Download Groups of Amphibians

Groups of Amphibians
Groups of Amphibians
• Modern Amphibians are divided into three main
groups
• 1. Salamanders
• 2. Caecilians
• 3. Frogs
Salamanders
• Salamanders share three common characteristics
– 1. elongated bodies
– 2. long tails
– 3. smooth, moist skin
• There are about 400 salamanders
• They are typically 10 cm to 0.3m in length
• Most are unable to stay away from water for long
periods of time
– Some salamanders can live in dry areas because they
remain inactive during the day time
• Some salamanders have tongues that can extend
to catch prey
Reproduction in Salamanders
• Fertilization can be external or internal for
salamanders
• Salamanders lay their eggs in water or in moist
areas
– When salamanders hatch from eggs they are
carnivorous
– Young salamanders resemble adult salamanders,
but young salamanders usually have gills
• A few species of salamanders will retain their external
gills when they become adults
Caecilians
• Caecilians are a highly specialized groups of
burrowing amphibians with small, bony scales
embedded in their skin
– They are also legless
• They are found in swamps in tropical regions
– Some Caecilians are aquatic organisms
• Caecilians grow to about 0.3m long but some
species can grow up to 1.2 m long
Caecilians
• Most caecilians are blind
– They have very tiny eyes located
beneath their skin or under bone
• All caecilians have teeth to
help them catch and consume
their prey
– They eat worms and other
invertebrates
– Caecilians find their prey by
using a tentacle on the side of its
head that can sense chemicals
given off by the prey
Reproduction in Caecilians
• During breeding male
caecilians deposits
sperm directly into a
female
• Some species lay eggs,
which females will
guard until the eggs
hatch
• In other species young
are born alive, and they
are provided nutrition
by their parents
Frogs and Toads
• There are about 4,000 species of
frogs and toads
• Frogs and toads live in a variety of
environments including: Desserts,
rain forests, valleys, mountains,
ponds, and puddles
• Adult toads and frogs are
carnivores
– Frogs wait for their prey to pass them
– They then catch their prey by using
their long, sticky tongues that extend
rapidly
Frogs vs. Toads
Frogs
Toads
• The frog body is adapted for
• Toads have a squat body and
jumping
shorter legs
• It has long powerful legs that
provide the power for jumping • Toads skin is not as smooth as
frogs because it is covered in
• They have smooth and moist
bumps
skin
Reproduction in Frogs
• Frogs depend on water to complete their life
cycle
• The female releases her eggs into the water
and the male’s sperm fertilize the eggs
externally
• The fertilized eggs hatch into swimming,
fishlike larval forms called tadpoles
Frog Life Cycle
•Tadpoles breathe with gills and feed mostly on algae
•After a period of growth hind legs appear on the tadpole
•The tadpole will continue to grow into an adult and the tail and gills will
disappear
•This process of great physical change is called metamorphosis