13 April 2009

Back to Berlayar at dawn

Having been to Berlayar Creek mangroves on two afternoons, I hoped to see more during the cool, dark pre-dawn. Also, the tide is much lower today.I also wondered: how does this shore compare with Labrador? Which lies just around the corner. And with Sentosa? Which lies across a narrow channel from this shore.

First off, no, those white balls in the photo above are not turtle eggs on the shore. Those are golf balls that escaped from the Keppel Club golf course. Alas, golf balls were the most abundant 'creatures' I saw. Nevertheless, the shores are quite lively with some surprises.
There were many Haddon's carpet anemones (Stichodactyla haddoni) all over the shore. On the sandy stretches, on the seagrassy portions and among the coral rubble and even rocky areas. They came in all colours from bluish-grey to green. Although I didn't see any purple ones. In this respect, this shore is somewhat like a northern shore like Chek Jawa. On the nearby shores of Labrador and Sentosa, in contrast, I don't see many of these anemones.Taking a closer look, one of the carpet anemones had tiny little anemone shrimps in it!There was also one medium-sized Giant carpet anemone (Stichodactyla gigantea). Alas, it did not have any resident animals. Elsewhere, these anemones are home to False clown anemonefish (Amphiprion ocellaris) and the larger Five-spot anemoneshrimp (Periclimenes brevicarpalis).I also saw one Wriggly star anemone among the coral rubble. This sea anemone was quite commonly seen on Labrador's reefs, and also on Sentosa which lies opposite Berlayar Creek.There were a few Frilly sea anemones (Phymanthus sp.), one Plain frilly sea anemone was seen among the rocks, and this Six-point frilly sea anemone was seen in a sandier spot. These anemones are quite common on all our reefs.This looks like a Striped sand anemone, which so far I've only seen on our Northern shores. There were also lots of Banded bead anemones in crevices on the rocks.There were quite a few clumps of these Spiky flowery soft corals (Family Nephtheidae). Elsewhere, these often shelter tiny brittle stars and other small creatures. But I didn't find any today.There was also one large Asparagus flowery soft coral in deeper water. I've not seen this at Labrador or Sentosa, so it's a first for me for that corner of our shoreline. These are more commonly seen on offshore islands like Sisters and Pulau Hantu.There were a few clumps of colonial anemones (Order Zoanthidea), mostly Button zoanthids (Zoanthus sp.).

Missing from this shore are the large leathery soft corals (Family Alcyoniidae) that are common Sentosa. But these are also not seen on Labrador, so it's not a big surprise.

There are some living hard corals on the shore, but very very few. These are photos of ALL those that I saw. Most of them were Favid corals (Family Faviidae).The Zebra coral (Oulastrea crispata) is tough and can be found on almost all our shores. A few small colonies were seen today.
This is probably a Favid coral, with honey-comb shaped corallites.Another Favid coral, with ladder-like corallites.Probably a Pore coral (Family Porites), forming a lumpy, sort of branching colony.Another Pore coral, also somewhat lumpy.On the rocks were a variety of sponges (Phylum Porifera).The most numerous sponge was the Sponge green seaweed (Codium sp.) one that forms flat branching structures. This organism is actually a combination of sponge and algae!Another common sponge on the shore was this blue encrusting sponge, which is possibly Clathria sp. and often has spatula-like projections from an encrusting base.Sponges, corals and encrusting animals usually means other exciting creatures that feed on them, such as nudibranchs. While I didn't see any nudis, I did spot this Blue-spotted flatworm (cf Pseudoceros indicus). I usually see this flatworm more commonly on our Northern shores.
The fanworm (Family Sabellidae) I often describe as a Vegas dancing worm. It has feathers on its head! Other worms encountered include some bristleworms (Class Polychaeta) and acorn worms (Class Enteropneusta).

Some interesting snails were encountered, including this pretty Olive snail (Family Olividae).
It was burrowing in the sand and it has a purple mouth.Also burrowing in the sand was this Elegant banded creeper snail (Family Cerithidea) with a spout at the tip of its shell. Ploughing in the sand were all kinds of whelks. The Black whelk (Nassarius pullus) has a broad base at the shell opening.While the tiny Prickly whelks (Nassarius crenoliratus) have tiny spikes on their shells. Whelks are active scavengers. A choice morsel such as a dead crab or fish is a magnet for these snails which hurry as fast as they can to the feast. They have been described as "extremely bold and agile".

As for bivalves, there were small oysters (Family Ostreidae) stuck on hard surfaces.And this one single large Fan shell (Pinna sp.).

There were not too many echinoderms on the shores.It was surprise to come across the Ball sea cucumber (Phyllophorus sp.) in a sandy stretch. I usually encounter this animal more commonly often on our Northern shores. Although I did see them on Sentosa, on the sandy stretch that has since been reclaimed for the Integrated Resort.I looked very hard and finally found ONE Cake sand dollar (Arachnoides placenta). I felt sure they would be here as they are found across the water on Sentosa. I've not found these on Labrador.

As for crustaceans, there were a lot of hermit crabs of all kinds. There were some Moon crabs that swum off before I could photograph them, and lots of fiddler crabs too quick to sneak up on. The pools were teeming with tiny shrimps and snapping shrimps (Family Alpheidae).There was a tiny black crab that I think is a juvenile Flower crab (Portunus pelagicus) and of course, many Hairy crabs (Pilumnus sp.). But I didn't see too many other reef crabs such as the Egg crabs (Family Xanthidae).

There were lots of little fishes in the pools and streams.This is probably the Common frill-fin goby (Bathygobius fuscus). I don't think it has an association with the snapping shrimp and they just happen to be near one another as the pool was shrinking.As the tide came in, the mudskippers came out to play! I saw the Gold-spotted mudskipper (Periophthalmus chrysospilos) (photo on the left) and the Silver-lined mudskipper (Periophthalmus argentilineatus) (photo on the right). Their common names explain their features quite well!And in the streams flowing out of the mangroves into the sea, were lots of tiny little fishes!

Seagrasses are an important ecosystem and Berlayar Creek does have some meadows.
What a delightful surprise to encounter Tape seagrass (Enhalus acoroides) in deeper water. Alas, only two clumps. There is, however, a lot of healthy Spoon seagrasses (Halophila ovalis) everywhere else on the shore.

The shores also had a variety of seaweeds.Here are representatives of the major seaweed groups: The branching, stem-like red seaweed Gracilaria sp., the flat fan-shaped brown seaweed Padina sp., and the ribbon-like green seaweed Ulva sp. Other seaweeds seen included the green Sea grapes and other Caulerpa species, as well as some Sargassum seaweeds (whose seasonal bloom, thankfully, has ended).

Berlayar Creek is interesting as it has some mangroves, leading to sandy and rocky shores and seagrass areas. Although all these ecosystems are tiny, they do illustrate a more complete range of coastal ecosystems than any other location nearby.

From what I've seen, the Creek has some aspects of our Northern shores, as well as of our Southern reefs. So it's quite an interesting location!

I also saw some interesting plants today and did a separate post about them.

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