull Sharks in Fresh Water? • Bull sharks can live in both the sea and fresh water. They have been found in the Amazon, Ganges, Mississippi and Australian rivers.
Goblin Sharks Found only in deep waters, are extremely rare, live on fish and octopus, grow to apprx. 10 ft.
Structure of Sharks • Sharks are living fossils because today’s form closely resembles fossilized forms.
Shark’s Adaptations • Lateral line organ picks up sound vibrations in the water • Ampullae of Lorenzini pick up the electrical impulses of the nervous system • Streamlined body shape allows them to move quickly through the water • Caudal (tail) fin is used for forward thrust
More shark adaptations • Teeth are serrated like a steak knife and are used to sever food into smaller pieces • Sharks must be in constant motion or in moving water because they will sink and need the oxygen to keep flowing over their body • Can detect the smell of blood from miles away
Shark Anatomy Lateral Line Organ
Reproduction • Fertilization is internal and the shark usually gives birth to live babies, but some sharks produce eggs in cases that they attach to seaweed • Males have claspers to transfer sperm to the female reproductive tract.
Human Influence Each year over 30 to 100 million shark are killed by nets, for food or for sport.
Research Researchers combine shark cartilage and cow collagen to make sheet to place over a burn victim’s skin. The patient’s cells invade, absorb and replace the sheet with new human skin.
Protection Great whites are now protected along the coast of California, Australia, South Africa and the Maldives. Wildlife Conservation Society has begun a tagging program.