Comparing Freshwaterwater And Freshwater Fish

Daelyn Sagert

November 28, 2017

Comp 1 4th hour

Compare and Contrast

Freshwater Fish versus Saltwater Fish Freshwater fish and saltwater fish are very similar in a lot of ways, but also have differences between them so you can tell them apart. Marine water (saltwater) equals over 96 percent of the water on Earth and over 70 percent of Earth’s total surface. Freshwater is less than four percent of Earth’s total water and is about one percent of Earth’s surface (Freshwater Fish). Interestingly a few species of fish can live in either freshwater or saltwater, but for the majority, they must live in a specific environment. All species of fish used to live in a saltwater environment until certain geological events (earthquakes, volcanic activity, etc.) occurred, creating conditions that isolated groups of fish. The new habitats, included freshwater, and new food sources caused fish to either adapt, or to die (Lohrey). When looking at similarities in freshwater fish and saltwater fish, a big similarity is their anatomy. There are no anatomical differences when looking at the big spectrum, nothing distinguishes freshwater and saltwater fish from each other in that sense (Freshwater Fish). For both types of fish, the composition of the

There is one difference in their anatomy and physiology, and that is how the fish regulate the water and salts in their internal cells. Most freshwater and saltwater fish maintain a salt level in their blood, but those levels are different for both types. The chloride cells in freshwater fish are designed to pump sodium, calcium, and chloride into the fish. Freshwater fish are usually more adaptable to their environment, and more “stable” than saltwater fish. (Freshwater Fish). Body tissues are a huge difference in these types of fish (osmoregulation), and it shows a major difference between freshwater and saltwater fish