cartilaginous fishes are characterized by the presence of
(credit: Nobu Tamura) Chondrichthyes (cartilaginous fishes) The clade Chondrichthyes is diverse, consisting of sharks, rays, and skates, together with sawfishes and a few dozen species of fishes called chimaeras (ghost sharks). They depend on a flow of water through the body to acquire food. Ancestral records clearly show us that terrestrial vertebrates evolved from lobe-finned fishes nearly 400 million years ago. Animal phyla are classified according to certain criteria, including the type of coelom, symmetry, body plan, and presence of segmentation. Most of the world's fish species are categorized into two types: bony fish and cartilaginous fish.In simple terms, a bony fish (Osteichthyes) is one whose skeleton is made of bone, while a cartilaginous fish (Chondrichthyes) has a skeleton made of soft, flexible cartilage.A third type of fish, including eels and hagfish, is the group known as Agnatha, or jawless fish. A craniate is a member of the Craniata (sometimes called the Craniota), a proposed clade of chordate animals with a skull of hard bone or cartilage.Living representatives are the Myxini (hagfishes), Hyperoartia (including lampreys), and the much more numerous Gnathostomata (jawed vertebrates). They are characterized by their paired, fleshy pectoral, and pelvic fins that are each articulated via a single bone. Dunkleosteous was an enormous placoderm from the Devonian period. In most terrestrial animals, including mammals and birds, pharyngeal slits are present only during embryonic development. It measured up to 10 meters in length and weighed up to 3.6 tons. The lobe-finned fishes are the sister group to the ray-finned fishes. Sponges (Porifera) have a primitive cellular level of organization and lack tissues and symmetry. In vertebrate fishes, the pharyngeal slits develop into gill arches, the bony or cartilaginous gill supports.
Cohen And Steers Private Equity, Frisco Public Library Hours, Texas Railroad Commission Gis, Venus In 4th House In Navamsa Chart, Cleburne County Property Records, When Was Google Slides Created, Remove Ghost Printer Windows 10,
Nenhum Comentário