Slide 1

Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Chondrichthyes Subclass: Holocephali Subclass: Elasmobranchii Superorder Batoidea Superorder Selachimorpha Slide 2 Cartilaginous Fish Includes: Sharks Rays Skates Ratfish/Chimeras/Ghost fish Slide 3 General Characteristics: Jawed fish Skeleton made of cartilage Lack swim bladder Teeth & vertebrae sometimes calcified Slide 4 General Characteristics: Possess movable jaws Mouth is ventral, underneath the head Countershading the ventral sides are light colored while the dorsal sides are darker creating a simple camouflage Slide 5 Evolution: Earliest relatives found in the Devonian Age Modern looking sharks first appear in the Jurassic Era Slide 6 Evolution Megalodon Ancient Shark Largest predatory fish ever Twice the size of a Great White Slide 7 Subclass Holocephali Includes: Ratfish/Chimeras Deep water fish Large head & eyes Gill slits covered by a flap of skin No scales, skin instead Caudal fin developed into rat-like tail Eats crustaceans & mollusks Slide 8 Subclass Elasmobranchii Includes: Sharks, Rays, & Skates Denticles streamlined scales made of the same material as their teeth Slide 9 Energy Efficiency: 1. Cartilage skeleton make them lighter, thus takes less energy to remain buoyant 2. Buoyant oils in liver 3. Fins at angles to provide lift 4. Skin elasticity transfers energy to tail 5. Scales reduce friction (smooth towards tail, rough towards head) 6. Store urea to maintain similar density to water Slide 10 Superorder Batoidea Includes: Skates, Rays, & Sawfish Flattened body Demersal live on the ocean floor Gill slits on ventral (bottom) side Slide 11 Skates & Rays Pectoral fins are flat and expanded Head fuses with pectoral fins with eyes on top Slide 12 Skates vs. Rays Slide 13 Stingrays Equipped with a stinging spine Spine connected to venomous glands Teeth modified into grinding plates Slide 14 Manta & Devil Rays Not bottom dwellers instead choose to swim Slide 15 Sawfish vs. Sawshark Sawfish categorized with the rays while sawshark categorized with the sharks Sawfish have ventral gill slits, smaller and flatter body Sawshark have gill slits on the side, rounded body, bigger overall, and presence of barbels Slide 16 Superorder Selachimorpha Includes: Sharks Gill slits on the side Paired & unpaired fins Most are quite mobile and designed for fast swimming Slide 17 Paired vs. Unpaired fins Paired: Pectoral & Pelvic Comparable to our arms and legs Unpaired: 1 st Dorsal, 2 nd Dorsal, Anal, and Caudal All found along mid-line Slide 18 Scales Scales are very small and sharp Same composition as the teeth Slide 19 Jaws Made of bone Contain the disposable teeth In some species capable of extending jaw out from body Slide 20 Teeth Same composition as the scales Continually shed and replaced by the rows behind Slide 21 Respiration Must swim to force water through their gills Some such as nurse sharks can get enough oxygen so they do not need to swim (pumping mechanism) Sharks that do not have this mechanism go through active periods and rest periods where they lower body functions Slide 22 Digestion Very short esophogus Stomach can be up to 1/3 the length of the shark Intestine is really small, only about a foot Slide 23 Nervous System Lateral line used for sensing vibrations in the water Slide 24 Nervous System Ampullae of Lorenzini Jelly filled canals that can detect electrical fields, magnetic fields, temperature, salinity, water pressure, etc. Electroreception Slide 25 Nervous System Paired external nostrils that lead directly to the brain Very acute sense of smell, can detect concentrations as low as one part per billion Slide 26 Shark Classification Two Sub-Orders: Galeomorphs & Squalomorphs Further broken down into orders Slide 27 Order Heterodontiformes: Bullhead Sharks Pig like snout Bottom dwellers Slide 28 Order Orectolobiformes: Carpet Sharks Very short mouths Upper lobe of caudal fin extended with reduced lower lobe Includes filter feeders Slide 29 Order Lamniformes: Mackerel Fish Larger front teeth Include some of most popular Most are active predators Functionally warm- blooded Slide 30 Order Lamniformes: Goblin Sharks Mitsukurindidae Sandtiger Sharks Carchariidae Slide 31 Order Lamniformes: Ragged-Tooth Sharks Odontaspididae Thresher Sharks Alopiidae Slide 32 Order Lamniformes: Megamouth Shark Megachasmidae Crocodile Sharks Pseudocarchariidae Slide 33 Order Lamniformes: Basking Shark Cetorhinidae Mackerel Sharks Lamnidae Slide 34 Order Carcharhiniformes: Ground or Whaler Sharks Adaptable to many environments, even estuarine and freshwater Flappable lower eyelids Slide 35 Order Carcharhiniformes: Whaler Sharks Carcharhinidae Hammerhead Sharks Sphyrnidae Slide 36 Order Carcharhiniformes: Cat Sharks Schliorhinidae Slide 37 Order Chlamydoselachi Frilled Shark Eel like body Teeth are three pronged Deep water Slide 38 Order Hexanchiformes Cow Sharks Deep water Very little is known Slide 39 Order Echinorhiniformes Bramble Sharks Thick tail stalk Has bumps on skin hedgehog shark Slide 40 Order Sqauliformes Dogfish Sharks Large ranges of sizes Generally best known shark Slide 41 Order Sqauliformes Greenland Shark (21 feet +) Dwarf Laternshark Slide 42 Order Squantiniformes Angel Sharks Flattened bodies Gills on ventral side Mouth at end rather than ventral like rays and skates Slide 43 Order Pristiophoriformes Sawsharks Similar to sawfish, but skinnier and have sensitive barbs on snout Alternating long short teeth