Common Group Name: Amphibians

Phylum:Chordata Examples: Salmanders Frogs and Toads Caecilians

Body Plan Vertebrate Bilateral Symmetry Adaptations for living partially on land: Lungs Leg Bones Thin skin lined with blood vessels

Feeding Herbivore as tadpole, carnivore as adult Path of food: Mouth- esophagus- stomach- small intestine- (organs that aid in digestion: pancreas, liver, gallbladder)- large intestine (colon)- cloaca- anus

Respiration Lungs replace gills as it reaches adulthood. Breathe through nares (nostils) Some gas exchange continues through skin. Some species have well developed lungs, some species have no lungs.

Circulation Closed Circulatory System Forms a “Double Loop” Loop #1: oxygen poor blood from the heart to the lungs and skin- oxygen rich blood back to the heart. Loop #2: oxygen rich blood from heart to the body and oxygen poor blood from the body back to the heart (Back to loop #1) 3-chambered heart: left atrium, right atrium, ventricle (thicker walls to pump)

Excretion Kidneys to filter wastes from blood. Urine is produced in kidneys and travels through ureters into the cloaca to exit. Small urinary bladder

Response Same basic parts as the fish Well-developed system Sense Organs: Eye covered by a Nictitating Membrane Tympanic Membrane allows them to hear. Lateral Line Systems that detect water movement

Movement Larvae move like fish Adults use limbs like legs and arms. Frogs have well-developed hind limbs to jump. Toes suitable for climbing or moving through water.

Reproduction In most species female lays eggs in water and male fertilizes them externally. Salamanders fertilize internally Male squeezes female which causes female to release eggs. Metamorphosis occurs: egg-fertilization- tadpoles- young frog- adult frog Most abandon eggs

Incomplete Metamorphosis- immature forms lack functional adult structures but look like mini-adults similar appearance throughout life. Complete Metamorphosis- animals undergo dramatic physical changes. Larva (different from parent) develops into pupa (looks different from larva) then completely remodels again to become adult. Incomplete Complete

Other Information Frog skin countershading- mix of dark and light to blend into surroundings. Frogs have maxillary teeth along upper jaw and vomerine teeth to hold prey. Amphibian means: “double life” emphasizing they live in water and on land. Moist skin contains mucus glands Lack scales or claws