Perch Dissection Lab:
Domain Eukarya
Kingdom Animalia Phylum Chordata Superclass Osteichthyes Class Actinoptergii Procedure:
Ecology of the Class Actinopterygii: Most fish spend their entire lives in either fresh or ocean water. Freshwater fish cannot tolerate the high salt concentration in salt water because their kidneys need to keep an internal water balance. Ocean fishes cannot tolerate the low salt concentration in fresh ecosystems. Some species of fish can move to and from salt and fresh environments. For example, salmon, lampreys, and sturgeons live in the ocean but migrate to freshwater to breed. These types of fish are called anadromous. Catadromous fish live in freshwater but breed in the ocean. The eggs of catadromous fish are carried by currents in the North Atlantic Ocean to shallow coastal waters.
Groups of Fishes: All living fishes can be classified into three groups: jawless, cartilaginous, and bony. Jawless fishes have no teeth or jaws. Their skeletons are made of fibers and cartilage, which means they lack vertebrae.One of the classes of jawless fish is the lampreys. They are filter feeders as larvae and parasites as adults. The other class, hagfishes, have worm-like bodies and four or six short tentacles around their mouths. They feed on dead and dying fish by using a toothed tongue. Sharks and their relatives are cartilaginous fish. Bony fishes make up the class Osteichthyes. Their skeletons are made of hard, calcified tissue called bone. Almost all of them belong to the group of ray-finned fish. |