Winter Fishtival: Coral Reef Fun Facts

Join us for hands-on activities, special talks and opportunities to learn more about the care and feeding of the Aquarium's fish, birds, tide pool animals and marine mammals during Winter Fishtival! Each day we'll highlight a different sea animal and activity. Today the featured animal is the coral reef. Here are some fun and interesting facts about coral reefs.

There are two types of coral, stony corals and soft corals. Here are some interesting facts about each type.


Stony Corals

  • Main reef building corals
  • Closely related to sea anemones
  • Produces a calcium carbonate skeleton. This skeleton provides a support structure on which the polyps live and provide protection when polyps retract within it.
  • Coral colonies can expand in size by budding of new polyps
  • They are found from the intertidal zone to deep ocean trenches (6000 m)
  • 6000 different species exist.


  • They eat anything from small fish to small zooplankton
  • Most corals feed at night and are contracted during the day
  • The waste product of food caught by polyps (phosphorus and nitrogen) is cycled to the algae to help with growth.

Coral Reef Development:

  • Individually, most corals measure less than half an inch across, yet collectively they have built the largest organic structures on earth – the Great Barrier Reef!
  • Coral can grow 1cm – 10cm a year
  • Coral fossils date back from the Precambrian age


Soft Corals

  • Most abundant in the Indo-Pacific
  • Feed during the day so you will see the polyps
  • Polyps are connected similar to stony corals (if colonial)
  • Sub classes of soft corals are the Octocorallia. These include: sea pens, sea fans, whip corals and pipe corals.
    • 8 tentacles around the polyp and pinnate (has side branches like a feather)

Come visit the Aquarium to learn more about coral reefs at Winter Fishtival. Tomorrow’s featured animals are tide pool animals!

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