test 4 Flashcards
ecology on how many scales in coral? what are they?
3 scales of ecology
polyp, reef, global
what are most corals?
hermatypic
- corals that photosynthesize
what water temp do corals prefer? why is this sometimes bad?
25-31 C
very close to the range of denaturation and death of animals - which would be from 35-37 C start happening
what salinity levels do corals prefer?
high salinity
34-37 SSU
open water but not
- on the coast but need lots of water around them
what light levels do corals prefer?
high light levels but not too much to cause damage
found in shallow water (upper 30m)
what nutrient levels are preferred by corals?
low nutrient levels - oligotrophic
higher levels lead to eutrophication which is bad bc overgrowth of things like algae
why aren’t corals found at the same latitudes on the west coast (30N and 30S)?
temperature dependent
gyres effect local water
- tropical !!!!
what is the main deterministic thing in corals and reefs? (most important factor)
TEMPERATURE
- an example of baja
what are two examples of corals with and without symbionts?
zooxanthellate corals
azooxanthellate corals
- non-hermatypic
- no photosynthetic symbionts
how to corals reproduce?
sexually and asexually
- helps for coral ecological domination
- by creating huge biogenic structures
only sexual reproduction can help them spread and have genetic diversity
what is the downside of asexual ?
cant produce new colony, just grows on existing and is genetically identical
two types of asexual reproduction?
budding
fragmentation
- can happen naturally from storms
- can create new colonies
- broken pieces grow 25-50X faster
different types of sexual reproducing corals
hermaphroditic
gonochoric
coral tricks
two methods of coral feeding
heterotrophic
- can capture prey w stinging cells (nematocysts) -MAIN
- can used DOM directly from water column
autotrophic
- symbionts
– zooxanthellae photosynthesis
– these use byproducts of this and protection from predation
- more reef forming corals use this
holobiont
the entire community of living organisms that make up a single healthy organism
nothing lives alone
everything is a part of a holobiont – like microbial bacteria –> symbiosis
symbiosis is a ___
spectrum
Coral dysfunction: Coral bleaching
zooxanthellae when they leave (expelled or lyse) the colours disappear
highly associated w mortality when bleached
dead dead when covered in algae
Coral dysfunction: ocean acidification
long term trends
- associated w pH
acidity increasing when pH goes down
slows the rate at which coral reefs generate calcium carbonate
- this slight change can have longterm impact dragging down other things
crustose calcifying algae (CCA) – need this for larval settlement
Coral dysfunction: algal overgrowth
long term trends
- associated w pH and Sea surface temp increase
more nitrogen in water favours algae and not coral
algae dominates when eutrophication
algae always there but problem when too much
three main types of fish in reefs
parrotfish - most biomass and most important
– they eat off of coral
- makes pink beaches (w poop)
surgeonfish
damselfish
parrotfish
- most biomass and most important
– they eat off of coral - makes pink beaches (w poop)
getting fished out bc tasty
- contributing to algal overgrowth bc these eat algae
change sex over lifetime
represents keystone holding coral reefs together
semelparous
spawn once then die
iteroparous
spawn more than once
