Amphibians are vertebrates that live both on land and in water. They are classified into three orders: Anura (frogs and toads), Caudata (salamanders and newts), and Apoda (caecilians). Amphibians are ectothermic, have permeable skin, lay eggs, and undergo metamorphosis from aquatic larvae to terrestrial adults. Each order has distinct characteristics - Anura live in moist areas and catch insects with their tongues, Caudata live in water and can regenerate limbs, and Apoda are worm-like and blind burrowers.
2. Classification
Domain
• Eukaryota
Kingdom
• Animalia
Phylum
• Chordata
Class
• Amphibia
Order
• Anura
• Caudata
• Apoda
Family
• 85
families
for Anura
• 15
families
for
Caudata
• 10
families
for Apoda
Genus Species
• ±5000
species
for Anura
• ±500
species
for
Caudata
• ±170 for
Apoda
3. Basic
Characteristics
of amphibians
• Amphibians are vertebrates, meaning that
they have a vertebral column and
consequently an endoskeleton
• They are ectotherms and depend on the
surrounding environment for their internal
temperature (in lay terms, they are cold-
blooded)
• Have a soft and moist skin which is used
during breathing as well
• They are oviparous and therefore lay eggs
4. Order - Anura
• Typical examples include frogs and toads
• Fun fact: Anura means “without tail”
• Generally, inhabit moist environments almost anywhere on the planet
• Their diet during adulthood is mostly composed of small insects and some
plants (insects are caught utilising a sticky tongue like a cowboy’s lasso).
• Theis skin pigments allow them to camouflage with their environments
5. Order - Caudata
• Typical examples include salamanders and newts
• They are limited to living in moist environments because their skin acts as
a respiratory organ
• Newts are terrestrial but return to the waters during breeding seasons
• Salamanders have a diverse range of life cycles, and some families are
paedomorphic
• Fun fact: Salamanders can regrow injured body parts
6. Order - Apoda
• This order consists of caecilians
• Apoda means “naked like a snake”
• They are wormlike and appear segmented because of skin folds that overlie separations
between muscles bundles
• They have skin over their eyes and are most likely blind
• They burrow into the ground
• They eat soil and worms
7. Life cycle
(Metamorphosis)
• Females lay fertilised eggs in “safe’ spaces
• The eggs hatch into small larvae called tadpoles
• Larvae grow as they feed (mainly algae and small
plant material)
• As larvae metamorphosises, limbs begin to grow, it
exchanges gills for lungs and makes its way to land
where it resorbs its tail till it reaches adult body size