We boarded the boat at around 6 am and reached the island 45 minutes later. Soon, we began the short walk along the along the road leading to the forest. It's nicknamed: the F1 Race Track - because it really resembles a race track.
Sea cucumbers are relatives of the sea star- they have the five-point radial symmetry, though they do not resemble their relatives very much! Also, they have tube feet all around its body to help it move about. They usually move about to feed on the detritus found in the sand.
In order to breathe, they pump in water via their anus through what is called the "respiratory trees", which enables the oxygen to be absorbed. The water is flushed out the same way. It is often hard to tell the difference between the head and the anus because they look pretty much the same!
When stressed, sea cucumbers can become soft or even hard. This is due to its mutable tissues which enable it to soften or harden. In order to protect itself, the sea cucumber is poisonous to eat and are able to 'vomit' their internal organs when provoked. In reproduction, these single-sex animals release sperm/ eggs into the nearby water and external fertilization takes place.
Still awaiting ID but it is definitely an eel. This was spotted by one of the participants! Wow, a keen eye. This little fish was about 10 cm in length at the most.
Eels have no dorsal and anal fins, and only have one long, ribbony tail fin. They tend to like to hide in rock crevices and holes, like this one here. So most of their body length is actually unexposed!
This sea star is usually found in the deeper waters and less frequently in the intertidal areas. Like all sea stars, it has a five-point radial symmetry and has a central mouth on the underside. In addition, it is a haemaphrodite (which means its both male and female) but it cannot self-fertilize. The juveniles have arms that are better defined than their adults.
They are filter feeders that do not move at all. This means that when the tide comes in, the gills of the oysters filter food particles from the sea water. They remain stationary on rock substratum for as long as they plant themselves there at the larval stage. They are bivalves, as they have two parts to the shell.
These spider conches are very beautiful and have spikes along its shell, which is why many people love to collect the shells of these animals, resulting in the loss of many of these conches. ): The conches only develop the spikes as they grow older; and these spikes are like 'weapons' that intimidate predators.
On the other hand, the conch itself is a predator. It hunts on small animals. To move about, it uses its foot to help it 'jump'.
They usually grow on logs.
Some information on it on my other blog post here.
On reflection, today's trip was really enriching because I got to learn from my participants as well, one who is well-versed in the ins-and-outs of Semakau & is a diver, and the other who took a natural history module of Singapore. ;) Also learnt to stop and take a look at the animals/plants all around!
Some photos taken today, compiled into a contact sheet;
For other accounts, you can read:-
1. KS's blog entry here
2. SY's blog entry here
3. JL's blog entry here