Very often, we hear of people campaigning to conserve birds and mammals
- colourful and attractive creatures which easily prick the conscience of
the layman and "nature lovers".
Hardly any emphasis, however, is ever bestowed on the lower vertebrates,
e.g., reptiles, amphibians, fish, and most invertebrates, with the
glaring, biased exception of corals and butterflies! While these "creepy-crawlies"
or "slimy things" may not be visually so pleasant to the majority
of human perceptions, they are equally, if not more vulnerable.
We take fishes for granted, probably also because we see them in aquaria
so often. Some of our primary freshwater fishes however, are probably
amongst the most threatened of Singapore's wildlife. Even today, it
is not surprising to find students exclaiming that guppies, mollies
and tilapias are part of Singapore's "natural heritage". Who can blame
them? What other kinds do they really see or hear about which are
What causes many of the indigenous fishes to be labelled as endangered
or rare? The reasons are many, of which the main cause is development.
Singapore island has indeed changed a great deal in the past century.
Large areas of forest have been destroyed to make way for factories
and housing estates; many forest streams and other natural water channels
have been lined with concrete, soiled with pollutants or buried under
the construction of catchment reservoirs. As such the home range for
certain native fishes shrank considerably, with only small populations
still hanging on in the few lesser disturbed streams of the Central
In 1934, two well known ichthyologists reported 52 indigenous primary
freshwater fishes from Singapore. Only about 29 survive today, an
almost 30% loss! Of these 29 species, 18 are endangered. This means
that 62% of our native primary freshwater fish fauna is threatened
following fishes have all almost certainly vanished, unable to adapt
to the changing conditions of an urbanised Singapore. Fortunately,
they are still present in Malaysia. Every effort must now be made
to ensure that the remaining natural fish fauna does not go the
Photo: Esther Koh
Photo: Esther Koh
Banded Leaf Fish
Another major problem is that of commercial fish collectors for the
aquarium trade. Commercially important species like the Harlequin
Rasbora, Pygmy Rasbora, Six-Banded Tiger Barb
and Banded Eel-loach, to name a few, have been
so heavily depleted that they are now very difficult to see in the
Casual collection of fish for any purpose whatsoever within the stated
nature reserve boundaries is illegal and should not be practised without
a permit issued by the Public Utilities Board or Nature Reserves Board.
A possibly troublesome problem is the introduction of foreign animals
into our waterways.
It is significant to note that in urban Singapore, most of the common
fishes seen are introduced ones. Tilapia, guppies
and mollies abound. All are "immigrants" which have adapted well
to a concretised environment. Fortunately, these fishes are scarce
in the catchment areas.
The number of established exotic species has increased from about
seven species in 1934 to at least 14 at the time of writing. Foreign
animals, once established, can have detrimental effects on the indigenous
flora and fauna in that they may out-compete some native species,
or introduce diseases which may prove fatal to them.
The ornamental fish trade has played a major role in the establishment
of several alien species, e.g., the Mollies, Flying
Barb, Red-tailed Rasbora and Armoured Sucker
Aquaculture has introduced cyprinids like the Chinese Barb and Striped
The introduction of various livebearers to combat mosquitoes (e.g.,
Guppies and Mosquito Fishes) can also be a potential threat to the
fishes, however, will probably become established in Singapore in
the years to come. They will then join the ranks of the numerous
"immigrants", several of which are already Singapore's
most common fishes.
Photo: Tan Bee Hong
Photo: Tan Bee Hong
Fishes in Singapore
Amazing Fishy Facts
About the guidebook