Transcript Amphibia & Reptilia

Amphibia & Reptilia
Aquatic Ecology
Overview
• <100 species of Amphibians in N.America
– Divided into frogs, toads, salamanders & Newts.
• 23 species of crocodilians worldwide (all
aquatic)
• 5000 species of frogs & toads
• 500 species of salamanders (many are aquatic)
• A few hundred aquatic snakes
• Approx. 300 turtle species (most are aquatic)
• Only a few lizards living close to fresh water.
External Structure, Appearance, &
Anatomy
• Most have 4 legs
(adult forms), except
for snakes
Habitat
• Amphibians are major group of tetrapods that
spend majority of life in fresh water.
• Most juvenile amphibians live a fish-like
existence & leave water as adults.
• FW snakes & turtles also live underwater, but
need to surface for respiration.
• Aquatic tetrapods use burrows
– Aestivation = burrow part of the day to survive hot
weather
– Hibernation = survive cold weather or take care of
young
Swimming & Escape Behavior
• Large Body Size =
Fast powerful
movements
Feeding Preferences & Behavior
• Most tend to be at top
of food chain b/c of
size.
• Most are carnivorous,
however some can be
omnivorous
Life Cycle
• Most species have
separate sexes, eggs are
fertilized, & zygote
develops into a larval
(embryonic) form, then
juvenile, & then adult.
• Eggs of amphibians are
laid in water = jelly
masses
• Reptiles lay leatheryshelled eggs in moist
vegetation or sand near
water.
Ecological Importance
• They are extremely
important because they
help control pest animals
(rodent and insects) and
they in turn serve as food
for many other wild
animals (mink, raccoons,
skunks, owls, hawks,
herons, and many fish
species).
• Threatened due to habitat
loss/destruction.
Eastern Box Turtle
Anthropogenic Threats
Local Species