No they are not.
Flows out of water into plants that are consumed by animals
They get it from carbohydrates in their food.
Yes.
Sugar molecules
Lipids
Marine animals do not break down water molecules into oxygen, just like we don't. They breathe O2 gas that is in solution in the water.
organic molecules (those containing carbon) although animals are mostly water
Sterol
Alcohol fermentation
No, respiration itself does not require pigment molecules. Respiration is the process by which cells generate energy from nutrients. Pigment molecules are mainly involved in processes such as photosynthesis or oxygen transport.
chemical bonds and organic molecules. respectively.
Yes, they use it to break down the food molecules into energy.