Amphibians form a class of vertebrates. Vertebrates are animals that have backbones their surround their nerve cords. The nerve cord is found along the back of the animal. The bodies of most vertebrates have a head and a trunk. Many vertebrates have two pairs of limbs attached to the trunk.
Amphibians go through a two-stage life cycle. They are laid in water or a damp environment to keep from drying out. They experience a metamorphosis or change in appearance from the baby to adult. When an amphibian hatches, it is in a gilled larva form. In frogs and toads this larva is called a tadpole.
There are three basic groups of amphibians. The first group is frogs and toads, the second are newts and salamanders, and the third one is worm-like animals called caecilians that are found only in the tropics. Amphibians are cold blooded, which means the body temperature is the same as the surrounding air, water, or soil. Some frogs can survive in freezing temperatures. The frog's body produces a chemical that acts like the antifreeze we use in cars. This chemical keeps the cells alive during the freezing temperatures. Amphibians have soft, generally moist skin without scales. Most amphibians have lungs like other vertebrates.
All amphibians use their skin to take oxygen. Many breathe through gills. There are more than 4,000 species of amphibians. Frogs and toads are the most with 3,438 species frogs have smooth skin and long limbs. Toads have warty skin and short limbs.
Salamanders and newt have long bodies, long tails, and two pairs of legs. There are 320 species of salamanders. The life span of a salamander, depending on its species, it may live up to 1 to 60 years. Salamanders can be short, but some can grow up to be very long, such as the giant salamander of Japan. They are brightly colored, often brown, black, yellow, or red. The skin contains many glands, some secreting mucus to help maintain moisture and other secreting a toxic irritating liquid when the animal is frightened.
From those reptiles and fish came the amphibians. The amphibians were the predecessors to the first mammals. ... Amphibians are animals, which can live both on land as well as in the water. ... Eventually reptiles began to evolve from the amphibians. This occurred around ten million years after the first amphibians. ...
Amphibians have lived on our earth longer then humans and adapt to a wide variety of habitats over the years. A recent study had proved that human neglect and ignorance has greatly impacted the amphibian population. In the remaining amphibian populations deformities such as extra eyes, or limbs have been reported in as many as 44 states. Some deformities are natural but in some areas up to 60% of amphibians have been reported ta have these defects. ... However not even amphibians have been able to adapt to our recent neglect of the mother earth. ...
This type of reproduction strategy is the main type in amphibians. ... Adult amphibians are almost completely carnivorous. ... Fish, amphibians, and reptiles are ectothermic. ... Amphibians have large eyes for good vision. ... Amphibians use the kidneys to eliminate waste. ...
Herpetology is the study of reptiles and amphibians, but there is a lot more to Herpetology than just the studying of the reptiles and amphibians. Since reptiles and amphibians are everywhere, it is a worldwide study. ... More and more people became interested in breeding herps (Reptiles and amphibians). ... Reptiles, like amphibians, are entirely cold blooded. ... Most reptiles lay eggs, but unlike amphibians, reptile eggs are laid on land. ...
Fossil studies have shown that reptiles evolved from amphibian ancestors in the carboniferous period about 340 million years ago. Reptiles surpassed amphibians on land because they had survival advantages. These include they have a strong flexible skeleton, dry, scaly skin covering in moisture and eggs with protective shell so they won't dry out unlike amphibians who need water. ... This type of egg is makes them different from amphibians. ...
There are 5 kinds of chordates in the world: fishes, amphibians, reptiles, birds, and mammals. ... Second, We know amphibians are the animals able to live both on land and in water, they are the most primitive of the terrestrial vertebrates, are intermediate in evolutionary position between the fish and the reptile. ... Amphibians lay eggs in water or in a protected place where their moisture will be conserved. ... Unlike amphibians, they do not possess gills or breathe in water at any stage of their development, and they lay their eggs on the land. ... In conclusion, fishes, amphibians, repti...
Discovered in 1966 by JM Savage, the remarkably colored amphibian was a mystery to scientists (www.bbc...). ... The mating of the extraordinary amphibian begins with the extensive rainfall of May and April. ... Scientists are at a loss to what's causing the disappearance of this creature, as well as a number or other amphibians. ... Amphibians such as the Golden Toad are particularly susceptible to such a disaster. ...
Neural induction is initiated when the ectoderm is exposed to signals emanating from Spemann's organiser in amphibians, or its functional equivalents - the nodes in amniotes. ... Some variation may be the result of the obvious differences in embryonic morphogenesis between amphibian which at the onset of gastrulation consists of a hollow ball of cells and avian which develop from a flat epiblast. ... This idea is supported by the observation that the avian node can substitute for the amphibian organiser in neural induction assays. ... It seems unlikely, however, that amphibians have de...