Friday, December 19, 2008

Finally... some decent bugs (macroinvertebrates) found in a local pond (17 Dec 2008)

It is amazing how nature can be around you and yet you have no idea that it exists. Case in point. A forest stands opposite my workplace and I have never wanted to check it out since it looks rather small and there is no clear path going in. This is until I stumbled upon this blog describing this interesting patch of forest filled with a rich variety of fauna. The rest is history.

The most relevant discovery is a nice, tranquil and best of all, natural pond within the forest. This is especially useful for conducting my water quality workshops without the need to travel far from campus. At first glance, the pond appeared to be a muddy pool of water with the mud probably caused by run-off from an adjacent construction site. This doesn't look good for finding a healthy community of aquatic bugs.

Refusing to be deterred, I made a second trip here with Esther and gang. Upon closer look, the pond is filled with hydrilla and bubbles are constantly bursting at the surface. Perhaps, the dissolved oxygen level is better than expected. (Forgive me for not bringing along my DO meter.)

After some digging around at the bottom and sweeping in whatever gets dug up, were we surprised at what we found. Mayflies, dragonflies, damsel flies, water stick insect (first time I saw a live one!), leech (first time I saw one in Singapore!), chironomids, sludge worms (lots of them), beetle larva and pond skaters on the surface. Did I mention mayflies? Yes, the water quality must be better than it seemed.

The best thing about field work is you see living things living, moving and in their original colours. Do you know that mayflies and damsel flies can be green? Nothing beats seeing live, red bloodworms (chironomids). Live ones are far more exciting than the boring and uniformly white or brown specimens (dead by the way) in collection jars in the lab.

Figures (L-R, T-B): Pandan grows abundantly around the pond, someone mentioned that these are potent mosquito repellents. I am skeptical; beetle larva attached to a dead leaf in the pond; damsel fly (top) and water stick insect (bottom); Albizia trees crowd the sky; Seemingly muddy and lifeless pond; aquatic leech attached to underwater hydrilla, doesn't seem to feed on human blood; aggressive predator - dragonfly, and some snail shells.

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