This "stick" coral, an
Acropora (a gift of James Lawrence), looks and feels like it is
made of chaulk. Notice the flaring near the bottom of the left
stick: this is where it grew out after I originally placed it on
another rock. Thus, even though it is so brittle, it does grow.
Here is a closeup of the smaller
bud on the right: notice the soft polyps which are clearly
sprouting from the main stalk. It is the growth of these tiny
creatures which creates the sticks.
This is a "Sun Coral".
It feels like it has been cast from plaster, and is not very
appealing when it is dormant, as below.
Here it is when the polyps are
extended. Strangely, for a creature which emulates the sun, it
comes out mostly at night, and likes to live in dark places. This
makes it difficult to photograph, as the above image bears out.
This branching coral sports soft
tips. It is called a Trumpet Coral.
This is a structural variant of
the Trumpet Coral, and is called a Torch Coral. The greenish
yellow tipped tentacles wave to and fro in the water, almost like