Marine fish are fish that live in seawater.
Categorisation of saltwater fish by habitats
- Coastal fish (also offshore fish or neritic fish) inhabit the sea between the shoreline and the edge of the continental shelf
- Deep sea fish live below the photic zone of the ocean, i.e. where not enough light penetrates for photosynthesis to occur
- Pelagic fish live near the surface of the sea or a lake
- Demersal fish live on or near the bottom of the sea or a lake
- Coral reef fish are associated with a coral reef.