Transcript Coral Polyps Power Point

Coral Polyps
Facts About Corals:
·phylum cnidaria: stinging cells
· coral polyps are very small: ¼ to 2 inches
· two types of corals
~hard and soft polyps
· billions of coral polyps make up a reef
· reefs are mainly made up by hard corals
· corals can live in solitary environments
Hard Corals (stony corals)
·secrete a hard external skeleton
·have tentacles in multiples of six
·live individually or in colonies
·both large polyp and small polyp corals
·usually reproduce by spawning and budding
·calcareous skeletons have been deposited
over many years and cemented together to
form reefs
Hard Corals (stony corals)
·shapes are influenced by water movement
~where wave crash the reef front the
corals have thick branches or massive
boulder shape
~where water is calmer and
deeper the branches are more
delicate or formed into plates to
absorb maximum light
Large Polyp Hard Corals
Usually branching or plated
Small Polyp Hard Corals
Usually branching or plated
Soft Corals - Octocorals
·grown in colonies on the reef, but do not
build reefs
·soft and flexible skeleton that sways in
the water
·grow well in strong currents with access
to a lot of plankton
·have eight tentacles
Soft Corals - Octocorals
·not all corals are actually soft
·have feathery look from the sided
branching pinnules
Structure of the Coral Polyp
Structure of Stony Coral Polyps
·opening at one end is the mouth
·opens directly into the stomach
·waste expelled from same opening
·mouth surrounded by tentacles
·digestive filaments called mesenteral fibers
Structure of Stony Coral Polyps
·tentacles with nematocysts paralyze prey
Endosymbionts
•Zooanthallae,
microscopic algae,
grow on coral polyps
• Through
photosynthesis food
and oxygen are
produced for coral
•Consumes some of
polyp’s waste
Coral Skeletons
·Polyps secrete calcium carbonate
forming skeletons
·grow
vertically
and can
retreat into
their
exoskeleton
Coral Skeletons
Coral growth
can
be traced
through
rings in its
skeleton
Coral Reproduction
•Sexual: release of
sperm into water that
might meet with eggscalled spawning
•Asexual: budding or
when a coral breaks
off and grows in a new
location