Colourful Fiddler Crabs at Pulau Ubin

Today, I was back at Pulau Ubin with SY. Just came here 2 weeks ago, but due to the rain, many of my photos did not turn out well with everything wet. I wasn't able to see any Chimney-building Fiddler Crabs (likely to be Uca triangularis according to Prof Peter Ng). Thus, I decided to make another trip to the island.

Not sure if it's due to the sunny weather, we were overwhelmed with many fiddler crabs in various colours!


There are red ones... (It's not quite obvious, but if you look closely, you may notice that the burrow looks somewhat raised. Some can be a little taller, like a chimney.)


Yellowish-orange ones...


Blue ones...


White ones...


Maroon ones...


And black ones too! The carapace of all the above crabs had similar shapes, but the sizes were distinctive different. The smaller ones were all less than 2cm wide including the legs, while bigger ones (the last 2 photos) were about 5cm wide or more. Prof Ng had previously commented that the bigger ones could be Uca dussumieri, but without specimens, it's hard to say for sure.


Other than crabs, we saw several other interesting animals too, such as this Black Carpenter Bee (Xylocopa latipes). This species of carpenter bee is probably the biggest bee in the world, reaching to a length of 35mm! Carpenter bees usually burrow into wood to nest, thus earning its common name. The above is probably a male bee, with its distinctive lighter-coloured front legs.


A population of Cicada (Family Cicadidae) appeared to have just emerged from the ground and shed their nymph exoskeleton. We saw lots of them on a tree by the road side.


Talking about trees, I went back to the patch of Gedabu trees (Sonneratia ovata) I found during my last trip to Pulau Ubin. Fortunately, it was still fruiting, and I managed to get several nice shots of the fruits.


The propagule of the Tumu Putih (Bruguiera sexangula) was still there too! This time round, I managed to take a photo of it without having too much reflection, since the leaves were not wet like the previous time.


One of the Tengar Trees (Ceriops tagal) was fruiting too. You can differentiate this species from the other species of Ceriops found locally by its smooth fruit (the fruit refers to the brown thing on top. The green and long portion is the hypocotyl).


Ceriops zippeliana, on the other hand, has a rougher fruit with patchy patterns. When the hypocotyls of this species mature, they will have red collars, while the previous species will have white or yellowish collars.


The tall Lenggadai (Bruguiera parviflora) was still flowering as per my last trip, but had not developed any seedlings yet.


We also saw several flowering Teruntum Bunga Puteh (Lumnitzera racemosa) with their pretty little white flowers, but the several Teruntum Merah we came across were not blooming though. the latter have red flowers.


Several Mangrove Cannonball Trees, otherwise also known as Nyireh Bunga (Xylocarpus granatum), were fruiting. The fruits were big and round, just like cannon balls!


This Waxflower (Hoya sp.) is pretty climber with waxy flowers that belongs to the milkweed family (Asclepiadaceae). This family got its common name, Milkweed, from the white sap present in most species. The Waxflower has thick, waxy flowers and leathery leaves to retain moisture, an adaptation to the dry coastal environment.


The few Delek Air (Memecylon edule) trees were blooming with bunches of bluish-purple flowers.


The Shoreline Purslane (Sesuvium portulacastrum) can be commonly found on many of the coastal areas of Singapore.

Not long after I took the photo above, it started pouring. We were lucky to be able to find a shelter to wait for the rain to stop. But unfortunately, when we were cycling back to the jetty, it rained again just before we were about to reach the volunteers' hub!

Well, fortunately, I had already taken all the photos I wanted, and were already very satisfied with the trip. So guess the rain brought a cooling end to our hot day out! :)