Corals Flashcards
What phylum are corals in and why?
Cnidaria , presence of stinging cells on tentacles used to capture prey and as defense
What is the soft body of the coral called and what is it enclosed by?
Polyp
Hard shell of calcium carbonate
What is the advantage of having a cup shape
The tentacles can retract into it for safety
Hermatypic corals are what type of corals? What do they normally contain, how are they distributed
Reef builders
Zooxanthellae symbiotic photosynthetic dinoflagellates
Temperature and water quality
Ahermatypic corals , what are they the opposite of
Do not build reefs
No zooxanthellae
Not restricted
Corals live in what kind of water ? And what does this word mean
Oligatrophic, low nutrient
What is the definition of coral reefs ? What do they share and why?
Groups of coral polyps interconnected by thin layers of tissue
Nervous system and digestive connection
Entire colony came from on polyp that reproduced asexually to form
What does each polyp lay down so that the rest builds ? How wide is each polyp , however …..
CaCO3
1-3 mm
Large sizes and weigh several tons
If zooxanthellae are supplied with enough ? They can feed the whole coral
Light
How much percent of energy is from zooxanthellae
98%
Difference between feeding at night and during the day
Day autotrophic (zooxanthellae) Night heterotrophic (tentacles)
What are the stinging cells called , what do they allow them to feed on? What do corals produce to capture these small organisms
Nematocysts , small organisms in the water like zooplankton , mucous
How else can corals feed (think extensions) ?, what do these filaments secrete?, how do they extend these ?
Extensions of gut wall called mesenterial filaments
Digestive enzymes
With enzymes lowing coral to feed and digest food outside of the body
Conditions required for reef growth(7)
Hard substrate Light optimal Narrow temperatures Narrow salinity ranges Low sediment load in water Low pollution Narrow range of pH
Corals produce which two ways? Asexual reproduction allows for? Sexual reproduction results in the creation of ?
Sexually and asexually
Growth of buds from single polyp
Planula larvae that is able to ride on water currents to new environment (settle out to begin growth on existing reefs or other substrate )
Light must be able to penetrate in order for what to take place? Corals are normally found in what waters due to this? However some may be found as far down as ? Where are corals mostly found (land forms)
Symbiotic relationship between zooxanthellae and corals
Shallow
150 feet if penetration of light permits
Continental shelves near islands or seamounts due to light/depth dependency
What does antecedent topography mean ?
Dead corals
Reef building corals tolerate a low what as compared to other organisms ? Corals can only reproduce and grow at what temperature ? Water over what temperature can cause corals stress?
Temperature range
68 degrees Fahrenheit
86 otherwise bleaching occurs
What other events besides high temperatures can cause coral bleaching , widespread bleaching occurs because of events like
Poor water quality, increased sediment, wave stress or disease
El Niño (increased water temps) and hurricanes
Corals maintain good health in what salinity , where do they normally not exist ? Low salinity can result in what
35 ppt
Near mouths of rivers
Coral bleaching
What happens when suspended sediments land on corals ? What happens when there is reduced water clarity?
Cause damage
Zooxanthellae photosynthesis is reduced or stopped