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The vertebrate has a distinct head, with a differentiated tubular brain and three pairs of sense organs (nasal, optic, and otic). The body is divided into trunk and tail regions. The presence of pharyngeal slits with gills indicates a relatively high metabolic rate.
Several groups of vertebrates inhabit planet Earth. Let’s take a tour of the five main vertebrate groups alive today: the fishes, amphibians, reptiles, birds, and mammals.
One tentative classification based in cladistics separates the vertebrates into two superclasses (Agnatha and Gnathostomata). Agnathans are jawless, while the gnathostomates encompass the remainder of the jawed vertebrates.
Chordate, any member of the phylum Chordata, which includes the vertebrates, the most highly evolved animals, as well as two other subphyla—the tunicates and cephalochordates. Some classifications also include the phylum Hemichordata with the chordates.
The vertebrates can be divided broadly into two main groups based on the presence or absence of limbs: the fishes, which lack limbs, and the tetrapods, which have four limbs. Each group is further subdivided into categories based on common key features.
invertebrate, any animal that lacks a vertebral column, or backbone, in contrast to the cartilaginous or bony vertebrates. More than 90 percent of all living animal species are invertebrates. Worldwide in distribution, they include animals as diverse as sea stars , sea urchins , earthworms , sponges , jellyfish , lobsters , crabs , insects ...
Vertebrates have an internal skeleton formed of cartilage, bone, or both. The skeleton consists of a backbone (vertebral column), which partly encloses a spinal cord; a skull, which encloses the brain; and usually two pairs of limbs.
mammal, (class Mammalia), any member of the group of vertebrate animals in which the young are nourished with milk from special mammary glands of the mother. In addition to these characteristic milk glands, mammals are distinguished by several other unique features.
Fish, any of approximately 34,000 species of vertebrate animals (phylum Chordata) found in the fresh and salt waters of the world. Living species range from the primitive jawless lampreys and hagfishes through the cartilaginous sharks, skates, and rays to the abundant and diverse bony fishes.
amphibian, (class Amphibia), any member of the group of vertebrate animals characterized by their ability to exploit both aquatic and terrestrial habitats.