Download Coral Polyp Design - University of Hawaii

Coral Polyp Design
The basic unit of a coral is the coral polyp. Coral polyps consist of a sac-like gut
or body cavity enclosed by a mouth and surrounded by a ring of tentacles. The tissue of a
polyp is made of two distinct layers, the ectodermis (ecto-outer, derm-skin) and
endodermis (endo-inner, derm-skin).
Corals are mostly found within two subclasses of the class Anthozoa. The
Hexacorallia have tentacles in multiples of 6 and the Octocorallia have tentacles in
multiples of 8.
For this activity we’re going to make our own coral polyps and colonies out of
Play-Doh.
-Using the diagrams make two polyps, one from a Hexacoral and another from an
Octocoral containing the following parts:
 an endodermis and ectodermis
 a body cavity
 an oral disk/mouth
 tentacles
 zooxanthellae
Coral Skeletal Structure

Observe the different coral skeletons using the dissecting microscope.
Using the diagram 4-1 from your book, how many different growth forms do you
see with the different skeletons?

Examine 3 different coral specimens and record their features in table 4-1.

How are the cup features of the coral specimens different?

Which coral cup parts are lacking in a solitary coral like Fungia?

How does a colonial coral grow?

Which species would probably break during a storm? What skeletal features
make one coral more fragile than another?
Material developed for the University of Hawaii-Manoa GK-12 program (NSF grant #05385500).
Website: www.hawaii.edu/gk-12/evolution. Duplication for educational purposes only.