Went to Pulau Hantu for the first time this morning! (: But instead of guiding, i was one of the participants. Haha. I've decided to blog first before i forget all the stuff that i've learnt today. Heh. Marcus and Iris were our guides for today! (:
Before we hit the intertidal area, we walked along this path with some seashore trees that are well adapted to the harsh environment. Being near the shore, they are exposed to sea spray, and thus they have to conserve water within them.
One of the plants is the Casuarina Tree or the Rhu Tree (
Casuarina equisetifolia). This plant has leaves that are very reduced into tiny needle-like structures to help them reduce water loss. Also, these tiny needle-like structures are greenish as they contain chlorophyll in them, and thus helps the plant photosynthesize and make food.
As we walked furthur out, the ground was covered with the dried leaves of the Casuarina Tree, thus the ground was a bit soft.
Other than the Casuarina Tree, the Coconut Tree is also a common tree that can be found along beaches. To cope with the presence of strong winds, they have flexible trunks which enable them to sway with the wind without breaking. Unlike some other plants, the Coconut Tree has a fibrous root system to absorb as much water that drops to the surface of the ground as possible due to the dry environment. They have fruits that are very tasty! Yum yum :D
We also saw the
Calophyllum inophyllum, which is also known as the Beauty Leaves because it has very smooth secondary veins and the leaves feels a bit like plastic. Scientists have found out that this plant contains anti-HIV properties.
Soon, we reached the intertial area. The scene looks so familiar, yet so new. The ground was littered with the Creeper snails, thus it is important to walk in a single file when we're out at the intertidal area so as to minimize the damage done to the animals.
There were also algae everywhere. Algae comes in different forms. This one looks like a bunch of green hair...
while this one looks like the leaves of a plant. This algae actually deposits calcium carbonate in it, thus giving it a more hardy feel.
Besides the algae, sponges are everywhere too! Unlike algae, sponges are actually animals. They are pore-bearing and are very simple animals that filter feeds for food. They come in different shapes, colours and sizes. This is one of the things that we shouldn't touch as they have spicules in them which can cause pain when it is embedded in our skin.
And here's the Sand-sifting Sea Stars! (
Archaster typicus). They're called the Sand-sifting Sea Stars because they have many tiny tube feets underneath their bodies which help them sift through the sand to look for food, and also to move around. They can camouflage very well in the sand and are also very good burrowers, thus they can burrow into the sand when the tide goes out to prevent themselves from drying up on the exposed ground.
There are a few of them with their arms munched off. Ouch! Thankfully the Sea Stars have the ability to regenerate their arms. Hopefully they'll get their arms back soon! (:
Besides the Sand-sifting Sea Star, we also saw the Red Feather Star (Class Crinoidea)! This is the first time that i've seen a Feather Star i think. Sea Stars have pentaradial symmetry, which means its body part can be divided to 5 equal parts. Can you guess how many arms this Feather Star has? It actually has 25 arms! The Sea Stars have a water vascular system in them, which acts like our circulatory system. However, instead of having blood in them, they circulate sea water in them, thus we should not leave them out of water for too long.
Near us, there were a few Mangrove (Sonneratia alba) Trees with their conical roots sticking out of the soft ground. This enables them to absorb oxygen not only from the soil, but from the atmosphere too as the soil usually lacks of oxygen.
My second time seeing an Elbow Crab (Parthenope longimanus). It has arms that look like elbows, and also has hair on its body to trap sediments to help it camouflage better.
We also saw the Hairy Crab (Pilumnus vespertilio). It has a lot of hair on its body, also to help it trap sediments to enable them to camouflage in its habitat. When the crab goes into the water, the hair on its body will float up like a mop and breaks the outline of the crab.
And there's the Porcelain Fiddler Crabs (Uca annulipes) too! The males have a large claw to attract the attention of females, and also to fend off males from its territories. However, it also acts like a handicap to the crab as it cannot use it to feed because it is too big, and also attracts more attention from the predators too. Thus, the males use it to show to the females that they have the superior genes and are capable of protecting them, and this is very important in the animal world as they need to pass on their genes to ensure the survival of their own kind.
Another lifer! First time seeing a Rock Crab. It is quite small and usually hides under rocks for protection.
Soon, we hit the Seagrass area and strands of Tape Seagrass (Enhalus acoroides) can be seen. Unlike algae, Seagrasses are true plants that have roots to help them hold on to the ground. This can also help to prevent soil erosion along the shores.
We saw a few flatworms today and this is the first one that we saw. This brown flatworm has a very thin body that is only a few cells thick, thus it can breathe and excrete its metabolic wastes through its body walls by osmosis. Its thin body also enable it to move through crevices to look for food.
Iris found this little shrimp which has two little eyes that keeps staring at us. Super cute!
A bivalve found by the hunter seekers. They have a 2-part shell which opens when they are in water. They are also filter feeders that filter the sea water for food. The uneven patterns on their shells helps them to strengthen their shells and also make their shell lighter as less calcium carbonate is used to make the shells.
The hunter seekers also found a Black Lipped Conch (
Strombus urcea). It has two little eyes that peer out occasionally to look at its surroundings. Super cute! (:
Besides the Black Lipped Conch, there's also the Spider Conch! The undersides of the conch are usually very beautiful but the top side is usually covered by algae to help it camouflage among its surroundings. Spider Conches are collected in some parts of the world because of their beautiful shells, but this actually endangers their population.
Marcus found this Sand Collar on the ground. This is the egg case of a Moon Snail. When the eggs are hatched, little snails will emerge and the Sand Collar will disintegrate.
The Sea Nettle Jellyfish (
Chrysaora sp.) seems to be seasonally common these days. Saw a few of them today. Like other jellyfishes, they have tentacles with stinging cells which can sting quite badly.
And there's also the Hermit Crab. Hermit Crabs are not true crabs as they have a soft abdomen, thus they need shells for protection. As they grow, they'll look for a larger shell to change into. On some beaches that are littered with a lot of rubbish and the hermit crabs couldnt find a shell to fit in to, they may use the cans as ''shells''! Thus, we should not collect any shells, even dead shells, from the sea shores as the hermit crabs need them, or they'll have to run around the shore naked! x_x
As we reached out further to the reef area, we saw many beautiful soft corals. During low tide, it may look limp but when they are submerged in water, the tentacles can float around. As the corals are exposed to large amount of sun daily, they secrete this chemical to protect themselves from the UV rays of the sun. Some of them are cultivated to be made into the SPF in our sunblock.
Besides the soft corals, there are also the hard corals. This is a Brain Coral, which has a hard calcium carbonate skeleton. Corals are actually colonial animals, and it is like a HDB flat with a lot of animals living together. Although the corals are filter feeders, they also have algae living in them which supply most of the nutrients needed by the corals. In return, the coral provides the algae with protection and carbon dioxide to make food.
We also saw a Swimming Crab that was quite fierce. It ''kiapped'' Marcus' finger when he tried to pick it up. Ouch! The Swimming Crabs have a pair of paddle-like back legs that help them to swim quickly in the water.
There were a few Carpet Anemones around but we didn't see any Anemone shrimps or Nemo ): These Carpet Anemones have tentacles with stinging cells which can sting small fishes and the tentacles will help to move its prey to the mouth located at the center.
There's also capsules of Squids among the branching algae. The eggs are laid with an egg case and a layer of mucus to protect them from other predators, and also to protect it from desiccation. When the eggs are hatched, little squids will emerge.
We were also quite lucky to see not one, but TWO octopuses today! (: Thankyou Ron and Yushang for finding them! (: Octopus is one of the smartest invertebrates and they are capable of opening containers. One of the octopuses actually managed to lift up the other container covering it and escaped from the container!
Saw this flatworm a few times before, but it's always around this size and the sides are a bit torn. Why ah?? x_x
Other than the flatworms, we also saw a few nudibranchs today! (: This is the Black Margined Nudibranch (
Glossodoris atromarginata). Nudibranchs literally means naked gills. Unlike the fishes which have gills under their gill covers, the Nudibranchs have exposed feathery gills on their back. Some of the nudibranchs may secrete toxins into the water when they are stressed, thus we should not touch them.
This is the
Phyllidiella pustulosa which is one of the most toxic nudibranchs. It can kill the whole fish tank of fish if it releases its toxin in a fish tank. The bright colours on its body tells us that it is toxic and we should not touch them.
This is the Polka Dot Nudibranch (
Jorunna funebris) and it got its common name from the black spots on it's body that looks like polka dots.
As we headed back for the shore, we saw this Onch Slug (Family Onchididae) at the rocky area. They belong to the same group as the land snails, thus they have simple lungs instead of gills to help them breathe. Unlike other snails, the Onch Slug does not have a hard shell but a tough skin to protect itself. The tough skin can also help it to reduce water loss.
Besides the Onch Slug, we also saw many Nerites on the rocks. They feed on the algae that grow on the rocks by scraping them off with their radula. Some Nerites can be eaten raw or even toasted!
After we washed up, Marcus brought us to the wall with a many little burrows on the ground. Those are made by the nymphs of the lacewings. They have a very big jaw and their burrows will cause the ants to fall into the hole that they've dug as the angle is very steep, then it will feed on the ants.
Thankyou Ms Wang and Peiting for pointing out the errors! (:
