The term amphibian comes from the Greek from the Greek term "amphifibia" which means "both lives". It is used to define a type of vertebrates that can inhabit both water and land. When they are just tadpoles, their respiration is gill, and as adults their respiration is pulmonary. Some of them are: toads, frogs, salamanders, etc.
Amphibians differ from the rest of vertebrates in the transformation they undergo during their development. This was precisely what allowed them to adapt to the terrestrial environment. This rude change is called metamorphosis. This conversion has allowed amphibians to develop, not only a new respiratory characteristic, but it can be observed in the growth of their limbs and the appearance of sensory organs that proceed successfully in both environments. It is important to note that amphibians were the first vertebrates to acclimatize to a semi-terrestrial life
In addition to having a double life, amphibians are characterized by: having four legs in addition to five fingers on the upper extremities and four on the lower ones. They have a bare skin that allows it to absorb oxygen from the air and water through it. They have a respiration, branchial, pulmonary, and cutaneous (through the skin). Its reproduction is oviparous. External fertilization in frogs and toads and internal fertilization in salamanders. Their body temperature will depend on the temperature of the environment where they are, so they are cold- blooded animals.
Amphibians do not have a permanent temperature since it is something that they cannot control, since it is going to be subject to environmental conditions. The tongue is its capture organ, secreting a viscous liquid through many glands, which allows it to catch its food.
There is a great variety of amphibian species, some of them are: anurans, which are characterized by their lack of a tail, have uneven limbs and a spinal column attached to jumping. The caudates have equal extremities and have a tail. The gymnofions, also called apodos or cicilias, are distinguished by being diggers and lacking legs.
