Probably the last evening tide trip for me before the morning tide returns, I joined some friends to have a look at the sandy shore at Tanah Merah. The last time we visited this shore was June last year.
This shore is very rich because it has many sand dollars (caught the joke?). With the setting sun and the sand patterns, the shore is charming and gives us a sense of peace apart from the busy lifestyles of most Singaporeans.
At some parts of the shore, one may see some trails like this one. What is happening?
The trail is actually created by this Oval moon snail (Polinices mammatus) and the voracious snails was found hunting the Button snails (Umbonium vestiarum) that also littered the shore like the sand dollars. In response to the predator's chase, the snails will start leaping to try and escape from being eaten.
Another predator of the button snails will be this Plain sand star (Astropecten indicus) found by James. It was the only individual that was seen during the trip. Maybe more will come out after sunset.
There were quite a number of snails like this long Olive snail (Family Olividae) that may sometimes be mistaken as the venomous cone snails.
On a piece of rock, James found this drill that has just laid the purple egg capsules.
And while I flipped the same rock, I was glad to see this small Chiton that was seen before on this shore. Though it looks like a snail, chitons are molluscs and not crustaceans. They cling on tenaciously on rocks.
Another crustacean sighted will be the Spotted moon crab (Ashtoret lunaris) that started to be more commonly sighted after the sun set.
This pretty crab is the Sally-lightfoot crab (Grapsus albolineatus) and was found by James on the high shore where the seawall was. This crab is more active at night and seldom seen during daylight.
Skipping about near the water's edge are some of the Gold spotted mudskippers (Periophthalmus chrysospilos) like this. They are very cute but hard to get near to since they move away quickly at the slightest sense of danger when we approach.
On the drifts of Sea lettuce seaweed (Ulva sp.), Chay Hoon found this egg capsules belonging to cuttlefish.
On a closer look, it is exciting to see some forms of baby cuttlefishes from the interior of each capsule.
With Chay Hoon around, there will be higher chances of encountering slugs and indeed she found a huge Sea fan seaweed (Avrainvillea sp.) that is home to many Costasiella fan slugs (Costasiella sp.). Wow!
These slugs are slightly bigger than the usual ones we saw so it was easier to take a clearer shot of these creatures.
And we were surprised to see the electrifying-blue tips at their tentacles which are different from those others that we saw at other shores.
The cutest part of these slugs will be their eye spots that can be found at their anterior end. It gives the slugs a "pretty face". :)
Last but not least before we left the shore, we had some interesting moments observing this rather big cuttlefish that changes its colour to suit the sandy environment.
As mentioned by Ria, we were relieved to end the trip on a safe note with no stonefish accident. There was a recent accident at this exact shore by a shore researcher and that made us conclude that no shore is safe despite being almost completely sandy.
the cuttlefish's egg capsules are amazing!!
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