Classification of Fish

Whitney East Mr. Beall Speech 1200 October 24, 2012 draw Topical Classifying lean Specific Purpose To inform my audience about the different categorizations of seek. Central approximation Fish ar classified by their different characteristics which sorts them into different classes like Agnatha, class Chondrichthyes, and Osteichthyes. Introduction I. Classification of financial backing things helps people to understand how living organisms may or may not be related to each other. A. The system of classification we rehearse at present was invented 200 years ago by Carl Linnaeus.B. Carl Linnaeus system of classification groups organisms by their characteristics or features they grant in common. II. According to the book Vertebrate Biology by ORR Robert Fish, mammals, reptiles, birds, and amphibians be classified together as vertebrates because they all cast an internal backbone. III. In researching this particular topic, I learn that the most important characteristics used in search classification are the type of bone in their picture, the gill structure, the number and shape of fins, and the type of scales. IV.Now I will introduce you to the characteristics and the three different classes of fish. jawless (Agnatha), Cartilaginous (Chondrichthyes), and Bony Fish (Osteichthyes). Body I. The Agnatha class is the oldest group, similar to fish but with some(a) different characteristics. A. As explained in The Evolution of Vertebrate Design, certain characteristics like lacking jaws is what classified fish to this class. 1. The Agnatha class lacks an internal bone skeleton, jaws, and paired fins. 2. Instead of jaws, they have circular toothed mouths called cyclostomic. Which they use to suck blood from the side of their prey. . They have a smooth, scale less skin which is soft to the touch. B. on that point are two living groups of Agnatha the lampreys and Hagfish 1. Lamprey have a single dorsal nostril, a pineal eye, three fins (anterior, posterior, and caudal fin), and a long row or circular gill pouch openings. They make a living being a parasite that eventually kills the prey they fasten onto. 2. Hagfish have long eel-like bodies, no eyes, no true fins, a single nostril, up to ogdoad barbels (like whiskers/tentacles for fish) and have rows of horny teeth used to grasp food and draw it in. II.Chondrichthyes fish today include both fearsome predator characteristics and harmless characteristics. A. As explained in Vertebrate Biology, all Chondrichthyes lack true bone. 1. The Chondrichthyes fish have full cartilage skeletons. 2. They have teeth that are made of calcium which grow in rows throughout the fishs life. 3. They have a continuous pattern of fins and there external skin is entirely cartilaginous. B. Sharks, skates, and rays make up the Chondrichthyes class. 1. Sharks have pointed snouts and crescent-shaped shaped mouths with several(prenominal) rows of sharp triangular teeth.They have five gills on each side that ha ve individual gill slits shown externally. 2. Skates are rounded to diamond shaped. They have large pectoral fins extending from the snout to the insensible of their tail. The mouth and gills are on the underside of their bodies. Skates are bottom dwellers and trap their prey by displace down on their prey from above. 3. Rays can be classified into the following groups electric rays, sawfish, skates, and many families of rays that have slender whip like tails. III. The Osteichthyes ( worn fish) is the largest class of vertebrates with over 20,000 species.A. Stephen Savage states in the book Fish that, Osteichthyes have skeletons made of bone, flat scales, and gills. 1. Bony fish have a much stiffer skeleton because it is reinforced by calcium salts. 2. Bony fish also have acute eyesight strange other classes of fish 3. Bony fish have a special organ called a float blatter housed under their bony skeleton is a gas filled chamber that allows the fish to remain vagabond in the wat er. B. Tuna and Seahorses are examples of bony fish (Osteichthyes) 1. The tuna is stout in the middle and tappers to points at both ends.The tuna had two closely spaced dorsal fins on its back. The tuna is generally argentiferous dark blue color on its sides and silvery on its underside. 2. The seahorse has a heavy bony armor which makes them poor swimmers. They mostly anchor themselves with their tails to things like seaweed or other kinds of plants. They have a transparent dorsal fin on its back that propels them forward. Conclusion I. An animal is not a fish unless it has all the right characteristics II. No matter how different fish are, most fish share several basic characteristics fins, gills, scales, and hatch babies from eggs. III.Fish classification is sometimes confusing and difficult, but it is a useful way of study about different groups of fascinating fish around the world.Bibliography Animal Planet. N. p. , n. d. Web. 23 Oct. 2012. <http//animals. howstuffworks. co m/fish/fish-info5. htm>. ORR, ROBERT T. VERTEBRATE BIOLOGY. fourthly ed. PHILADELPHIA W. B. SAUNDERS, 1976. Print. Radinsky, Leonard B. The Evolution of Vertebrate Design Leonard B. Radinsky. Chicago University of Chicago, 1987. Print. Savage, Stephen. Fish. Austin,Texas Raintree, 2000. Print. Wallace, Holly. Classification. Chicago Heinemann Library, 2000. Print.