Reptile Reproduction (Lecture 7) Flashcards
reptiles as ectotherms
- derive thermal energy from external force to regulate body temp
- pro:great deal of flexibility of energy use through metabolism
- good at regulating thermal regulation
- move in cooler or warmer area to regulate body temp
reptiles have lower metabolic rate
- dont go through insufficient metabolic
- can survive even during droughts
life history
- how energy is utilize for growth, maintenance, and reproduction
- incredibly variable for animals
ex. sea turtle, dragon
sea turtle
- live 70-80 yrs.
- breed multiple times in life
- spends a lot of time in growth for sexual maturity(largest proportional cost)
Green sea turtle
- female lay 4-6 clutches every 3 to 6 yr.
- larger than
- lay in clucthes of 100 to 140, 4 to 6 times in the breeding season
- 2 months for baby eggs to develop
- high mortality risk of baby turtles
- large clutches to compensate for mortality risk
- send offspring through rapid dispersal phase to get food and be away from predator
- offspring swim flat chap for two days
- get picked up by currents and stay there for 10 yrs.(go from Great Barrier re
- settle back down on reef
- fall out 2k km of coastline in QUeensland
- start to chew on sea grass and algae for 30 yrs. until reaching sexual maturity at 40 yrs.
Green sea turtle
- female lay 4-6 clutches every 3 to 6 yr.
- larger than
- lay in clucthes of 100 to 140, 4 to 6 times in the breeding season
- 2 months for baby eggs to develop
- high mortality risk of baby turtles
- large clutches to compensate for mortality risk
life history differ between species and sexes
- female much more costly
- 5-6 yrs of energy
- move from feeding ground to courtship (400 km)
- extremely slow long life history
factors influencing evolution of reproductive life histories in reptiles
- temp has prolific effect
- diet (ecology)
- some are herbivorous but most are predators
- phylogeny(animals come from different group)
- limit of design
- dictate the amount of eggs laid
- limit of design
- not endlessly plastic or variable
reproduction quite essential
- very complex
- different depending on the sex
- female determine reproductive success by the number of eggs she is carrying
- males compete and fight with other males
- wound each other to prevent optimizing a female
variation of reptiles
10,000 species breeding difference -tortoise 45 yrs -dragons 9 months -only breed 2 egg -others 600
within specie variation
- animals trying to maximize fitness to optimize investment
- decisions based on environment
- sceloporus undulatus
- vary in size across the U.S.
- use energy to display life history
constraints on reproduction by environment
temp
=vast variation in temp across the yr.
-reptiles in Tasmania
temp
thermal timing and opportunity
hot and cold environment place very different constraints on offsprings
-prolific effect on sex determination
incubation determines sex
reproductive cycle
- temp alter reproductive timing
- have to turn on reproductive tract
- reproduce through a series of event
- mature switch reproductive tract
- takes month
- undergo courtship and mating (usually quick
- dictate timing and how long who have to go through the reproductive cycle
different thermal constraints-nt
northern territory
- midwinter and mid-spring reproductive switch
- incubate in spring
- hatch in late spring