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Deepseawaters Home Deepsea
AnimalsAustralian Brain Coral
Australian Brain Coral
Common Name: Australian Brain Coral
Scientific Name: Goniastrea Australensis
Description
 Brain corals look like round boulders, some reaching quite large
sizes. Like all corals, the Australian Brain Coral is a living
animal belonging to a group known as the 'coelenterates'
or jelly animals. The whole coral is a collective or colony
made up of thousands of individual coral animals called polyps.
Each polyp has a simple hollow body with a mouth in the centre
surrounded by tentacles. The polyps make the coral skeleton
by each secreting a wall and a floor of limestone (calcium
carbonate) around the outside of its body. The Australian
Brain Coral has its own distinctive pattern of ridges and
valleys formed by rows of polyps that share the limestone
walls. The colours vary, but it is most commonly green or
brown, sometimes with different coloured valley floors from
the walls..
Diet
The
polyps feed on tiny animals and particles from the water around
them. The growth of the coral colony is enhanced by the presence
of tiny plant cells, which live in the coral tissues. These
plants harvest energy from sunlight and pass back energy to
the coral to assist in the coral skeleton construction.
Behaviour
 Brain
corals mainly feed at night by extending their tentacles which
are armed with stinging darts called 'nematocysts'.
During the day their tentacles are retracted into the corallite
base. The nematocysts paralyse their prey, such as tiny shrimp,
and then their tentacles wave the prey into the mouth cavity
where the food is digested. When the food is absorbed into
the polyp, some of the nutrients are passed to other polyps
via the interconnecting living tissue. The polyp and interconnecting
tissue build up a limestone base (the coral skeleton) by extracting
calcium and carbonate ions from the seawater.
Life
History
 The
polyps of the Brain Coral reproduce by releasing sperm and
eggs into the water. These unite to form tiny round larvae
called 'planulae'. Planulae, float in the water for
a period of at least 5 days and those not eaten select a spot
suitable for beginning a new colony. When a planula settles,
it changes into a polyp, begins to secrete limestone and then
begins to feed and grow by budding to form a new polyp. This
process repeats itself many times resulting in the formation
of a new Brain Coral colony.
Habitat
They
are commonly found in shallow water such as intertidal reef
flats or fringing reefs, rocky shorelines and harbour breakwaters.
Special
Features or Habits
Brain
corals help form the foundations of coral reefs. Many corals
reproduce during spectacular mass spawning events that result
in slicks of eggs and coral larvae on the surface of the ocean.
This spawning only occurs over a few nights each year.
They
are the toughest of all corals and can tolerate several hours
of exposure to the tropical sun at low tide, silt and low
salinity.
Location
or Region Found
Found
on both coasts of Australia and the western Pacific from Japan
in the north to the Kermadec Islands in the south.
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