Reptiles reproduce through three main methods - oviparity where eggs are laid and hatch externally, viviparity with live birth, and ovoviviparity where eggs are retained internally and hatch within the mother's body. Turtles lay eggs in nests with no parental care, while snakes may be oviparous, ovoviviparous, or viviparous. Lizards also use these three reproduction methods and females exhibit dimorphism. Crocodilians only use oviparity, building nests and providing parental care until hatching.

1. Reptile
Reproduction & Diseases
By Mr. “It’s a boy” Chapman

2. Reproduction Methods
 Oviparous – egg layers
 Viviparous – live birth
 Ovoviviparous – eggs stay inside of
mother until they are ready to hatch, then
the eggs hatch inside of the mother and
babies come out like live birth.

3. Turtles
 Turtles are oviparous (lay eggs that hatch
later)
 Female turtles lay eggs in a nest that they
dig (usually in the soil or sand).
 The females leave after laying eggs, no
parental care

5. Turtle Eggs
 Eggs vary in size and
amount.
 Turtles Eggs:
 - Avg. 50 eggs
 - soft and hard shells
 - avg. 60 day incubation
 Soft shell 30 day
 Hard shell 18 months

6. Turtle Mating
 Males plastron are usually concaved, so
the male can climb on the back of the
female.
 Males uses his claws on the front limbs to
grasp the front edge of the females
carapace.

8. Snakes
 Snakes may be oviparous, ovoviviparous,
or viviparous.
 Most snakes are oviparous
 Snakes lay there eggs under rocks, hollow
logs, in the ground, or anywhere warm.
 Snakes also do not provide parental care.

10. Mating
 The male and female
will wrap around each
other until their
cloacae are together.
 Females may hold the
sperm for months
until they fertilize the
egg.

11. Incubation
 The temperature of the environment
controls how fast the babies develop.
 Egg layers:
 - 30-50 days after mating
 - lay 5 to 60 eggs
 Live bearing:
 - 90 to 150 days
 - 10 to 100 babies

12. Snakes Babies
 Snakes get out of
their eggs using a
tooth on their snout
to slice the egg open
called?
 Egg Tooth

13. Lizards
 Lizards are also OV, OVOV, and VIVI, but
most are OV.
 Lizards lay eggs in holes dug in the soil.
 Dimorphism –
 Definite difference you can see between
the male and females.

14. Mating
 Males attract females by displaying bright
body colors, engage in bobbing or body
movements to attract the female.
 Once accepted by a female the male will
grasp and bite the female’s neck to hold
her down.
 Females may hold or store sperm for long
periods before fertilization.

15. Lizard Incubation
 Small lizards (geckos and anoles):
 - 30 days
 - lay 1-2 eggs
 Large Lizards (monitors)
 - 120 days
 - 50 eggs
 Lizards also have an egg tooth

16. Crocodilians
 Crocodilians are only oviparous
 Crocodilians court females like lizards, but
they mate in the water.
 Females build nest out of water
 Eggs are laid in nest and then covered up
by the mother.

17. Parental Care
 Female show amazing
parental care.
 The female will not
eat during this time.

18. Incubation
 All crocodilians lay  The amount of eggs
hard shell eggs laid depends on the
 Alligators: age and size of the
 - lay 20-30 eggs female.
 Crocs:
 - lay 60-100 eggs
 Gharials:
 - lay 40 eggs