REPTILES

REPTILES

OVER VIEW

EXCRETION

Circulatory system

• Helps conserve body water.
• Excrete nitrogenous waste in the form of uric acid.
• Uric acid is less toxic than ammonia or urea.
• Little water dilution.

• Pulmonary loop carries deoxygenated blood from heart to the lungs and returns oxygated blood to the heart
• Systematic loop transports oxygenated blood to the tissues of the body, where oxygen and nutrients are unloaded and carbon dioxide is picked up and returns deoxygenated blood to the heart.

• Two Loops
• three chamber heart (exception: crocodiles)
• SEPTUM: wall of tissue that partilly divides a single ventricle and 2 atrias.
• SINUS VENOSUS: collects blood from the body and channels it into the right atrium.
• CONUS ARTERIOSUS: forms the base of the three large arteries existing from the reptilian heart.

NERVOUS SYTEM

• Optic lopes receive input from eyes.
• Rely on sight to detect predators and prey.
• Inner ear contains the receptors for sound.
• Snakes lack a tympanum and are sensitive only to low frequency sounds.
• Able to detect ground vibrations-transmitted to the columella by bones of the jaw.

ADAPTIONS TO LIFE

• Turtles and Tortoises lay eggs and lay them on land.
• Able to live successfully on land and water
• Can live whole life on land.

REPRODUCTION

SKIN

ECTOTHERMIC

Three reproduction methods among reptiles.

-Methods differnce based on how long eggs remain with the females.

• OVIPARITY: female reproductive track encloses eggs in a tough protective shell. Female then deposits eggs into a safe environment to hatch.
• example: Turtles
• OVOVIVIPARITY: One way ro reduce exposure to hazards is to keep eggs inside female for extended period of time.
• Eggs laid shortly before hatching.
• VIVIPARITY: Shell does not form around the egg.
• egg and young are retained within female until they are ready to be born.
• PARENTAL CARE: many reptiles provide no care for their eggs or young.
• Some species of izards and snakes guard and warm the eggs until they hatch.
• Crocodiles and Alligators provide greatest amount of parental care.

• Skin is moist and thin for rapid diffusion.
• Covered with thick scaly dry layer.
• Surface of skin prevents water loss with keratin
• Lipids and proteins make the skin water tight.
• Skin helps conserve body water and against infections, and injuries.

ECTOTHERMIC: Require very little energy because their metabolism is very slow, and they also need only about one tenth as much food as endotherm of the same size.

• TEMPERATURE ACTIVITIES: become dormant during the coldest months.
• ADVANTAGES: can run or swim at maximum speed only for short periods of time.
• Ectothermic metabolism cannot provide enough energy for sustained exertion.

DIGESTION

CHELONIA

DIVERSITY

• Made of 250 species of turtle/tortoises
• Turtles= Sea

-Sea Turtles have webbed feet and disc like shells.

• Tortoises- Land

-Tortoises have domed carapace

• Earliest fossil 200 million years ago

# OF SPECIES: 6,000

Squamata

• 5,500 species of lizards and snakes
• loose upper jaws, jointed to the skull.
• Most structurally diverse of the reptiles.
• 3,000 species of living lizards (i.e iguanas, zhamelions, geckos.)
• 2500 species of snakes.

• Chelonia
• Crocodilla
• Squamata
• Rhynvhocephalia:

How they feed

• Crocodiles capture prey by lying and waiting to attack.
• They have raives to prevent water from entering the air passage when they are under water.

Crocodilla

• Group most related to the dinosaurs.
• 21 species of large reptiles.
• Many of these species (Crocodiles, Alligators, Caimans, garial crocodiles) find homes in tropical and subtropical regions around the world.
• Eat Fish and Turtles or any animals that go into the water to eat/drink.

Rhynchocephalia

• ANCIENT group of reptiles.
• Only TWO living species.
• TUATARAS:
• spiny crest
• feed on insects/worms

• Takes place in warmer temps.
• mouth->Salivary ->esophagus->stomach->intestine->Cloaca.
• FOODS:
• Carnivores
• mice and other small animals
• fish