Amphibian = "________________"
Live part of life in water, part on land
Kingdom - Animalia
Phylum - Chordata
Subphylum - Vertebrata
Class - Amphibia
CHARACTERISTICS OF AMPHIBIANS:
1. Respiration by ________________, ________________, ________________
2. Thin moist ___________ with ___________ glands; no ___________
3. Feet (if present) are webbed
4. No claws
5. Larvae ________________; adults ________________
6. Larvae with ________-chambered heart; adult ________________
7. ________________ from aquatic larva to terrestrial adult
CLASSIFICATION:
Approx. 2000 - 3000 species.; Range in size from 1/2 inch to 5 feet.; Most common in tropics
Orders:
1. ________________ - "without legs" (caecilians)
2. ________________ - "visible tail" (salamanders)
3. ________________- "without a tail" (frogs & toads)
ORDER - ________________
Salamanders live in moist places near swamps, creeks, under logs, etc. Most are 4-6 inches long.
________________ - live entirely in water
Notable species:
1. ________________ - found in North America;
1-2 feet; never lose their gills.
________________ - never lose larval characteristics even though mature
2. American ________________ - largest American species; 2 ft.
3. ________________ salamander - largest in world; 5 ft.
4. ________________ - larval form of the Tiger Salamander that never reaches adulthood because of a thyroid deficiency.
Salamanders fertilize their eggs internally; and usually lay their eggs but some hatch internally.
________________ have long (1 to 4 ft.) worm-like bodies with no limbs. Feed on worms and small invertebrates; most are blind.
ORDER - ________________ (Frogs and Toads)
Frogs generally more ________________ than toads, with slimmer bodies, longer legs, and smoother skin.
Toads spend more time on ________________, have short, squat, bodies with lumpy poison glands in their skin.
Notable species and groups:
________________ - Rana catesbiana; (8 in.)
________________ Frog - largest in world (12 in.)
________________ frog or leopard frog - Rana pipiens
Ranidae - family of true frogs
Bufonidae - family of true toads
Hylidae - family of tree frogs
FROG ANATOMY
External:
Skin contains ________________ glands and ________________ glands.
Poison sacs distasteful to animals but can be fatal. Poison from one South American species is the most powerful venom known.
Dangerous species are usually ________________. Others are colored to blend in with their surroundings.
Bulging eyes can be retracted to hold food in mouth.
________________ membranes - eardrums
________________ membrane - a third, transparent eyelid for protection.
Nostrils allow breathing while partially submerged.
________________ tubes - equalize pressure on eardrums
________________ cords - bands of tissue that vibrate when air passes over them; used to make the croaking sound
________________ sacs - expandable membranes that expand and collect air after it passes over vocal cords; makes the croaking louder
INTERNAL STRUCTURES:
Digestive system -
________________
Sticky tongue hinged at ________________.
Maxillary teeth line upper jaw
Vomerine teeth - help in holding prey
Salivary glands
Esophagus
Stomach
________________ (duodenum & ileum) - absorbs food
________________ - a thin membrane that holds the small intestine in place
________________ (colon) - absorbs water
________________ - common chamber containing ducts from digestive, urinary, and reproductive systems
________________ - secretes digestive enzymes and insulin
________________ - secretes bile (aids in fat digestion) stores glycogen (animal starch)
________________ - stores bile from liver
Skeletal System:
Cervical vertebra - neck
Trunk vertebrae - upper back
Sacral vertebra - mid back
Urostyle - lower back
Pelvic girdle - where legs attach
Humerus - upper arm
Radio-ulna - forearm
Carpals - wrist
Metacarpals - hand
________________ - thigh
Tibia-fibula - lower leg
Tarsals - ankle
Metatarsals - foot
________________ - toes and fingers
Respiratory system:
3 ways to absorb oxygen: lungs, mouth, skin
Uses a pump system to force air into lungs.
Mouth cavity lined with blood vessels.
Vessels in skin remove carbon dioxide and absorb some oxygen.
Circulatory system:
_____________-chambered heart; 2 _____________, 1 _____________
Blood enters right atrium, passes to ventricle, passes through the pulmocutaneous arteries to the lungs, returns to the left atrium through the pulmonary vein, passes into the ventricle, and passes to the body through the carotid arteries (to head) and aortic arch (to body).
________________ circulation - to the lungs
________________ circulation - to the body
Nervous System:
Lateral line in tadpoles, not Adults
Brain divisions
Olfactory lobes - ________________
Optic lobes - ________________
Cerebrum - controls ________________, instinct, and voluntary movement
Cerebellum - controls ________________
Medulla oblongata - ________________ actions such as breathing, regulation of heartbeat
Excretory System:
________________ - remove wastes from blood
________________ - carry urine to cloaca
Skin removes carbon dioxide.
Frogs urinate approximately 25% of their body weight each day.
Reproductive System:
Sex organs internal; external fertilization
Females -
________________ - produce eggs
________________ - carry eggs to cloaca
Eggs enter the body cavity before entering the oviducts.
Males -
________________ - produce sperm
Sperm travel through tubes to the kidneys, then pass through the ureters to storage sacs called seminal vesicles.
During mating (called ________________) the male "clasps" the female from behind, presses his thumb pads into her back, causing her to release eggs. The male releases sperm to fertilize the eggs.
Eggs hatch into tadpoles which have gills, a small mouth for scraping vegetation, a tail, and no legs. Gradually the legs develop and the tail disappears, the mouth widens, lungs develop, the heart develops a third chamber, and the tadpole changes into an adult.
Metamorphosis can range from months to 3 yrs.
________________ - frogs must bury themselves in mud or deep in the ground to prevent freezing in winter because they are "cold-blooded", their body temperature varies with the environment.
________________ - a period of summer inactivity similar to hibernation due to excessive heat or drying. There is no drop in temperature with estivation.