learn only 3 things about them ...
Anemonefish need their anemones. Do not disturb them or
One anemone may be home to many anemonefishes.
fishes are threatened by over-collection for the aquarium
trade. Don't keep Nemo in your home, he belongs in the
famous by the cartoon "Finding Nemo", these fishes are
a delight and the highlight of a trip. Anemonefishes are commonly
seen among the sea anemones of our Southern shores. At low tide,
they may shelter in a pool further away while their anemone is left
high and dry.
What are anemonefishes? Anemonefishes
belong to the Family Pomacentridae.
Anemonefishes are in the subgroup Amphiprioninae in this family.
Features: To about 9cm. Besides being really cute and
colourful, the most amazing feature of anemonefishes is that they
can live happily among the tentacles of sea anemones that would
otherwise kill (and eat) other fishes, including larger ones.
The anemonefish is believed to develop this immunity slowly. To
acclimatise to a host anemone, an anemonefish will at first gingerly
swim among the tentacles, touching it with its fins then withdrawing
rapidly, in an elaborate dance. Only after some time will the fish
be able to dive right in among the tentacles. One theory is that
the fish smears mucus from the anemone all over itself. In this
way, to the anemone, the fish is just another part of the anemone.
Thus the sea anemone doesn't sting the fish. Another theory is that
the mucus of the fish (all fishes are covered in mucus) lacks substances
that trigger a sea anemone to discharge its stingers.
Experiments suggest anemonefishes may protect their host anemones
from predatory fishes such as butterflyfish. They may also clean
the anemone of parasites and remove dead tissues of the sea anemone.
Their swimming action may also increase water circulation around
the sea anemone and remove sediments that would foul the sea anemone.
Some studies suggest anemonefishes attract other fishes that are
captured and eaten by the sea anemone.
In return, the anemonefishes enjoy protection among the tentacles
of the sea anemone and may also feed on leftovers of prey captured
by the host sea anemone. In
captivity, the anemonefish and anemone can survive well without
each other. However, in the wild, the anemonefish being poor swimmers,
are soon eaten by larger fishes. The anemonefish also needs the
protection of a sea anemone to lay its eggs, usually under the oral
disk of the anemone.
What do they eat? Anemonefishes
eat mainly plankton. Some also graze algae from the surface or gathered
from the water.
Amazing gender switch: Anemonefishes
can change their gender. Often, a sea anemone will be home to several
anemonefishes of the same species. Usually the largest anemonefish
in the group is the female and the next largest is the functioning
male (although he is often less than half her size). Besides the
difference in size, there are generally no differences in patterns
or colours between the genders. If the female is removed from the
group, the male becomes a female and the next largest becomes the
dominant male. In this way, anemonefishes can continue to breed
throughout the year. Small anemonefishes are not necessarily younger,
just lower in the "pecking order". It is believed they
remain small because of the constant harassment by the dominant
Anemonefish babies: Anemonefishes
form permanent pair bonds that sometimes last for years. The male
usually selects the nest site, often a bare rock near the sea anemone
which he clears of seaweeds and other rubbish. The female eventually
helps out. After the female lays on the site, the male scrupulously
guards and cares for the eggs, keeping them well aerated and clean.
The female helps out sometimes. Larval fish that hatch from the
eggs drift with plankton for 8-12 days before settling to the bottom
and changing into a juvenile fish.
How does the baby fish find an anemone
host? Each species of anemonefish lives in a specific
species of sea anemone. Some species apparently follow chemicals
released by the suitable host anemone, others find one by sight,
for yet others, it is apparently simply by chance. One
study suggests the fishes use the smell of leaves from the rainforest
to find their way to a suitable habitat. Even so, this is not the
end of the problems for the young fish. If the anemone already has
resident anemonefishes, the new fish is usually bullied by the residents
and may even be driven away.
False Clown? Our clown anemonefish
(Amphiprion ocellaris) is called the False
clown anemonefish, to distinguish it from another closely related
fish called the Clown anemonefish (Amphiprion percula) which
lacks the black bands on the top edge of the dorsal fin.
Human uses: Clown anemonefishes
are among the most popular live aquarium fishes. Although captive
bred specimens are commercially available, these are far more expensive
than wild caught specimens. Thus, clown anemonefishes continue to
be unsustainably harvested from the wild. The pressure on wild populations
has risen tremendously due to the huge demand following the popular
"Finding Nemo" cartoon.
Status and threats: All our
anemonefishes are 'Vulnerable' in the Red List of threatened animals
of Singapore. Like other creatures of the intertidal zone, they
are affected by human activities such as reclamation and pollution.
Poaching by hobbyists and overfishing can also have an impact on
local populations. According to the Singapore Red Data Book, "habitat
protection and strict policing against illegal collection are required"
to conserve our anemonefishes.
Pulau Hantu, Nov 03
Pulau Semakau, Aug 08
Anemonefishes in three different sizes.
Kusu Island, May 05
A pair of very different sized
fishes in the same anemone.
Sisters Island, Jul 07
Eggs laid near the host sea anemone.
Terumbu Raya, Jun 15
Photo shared by Toh Chay Hoon on facebook.
Often the same anemone may also be
home to anemoneshrimps!
Pulau Hantu, Jul 07
on Singapore shores
|Amphiprion species recorded for Singapore
Wee Y.C. and Peter K. L. Ng. 1994. A First Look at Biodiversity
*additions from from Ng, P. K. L. & Y. C. Wee, 1994. The Singapore
Red Data Book: Threatened Plants and Animals of Singapore.
in red are those listed among the threatened animals of Singapore from Davison, G.W. H. and P. K. L. Ng and Ho Hua Chew,
2008. The Singapore Red Data Book: Threatened plants and animals of
+Other additions (Singapore Biodiversity Records, etc)
|| Amphiprion clarkii (Clark's
anemonefish) (VU: Vulnerable)
frenatus (Tomato anemonefish) (VU:
Amphiprion ocellaris (False clown anemonefish) (VU:
Amphiprion polymnus (Saddleback
anemonefish) (VU: Vulnerable)
Amphiprion perideraion (Pink skunk anemonefish) (VU:
- Toh Chay Hoon. 11 April 2014. Spawn of the saddleback anemonefish. Singapore Biodiversity Records 2014: 96.
- Jeffrey K. Y. Low. 2013. More noteworthy fishes observed in the Singapore Straits. Nature in Singapore, 6: 31–37.
- Toh Chay Hoon. 20 December 2013. Shrimps and saddleback anemonefish on carpet anemone off Pulau Hantu: Holthuis’s anemone shrimp, Periclimenes holthuisi and Saddleback anemonefish, Amphiprion polymnus. Singapore Biodiversity Records 2013: 126-127.
- Chou, L.
M., 1998. A
Guide to the Coral Reef Life of Singapore. Singapore Science
Centre. 128 pages.
- Wee Y.C.
and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
National Council on the Environment. 163pp.
G.W. H. and P. K. L. Ng and Ho Hua Chew, 2008. The Singapore
Red Data Book: Threatened plants and animals of Singapore.
Nature Society (Singapore). 285 pp.
- Allen, Gerry,
Fishes of South-East Asia: A Field Guide for Anglers and Divers.
Periplus Editions. 292 pp.
- Kuiter, Rudie
H. 2002. Guide
to Sea Fishes of Australia: A Comprehensive Reference for Divers
New Holland Publishers. 434pp.
Ewald and Robert Myers. 2001. Coral
Reef Fishes of the World
Periplus Editions. 400pp.
- Lim, S.,
P. Ng, L. Tan, & W. Y. Chin, 1994. Rhythm of the Sea: The Life
and Times of Labrador Beach. Division of Biology, School of
Science, Nanyang Technological University & Department of Zoology,
the National University of Singapore. 160 pp.