This is a halfbeak fish, so called due to its upper mandible (jaw) being much shorter than the lower one. They are only about 4cm in length and swim along at the water surface feeding on mosquito larvae (bless them!). I caught this one from our pond here in Thailand and put it in a small aquarium for a better look. I took these photographs from below the level of the water so the fish is the lower one and its reflection in the water surface is the upper one. With the wall as a background the water surface is invisible so it looks very strange! It then went back into the pond to carry on its good work.
