Dragging a slow shutter speed of 1/15th second with a fast spin of the housing means that the flash will freeze the motion of the artificially lit portion. The Natural Light surrounding will have motion blur. This leaves the clownfish at a distance with some ghosting from the motion blur. 1/15th is a slow shutter, but the strobe goes off for maybe a 10,000th second, which will stop any action or motion. This was shot at F-11 160 ISO with strobes set to TTL.
From Canon 8-15mm f/4L EF USM Fisheye