 |
|
|
Galaxy
corals
Galaxea
sp.*
Family Oculinidae
updated
Feb 09
Where
seen? These small hard corals with tall, distinctive star-shaped
corallites are commonly seen on many of our Southern shores.
The Family Oculindae includes the genera Galaxea recorded in
Singapore. Members of the family generally have corallites made up
of long tubes joined near the tips of the tube with a common skeleton
that is smooth.
Features: Colonies seen 10-20cm.
Colonies are rounded and small, forming irregular boulders and mounds.
Polyps and corallites about 1cm in diameter. The corallites are long
with a distinctive star-shape pattern at the tips. The walls are thin
and the skeleton is quite fragile. The polyps have short thin tentacles
often with white tips. The skeleton is covered by a very thin layer
of tissue. The polyps may produce very long sweeper tentacles (up
to 30cm) that clear the surrounding area of competiting corals and
other animals. Colours seen include blue, green, purple, brown or
reddish.
Galaxy friends: The spaces among
the tubular corallites provide shelter for all kinds of animals (mussels,
crabs, shrimps) often hidden deep within the colony.
Galaxy babies: Galaxea fascicularis has a unique
method of reproducing. There are two types of colonies. One type is
a female colony that produces only red eggs. Another type is hermaphrodite
that produces sperm and white 'eggs'. The eggs are not real eggs and
help the sperm to float up to the surface where they can fertilise
the real red eggs.
Human uses: These corals are among
those taken for the live aquarium trade. They often do poorly in captivity.
They are fragile and break easily, and collection techniques usually
result in poor specimens that quickly die from disease. In addition,
their habit of producing sweeper tentacles make them poor tank-mates.
Status and threats: None of our
galaxy corals are listed among the endangered animals of Singapore.
However, like other creatures of the intertidal zone, they are affected
by human activities such as reclamation and pollution. Trampling by
careless visitors, and over-collection also have an impact on local
populations. |
|

Long sweeper tentacles
Pulau Semakau, Sep 05
|
|
|
Galaxy
corals on Singapore shores
Kusu Island,
May 07
|
|
|
Pulau Hantu,
Aug 03
|
|
|
*Species
are difficult to positively identify without close examination.
On this website, they are grouped by external features for convenience
of display.
Family
Oculinidae recorded for Singapore
from
Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity
in Singapore.
in red are those listed among the threatened
animals of Singapore from Ng, P. K. L. & Y. C. Wee, 1994.
The Singapore Red Data Book: Threatened Plants and Animals of Singapore.
| |
Galaxea
cf astreata
Galaxea fascicularis |
|
|
References
- Veron, Jen.
2000. Corals
of the World
Australian Institute of Marine Science, Australia. 3 volumes.
- Chou, L.
M., 1998. A
Guide to the Coral Reef Life of Singapore. Singapore Science
Centre. 128 pages.
- Erhardt,
Harry and Daniel Knop. 2005. Corals:
Indo-Pacific Field Guide
IKAN-Unterwasserachiv, Frankfurt. 305 pp.
- Borneman,
Eric H. 2001. Aquarium
Corals: Selection, Husbandry and Natural History
T.F. H Publications. 464 pp
- Wee Y.C.
and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
National Council on the Environment. 163pp.
- Ng, P. K.
L. & Y. C. Wee, 1994. The
Singapore Red Data Book: Threatened Plants and Animals of Singapore
.
The Nature Society (Singapore), Singapore. 343 pp.
|
|
|