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How do reptiles differ from amphibians in their skin and development?
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Vertebrate
The major groups of vertebrates include fishes, amphibians, reptiles, birds, and mammals.
Reptiles and amphibians differ significantly in their skin structure and developmental processes, reflecting their distinct evolutionary adaptations to terrestrial and aquatic environments.
Skin Characteristics
- Amphibians: Typically possess smooth, moist skin that lacks scales. This skin is highly vascular and serves as a vital organ for respiration, allowing for cutaneous gas exchange.1234
- Reptiles: Have dry, scaly skin that is relatively impermeable to water, which helps prevent desiccation on land. Their skin is covered in epidermal scales composed of keratin, specifically beta keratin, which provides protection and structural integrity.1567
Development
- Amphibians: Most species lay gelatinous, shell-less eggs in water. These hatch into free-swimming larvae that often undergo metamorphosis to transition from an aquatic, gill-breathing stage to a terrestrial or semi-aquatic adult form.8139
- Reptiles: Are considered the first truly terrestrial vertebrates because they have dispensed with an aquatic larval stage. They typically lay large, shelled eggs on land, or in some cases, give live birth. Upon hatching, young reptiles generally resemble miniature adults and do not undergo a dramatic metamorphosis.6871