coral classification + ecology Flashcards
growth limits - bc temp and light?
- Temperature & Light –> - most at 25-50m
* Light impact -too bright or intense = can bleach
growth limit - how do they deal w too much light
• - can have mycosporine-like amino acids (protect from high sunlight)- sunscreen! Fragment the light - photoprotective
growth limit - temp?
• Corals are resistant to temps but have a narrow range -usually 25-30 degrees
reading on global warming and acidifiaction.
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growth limits - bioerosion? parrotfish ex
• Bioerosion –> by fish/invertebrates
○ Fish eating the coral- humans have fished a lot of the ones that eat the coral - ex
○ parrot fish Eat chunks of coral - beach sand is parrot fish scat :(
○ Can stimulate growth - not always bad
○ without them/ with less of them - Not as much bioerosion - but now they don’t grow as much
ex of top down effects on reefs caribbean nassau
• Many studies of top-down effects on reefs (ex. Caribbean Nassau Grouper, when near humans or not, e.g. hawaiian island reef tracts - 1 near humans 1 not)
○ Top down effects - categorize what fish are there when they study, before they go down
○ Humans prefer larger fish - caught and sold more
§ Ex. Caribbean Nassau Grouper - caught and sold for eating - fished out predatory fish in reef system - get explosions of smaller invertebrates as a result = excessive bioerosion from starfish
§ Explosion of the parrot fish - reef system starts to die off
§ Not allowed to fish on certain hawaiian islands - protected
impact of storms on coral?
hurricane damage - excessive storm can destroy them - broken into small fragments
impact of diseases on coral
○ diseases (white band, white plague, black band, brown jelly syndrome). - infection - coral is necrotic - not bleaching - distinctive features
coral predation?
• Predation –> Corals eaten & have defenses
• Ex. Small invertebrates graze coral (like gastropods) - some coral are toxic - contain high levels of hormones - taken in by invertebrates and used
lots of defense mechanisms include hormones - ie. Incorporate coral toxins into their systems
coral competition/ alleopathy?
• Competition (allelopathy) –> corals compete for space & light - indirect & contact killing - tentacles for feeding or attacking neighbors - can also release tentacles into the water column
great reef paradox?
reat Reef Paradox: faster growing corals do not dominate (grow to survive being killed by slower species) - ones growing fastest are not the most successful - slow growers are better at “hunting” - faster growing are just growing to survive
contact kill?
○ Contact kill ex - grows over and occupies area - tentacles to kill it
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• Fighting, one digesting the other
mutualism exs.
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why are corals hard to classify?
• Corals = can have various morphs.
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○ Same species - very different looking morphs
○ Coral taxonomy does not rely as much on morphology
what do coral morphs complicate?
Complicates conservation - morphs might be classified as a species - endangered but its not actually
difficulties w identifying coral + example - order to identify them
- difficult to identify - follow order: (identify species using a mix of genetic, morphology, & ecology).
- Difficulty with sibling species (closely related, look very similar) also difficult to identify
ex of coral identification issue
○ ex. Montastrea annularis - 3 forms lumped into 1 —> now know 3 species = M annularis, franski, and faveolata
○ . ▪ All 3 mass spawn*
○ Faveolata based on molecular, enzyme polymorphism, corallite structure, and life history
coral hybrids in lab?
○ M. faveolata (most distinct, hybridizes poorly)
○ M. annularis & franski (hybridize easily) -
○ M. franski spawns 2hrs ahead of others- - separation of a few hours - another argument for separate species along w genetics
○ M. faveolata & annularis (spawn together but incompatible gametes on reef system)
- Hybrids unlikely in Montastrea: spawning timed differently, sperm aging, gamete dilution & incompatibility
other possibility of identifying coral?
Another possibility is plasticity: allowing local adaptation specialization - flexibility of morphs
ex. Montipora species complex
