I took the photo of the Fish through the glass of my aquarium and avoided getting reflective particles in the water and glass by by pressing the lens against the glass and angling the externally attached flash upwards and holding a sheet of white card stock over the aquarium so the light would bounce back down onto the fish. Shooting straight on with the flash just made the water look murky.
The ceramic clown mask I photographed at the childrens museum in London, Ontario.
Next I brought both photos into photoshop, and masked around both fish and mask, added a black background layer, and made bubbles. Thus the ClownFish.