coral reef subject review

coral organisms are
tutorial available online at
composed of hundreds
oceanservice.noaa.gov/education/tutorial_corals/
to hundreds of thousands of individual animals.
2. Individual coral animals are called polyps________.
3. The mouth of individual coral animals is surrounded by a circle of tentacles_________.
4. After food is consumed by corals, waste products are expelled through the _____mouth_________.
5. Time of day when most corals feed: ___night__________.
6. To capture their food, corals use stinging cells called ___nematocysts_________________.
7. Nematocysts are capable of delivering powerful, often lethal, toxins_________.
A coral’s prey ranges in size from nearly microscopic animals called zooplankton______________9. Many corals collect fine organic particles in films and strands of ___mucous___________.
10. which live
Most reef-building corals
in their tissues.contain photosynthetic algae called ___zooxanthellae_________________
11. Corals and algae have a symbiotic__________ relationship.
12. Symbiotic algae supply corals with glucose, glycerol, and amino acids, which are the products of
___photosynthesis__________.
13. Tropical ocean waters are generally [rich or poor] poor__________ in nutrients.
14. The relationship between the algae and coral polyp facilitates a tight recycling_______ of nutrients,
which is the driving force behind the growth and productivity of coral reefs.
15. The unique and beautiful colors of many stony corals are caused by zooxanthellae______________.
16. ___physical stress_________ can cause coral polyps to expel their algal cells.
17. take
Coral ___
on a stark white
bleaching_
18. Because of their intimateappearance.
__________ occurs when coral
relationship with symbiotic
polyps expel
algae, reef-building corals
their algal cells, causing the
respond to the
colony to
environment like plants______.
19. water.
Because their algal cells need light for photosynthesis, reef corals require nutrient poor________
20. Although coral reefs require nutrient-poor water, they are among the most productive________ and
diverse marine environments.
21. Reefs form when polyps secrete skeletons of calcium carbonate________.
22. As they grow
vertebrate and invertebrate
, coral reefs provide
species.
structural habitat________ for hundreds to thousands of different
23. The skeletons of stony corals are secreted by the lower portion of the polyp. This process produces a cup,
or calyx______, in which the polyp sits.
24. The walls surrounding the corals’ skeletal cup are called the theca________.
25. The floor of the corals’ skeletal cup is called the basal plate________.
26. CBMS is a system of specially designed buoys that measure conditions that may cause bleaching on coral
reefs.
27. When polyps are physically stressed, they contract into their calyx so that virtually no part is exposed
above their skeleton. At other times, polyps extend out of the calyx. Most polyps extend the farthest when
they feed______.
28. ___branching_______ corals have primary and secondary branches.
29. Digitate______ corals look like fingers or clumps of cigars and have no secondary branches.
30. ____Table______ corals form table-like structures and often have fused branches.
31. Elkhorn______ coral has large, flattened branches.
32. ___Foliose_______ corals have broad plate-like portions rising in whorl-like patterns.
33. ___Encrusting_______ corals grow as a thin layer against a substrate.
34. Massive______ corals are ball-shaped or boulder-like and may be small as an egg or as large as a
house.

35. Mushrooms______ corals resemble the attached or unattached tops of mushrooms.
36. Coral reefs begin to form when free-swimming
other hard surfaces along the edges of islands or continents.
Coral larvae______ attach to submerged rocks or
37. Fringing
and surrounding islands.
______ reefs project seaward directly from the shore, forming borders along the shoreline
38. Barrier
open, often deep water.
______ reefs border shorelines, but are separated from their adjacent land mass by a lagoon of
39. An ___ Atoll
completely below sea level while the coral continues to grow upward.
_________ is formed when a reef has developed around a volcanic island that subsides
40. Massive corals have growth rates of 0.3 to 2 centimeters________ per year.
41. Bottom topography, depth, wave and current strength, light, temperature, and suspended sediments act on
coral reefs to create horizontal and vertical zones of living species. The reef flat______ is usually the
zone closest to shore, followed by the reef crest______ or algal ridge, then the buttress______
zone, and finally the seaward slope________.
42. (C).
Reef-building corals cannot tolerate water temperatures [above or below] below________ 18° Celsius
43. Most reef-building corals require very salty_____ water.
44. Reef-building corals’ requirement for high light explains why most reef-building species are restricted to
the epipelagic________ zone, the region in the ocean where light penetrates to a depth of approximately
70 meters.
45. sea floor
As adults, almost all corals are ___benthic_______, which means that they remain on the same spot on the
46. In ___asexual_______ reproduction, new polyps bud off from parent polyps to expand or begin new
colonies.
47. In sexual reproduction, coral eggs and sperm join to form free-floating, or planktonic, larvae called
___planulae_______.
48. Species that release massive numbers of eggs and sperm into the water to distribute their offspring over a
broad geographic area are called ____broadcast______ spawners.
49. The time between planulae formation and settlement is a period of exceptionally high
__mortality________ among corals.
50. Along many reefs, spawning occurs as a synchronized______ event, when all the coral species in an
area release their eggs and sperm at about the same time.
51. The long-term control of spawning may be related to temperature, day length and/or rate of temperature
change (either increasing or decreasing). The short-term (getting ready to spawn) control is usually based
on lunar______ cues.
52. The final release of gametes during spawning is usually based on the time of ___sunset_______.
53. Planulae exhibit positive ___________.
54. Once planulae settle on the bottom, they ___metamorphose_______ into polyps and form colonies that
increase in size.
55. Coral reefs support more species______ per unit area than any other marine environment.
56. Scientists estimate that there may be ____________ of undiscovered species of organisms living in and
around reefs. [how many?]
57. Coral reef biodiversity is considered key to finding new medicines______ for the 21st century.
58. Healthy reefs contribute to local economies through tourism________.
59. In developing countries, coral reefs provide critical __________ resources for tens of millions of people.
60. Coral reefs buffer adjacent shorelines from wave action and prevent erosion______, property damage
and loss of life.
61. Natural damage to coral reefs frequently occurs because of weather______.
62. Slow-growing corals that are damaged by storms may be overgrown by ___algae_______ before they can
recover.
63. Reefs also are threatened by ___low tides_______ that can cause shallow water coral heads to overheat
and dry out.
64. Increased sea surface temperatures, decreased sea level and increased salinity from altered rainfall can all
result from weather patterns such as ___El nino_______.
65. Corals are vulnerable to ___predation_______ by fishes, marine worms, barnacles, crabs, snails and sea
stars.
66. Human-caused, or ___anthropogenic_______ activities are major threats to coral reefs.
67. One of the most significant human-caused threats to reefs is pollution________.

68. When some contaminants enter the water, nutrient levels can increase, promoting the rapid growth of
___algae_______ and other organisms that can smother corals.
69. In many areas, coral reefs are destroyed when cyanide or dynamite are used for fishing______
activities.
70. Coral diseases generally occur in response to biological ___stressors________, such as bacteria, fungi and
viruses, and nonbiological stresses, such as increased sea surface temperatures, ultraviolet radiation and
pollutants.
71. Many scientists believe that the increased frequency of coral diseases over the last 10 years is related to
deteriorating water quality and increased ___temperatures_______ that may allow for the proliferation and
colonization of microbes.