Cattle

Cattle, name for the ruminant mammals of the genus Bos, and particularly those of the domesticated species, Bos taurus and B. indica. The term oxen, broadly used, refers also to closely related animals, such as the buffalo and the bison. Narrowly used, ox refers to a mature castrated male used for draft purposes. In referring to domestic cattle a grown male is a bull, a grown female a cow, an infant a calf, and an animal between one and two years old a yearling. A female that has not given birth is a heifer; a castrated male is a steer.

Most cattle have unbranched horns consisting of a horny layer surrounding a bone extension of the skull; these horns, unlike those of deer, are not shed. Some cattle are naturally hornless. Western, or European, domestic cattle (Bos taurus) are thought to be descended mainly from the aurochs, a large European wild ox domesticated during the Stone Age, extinct since 1627. A smaller species, the Celtic shorthorn, was the most important domestic ox of the Stone Age and may also be involved in the ancestry of B. taurus. The zebu, or Indian ox, B. indica, is the humped domestic species of Asia and Africa. Several B. indica breeds have been developed in the United States into the Brahman breed. The yak, B. grunniens, and other cattle species, wild and domestic, exist in Asia. Domestic cattle were first brought to the Western Hemisphere by Columbus on his second voyage.

In various societies throughout history wealth has been measured in terms of cattle—cattle is related to capital and chattel, and pecuniary is derived from pecus [Lat.,=cattle]. Breeding for improvement of beef and dairy qualities, practiced by the Romans, was established on scientific principles in the middle of the 18th cent. by English livestock breeder Robert Bakewell (see animal husbandry; breeding). Important beef breeds include Angus, Hereford, Simmental, Charolais, Limousin, Gelbvieh, Brahman, and Shorthorn. Important crossbreeds include Brangus (Brahman x Angus) and Santa Gertrudis (Shorthorn x Brahman). Major dairy breeds include Holstein-Friesian, Jersey, Guernsey, Brown Swiss, Ayrshire, and Milking Shorthorn. The importance of dual-purpose breeds has declined.

Cattle are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Artiodactyla, family Bovidae. See also beef; dairying.

Source: http://encyclopedia2.thefreedictionary.com/cattle

Mud Puppy

Mud puppy, common name for North American salamanders of the genus Necturus, found in rivers and streams throughout the E United States and SE Canada. The name derives from an erroneous belief that mud puppies bark. Like its relative, the European olm, the mud puppy exhibits neoteny, i.e., it reaches sexual maturity without losing its larval characteristics. Adults have lungs, characteristic of most adult salamanders, as well as gills, characteristic of larvae. Their short, sturdy limbs develop at an early stage. The mud puppy may reach a length of 12 in. (30 cm); it is reddish brown and black-spotted above and grayish below, with conspicuous bushy red gills at the sides of its head. It walks on river bottoms and feeds primarily on crayfish and aquatic plants. 

Mud puppies are classified in the phylum Chordata, subphylum Vertebrata, class Amphibia, order Urodela, family Proteidae.

Source: http://encyclopedia2.thefreedictionary.com/mud+puppies

Newt

Newt, name for members of a large salamander family, widely distributed in the Northern Hemisphere and including the common European salamanders. Newts are lizardlike in shape and are usually under 6 in. (15 cm) long including the slender tail. Some are brightly colored and secrete irritating substances. Like other salamanders, newts go through an aquatic, gilled larval stage. In some species the adults remain aquatic, although they lose their gills and breathe air; in others the adults are terrestrial, returning to water only to breed. Still other newts go through two adult stages: a terrestrial stage, during which they are called efts, is followed by a permanent aquatic stage. One such species is the common red-spotted newt (Diemictylus viridescens) of the E United States, known in its terrestrial stage as red eft. The 3-in. (7.5-cm) adult lays its eggs in spring on the stems and leaves of water plants. The greenish-brown larvae remain in the water for several months before emerging as efts, orange-red with a double row of black-ringed vermilion spots. The efts spend two or three years on land, hibernating in winter under leaves, and then return permanently to the water, becoming olive green and developing a broad swimming tail. 

Newts are classified in the phylum Chordata, subphylum Vertebrata, class Amphibia, order Urodela, family Salamandridae.

Source: http://encyclopedia2.thefreedictionary.com/newts

Salamanders

Salamander, an amphibian of the order Urodela, or Caudata. Salamanders have tails and small, weak limbs; superficially they resemble the unrelated lizards (which are reptiles), but they are easily distinguished by their lack of scales and claws, and by their moist, usually smooth skins. Salamanders are found in damp regions of the northern temperate zone and are most abundant in North America. Most are under 6 in. (15 cm) long, but the giant salamander of Japan (Megalobatrachus japonicus) may reach a length of over 5 ft (1.5 m). Most salamanders are terrestrial as adults, living near water or in wet vegetation, but some are aquatic and a few are arboreal, burrowing, or cave-dwelling. Most are nocturnal, and all avoid direct light. Salamanders are able to regenerate a lost limb or tail. They feed on small animals, such as insects, worms, and snails.

Most salamanders breed in water and are gregarious at breeding time, when there is usually a courtship display. In most species fertilization is internal. The male deposits sperm packets, which the female picks up with the cloaca; the sperm is then stored until fertilization takes place. The eggs, surrounded by gelatinous material, are usually laid in ponds or brooks, where they develop into aquatic larvae that can breathe by means of gills. A few salamanders breed on land, laying their eggs under rotting vegetation; the young pass through the gilled stage in the egg, emerging as miniature adults. Such strictly terrestrial forms are the red-backed salamander (Plethodon cinereus) and slimy salamander (P. glutinosus) of E United States and the slender salamander (Batrachoseps attenuatus) of the Pacific coast.

Most salamanders, including most that remain in an aquatic environment, go through a typical amphibian metamorphosis into air-breathing adults. Generally the adults have lungs, but in the large family of lungless salamanders (Plethodontidae) breathing occurs entirely through the skin and the lining of the throat. In a few salamanders growth occurs without metamorphosis, and the gilled, juvenile form is able to reproduce. This phenomenon (called neoteny) is found in the sirens (family Sirenidae) of S United States and N Mexico, in the mud puppies (family Protidae), and in the Mexican axolotl. 

Classification

There are over 200 salamander species, classified in approximately 60 genera and 8 families of the phylum Chordata, subphylum Vertebrata, class Amphibia, order Urodela.

Source: http://encyclopedia2.thefreedictionary.com/salamanders

Toad

Toad, name applied to certain members of the amphibian order Anura, which also includes the frog. Although there is no clear-cut distinction between toads and frogs, the name toad commonly refers to those species that have relatively short legs, stout bodies, and thick skins, and are less aquatic as adults than the long-legged, slender-bodied frogs.

Sometimes the term toad is restricted to the so-called true toads, members of the family Bufonidae. These are characterized by warty skins and prominent parotid glands behind the eyes and as a group are the most terrestrial of the order. In most the feet are only slightly webbed. They range in length from about 1 to 7 in. (2.5–18 cm). Most species belong to the genus Bufo; members of these species spend much of the time on land, generally near water. They generally live in cool, moist places and absorb moisture through the skin. The white fluid that they exude through the skin, as well as from the parotid glands, is very poisonous and causes intense burning if it comes in contact with the eyes or mouth; however, contrary to an old belief, it does not cause warts. Toads, like frogs, move on land by jumping and feed on insects and grubs. Also like frogs, they usually lay their eggs in water in strands of jelly. Fertilization is external. The egg hatches into a tadpole, a gilled, aquatic, larval toad that undergoes metamorphosis into the adult.

There are about a dozen Bufo species in the United States, among them the common American toad (Bufo americanus), Fowlers toad (B. fowleri), of the E United States, and the red-spotted toad (B. punctatus), of the Southwest. The cane, marine, or giant toad (B. marinus), a large toad native to Central and N South America, was widely introduced in warm regions (Caribbean, Pacific, Australia, and Florida) to control agricultural pests but is now regarded as an invasive species; they compete with and prey on native species, and their toxic secretions can kill predators.

The spadefoot toads, burrowing toads of the family Pelobatidae, are represented in the United States by several species of the genus Scaphiopus. Toads are classified in the phylum Chordata, subphylum Vertebrata, class Amphibia, order Anura.

Source: http://encyclopedia2.thefreedictionary.com/Toads