What is the most common type of fish in the world?

The most common type of fish in the world is the herring. Herring is a type of forage fish that belongs to the Clupeidae family, which is made up of small, oily fish that are found in the shallow, temperate waters of the North Pacific and North Atlantic Oceans. They are a staple food source for a variety of marine mammals, birds, and other fish species, making them a critical part of the marine food web.

Herring are also an important commercial species, with a global catch of approximately 2.3 million metric tons annually. They are used for human consumption, as well as for bait and animal feed. Herring are a valuable source of omega-3 fatty acids, which are essential for human health and have been shown to have a range of health benefits, including reducing the risk of heart disease and stroke.