Amphibian Proteins: Proteins obtained from species in the class of AMPHIBIANS.Amphibians: VERTEBRATES belonging to the class amphibia such as frogs, toads, newts and salamanders that live in a semiaquatic environment.Chytridiomycota: A phylum of fungi that was formerly considered a subdivision of Phycomycetes. They are the only fungi that produce motile spores (zoospores) at some stage in their life cycle. Most are saprobes but they also include examples of plant, animal, and fungal pathogens.Ranidae: The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.Anura: An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.Bufonidae: The family of true toads belonging to the order Anura. The genera include Bufo, Ansonia, Nectophrynoides, and Atelopus.Urodela: An order of the Amphibia class which includes salamanders and newts. They are characterized by usually having slim bodies and tails, four limbs of about equal size (except in Sirenidae), and a reduction in skull bones.Salamandridae: A family of Urodela consisting of 15 living genera and about 42 species and occurring in North America, Europe, Asia, and North Africa.Ambystoma: A genus of the Ambystomatidae family. The best known species are the axolotl AMBYSTOMA MEXICANUM and the closely related tiger salamander Ambystoma tigrinum. They may retain gills and remain aquatic without developing all of the adult characteristics. However, under proper changes in the environment they metamorphose.Ranavirus: A genus of IRIDOVIRIDAE which infects fish, amphibians and reptiles. It is non-pathogenic for its natural host, Rana pipiens, but is lethal for other frogs, toads, turtles and salamanders. Frog virus 3 is the type species.Ambystoma mexicanum: A salamander found in Mexican mountain lakes and accounting for about 30 percent of the urodeles used in research. The axolotl remains in larval form throughout its life, a phenomenon known as neoteny.Reptiles: Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.Amphibian Venoms: Venoms produced by frogs, toads, salamanders, etc. The venom glands are usually on the skin of the back and contain cardiotoxic glycosides, cholinolytics, and a number of other bioactive materials, many of which have been characterized. The venoms have been used as arrow poisons and include bufogenin, bufotoxin, bufagin, bufotalin, histrionicotoxins, and pumiliotoxin.Triturus: A genus of aquatic newts in the Salamandridae family. During breeding season many Triturus males have a dorsal crest which also serves as an accessory respiratory organ. One of the common Triturus species is Triturus cristatus (crested newt).Xenopus laevis: The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.Metamorphosis, Biological: Profound physical changes during maturation of living organisms from the immature forms to the adult forms, such as from TADPOLES to frogs; caterpillars to BUTTERFLIES.Bufo arenarum: A species of the true toads, Bufonidae, found in South America.Rana pipiens: A highly variable species of the family Ranidae in Canada, the United States and Central America. It is the most widely used Anuran in biomedical research.Xenopus: An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.Bufo marinus: A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.MycosesRana catesbeiana: A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.Ponds: Inland bodies of standing FRESHWATER usually smaller than LAKES. They can be man-made or natural but there is no universal agreement as to their exact size. Some consider a pond to be a small body of water that is shallow enough for sunlight to reach the bottom.Animal DiseasesNotophthalmus viridescens: A species of newt in the Salamandridae family in which the larvae transform into terrestrial eft stage and later into an aquatic adult. They occur from Canada to southern United States. Viridescens refers to the greenish color often found in this species.Embryo, Nonmammalian: The developmental entity of a fertilized egg (ZYGOTE) in animal species other than MAMMALS. For chickens, use CHICK EMBRYO.Endangered Species: An animal or plant species in danger of extinction. Causes can include human activity, changing climate, or change in predator/prey ratios.DNA Virus Infections