What are three physical requirements for coral growth?
Corals need warm water, a hard substance, and sunlight
Coral is considered to be the major organism that builds the reef structure. What is another major contributor to reef formation, and how does it build reef?
Encrusting coralline algae also aid in reef building. They do this by growing over and trapping soft sediments and rubble, creating a new layer of hard substrate
Identify these creatures as reef builders or reef inhabitants: soft coral; hard coral; coralline algae; coral grouper; crabs
a. Soft coral-reef inhabitants
b. Hard coral-reef builders
c. Coralline algae-reef builders
d. Coral grouper- reef inhabitants
e. Crabs-reef inhabitants
To what phylum and class do corals belong?
Phylum Cnidaria and Class Anthozoa
To what subclass do soft corals belong? To what subclass do stony corals belong?
Soft corals: subclass Octocorallia ; Stony corals: subclass Zoantharia
study the structures of the illustration of the coral
A storm passes over a coral reef, breaking off bits of coral as it goes. In what way can this be helpful to the overall growth of the coral reef?
The broken pieces of coral are able to continue growing, thus expanding the overall reef’s size
What are two ways that coral can asexually reproduce?
By producing gemmules or a piece of existing live coral is broken off, forming a new coral colony.
List two possible benefits of the mass spawning of corals.
Mass spawning of corals allows for the possibility of more gametes surviving predators and seasonal currents may be more beneficial to the planktonic larvae.
Explain how direction of polyp reproduction affects the growth of encrusting and boulder corals, branching corals, and foliacious corals.
When coral polyps reproduce mostly vertically, the resulting formation is a branching coral.
When polyps reproduce mostly horizontally, the result is encrusting or boulder corals.
And when there are nearly equal directions of reproduction, the coral is foliaceous.
What are two purposes of mucus movement on corals?
To push food toward the mouth and move trapped sediments off the coral’s body .
What three feeding methods can coral employ?
- Photosynthesis of the zooxanthellae
- Trapping and eating plankton
- Extend coiled filaments from their gut to digest food particles
Name three major areas of a fringing reef. Which area usually has the most prolific coral growth?
Reef flat, reef crest, and the reef slope. The reef crest is usually where coral growth is most prolific
What most likely causes “spur and groove” on the fore-reef slope of a barrier reef?
strong wind and wave movements
Besides the “spur and groove” structures, what structures on a barrier reef are not found on a fringing reef?
The back reef slope, a lagoon, and possibly a sand cay
In some parts of the ocean, there appear to be dead atolls located well beneath the surface of the ocean. How could their presence be explained?
The volcanic base they likely are growing on sank more quickly than the speed of coral growth, bringing the coral down below the photic zone so it could no longer live.
Or the ocean levels may have risen more quickly than the coral could grow, again causing the coral to be too deep for light penetration.
On which side of an atoll will you find spur-and-groove formations and coralline algal ridges: windward or leeward? explain why.
The windward side because this is the area of greater wind and wave action
Why do coral reefs have a high primary production rate despite their location in nutrient poor water?
The coral reef efficiently recycles its nutrients and produces its own fixed nitrogen.
Next to zooxanthelae, seaweeds are a major primary producer on a reef. What two factors prevent their overgrowth of the reef area?
- nutrient poor water
- constant grazing of reef fish
If coral has a slow growth rate, what are two possible ways it can attack adjacent colonies to create more space for itself?
- move its gut out and eat its neighbors
- stinging tentacles that injure the coral neighbors
If coral has a fast growth rate, how could it create more space for itself?
It can grow above its neighbor and block it from the sun and killing them
Since soft corals do not produce an exoskeleton, what supports them?
Spicules
Soft corals grow much faster than hard corals. Why don’t they take over a coral reef?
It’s easier for them to get destroyed by the intense waves and they need more specific conditions to. thrive
You have learned that there are many mutualistic associations between reef organisms, many cohabitating with each other for mutual benefit. How does this make the reef more efficient as a habitat?
If organisms cohabitate with each other it can provide potentially double the amount of organisms that can life within the reef
