Larval Leaf Scorpionfish (photograph by Chris Newbert, Minden Pictures). Lacking any other defense, many larval fish have adapted transparency as a method of camouflage—such as this tiny, see-through larval leaf scorpionfish in Hawaii.
The Oarfish is a rare, solitary, and giant denizen of the ocean depths (arguably larger than a Whale Shark. (The as opposed to the Whale Shark, in the Guinness Book of World Records.)) and is a filter feeder, comfortable cruising at depths of 200 m.