amphibians. characteristics ectothermic, tetrapod vertebrates with a endoskeleton that are...
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CharacteristicsEctothermic, Tetrapod Vertebrates with a endoskeleton that are restricted to moist or aquatic environmentsSmooth moist skin developed for protection, water and temperature regulation, and gas exchange
Amphibious LifestyleLiving in two different media (water and land) allows these organisms to take advantage of characteristics that each environment has to offer while limiting the competition between the fully aquatic and herbivorous larval stage and the amphibious and carnivorous adult stage
Habitat AdvantagesWaters AdvantageWater shows less fluctuation in temperature than land, and is thus a very stable environment. Likewise, its buoyancy help support the body or aquatic organisms.
Lands AdvantageAir on land holds 20% more oxygen than water, and thus land dwelling amphibians can be more active
EvolutionAmphibians diversified into two distinct lineages, the amniote lineage that gave rise to the reptiles, birds, and mammals, and the non-amniote lineage that gave rise to current amphibiansIchthyostega
ClassificationOrder GymnophionaOrder CaudataOrder Anura
Order Gymnophiona (Caecilians)Caecilians are worm-like amphibians that appear segmentedThey are confined to tropical regions of the world and are burrowing creatures that feed on soil invertebrates
Order Caudata (Salamanders)Salamanders tend to have unspecialized paired limbs and a tailMost salamanders live in moist forested habitatsThey have internal fertilization and lay their eggs in moist or aquatic habitats
Order Anura (Frogs & Toads)Frogs & Toads have specialized hind limbs and lack a tail as adults (anura = witout tail)Most frogs & toads live in aquatic habitats, have external fertilization, and develop through metamorphosis from aquatic larval tadpoles into more terrestrial adults