Corals

Question 1

What are corals?

Answer 1

animals related to sea anemones; colonial organisms

Question 2

Basic structure of a coral

Answer 2

the polyp

Question 3

Nematocysts

Answer 3

stinging cells on the end of coral tentacles; target small organisms that get too close, using them as food source

Question 4

What resides within the polyp?

Answer 4

digestive and reproductive tissues

Question 5

What is a coral skeleton composed of?

Answer 5

calcium carbonate

Question 6

Zooxanthellae

Answer 6

single-celled algae

Question 7

Explain the symbiotic relationship between coral and zooxanthellae

Answer 7

coral is the host, zooxanthellae photosynthesize to produce food, providing some nutrition for the coral; in exchange, the coral provides nutrients

Question 8

What are most tropical reefs composed of?

Answer 8

true stony coral (each polyp sits in calcium carbonate cup)

Question 9

What are the most important reef builders?

Answer 9

stony corals

Question 10

Anthozoans

Answer 10

class of Cnidarians; carnivorous; asexual or sexual reproduction

Question 11

2 categories of anthozoans

Answer 11

hexacorals and octocorals

Question 12

Hexacorals

Answer 12

have smooth tentacles, often in groups of six (ex: true stony corals, black corals, sea anemones)

Question 13

Octocorals

Answer 13

have eight tentacles, each having tiny branches along the sides (ex: soft corals, blue corals, seafans, organpipe corals)

Question 14

What phylum do corals fall under?

Answer 14

Cnidaria

Question 15

Asexual vs. Sexual Reproduction

Answer 15

asexual important for increasing colony size; sexual important for increasing genetic diversity and creating new colonies

Question 16

Asexual Reproduction

Answer 16

results in cloned polyps or colonies

Question 17

Budding

Answer 17

a coral polyp reaches a certain size, dividing to produce a genetically identical polyp

Question 18

Fragmentation

Answer 18

a piece of a colony breaks off to start a new one

Question 19

Sexual Reproduction

Answer 19

sperm fertilizes eggs, often coming from other colonies to do so; eggs grow into free-swimming larva

Question 20

2 forms of Sexual Reproduction

Answer 20

external and internal

Question 21

External Reproduction

Answer 21

larvae settle on suitable substrate, grow into polyps; colonies release a ton of eggs and sperm into the water

Question 22

Mass Spawning

Answer 22

large spawning event that usually occurs at night; spawning usually only happens once a year

Question 23

Internal Reproduction

Answer 23

corals brood their eggs in the body of a polyp and release sperm into the water; as sperm sinks, polyps containing eggs take them in and fertilize them

Question 24

What is the typical size of an individual coral polyp?

Answer 24

less than half an inch

Question 25

What is the structure of a reef system, from smallest to largest?

Answer 25

coral joins other corals to form a colony, colonies form reefs

Question 26

Fringe Reefs

Answer 26

reefs that fringe along the coastline of a nearby landmass

Question 27

How fast can corals grow?

Answer 27

6 inches per year

Question 28

What is the typical speed of coral growth?

Answer 28

less than an inch per year

Question 29

Where are reef-building corals found?

Answer 29

in shallow tropical and subtropical waters

Question 30

Where do deep-sea corals thrive?

Answer 30

in dark, cold water

Question 31

Characteristics of deep-sea corals

Answer 31

do not have zooxanthellae, do not need sunlight or warm water to survive, grow very slowly, can be found on seamounts (underwater peaks)