Biology of Fishes Exam 1 - Fish live in many different parts of the world They can be found in ponds lakes rivers streams and oceans The diversity of

Biology of Fishes Exam 1 - Fish live in many different...

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Fish live in many different parts of the world. They can be found in ponds, lakes, rivers, streams, and oceans. The diversity of the many species of fish is dependent upon their characteristics and the roles that they play in our ecological system. Fish morphology is the variety of the external anatomy among fish species. The body structure of a fish can help determine the predation style, depth, and other swimming mechanisms thatare required for survival. For example, the type, size, and arrangement of the fins are related to their ecological function. All fins are supported by fin rays, but the bony fishes (Osteichthyes) are flexible and have segmented and branched fins and the cartilaginous fishes (Chondrichthyes) have stiff, unsegmented fins. Fish are very diverse in their morphology. They come in all shapes and sizes and their body form and function work together and examination of their body shapes give insight to their lifestyles. Majority of fish are categorized between six broad categories which are based upon their body configuration. Fish share common internal morphological characteristics such as, fins, gills, scales, lateral line, and a peduncle. The soft-rayed fish represents the ancestralbody shape which is adapted for endurance in swimming and cruising. These types of fish have one dorsal fin and an adipose fin. Spiny-rayed fish are laterally compressed and dorsoventrally deepened body and it is used for maneuverability. These types of shish and two dorsal fins, the first dorsal fin has spiny projections and then a soft-rayed fin.The first species the Lepisosteusosseus, Longnose Gar, are prominent in North and South America and the Caribbean. They have an elongated, fusiform body shape, and it resembles a torpedo. They are classified as lie-in-wait predators are piscivores, who mainly eat other fish. They are called lie-in-wait predators because their body shape allows them to ambush their fast-swimming prey. They have flat heads and have a long, large, terminal mouth filled with caniniform teeth. They possess a large caudal fin and their anal and dorsal fins are onthe back end of their body often aligned, this gives them the right amount of thrust it needs to launch itself at high speeds towards its prey. They are olive brown in color with a white belly. Dark spots can be found on the median fins and, in individuals from clear water, on the body. (Page and Burr, 1991; Becker, 1983). They have aheavy armor of interlocking, rhomboid, ganoid scales (Ross, 2001), which is essential in protection. The ganoid scales are composed of two layers, an outer layer of ganoin and an inner layer of isopedine, both of which are
penetrated by blood vessels. As a result of this armor, the longnose gar has no major predators. L. osseuslive in a variety of lowland habitats, such as larger rivers, lakes, and reservoirs. They can live in salty water and are common in the deeper bayous along the Gulf Coast (Goodyear, 1967).L. osseuscan tolerate high water

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