coral reefs Flashcards
who are coral reefs related to
jelly fish and sea anemone
where do coral reefs dominate
shallow tropical waters
what do coral reefs provide
ecosystem
what is the dominate organism
hard coral
what is each coral known as
polyp
describe the structure of the hard coral
secrets a cup like skeleton made of calcium carbonate into which it can withdraw
what do the coral reefs form
a million form a dense colony of connected organisms as they grow their skeletons gives rise to a reef community
how do coral reefs catch their prey
their mouth is surrounded by tentacles containing a stinging cells called nematocysts to paralyse their prey
what is the prey of the coral reefs
zooplankton
microscopic marine animals
are coral reefs herbivores carnivores or omnivores
carnivores
what lives within the tissue of the polyp
zooxanthellae
microscopic algae
what is the purpose of zooxanthellae
have a symbiotic relationship with the coral which is mutualistic
how does the zooxanthellae help the coral
help with nutrition of coral and its ability to form its calcium carbonate skeleton
how does the coral help the zooxanthellae
provides a habitat
use waste product of corals as raw materials for photosynthesis
how do corals reproduce
asexually and sexually
how does asexual reproduction occur
environment factors are suitable and new individual buds form from each parent polyp resulting in increased size of the colony
how does sexual reproduction occur
sperm are released into the water and are drawn into the cavity of another polyp
Fertilised eggs develop within cavity and result in the formation of free swimming planula larvae which are released into the water
Planulae move through water for a short time before settling on an appropriate hard substrate
what does sexual reproduction result in
dispersion of various coral species and the colonisation of new areas
what temperature is required for optimal growth of coral reefs
23-25
what do coral reefs not tolerate
long exposure to air
what depth do they stop growing at and why
below 50-70 m as their symbiotic algae need sunlight for photosynthesis
why do coral reefs not settle in areas of high sedimentation
sediment settling on coral reefs interferes with their feeding mechanisms
how does high wave action assist coral reefs
oxygenates water, brings in fresh food supplies and helps to remove any settled sediment
what are other animals associated with corals
Soft coral such as sea fans and sea whips and other sedentary organisms such as sea anemones grow attached to the hard reef skeleton
Echinoderms like sea urchin and starfish abundant
Crustaceans as well such as spiny lobster and crabs
A variety of reef fish seek shelter among crevices of the reef and their brilliant colours serve as species identification
list 5 benefits of coral reefs
Coral reefs generate income from tourism and fishing
Generate food - reef fish (groupers, snappers and grunts) and reef creatures (lobster and conch)
Contribute greatly to white sand typical of caribbean beaches
Protect coastline from erosion by acting as breakwaters
Home to about million different animal species such as turtles sea anemone clown fish starfish
list five dangers to coral reefs
Invasion of reef by man however can damage the corals amd result in the death of a number of species by breaking off pieces making jewellery
Reefs can be severely affected by tropical storms and hurricanes whose powerful forces can destroy even solid reef structure
Explosions of populations of coral reef predators such as crown of thorn starfish (acanthaster planci) in the pacific have also caused serious damage
Major destroyer of coral reefs is man
Boat anchors pull away the structure of the reef
