1. Andrea Carrasquero Michelle Perez

2. Fishes A fish is any aquatic vertebrate animal that is covered with scales, and equipped with two sets of paired fins and several unpaired fins. Most fish are "cold-blooded," or exothermic, allowing their body temperatures to vary as ambient temperatures change. Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams to the abyssal depths of the deepest ocean. At 31,500 species, fish exhibit greater species diversity than any other class of vertebrates.

3. Types of Organism Marine Fish Tropical Fish Freshwater Fish

4. Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations in order to keep the ion concentration of their bodies balanced. 41% of all known species of fish are found in freshwater

5. Marine Fish Marine biology is the study of life in the oceans and other saltwater environments such as estuaries and wetlands.

6. Tropical Fish Tropical fish include fish found in tropical environments around the world, including both freshwater and salt water species. Fish keepers often use the term tropical fish to refer only those requiring fresh water, with saltwater tropical fish referred to as marine fish.

7. Reproduction Fish breed in different ways. There are two main strategies that fish use: egg laying and live bearing. Live bearing female fish are internally fertilized by the male fish, and carry the fry for about a month before delivering them. Egglaying fish lay eggs instead of giving birth to little fish. Egg layers have many methods of laying eggs. For example, substrate spawners lay eggs in protected areas such as plants, rocks, wood. Mouth brooders actually keep their eggs in their mouths until the eggs hatch.

8. Fish Structure Fish are aquatic animals. They are part of the aquarium ecosystem. Like all animals fish eat, breathe, reproduce, excrete waste and adapt to their environment. Different kinds of fish reproduce in different ways, and eat different kinds of food.