Is this a mosquito larvae?
This appears to be the shed exoskeleton of some immature diptera, perhaps a mosquito though it is hard to tell for sure from these images. Best to remove a moving insect that you see in your tank using a screen or cup to scoop out the insect and then place the insect into a container with clean water to take a better picture.
Dear Dr Gerry
Thank you. Please see whether the "bug" skeletal remains are clearer in the attached photos.
This time I managed to also capture a photo of a bug but I am not sure if this one is related to the skeletal remains.
Note that these tiny "bug" skeletal remains are taken at 8x zoom using my phone camera. I took one photo with my finger on the box to show how tiny these skeletal remains are.
The skins or exoskeletons look like they belong to a mosquito or a midge. The cream-colored insect is not from the shed exoskeletons. This other insect likely just fell into your tank. If you want to confirm the insect species, you might consider contacting someone at the University in Singapore to see if they can identify specimens that you bring in to them.