Fishing techniques are methods for catching fish. The term may also be applied to methods for catching other aquatic animals such as molluscs (shellfish, squid, octopus) and edible marine invertebrates. There is an intricate link between various fishing techniques and knowledge about the fish and their behaviour including migration, foraging and habitat. The effective use of fishing techniques often depends on this additional knowledge. Which techniques are appropriate is dictated mainly by the target species and by its habitat.