Types of Corals Types of Reefs 1/18 Types of Corals Types of Reefs

Pillar (Digitate) Coral 3/18 Pillar (Digitate) Coral Upward cylinders Look like fingers or cigars No secondary branching

Table Corals Plate like with polyps extending upward 4/18 Table Corals Plate like with polyps extending upward Increased surface area for photosynthesis Easier for tentacles to capture zooplankton

2/18 Branching Coral Primary and secondary branches Resemble bushes

Elkhorn Coral Thick, sturdy, flat, antler-like branches Fast growing 5/18 Thick, sturdy, flat, antler-like branches Fast growing Survive in heavy wave action

Foliase Coral Whorl-like pattern Look like flower petals 6/18 Foliase Coral Whorl-like pattern Look like flower petals Increased surface area Provide shelter for animals between “petals”

8/18 Massive Corals Ball/boulder shape Very sturdy Very slow growing

Encrusting Coral Grow flat instead of up Adhere to rock 7/18 Encrusting Coral Grow flat instead of up Adhere to rock Protected from wave action

Mushroom Coral Mushroom shape Flat or dome oval Solitary Unattached 9/18 Mushroom shape Flat or dome oval Solitary Unattached Indo-Pacific waters

10/18 Types of Reefs

Fringing Reefs 11/18 Most common Project seaward from the shore

Barrier Reefs Border shorelines 12/18 Barrier Reefs Border shorelines Separated from land by lagoon of open, often deep water land fringe barrier

Atoll Fringe reef forms Volcanic island subsides 13/18 Atoll Fringe reef forms Volcanic island subsides Usually circular with central lagoon

Parts of the Reef Determining Factors Bottom topography Depth 14/18 Determining Factors Bottom topography Depth Wave action Current Temperature Light Sediment

15/18

Reef Flat Zone 16/18 Sheltered side of reef Variable temp and salinity Variable depth: exposed at low tide Protected from waves Seagrass beds Substrate: loose sand and coral Encrusting and filament algae common

Reef Crest 17/18 Exposed at low tide Highest point on reef Severe wave action: little live coral Stout branching coral Small animals live protected among nooks and crannies

Fore Reef 18/18 Low tide mark to deep water Deep channels between buttresses Butresses: stabilize reef and dissipate wave action Channels: drain reef debris & sediment to deeper water Abundant O2 + hiding spaces = small fish Small fish bring big fish! Yummy! Deep dark water = sponges, & non-reef building coral