Life history
-sequence of developmental stages from birth to death
Growth, Reproduction, Senescence, Mortality

All of this activity takes energy - must be apportioned
Growth
Reproduction
Respiration
Feeding
Mate Seeking
Defense
Growth
Reproduction
Respiration
Feeding
Mate Seeking
Defense
Different investment patterns

Aclonal Life History recruitment
Sexual reproduction
Death

Clonal Life History recruitment
Fission Fission Fission
Death
Sexual reproduction

Concept of the Individual in Corals
1. Morphological - Polyp (= ramet)

Concept of the Individual in Corals
2. Physiological - Groups of connected polyps

Concept of the Individual in Corals
3. Genetic - All polyps and colonies derived from the same zygote (Genet)

Asexual reproduction in corals - Budding
Intratentacular Extratentacular

Asexual reproduction in corals - Budding
Intratentacular Extratentacular
Can stay in place = growth
Can detach and grow elsewhere
= asexual reproduction

Asexual reproduction in corals - Budding

Asexual reproduction in corals - Fragmentation

Partial colony mortality
Dead areas
Three colonies but one genetic individual

Costs and Benefits of Fragmentation
Benefit - risk of genet mortality
-spread over several colonies
Costs
-disrupt physiological function
- possible decrease in fecundity
- possible postponement of sexual reproduction

Asexual reproduction in corals - Polyp Bailout
Coral Budding

Sexual Patterns
1. Gonochoristic (dioecious) 2. Hermaphroditic (monecious)

Development Patterns
1. Brooders
-retain embryo
2. Spawners
-free-spawning

Development Patterns
Can these patterns be related to life history/structure/habitat?
1. Related to whether species is r- or K- selected?
X
2. Related to depth?
-shallow should brood, deeper should spawn
X
3. Related to the size and structure of the coral?
-small, branched corals should brood, larger massive corals should spawn
X
4. Related to habitat stability?
-corals in predictable habitats should brood
?

Strategies Revisited
All life functions can be seen as competing with each other for energy
1. Growth rate and reproduction
Growth rate
Size

Strategies Revisited
All life functions can be seen as competing with each other for energy
1. Growth rate and reproduction
Growth rate or calcification rate
Breeding season
Pavona
Time of year

Strategies Revisited
All life functions can be seen as competing with each other for energy
2. Polyp size

Strategies Revisited
All life functions can be seen as competing with each other for energy
3. Allocation of energy (within reproduction)
25-50% of colony biomass as planulae
Pavona
50 – 180% of colony biomass as planulae

Strategies Revisited
All life functions can be seen as competing with each other for energy
3. Allocation of energy (within reproduction)
Across species planulae eggs
Mean diameter
(µm)
Fecundity / year

Strategies Revisited
All life functions can be seen as competing with each other for energy
4. Temporal variation in fecundity
Size
Brooders
Spawners
Time

Strategies Revisited
All life functions can be seen as competing with each other for energy
4. Temporal variation in fecundity
Age or size?
Goniastrea
-complex interaction
Montastrea

Gametogenic cycles gametogenesis ovogenesis spermatogenesis spawn quiescence gametogenesis
Correlated with a. Change in sea temperature b. Lunar/tidal cycles c. Photoperiod
Time

Gametogenesis

Gametogenesis

Release of sperm and egg packets

Release of sperm and egg packets
Coral Spawning

Release of sperm and egg packets

Release of sperm and egg packets

Free spawning coral

Synchrony in spawning
Sea temperature
Tidal cycle
Photoperiod

Synchrony in spawning
Goniastrea
- Low tide, late afternoon
- Low tide, evening

Synchrony in spawning
-grind up male polyps
-expose female polyps to extract
Caryophyllia
-egg release by exposed females

Development Patterns
-effects on planula larva
1. Brooders
- immediately competent
- larger
- have all zooxanthellae
2. Spawners
- lag time until competence
- smaller
- must acquire zooxanthellae

Predation on spawned gametes

Larval Settlement
-success depends on ability to identify site for settlement and metamorphosis
Substrate type
Salinity (>32 ppt)
Illumination
Water motion
Sediment level
Chemical signals from algae, biofilms, conspecifics
Settlement & metamorphosis

Summary
Planulae
Zygote
Sample and assess subtrate: prepare to settle
Planulae released from individual polyps
Brooders internal fertilization
Broadcasters external fertilization
Young primary polyp
Asexual colony growth