Amphibians Flashcards
What are life history strategies
Patterns of resource acquisition and allocation exhibited by organisms during their lives
How did life history strategies evolve
Through natural selection to maximise individual fitness
How many generations did it take to grow from a mouse to an elephant
24 million
What are components of life history
Growth Development Maintenance Survival Reproduction
Factors which influence fitness
What is the Darwinian demon
Hypothetical organism that can maximise all aspects of fitness simultaneously
Why do biologists use the Darwinian demon
To understand different life history strategies of different organisms
Why are not all resources maximised
Think of it as you’ve only got a certain amount of money but you’ve got to maximise reproductiion, growth, Maintenance etc
Don’t have enough money to maximise all at the same time
What is the idea of trade off
Energy is limited so energy allocated to one function is not available for another
What is a iteroparous
Atlantic salmon
What is the semelparous
Sockeye salmon
How does the Atlantic salmon allocate its energy
In reproduction and survival
Reproduces many times
How does the sockeye salmon invest its energy
All into reproduction
Reproduces ones then dies - no energy left for survival
In breeding attempts what is there a trade off between
Quality and quantity
Explain the trade off between quality and quantity for ocean sunfish
They produce millions of eggs
Most eggs will be eaten or die
Because lots are produce high chance a couple will survive
Focuses of quantity not quality
Describe the breeding trade off for Lemon sharks
Gives birth to a few live young
Invest a lot into offspring so they survive
Focuses on quality over quantity
Rhinatrematidae
Caecilians
How many species of rhinatrematidae
9
Ichthyophidae
Caecilians
How many species of ichthyophidae
36
Uraeotyphlidae
Caecilians
Have many species of uraeotyphlidae
4
Scolecomorphidae
Caecilians
How many species scolecomorphidae
5
Caeciliidae
Caecilians
How many species of caeciliidae
100
Land preference of rhinatrematidae
Terrestrial with aquatic larvae
Land preference of ichthyophidae
Terrestrial with aquatic larvae
Land preference of uraeotyphlidae
Terrestrial
Land preference of scolecomorphidae
Terrestrial
Type of reproduction of scolecomorphidae
Viviparous
Land preference of caeciliidae
Terrestrial with aquatic oviparous and viviparous species
How big are caecilians at birth
30-60% of the mothers body length
What is the initial growth of the caecilians supported by
Yolk
How to embryos of caecilians feed
Scraping the oviduct walls with specialised embryonic teeth
What does the epithelium of the oviduct in caecilians mother’s oroduce
Creamy substance
Explain how caecilians focus on quality trade off rather than quantity
Produce 1 or 2 offspring
Huge energy investment by mum
Maximises survival of offspring
What % of salamanders have external fertilisation
10
What % of salamanders have internal fertilisation
90
Do salamanders have an intromittent organ
No
How do salamanders reproduce
Male produces spermatophore which sticks to sediment
Male waltz with female
Male places female cloaca over spermatophore
How do male salamanders turn on females
Bites female to release hormones
Or
Releases hormones into the water
How do most salamanders give birth
Lay eggs in water
Are the larvae of salamanders gill and aquatic and then turn into terrestrial adults
Yes
How many species of salamander are viviparous
4
How does the European salamander give birth
Gives birth to small larvae which get their nutrition from yolk
Yolk pouch is carried around
How do alpine salamanders give birth
Larvae retained in female
Female gives birth to fully developed young
Where does the young of alpine salamanders get their nutrition from
Oviductal secretions
What is paedomorphosis
Has juvenile features as adult
How do axolottles turn into adukts
Add iodine to their water
How many species of anurans have internal fertilisation and are viviparous
6
What % of anurans don’t have a tadpole stage
20%
Explain anuran parental care
Yolk eggs to nourish larvae
Lay eggs on leaves or in nests
Adults guard eggs
How do dart poison frogs show parental care
1-3 offspring
Carry tadpoles on back
Feed them unfertilised eggs
How do pygmy marsupial frogs show parental care
Skin is spongy on back
Female brooks eggs on her back under the skin until developed into a well formed tadpole
Goes into water
Tadpoles emerge from skin on back
Produces 8-10 off spring
What do variations in life history reflect
Differing allocations of resources to competing life functions
What are life history strategies
Adaptive strategies that maximise individual fitness
