Amphibians

General Characteristics Hindlegs for jumping   Webbed feet Larvae aquatic and fish – like with gills Adults terrestrial with lungs Moist skin with mucous glands Lack scales and claws

Classification Order Urodela – salamanders and newts Order Anura – frogs and toads

Feeding Tadpoles filter feeders Adults carnivores with tongue attached at the front for quick extension Mouth to esophagus to stomach to small intestine to large intestine to cloaca where wastes are stored Liver, gall bladder and pancreas secrete digestive enzymes

Respiration Larvae breathe through skin and gills In adults, lungs developed with a blood supply through capillaries and folds to increase surface area Mouth and skin also serve as gas exchange areas   Most carbon dioxide leaves through skin Force air into lungs by buccal respiration (through mouth)

Circulation Double loop Three chambered heart carries oxygen – poor blood from heart to lungs and takes oxygen – rich blood back to heart second loop transports oxygen – rich blood to the body Three chambered heart Left atrium, right atrium, ventricle

Excretion Kidneys filter wastes from blood Excrete urine into cloaca

Response and Movement Tympanic membrane for hearing Front and back legs are used in a variety of ways   Eyes large and protected from damage and kept moist by transparent nictitating membrane Tympanic membrane for hearing Well developed nervous and sensory system Hearing vital to survival and reproduction Behaviour to regulate body temperature Hibernation – reduce metabolism during cold weather Estivation – similar but during hot weather

Reproduction External fertilization Eggs or sperm leave the body through the cloaca   Eggs covered with sticky substance to provide nutrients Attaches eggs to underwater plants Some amphibians show parental care