SHARKS Classification Class ______________________________________________ includes sharks, rays and their close relatives. Sharks and rays share a basic anatomy that classifies them together. Sharks and rays are jawed fish,that lack a ______________________________, and have cartilaginous skeletons. Cartilage is lighter than bones and helps the shark to float. TEETH Sharks have a “conveyor belt” of _________________________________ of teeth. They swing into place as old teeth wear out and fall away. Reproduction Sharks differ in their reproductive strategy. Sharks and rays produce fewer, but more mature offspring. Most fertilize their eggs _________________________________. The male deposits sperm in the female via a pair of copulatory organs called ____________________________________ found at the base of the pelvic fins. The female lays an egg case in which the juveniles develop for up to six months at which time one or more sharks or rays emerge. A few shark species are ______________________________________ – the eggs hatch within the mother’s body. They give birth to live young rather than egg cases. Shark Egg Sacs Oviparous sharks Lay eggs. They are also known as A ______________________________________. Countershading Dark shading on ____________________________ surface. Light shading on ____________________________ surface. Dermal Denticles Scales are actually made of the same material as _____________________________________. Called dermal denticles. Tip: Pet a shark like you pet a cat, from head to tail. Shark Senses ____________________________________________ – lines of sensory hair along the length of the body that detect water motion and vibrations. Shark Senses _________________________________________________ – the ability to sense minute electricity created by muscles and nerves. Sharks and rays have organs called __________________________________________________ which you can see as visible pits near their snouts used to detect the electrical current. Sharks have a sense of smell that detect incredibly diluted substances. Internal Anatomy The _________________________________________ is the largest organ in a sharks body. It is oily and aids in buoyancy since sharks lack a swim bladder. We will continue to learn more about the internal and external anatomy of a shark when we begin the spiny dogfish shark dissection. THE END