3 New Sea Cucumbers at Semakau

It never even occurred in my dreams that we would be able to find 3 new sea cucumbers on Semakau in one trip! We had visited Pulau Semakau so many times, and although I had expected to find new sea cucumbers that were not recorded from the island previously, I was still very much surprised (though it's a pleasant one) to actually find 3 of them!


Found this Ball Sea Cucumber (Phyllophorus sp.) half buried in the sand. This sea cucumber is very common on our northern shores, but this was my very first time seeing it on Semakau! It usually hide in the sand, and during high tide, only its tentacles will be out in the open, picking up edible tiny decaying matter from teh water to feed on.


Also at the sandy area, I saw a lump in the sand, and decided to check if anything was underneath. And indeed, this was what I found - a Holothuria notabilis sea cucumber! This was yet another new record for Semakau.


Not to far away, I saw another lump, and there's another one underneath!


And the third new record was spotted by Peiting. It's a Brown Sandfish Sea Cucumber (Bohadschia vitiensis). This sea cucumber can eject white sticky threads which stick to and confuse its predators.

Apart from these 3 new sea cucumbers, we also saw a number of other interesting stuff.


July managed to find a Galloping Sand Star (Stellaster equestris) again. Later, Marcus spotted another one. Both of them appear to be in a rather bad shape though. Their colours were somewhat faded, and their arms are partiall broken. We would have thought that they were dead except that they were still moving.


The Upside-down Jellyfish (Cassiopea sp.) appear to be in season, and I saw many of them. This jellyfish is usually found in this position, as it harbours algae in its body and being upside-down exposes the the algae to more sunlight for photosynthesis, The algae will share the food produced with the jellyfish, and in return, they receive shelter and protection.


I was rather surprised to see many Hell's Fire Sea Anemone (Actinodendron sp.) too! I certainly did not recall seeing so many of them the last time I visited this area. This sea anemone can give very painful stings, hence its common name.


We saw so many dead sand dollars (Arachnoides placenta) that I was really glad when I finally found one that was still alive!


The sandy beach had lots and lots of Sand-sifting Sea Stars (Archaster typicus), and here's a special one with only 4 arms instead of the usual 5.


We saw a number of Bigfin Reef Squids (Sepioteuthis sp.) too. The 2 above were spotted by July. They were really cooperative and did not really move much as we took their photos.


It was nice to see a Knobbly Sea Star (Protoreaster nodosus) near the seagrass area. We later found a few more, and in fact, July who was walking at the outer edge when we were combing the area came across more than 20 of them!


I spotted this pair of Flower Crabs (Portunus pelagicus) near one of the knobblies I found. The male was the more brightly colour one, and it was probably guarding the female, waiting for her to moult before it can mated with her.


Tube Anemones were somehow not as common on our southern shores compared to our northen shores. These animals live in a tube made from sand and mucus.


One of the more commonly seen sea cucumber was this Sandfish (Holothuria scabra). This sea cucumber is also the one normally served in restaurants. It need to be properly processed to remove its toxins before it can be eaten though.


As per other Semakau trips, we saw quite a few Noble Volutes (Cymbiola nobilis) laying eggs. It's always nice to see them laying eggs, even though I had seen it so many times.


On my way back to the forest entrance, I came across this Dragonfish Sea Cucumber (Stichpus horrens) in the seagrass meadow. This sea cucumber has an interesting way it defend itself - it can actually drop off part of its skin to distract would-be predators.


And just when I had cross the seagrass meadow, July shouted that he found a Pentaceraster mammilatus! Have not seen a Pentaceraster on Semakau for almost a year!

We were really lucky that the weather held and everyone had a good time with new discoveries!