This document discusses the characteristics, evolution, feeding, and respiration of fish. It notes that fish generally have paired fins, scales, and gills. Originally fish were armored and jawless, but in the Devonian Period fish evolved paired fins and jaws. Fish can feed in different ways depending on their environment, including herbivores, carnivores, parasites, filter feeders, and detritus feeders. Gas exchange occurs through gill filaments and blood circulates through fish in one loop.

1. 30-2: Fishes Paige Steiding 6 ° Biology

2. The Characteristics Of Fish All of the characteristics of fish are generalizations because the diversity between fishes is so large These characterizations include: Paired fins Scales Gills

3. The Evolution Of Fishes Originally, Fishes were armored and jawless In the Devonian Period, or the Age of Fishes, Fish developed paired fins and jaws These adaptations were incredibly helpful in increasing the fitness of fish

4. Feeding Different populations of fish from the same species can feed different ways depending on their environment Types of feeders include herbivores, carnivores, parasites, filter feeders, and detritus feeders

5. Respiration And Circulation In fish, gas exchange occurs in the gill filaments, which filter out oxygen and let the rest of the water pass out through the gill slits Some fish, called lungfish, possess organs that act as lungs Blood flows through fish in one circular loop

6. Works Cited &quot;The Devonian Period.&quot; Faculty and Staff, Georgia Perimeter College . Web. 31 Mar. 2010. <http://facstaff.gpc.edu/~pgore/geology/geo102/devonian.htm>. &quot;Fish Pictures, Pictures of Fish, Fish Facts - National Geographic.&quot; Animals, Animal Pictures, Wild Animal Facts - National Geographic . Web. 29 Mar. 2010. <http://animals.nationalgeographic.com/animals/fish.html>. &quot;Fish under Water Image by RoShute on Photobucket.&quot; Image Hosting, Free Photo Sharing & Video Sharing at Photobucket . Web. 29 Mar. 2010. <http://media.photobucket.com/image/fish%20under%20water/RoShute/Under%20Water%20Life/1554ajq.jpg?o=12>. &quot;Kinds of Fish.&quot; Earthguide: Educational Resources in Earth, Marine, Environmental and Planetary Sciences . Web. 31 Mar. 2010. <http://earthguide.ucsd.edu/DFL_ed_prelim/kinds/pop_life_long_lived.html>. Miller, Kenneth R., and Joseph S. Levine. Prentice Hall Biology . Upper Saddle River, N.J.: Prentice Hall, 2002. Print. &quot;Pikes (No, Not Pike Street Market in Seattle&.) Predators.&quot; SwittersB & Fly Fishing . Web. 31 Mar. 2010. <http://swittersb.wordpress.com/2009/10/26/pike-no-not-pike-street-market-in-seattle/>. &quot;Queen Angelfish - Holacanthus Ciliaris.&quot; Tropical Fish, Aquarium Fish, Care for Saltwater and Freshwater Fish, Aquarium Setup . Web. 31 Mar. 2010. <http://www.fishlore.com/profile-queenangelfish.htm>.