Demersal
Living on or just above the bottom rather than in open water - the habit of flatfish, gobies, groupers and most of what you photograph on a sandy slope.
Demersal describes animals that live on or just above the seabed rather than in open water. It is a statement about where an animal spends its time, not about what it is: flatfish, gobies, lizardfish, scorpionfish, most groupers and every crab are demersal, and so are the eggs that sink instead of drifting.
Bottom life shapes the body. Demersal fish tend toward flattened or squat shapes, camouflage that matches sand or rubble, eyes placed high, and mouths that work downward or scoop upward from a resting position. Many have given up the swim bladder entirely, since neutral buoyancy is of little use to an animal that spends its life in contact with the bottom.
The opposite term is pelagic - the open-water animals, from a passing trevally to a whale shark. A good many reef species move between the two, hunting up in the water and resting on the bottom, which is why the label describes a habit rather than a category.
Found in70
