| Phylum Chordata
> Subphylum Vertebrata > Class Reptilia
on our shores
learn only 3 things about them ...
Most of our marine snakes will not bite if you leave them
alone. Don't touch them!
Snakes may be well camouflaged or hidden. Watch where
you step and where you put your hand.
snakes have special adaptations to their aquatic environment.
Snakes are sometimes seen on many of our shores and mangroves and
even swimming in our deeper waters. Some are seasonally more common,
others are shy and well camouflaged and thus hard to spot even though
they might be quite common. Some terrestrial snakes are also commonly
seen near the coast, though they stay firmly on dry land.
What are snakes? Snakes are vertebrates
like you and me, i.e., they have a backbone and internal skeleton.
Some snakes have returned to the sea and live on the shore or even
in deeper waters and far out in the ocean.
snake features: Snakes on our shores are well adapted to
their habitats, some are so well adapted that they can no longer move
easily on land. Some, like the Yellow-lipped
sea krait (Laticauda colubrina) has a paddle-like tail
to swim with. Others, like the Banded file
snake (Acrochordus granulatus) have a loose granulated
skin to better grasp slippery fish.
Like other land snakes, the snakes on our shores have scales. Although
some have lost the broad scales that land snakes have along the bottom
of their bodies and which are used to grip the surface and move. Without
these ventral scales, some sea snakes are helpless on land.
Snakes on our shores don't have gills. So they must come up regularly
to the surface to breathe. Sea-dwelling snakes usually have nostrils
with valves to keep out water, and enlarged lungs which store air
so they can stay underwater longer as well as to help in bouyancy
control. Some of these snakes can also take in air through the skin.
Sometimes confused with eels and
other long fishes. Unlike fish, snakes do not have gills. Here's more
on how to tell apart sea snakes,
eels and eel-like animals.
Are our shore snakes dangerous?
Snakes that live in the sea include some with the most potent venom.
But most sea snakes, including venomous sea snakes, are gentle and
will not bite unless provoked. If you leave the snake alone and don't
touch it, it will not harm you.
What do they eat? Generally, snakes
on our shores eat mostly fish. The favourite prey of the Yellow-lipped
sea krait (Laticauda colubrina), for example, is eel! But
as a group, they eat a variety of prey including crabs, prawns and
other animals. Some specialise in a particular kind of prey.
What do they drink? A study found
that some sea snakes need to drink freshwater and won't drink seawater.
Sea snakes may also drink water from the "lens" of freshwater that
sits atop saltwater during and after rainfall, before the two have
had a chance to mix. That would explain why some seawater lagoons,
where the waters are calmer due to protection from reefs, are home
to dense populations of sea snakes - the freshwater lens persists
for longer periods before mixing into saltwater. The "long-standing
dogma" is that sea snakes drink seawater, with internal salt glands
filtering and excreting the salt. In fact, the snakes' salt gland
may help the snakes with ion balance - moving excess salts from the
report on the wild shores of singapore blog.
Water babies: Most snakes on the
shores give birth to live young. But the Yellow-lipped
sea krait (Laticauda colubrina) lays eggs on coral reefs.
watersnake can be
commonly in our mangroves but are
only active after dark.
Sungei Buloh Wetland Reserve, Nov 03
The Yellow-lipped sea krait
is sometimes seen on our reefs.
Pulau Hantu, Apr 06
The Banded file snake is a gentle
creature sometimes seen in our mangroves.
Pulau Sekudu, Jul 05
Snakes can swallow prey
bigger than their heads!
Pasir Ris Park, Mar 07
uses: Sea snakes are harvested for food and the traditional
medicine trade as well as for their skin. As usual, overharvesting
can affect populations.
Status and threats: Our
sea snakes are considered uncommon but are not listed among
the threatened animals of Singapore. However, like other creatures
of the intertidal zone, they are affected by human activities
such as reclamation and pollution.
Like other snakes, sea snakes
and water snakes also have a forked tongue.
Sungei Buloh Wetland Reserve, Nov 03
The sea snake has a paddle-shaped tail
to help it swim in the water.
Sisters Island, Nov 03
- Chim Chee Kong. 25 April 2014. Snakes
of St John's Island. Singapore Biodiversity Records
- Lim, Kelvin
K. P. & Francis L K Lim, 1992. A
Guide to the Amphibians and Reptiles of Singapore. Singapore
Science Centre. 160 pp.
- Cox, Merel
J., Peter Paul van Dijk, Jarujin Nabhitabhata and Kumthorn Thirakhupt.
Photographic Guide to Snakes and Other Reptiles of Thailand, Peninsular
Malaysia and Singapore New Holland.