Evolution is the process from which all living organisms have developed from primitive life forms through changes occuring over spans of billions of years. All organisms evolved through years of changes formed by chemical and physical processes that are still taking place today.

Fish have been evolving for five hundred and thirty million years. there are about twenty two thousand different species of fish. the species of fish in the diagram is the Largemouthed Bass. The Largemouth Bass has six different types of fins. The pectoral and pelvic fins assist with steering,stopping and hovering. The dorsal and anal fins help the fish from rolling over onto its side. the caudal fin is the fin that produces most of the propulsion to move the fish forward. over time this fish has developed these different types of fins to allow the fish stability and speed to ecscape preditors. Along with a defence mechinism that are the spinny protruberences on the dorsal fin. the lateral line is a wonder of adaption and evolution. The lateral line is a senory organ that is filled with fluid sac with hair-like sensory appartus that senses water currents, pressure, and movement in the water vie under water vibrations, and is capable of determining the direction of it their source. it uses a series of pores that are open to the water, which enables it to sense the water.It is ovious that the lateral line was developed over time through adaption for the purpose of detecting preditors, pry, and mates. without this lateral line the largemouth bass would have an extremely hard time surviving in the ecosystem that it currently resides. The air bladder is also a producted of evolution. it is a hollow, gas-filled balance organ that allows a fish to conserve energy by maintaining neutral buoyancy in the water. Without this air bladder the big mouth bass would have to consumes more food to produce the energy it would need to keep its self from sinking to the bottom of the lake, stream or pond where it lives. The kidney is very imortant part of this organisms internal system it filters liquid waste materials from the blood. It also regulates the water and salt concentrations within the fish's body, allowing it to life in either fresh water, salt water or in some cases both. Gills are the breathing apparatus of fish and are highly vascularized giving them their bright red cover. An operculum is a flexible bony cover that protects the delicate gills. water is inhaled through the mouth, passes over the gills and exhaled from beneath the operculum. though it is not the ltest daption of fish gills are the mos important adaption of them all. it allows fish to live and breathe in an enviorment that is comsposed of mostly water.
What a fish primarially eats effect the structure of the fish such as the mouths shape the larger the mouth the large the prey it can consume. This alone is evidence of adaption. As the body grows it needs to consume more food to sustain energy so as the body grows so does the mouth to consume larger prey. The bass fish is a piscivorous (meaning it eats other fish) because of that it has a short intestinal tract because it takes less time for food to be breaken down by chemical reaction and digested. over ish that are herbivorous require longer intestines becausd plant matter is usually tough and fibrous and more difficult to break down into usable components. The Pyloric Caeca is the organ with finger like projections is located near the junction of the stomach and the intestines. We do not entirely understand its fuction but it is know to secrete enzymes that aid in digestion, or may fuction to absorb food, or do both. the liver plays an important role in digestion where it secretes enzymes that break down fat. The liver also serves as a storage facility for fat and carbohydrates. The liver is also important in the destruction of old blood cells and in the maintaining of proper blood chemistry, as well as playing a role in nitrogen excretion. the Goonads are the reproductive organs in the fish. The female bass produces eggs that are bright orange and unmistakeable during spawning season, The male organs, which produce milt for fertilizing the eggs, are much smaller and white but found in the same general location