Amphibians


 * Kingdom**: Animalia
 * Subkingdom**: Vertebrata
 * Phylum**: Chordata
 * Class**: Amphibia


 * Body Plan**: Mouth, Anus, Fins (before metamorphosis), Vertebrae, Nervous System
 * Germ Layers**: Ectoderm, Endoderm, Mesoderm
 * Symmetry**: Bilateral


 * Habitat:** Typically found in rain forests and other wet environments. Widespread, but always centered around water.


 * Movement**: The cerebellum coordinates muscles. Signals are sent through the spinal cord and regulate activity.


 * Skeletal System**: Cranium, spine, rib cage, long bones, and short bones in limbs. Amphibians generally have four limbs, and bones are hollow and lightweight.


 * Evolutionary Advancement**: Prehistoric fish developed limbs and primitive lungs for breathing in stagnant pools. Adaptations helped them stay out of the water for increasing periods, but water is still needed for the shell-less eggs and the larval stage.


 * Special Adaptations**: Many amphibians are nocturnal, and can hide during the day. Camouflage is also widely used. Some amphibians also secrete poisons to ward of predators.


 * Feeding Patterns**: Amphibians swallow prey whole, with minimal chewing in oral cavities in some cases. They have voluminous stomachs, and sphincters separating the esophagus from the oral and stomach cavities.

Skin is also used to exchange gases in both water and air.
 * Respiration:** In the juvenile stage, gills oxygenate blood. In the adult stage, gills are lost and lungs develop.


 * Circulation**: Hearts consist of a ventricle and two atria to pump blood. They are cold blooded, and use environment to keep blood a constant temperature.

the final metabolic products. Liver secretions collect in the gall bladder. Waste is filtered in kidneys and transported to the urinary bladder, to be passed out of the cloacal vent.
 * Excretory**: Amphibians have a pancreas, liver and gallbladder. The liver regulates blood sugar, and produces


 * Nervous**: Nervous system consists of a central brain, a spinal cord, and nerves. The brain consists of a cerebrum, midbrain, and cerebellum. Olfactory and optic lobes process smell and sight.


 * Reproduction**: Eggs are laid which hatch into tadpoles. Many eggs are laid, and depending on the species some parenting can be seen.

http://www.amphibian.co.uk/ http://www.wildanimalsonline.com/amphibians/ http://www.amphibiainfo.com/biology/
 * Sources**:

http://farm2.staticflickr.com/1198/5108294951_6bfe0d1261_z.jpg
 * Pictures**:



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