Points to Consider
- Juvenile bichirs, a type of fish, have external gills, a very primitive feature that they
hold in common with larval amphibians. Think about how the external gills could be
a transition between internal gills and lungs? - Lungfish and bichirs have paired lungs similar to those of tetrapods and must rise to
the water’s surface to gulp fresh air through the mouth and pass spent air out though
the gills. Discuss how lungfish could be similar to and different from tetrapods in the
way they breathe? - The structure, the pineal body, located in the brain, performs many different functions
including detecting light, maintaining circadian rhythms and controlling color changes.
What structures could perform similar functions in amphibians, as a result of living
on land?
13.3 Lesson 13.3: Amphibians.
Lesson Objectives
- Describe amphibian traits.
- List the features of salamanders.
- Compare and contrast frogs and toads with other amphibians.
- Describe the roles of amphibians.
Check Your Understanding
- What are some adaptations that amphibians, like fish, have for living in the water?
- What are the characteristics that amphibians share with all other vertebrates?
Introduction
What group of animals begins its life in the water, but then spends most of its life on land?
You were right, if you guessed amphibians. Amphibians are a group of vertebrates that has
adaptations for both aquatic and terrestrial lifestyles. Evolutionarily, their ancestors made
the transition from the sea to land. They comprise approximately 6,000 species of various
body types, physiology, and habitats, ranging from tropical to subarctic regions.