AnatomyOne way to identify a fish is by their body structure, they have fins and a backbone. The anatomical adaptation of their fins helps them survive and makes them and marine animals unique in that they use them to maintain position, move, steer and stop. Most fish have scales and breathe through gills. Most fish also have a layer of mucus that helps them prevent infections. Among those we consider "fish", there are many that do not look much like land creatures. The strangest fish species are found in the deep waters of the ocean, such as the Pacific Barreleye, which is distinguished by the fact that its head is a transparent shield filled with liquid. Other strange-looking fish include the sheepshead fish and the parrotfish. The body structure of the amphibian is different depending on the species you are looking at. The general characteristics of a frog's body, for example, are very similar to human anatomy. Both humans and frog have the same types of organs and organ systems. The anatomy of the frog, however, is much simpler. As in other higher vertebrates, the frog's body is divided into a head, a short neck and a trunk. The flat head contains the brain, mouth, eyes, ears and nose. A short, almost rigid neck allows only limited head movement. The frog is covered with a soft, thin and moist skin composed of two layers, an outer epidermis and an inner dermis. This is a special anatomical adaptation present in all amphibians and which helped them survive. As for the unique species of amphibians, noteworthy are the Chinese giant salamander, the purple frog and the elm tree, which is a blind salamander with transparent skin that lives underground, hunts its prey with smell and electrosensitivity and can survive without food for 10 years.W...... middle of paper ......and found in various types of habitats, bats in the skies, whales and dolphins in the sea and giants like the elephant on the land . Mammals, being the dominant class of the current era since the Cenozoic era, influence the environment the most, mainly because humans are the dominant species on the planet. Man's niche in the ecosystem can be seen in all aspects of the current state of the planet. The acquisition and consumption of natural resources, pollution and deforestation are some of the roles that mammals, humans, have on the biome in which they live. Behavior The fish are oviparous, there are some that are ovoviviparous. Amphibians are oviparous, there are some that are ovoviviparous. Reptiles are oviparous, there are very few ovoviviparous ones. All birds are oviparous. Mammals are viviparous, with the exception of four species of Echidna and Platypus, which are oviparous..