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Flashcards in Corals Deck (53):

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?

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 .....

1-3 mm
Large sizes and weigh several tons


If zooxanthellae are supplied with enough ? They can feed the whole coral



How much percent of energy is from zooxanthellae



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
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


Low levels of p........ Can kill ? High nutrient levels allow what to rise ? Increased algal growth can shade ?

Algae levels
Light sensitive corals and zooxanthellae


Which corals seem to be dominant in shallower waters and why? Which corals seem to be dominant in deeper areas and why?

Taller more branching , intense competition for space and light
Flatter forms, assist in catching all light possible


Seven types of corals

Plate like, foliaceous (leaf like), columnar, massive, branching, free living, encrusting


The rest of the examples without importance

Cnidarians (hydrozoans or anemones )
Sponges cement rubble into substrate


What is cementation and what does it contribute to?
What is this process balanced by (2 things)

Secondary secretion
Build up of reef structure
Erosion and consumption


Fringing reefs are the ... And most... Form or reef ? Where do these reefs develop near ? The develop as what ?

Simplest and most common
The shore in tropical areas
Narrow strips along the shore
Some can encircle


What do fringing reefs consist of ? The reef is ..., .... And ..... And may be exposed at what tide ? The reef slope is much more ? And is not exposed to what? What is the reef crest ? Growth is normally high in what area

Inner reef flat and outer reef slope
Flat, wide, gently sloping
Low tide
Steep, air
Shallow upper edge of the reef coast
Reef crest


What does the reef slope contain on fringing reefs ? The number of species is higher in which two places on fringing reefs ? Why is growth slower on reef flat ?

Living and dead corals : sea grasses, soft corals, algae a and invertebrates
Slope and crest
Runoff from land like sediment freshwater pollution and wave action


Where do barrier reefs grow ? How are they different from fringing reefs ?, which is the second largest barrier reef in the world and where is it?

Along shore or farther from shore
Deep lagoon between shore and reef
Belize Central America


What is the typical construction of a barrier reef ? The slope of the fore reef is much more... Than the back reef slope , what happens to the depth in this area ?

A back reef slope , a reef flat, a crest me a fore reef slope
Depth drops quickly


What happens on the back reef slope or reef flat , enough sediments may accrue to form what? These islands are called what in Florida and what every where else

Waves wash up sediment on to these parts and causes reduced coral growth
Keys/ cases


Where is coral growth normally the highest on barrier reefs ? As the same with fringing reef where is species diversity greatest?

Reef crest or just below crest on the fore reef slope
Just below reef crest


What is the length of the Great Barrier Reef system ? The width varies from what to what ? Many what exist along the reef system

1200 miles


Definition of atoll? What may be a part of the atoll structure ?, width variation?

Reef structure surrounding a central lagoon
Sand Cayes
Less than One mile to over 20


Atolls form when what is formed ? The coral begins as what type of reef , what lowers the level of the island over time ?, eventually the island disappears leaving what behind?

Volcanic island
Fringing reef
Weathering and geological activity
Utter band of coral surrounding lagoon


Which atoll has the classic formation ? What is it the site of? What is at the top

Us nuclear weapon testing
Bomb craters


What does and atoll possess ? The inner slope vs the outer slop and the depth of the lagoon? Where are the two largest atolls

Reef flat and inner and outer reef slopes
Inner more gradual
200 feet or less
Maldives Indian Ocean and Marshall Islands pacific


The water column surrounding the reef is normally very low in? And what is this lack due to ?

Location of the reefs far from sedimentation sources like rivers


Due to low nutrient content the reef does not support the degree of ? The food chain is based around the primary production of ? How does the coral benefit the zooxanthellae ? What does zooxanthellae give to corals

Primary production by phytoplankton seen in other marine communities
Zooxanthellae in body of corals and other organisms
Carbon dioxide , nitrogen,phosphorous (by products)
Organic molecules to corals


Cyanobacteria present on the reef are able to do what? What can also feed reef inhabitants ? Water currents bring what to reef communities

Fix nitrogen which is then available to other inhabitants who feed on cyano bacteria
Sea grasses and algae
Phytoplankton and zooplankton


How can coral reefs deter predators (think producing what?) and is common in what ? These chemicals can be released into?

Producing toxic or foul tasting chemicals
Soft corals and sponges
Water to kill organisms or limit growth surrounding organisms


Other reef dwellers may produce ? To deter ?
Sponges produces spicules of ? Or?
Soft coral produce ? Needles known as ?

Hard structures, predation, spicules, calcium carbonate, silica, calcium carbonate, sclerites


What algae a grown in an encrusting form? What problem does this cause

Coralline, difficult feeding


Tough competition for what in reefs?

Space and light


How do coral limit the competition? What does this do

Growing fast and upright, Maximizes ability of quick reproduction


Another way to limit competition?

Grow slow but massive


Ways that coral feed

Directly or sting each other when come in contact


What other things do corals compete with

Algae, sea grasses, invertebrates


What other organisms compete for limited resources? How do they compete? What do each have?

Fish and crustaceans, feeding in slightly different areas or ways, ecological niche.


What are you bringing Sydney tomorrow ?



What are you bringing Sydney tomorrow ?



First two structures that aid in reef building

Coralline algae (also produce calcium carbonate)
Soft corals such as sea whips and sea fans