Amphibians: The First Terrestrial Vertebrates Chapter 19 Mrs. LaLone

Tetrapod – “four-feet” First True tongue Highly glandular skin Secretions aid in protection Prevents from drying out Ectothermic Excrete Ammonia or Urea

Feeding Habits Adult amphibians are Carnivores Larvae are herbivores Use Jaws or tongue to seize prey Larvae are herbivores

Respiration Cutaneous Respiration – Pulmonary ventilation gas exchange across skin Occurs on land or in water Requires a moist surface Pulmonary ventilation Occurs by buccal pump mechanism Muscles of mouth and pharynx create a positive pressure to force air into lungs

Nervous System 3 Subdivisions of Brain Forebrain Midbrain Hindbrain Olfactory centers regions that regulate color change & organ function Midbrain Contains optic tectum that processes sensory info Processes visual sensory information Initiates motor responses Hindbrain Motor coordination Regulates heart rate Orchestrates Respiration

Eyes Vision is one of the most important senses Primarily sight feederse Respond to movements of their prey Except caecilians

3 Orders of Modern Amphibians Order Caudata – “bears tail” Salamanders Order Gymnophiona – “naked like a snake” Caecilians Order Anura – “without tail” Frogs & Toads

Order Caudata – Salamanders “Newts” Olfaction helps in prey detection Possess a tail throughout life Live in moist forest floor litter; caves Have aquatic larvae Some lay eggs on land Internal fertilization (spermatophore; female picks up)

Order Gymnophiona – Caecilians Olfaction – helps in prey detection Blind Worm like Burrowers Internal fertilization

Order Anura – Frogs & Toads Diverse diet - Bullfrogs will prey on small mammals, birds, other frogs Moist environments Adults lack tails External Fertilization Aquatic eggs and larvae (tadpoles) Undergo Metamorphosis (change from larva to adult) Hear with Tympanic Membrane 3 Chambered heart – 2 atria & 1 ventricle Frog vs Toad